U.S. patent application number 15/130501 was filed with the patent office on 2017-03-16 for wastewater treatment systems and methods.
The applicant listed for this patent is ALCOA INC.. Invention is credited to Jaw K. Fu, Shannon L. Isovitsch Parks, John R. Smith, Sarah K. Strano.
Application Number | 20170073260 15/130501 |
Document ID | / |
Family ID | 51164383 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170073260 |
Kind Code |
A1 |
Strano; Sarah K. ; et
al. |
March 16, 2017 |
WASTEWATER TREATMENT SYSTEMS AND METHODS
Abstract
The instant disclosure is directed towards methods of treating
wastewater and related systems, where the system includes: a first
zone comprising at least one anaerobic tank, and a second zone
comprising at least one engineered wetland. In some embodiments,
the system includes a third zone comprising at least one bauxite
residue cell.
Inventors: |
Strano; Sarah K.;
(Pittsburgh, PA) ; Isovitsch Parks; Shannon L.;
(Sarver, PA) ; Fu; Jaw K.; (Murrysville, PA)
; Smith; John R.; (Pittsburgh, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ALCOA INC. |
PITTSBURGH |
PA |
US |
|
|
Family ID: |
51164383 |
Appl. No.: |
15/130501 |
Filed: |
April 15, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14152604 |
Jan 10, 2014 |
9315406 |
|
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15130501 |
|
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61751524 |
Jan 11, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C02F 1/281 20130101;
Y02W 10/10 20150501; C02F 3/2813 20130101; Y02W 10/18 20150501;
C02F 3/284 20130101; C02F 2101/20 20130101; Y02W 10/33 20150501;
C02F 2101/203 20130101; C02F 2103/003 20130101; C02F 9/00 20130101;
Y02W 10/37 20150501; C02F 1/42 20130101; C02F 3/327 20130101; C02F
2101/32 20130101; C02F 2101/308 20130101 |
International
Class: |
C02F 9/00 20060101
C02F009/00 |
Claims
1. A method of treating wastewater, comprising: flowing a
wastewater stream through at least one anaerobic settling and
treatment tank, wherein the anaerobic settling and treatment tank
comprises: a bottom and at least one sidewall, an influent end and
an effluent end in liquid communication with a control volume in
the tank, wherein the control volume is configured to retain
wastewater; wherein the tank further comprises a baffle
configuration, including: a baffle located adjacent to the influent
end and configured to distribute the flow of wastewater into the
tank; and at least one member configured between the baffle and the
effluent end wall, wherein the member configured to promote mixing
and flow distribution of the wastewater, and a settling promoter
configured along the effluent end sidewall and configured to
promote settling of solids prior to discharge from the effluent
end; wherein the baffle configuration is configured to flow
wastewater through the tank along at least one predetermined flow
path at a surface overflow rate of at least 0.25 m/hr; and treating
the wastewater in the anaerobic settling and treatment tank via the
baffle configuration and surface over flow rate to remove at least
75% of organics from the wastewater stream to provide a low
organics wastewater stream; flowing a low organics wastewater
stream into an engineered wetland from the anaerobic settling
treatment tank effluent, wherein the engineered wetland is in
liquid communication with the anaerobic settling and treatment
tank; aerating the low organics wastewater stream, wherein aerating
the low organics wastewater is sufficient to sustain aerobic
bacteria; treating the low organics wastewater stream in the
engineered wetland to remove: ammonia from the low organics
wastewater to a content of not greater than 8 ppm, wherein the
engineered wetland comprises a pore water hydraulic retention time
of not greater than 4 days; discharging a treated water stream from
the engineered wetland.
2. The method of claim 1, wherein the settling promoter comprises
an angle baffle configured to the sidewall proximate an effluent
end.
3. The method of claim 1, wherein the settling promoter comprises a
discontinuous region along the at least one sidewall proximate an
effluent end.
4. The method of claim 1, wherein the anaerobic settling tank
comprises a plurality of members spaced apart from one another,
between the baffle and the settling promoter.
5. The method of claim 4, further comprising three members, spaced
equidistant from each other and comprising the same angled position
within the tank, wherein the three members are located proximate to
a lower end of the tank.
6. The method of claim 1, wherein aerating comprises aerating the
low organics wastewater at a rate of at least 1.1 scfm/gpm
wastewater.
7. The method of claim 6, wherein aerating is sufficient to sustain
a dissolved oxygen content of at least about 80% of saturation of
the low organics wastewater at a given temperature.
8. The method of claim 1, wherein the engineered wetland is
comprises a pore water hydraulic retention time of at least about
0.25 day.
9. The method of claim 1, further comprising, prior to the
discharging step: flowing a low nitrogen wastewater stream from the
engineered wetland to an inlet of at least one polishing cell
having media including bauxite residue, where the cell is in liquid
communication with the engineered wetland, wherein the polishing
cell comprises at least one sidewall, an inlet and an outlet
configured to encase the media within the cell, wherein the cell is
configured to permit the low nitrogen wastewater stream to flow
therethrough via the inlet and outlet, and treating the low
nitrogen wastewater via the via the media to remove at least about
30% pathogens from the low nitrogen wastewater; and flowing a
polished water stream from the effluent from the cell.
10. The method of claim 1, further wherein the system comprises a
hydraulic retention time of at least 12 hours to not greater than 6
days.
11. A method comprising: analyzing a wastewater stream to determine
a contaminant profile, the contaminant profile comprising: at least
one contaminant; selecting a target cleaned water stream profile,
wherein the cleaned water stream profile comprises upper limits of
the quantities of contaminants present in the contaminant profile;
and selecting, based on the target cleaned water stream profile and
the contaminant profile of the wastewater stream, a number of tank
modules, based on the contaminant profile; selecting, based on the
target cleaned water stream profile and the contaminant profile of
the wastewater stream, a number of engineered wetland modules,
based on the contaminant profile; selecting, based on the target
cleaned water stream profile and the contaminant profile of the
wastewater stream, a number of bauxite residue modules, based on
the contaminant profile; configuring a wastewater treatment system,
where the system comprises a first zone having the number of tank
modules, a second zone comprising the number of engineered wetland
modules, and a third zone comprising the number of bauxite residue
modules to define a wastewater flow path; flowing the wastewater
stream through the flow path defined by the first zone, the second
zone, and the third zone of the system; treating the wastewater via
the system to remove contaminants via the first zone, the second
zone, and the third zone; and discharging a cleaned water stream,
wherein the cleaned water stream comprises a cleaned water stream
profile which corresponds to the target cleaned water stream
profile.
12. The method of claim 11, further comprising: replacing at least
one module of the tank modules, wetland modules, or bauxite residue
modules after a predetermined amount of time.
13. The method of claim 12, further comprising: replacing at least
one module of the tank modules, wetland modules, or bauxite residue
modules after a predetermined amount of wastewater has been
treated.
14. The method of claim 12, further comprising monitoring at least
one module in the wastewater treatment system to assess the
effectiveness of the module.
15. The method of claim 12, further comprising moving at least one
module via a transport device configured to the module to allow
mobility of the module.
16. The method of claim 15, wherein the transport device is
selected from the group consisting of: wheels, a track and wheels,
a plurality of rollers, a conveyor belt, and combinations
thereof.
17. The method of claim 11, connecting the plurality of modules in
the system via connection ports as the inlet and outlet.
18. A method of treating wastewater, comprising: flowing a
wastewater stream through at least one anaerobic settling and
treatment tank, wherein the anaerobic settling and treatment tank
comprises: a bottom and at least one sidewall, an influent end and
an effluent end in liquid communication with a control volume in
the tank, wherein the control volume is configured to retain
wastewater; wherein the tank further comprises a baffle
configuration, including: a baffle located adjacent to the influent
end and configured to distribute the flow of wastewater into the
tank; and at least one member configured between the baffle and the
effluent end wall, wherein the member configured to promote mixing
and flow distribution of the wastewater, and a settling promoter
configured along the effluent end sidewall and configured to
promote settling of solids prior to discharge from the effluent
end; wherein the baffle configuration is configured to flow
wastewater through the tank along at least one predetermined flow
path at a surface overflow rate of at least 0.25 m/hr; and treating
the wastewater in the anaerobic settling and treatment tank via the
baffle configuration and surface over flow rate to remove at least
75% of organics from the wastewater stream to provide a low
organics wastewater stream; flowing a low organics wastewater
stream into an engineered wetland from the anaerobic settling
treatment tank effluent, wherein the engineered wetland is in
liquid communication with the anaerobic settling and treatment
tank; aerating the low organics wastewater stream, wherein aerating
the low organics wastewater is sufficient to sustain aerobic
bacteria; treating the low organics wastewater stream in the
engineered wetland to remove ammonia from the low organics
wastewater to a content of not greater than 8 ppm to provide a low
nitrogen wastewater stream, wherein the engineered wetland
comprises a pore water hydraulic retention time of not greater than
4 days; flowing the low nitrogen wastewater stream from the
engineered wetland to an inlet of at least one polishing cell
having media including bauxite residue, where the cell is in liquid
communication with the engineered wetland, wherein the polishing
cell comprises at least one sidewall, an inlet and an outlet
configured to encase the media within the cell, wherein the cell is
configured to permit the low nitrogen wastewater stream to flow
therethrough via the inlet and outlet, and treating the low
nitrogen wastewater via the via the media to remove at least about
30% pathogens from the low nitrogen wastewater; and discharging a
treated water stream from the engineered wetland.
19. The method of claim 18, further wherein the system comprises a
hydraulic retention time of at least 12.5 hours to not greater than
6.5 days.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Application Ser.
No. 61/751,524, entitled "Wastewater Treatment System and Methods"
filed on Jan. 11, 2013, which is incorporated by reference in its
entirety.
FIELD OF THE INVENTION
[0002] Generally, the instant disclosure is directed towards a
wastewater treatment system for removing contaminants, organics,
inorganics, metals, pathogens, particulates, pharmaceuticals,
nutrients, and/or personal care products from wastewater to a
quality suitable for permitted discharge, recycle, and/or reuse.
More specifically, the instant disclosure is directed towards a
system including three zones for wastewater treatment, including an
anaerobic settling/treatment tank, an engineered wetland, and a bed
of metal oxide type media (e.g. bauxite residue).
BACKGROUND
[0003] Prior to discharge into the environment or recycle for
beneficial use, wastewater must generally be within certain
prescribed limits for various contaminant levels. Conventional
wastewater treatment systems may be onerous, costly, time
consuming, and require a high amount of energy to run and operate
the system.
SUMMARY OF THE DISCLOSURE
[0004] Broadly, the present disclosure relates to systems and
methods for treating wastewater. More specifically, the instant
disclosure is directed towards removing organic material, suspended
solids, particulates, metals, emulsified oils and grease,
pharmaceuticals, nutrients, personal care products, pathogens,
bacteria, microorganisms, and viruses from a wastewater stream via
a wastewater system having three zones, including: a first zone
comprising at least one anaerobic settling/treatment tank; a second
zone comprising at least one engineered wetland configured for
aeration (e.g. varying degrees of aeration); and a third zone
comprising at least one cell having a metal oxide type media
therein (e.g. bauxite residue; BR/ZVI; and other media in
conjunction with bauxite residue).
[0005] Without being bound to a particular mechanism or theory, it
is believed that the combination of these three zones (and/or
components) is combinable to yield a wastewater treatment system
which removes a contaminated wastewater stream having various
classes/types of contaminants to below legal limits and/or to a
quality suitable for reuse/recycle.
[0006] Without being bound to a particular mechanism or theory, it
is believed that as the first zone removes a large portion of
BOD/COD/TOC from the wastewater treatment stream, the engineered
wetland is specifically configured to focus on nitrogen removal,
pathogen removal (e.g. as indicated by fecal coliform or e. coli),
BOD/COD (e.g. up to an additional 10%, or up to the remaining
BOD/COD) and/or remaining suspended solids.
[0007] In one aspect, a wastewater treatment system is provided,
comprising: at least one anaerobic settling/treatment tank, wherein
the tank comprises a plurality of baffles (e.g. horizontally and or
vertically) spaced along the length thereof, wherein the primary
settling tank configured to receive wastewater and remove solid
particulates therefrom; an engineered wetland, in liquid
communication with the settling/treatment tank, wherein the
engineered wetland comprises an aeration system along a bottom
portion thereof, wherein the engineered wetland is configured to
remove residual organics, nitrogen, phosphorous related nutrients,
BOD, CBOD, TSS, ammonia, nitrate, pharmaceuticals, personal care
products, bacteria, viruses and inorganic constituents from the
wastewater. In some embodiments, the system further comprises at
least one metal oxide cell (e.g. bauxite residue), in liquid
communication with the engineered wetland, wherein the metal oxide
cell comprises a module encasing a media (e.g. bauxite residue),
wherein the module is configured to permit water to flow there
through, further wherein the cell removes bacteria, viruses,
ammonia, pharmaceuticals, and personal care products from the
wastewater; further wherein, via the system contaminants are
removed.
[0008] In another aspect of the instant disclosure, a method is
provided, comprising: flowing a wastewater stream having
contaminants therein through an anaerobic settling/treatment tank,
wherein the anaerobic settling/treatment tank removes a portion of
suspended solids and organic material, flowing the wastewater from
the anaerobic tank (e.g settling and treatment tank) through at
least one engineered wetland, wherein the engineered wetland
comprises an aeration system that aerates the wastewater, wherein
via the engineered wetland, contaminants are removed. In some
embodiments, the method further comprises flowing the wastewater
from the engineered wetland through at least one cell comprising
bauxite residue, wherein the cell polishes the wastewater stream to
provide a cleaned water stream/effluent.
[0009] In yet another aspect of the instant disclosure, a method is
provided. The method comprises the steps of: flowing wastewater
through a wastewater treatment system comprising an anaerobic
settling/treatment tank; an engineered wetland; and a cell
comprising bauxite residue, wherein the wastewater system removes
contaminants from a wastewater stream to below permit levels.
[0010] In still another aspect, a method of treating wastewater is
provided, comprising: flowing a wastewater stream through at least
one anaerobic settling and treatment tank, wherein the anaerobic
settling and treatment tank comprises: a bottom and at least one
sidewall, an influent end and an effluent end in liquid
communication with a control volume in the tank, wherein the
control volume is configured to retain wastewater; wherein the tank
further comprises a baffle configuration, including: a baffle
located adjacent to the influent end and configured to distribute
the flow of wastewater into the tank; and at least one member
configured between the baffle and the effluent end wall, wherein
the member configured to promote mixing and flow distribution of
the wastewater, and a settling promoter configured along the
effluent end sidewall and configured to promote settling of solids
prior to discharge from the effluent end; wherein the baffle
configuration is configured to flow wastewater through the tank
along at least one predetermined flow path at a surface overflow
rate of at least 0.25 m/hr; and treating the wastewater in the
anaerobic settling and treatment tank via the baffle configuration
and surface over flow rate to remove at least 75% of organics from
the wastewater stream to provide a low organics wastewater stream;
flowing a low organics wastewater stream into an engineered wetland
from the anaerobic settling treatment tank effluent, wherein the
engineered wetland is in liquid communication with the anaerobic
settling and treatment tank; aerating the low organics wastewater
stream, wherein aerating the low organics wastewater is sufficient
to sustain aerobic bacteria; treating the low organics wastewater
stream in the engineered wetland to remove: ammonia from the low
organics wastewater to a content of not greater than 8 ppm, wherein
the engineered wetland comprises a pore water hydraulic retention
time of not greater than 4 days; discharging a treated water stream
from the engineered wetland.
[0011] In some embodiments, aerating comprises aerating the low
organics wastewater at a rate of at least 1.1 scfm/gpm
wastewater.
[0012] In some embodiments, aerating is sufficient to sustain a
dissolved oxygen content of at least about 80% of saturation of the
low organics wastewater at a given temperature.
[0013] In some embodiments, the method comprise: flowing a low
nitrogen wastewater stream from the engineered wetland to an inlet
of at least one polishing cell having media including bauxite
residue, where the cell is in liquid communication with the
engineered wetland, wherein the polishing cell comprises at least
one sidewall, an inlet and an outlet configured to encase the media
within the cell, wherein the cell is configured to permit the low
nitrogen wastewater stream to flow therethrough via the inlet and
outlet, and treating the low nitrogen wastewater via the via the
media to remove at least about 30% pathogens from the low nitrogen
wastewater; and flowing a polished water stream from the effluent
from the cell.
[0014] In some embodiments, the bauxite residue cell is used in
place of the discharge step. In some embodiments, flowing a
polished water stream from the effluent of the cell comprises the
discharge step.
[0015] In another aspect of the instant disclosure, a method is
provided, comprising: analyzing a wastewater stream to determine a
contaminant profile, the contaminant profile comprising: at least
one contaminant; selecting a target cleaned water stream profile,
wherein the cleaned water stream profile comprises upper limits of
the quantities of contaminants present in the contaminant profile;
and selecting, based on the target cleaned water stream profile and
the contaminant profile of the wastewater stream, a number of tank
modules, based on the contaminant profile; selecting, based on the
target cleaned water stream profile and the contaminant profile of
the wastewater stream, a number of engineered wetland modules,
based on the contaminant profile; selecting, based on the target
cleaned water stream profile and the contaminant profile of the
wastewater stream, a number of bauxite residue modules, based on
the contaminant profile; configuring a wastewater treatment system,
where the system comprises a first zone having the number of tank
modules, a second zone comprising the number of engineered wetland
modules, and a third zone comprising the number of bauxite residue
modules to define a wastewater flow path; flowing the wastewater
stream through the flow path defined by the first zone, the second
zone, and the third zone of the system; and treating the wastewater
via the system to remove contaminants via the first zone, the
second zone, and the third zone; and discharging a cleaned water
stream, wherein the cleaned water stream comprises a cleaned water
stream profile which corresponds to the target cleaned water stream
profile.
[0016] In some embodiments, selecting is based upon the discharge
permit levels for a particular contaminant. In some embodiments,
selecting is based upon quantity/amount of contaminant in the
wastewater stream to be treated. In some embodiments, selecting is
based upon the total number of modules in a zone (e.g. where each
module in a zone will remove a portion of a contaminant to provide
an additive effect at the desired target contaminant profile). In
some embodiments, selecting is based upon the number of zones (e.g.
where a category of contaminants or type of contaminant is removed
in both zones) and/or modules in each zone.
[0017] In some embodiments, the method comprises: replacing at
least one module of the tank modules, wetland modules, or bauxite
residue modules after a predetermined amount of time. In some
embodiments, the method comprises: replacing at least one module of
the tank modules, wetland modules, or bauxite residue modules after
a predetermined amount of wastewater has been treated. In some
embodiments, the method comprises: monitoring at least one module
in the wastewater treatment system to assess the effectiveness of
the module.
[0018] In some embodiments, the method comprises moving at least
one module via a transport device configured to the module to allow
mobility of the module. Some non-limiting examples of the transport
device include: wheels, a track and wheels, a plurality of rollers,
a conveyor belt, and combinations thereof.
[0019] In some embodiments, the method includes: connecting the
plurality of modules in the system via connection ports as the
inlet and outlet.
[0020] In another aspect, a method of treating wastewater is
provided, comprising: flowing a wastewater stream through at least
one anaerobic settling and treatment tank, wherein the anaerobic
settling and treatment tank comprises: a bottom and at least one
sidewall, an influent end and an effluent end in liquid
communication with a control volume in the tank, wherein the
control volume is configured to retain wastewater; wherein the tank
further comprises a baffle configuration, including: a baffle
located adjacent to the influent end and configured to distribute
the flow of wastewater into the tank; and at least one member
configured between the baffle and the effluent end wall, wherein
the member configured to promote mixing and flow distribution of
the wastewater, and a settling promoter configured along the
effluent end sidewall and configured to promote settling of solids
prior to discharge from the effluent end; wherein the baffle
configuration is configured to flow wastewater through the tank
along at least one predetermined flow path at a surface overflow
rate of at least 0.25 m/hr; and treating the wastewater in the
anaerobic settling and treatment tank via the baffle configuration
and surface over flow rate to remove at least 75% of organics from
the wastewater stream to provide a low organics wastewater stream;
flowing a low organics wastewater stream into an engineered wetland
from the anaerobic settling treatment tank effluent, wherein the
engineered wetland is in liquid communication with the anaerobic
settling and treatment tank; aerating the low organics wastewater
stream, wherein aerating the low organics wastewater is sufficient
to sustain aerobic bacteria; treating the low organics wastewater
stream in the engineered wetland to remove ammonia from the low
organics wastewater to a content of not greater than 8 ppm to
provide a low nitrogen wastewater stream, wherein the engineered
wetland comprises a pore water hydraulic retention time of not
greater than 4 days; flowing the low nitrogen wastewater stream
from the engineered wetland to an inlet of at least one polishing
cell having media including bauxite residue, where the cell is in
liquid communication with the engineered wetland, wherein the
polishing cell comprises at least one sidewall, an inlet and an
outlet configured to encase the media within the cell, wherein the
cell is configured to permit the low nitrogen wastewater stream to
flow therethrough via the inlet and outlet, and treating the low
nitrogen wastewater via the via the media to remove at least about
30% pathogens from the low nitrogen wastewater; and discharging a
treated water stream from the engineered wetland.
[0021] In some embodiments, the system comprises a hydraulic
retention time of at least 12.5 hours to not greater than 6.5
days.
[0022] In one aspect, a method of treating wastewater is provided,
comprising: directing wastewater through at least one anaerobic
settling and treatment tank, wherein the anaerobic settling and
treatment tank comprises: a bottom and at least one sidewall, an
influent end and an effluent end in liquid communication with a
control volume in the tank, wherein the control volume is
configured to retain wastewater; wherein the tank further comprises
a baffle configuration, including: (a) a hockey stick-shaped baffle
located adjacent to the influent end and configured to distribute
the flow of wastewater into the tank; and (b) at least one member
configured between the hockey stick-shaped baffle and the effluent
end wall, the hockey stick-shaped baffle configured to promote
mixing and flow distribution of the wastewater, and (c) a settling
promoter configured along the effluent end sidewall and configured
to promote settling of solids prior to discharge (e.g. and/or
prevent short circuiting by mixing of the wastewater in the control
volume); wherein the baffle configuration is sufficiently designed
to direct wastewater through the tank along at least one
predetermined flow path at a surface overflow rate of at least 0.25
m/hr (e.g. to not greater than 0.75 m/hr); and wherein, via the
baffle configuration and the velocity, the anaerobic settling and
treatment tank is configured to remove at least 75% (e.g. to not
greater than 99.9%) of organics from the wastewater stream (e.g.
measured via BOD, COD); directing wastewater to an engineered
wetland from the anaerobic settling treatment tank, wherein the
wetland is in liquid communication with the anaerobic settling and
treatment tank, wherein the engineered wetland comprises an
aeration system along a bottom portion thereof, wherein via the
anaerobic settling tank, the wetland is configured to: remove
ammonia from the wastewater to a content of not greater than 8 ppm,
wherein the engineered wetland comprises a pore water hydraulic
retention time of at least about 0.25 day (e.g. to not greater than
2 days).
[0023] In some embodiments, the wetland influent comprises a COD of
not greater than 400 ppm and influent BOD of not greater than 250
ppm.
[0024] In some embodiments, the surface over flow rate of the
anaerobic tank is: at least 0.25 m/hr; at least 0.3 m/hr; at least
0.35 m/hr; at least 0.4 m/hr at least 0.45 m/hr, at least 0.5 m/hr;
at least 0.55 m/hr; at least 0.6 m/hr; at least 0.65 m/hr; at least
0.7 m/hr; or at least 0.75 m/hr.
[0025] In some embodiments, the surface over flow rate of the
anaerobic tank is: not greater than 0.25 m/hr; not greater than 0.3
m/hr; not greater than 0.35 m/hr, not greater than 0.4 m/hr; not
greater than 0.45 m/hr; not greater than 0.5 m/hr; not greater than
0.55 m/hr; not greater than about 0.6 m/hr; not greater than 0.65
m/hr; not greater than 0.7 m/hr; or not greater than 0.75 m/hr.
[0026] In some embodiments, the method comprises removing ammonia
from the wastewater to a content of not greater than 1 ppm.
[0027] In some embodiments, the anaerobic settling and treatment
tank is configured to promote settling of solids (e.g. via the
baffle configuration) and/or the surface overflow rate.
[0028] In some embodiments, the anaerobic settling tank is
configured to promote mixing of the wastewater in the tank, via the
baffle configuration (e.g. in the mixing zone, located above the
solids zone).
[0029] In some embodiments, the settling promoter comprises an
angle baffle configured to the sidewall proximate an effluent end.
In some embodiments, the settling promoter comprises a
discontinuous region (e.g. raised ridge, arcuate portion extending
towards the inner control volume of the tank, etc) along the at
least one sidewall proximate an effluent end.
[0030] In some embodiments, the settling promoter is configured to
act as a directional mixing baffle (e.g. direct wastewater towards
the mixing zone).
[0031] In some embodiments, the directional mixing baffle is angled
in the same manner as the lower portion of the hockey-stick shaped
baffle, when compared to the bottom of the tank. In some
embodiments, the directional mixing baffle (e.g. member) is angled
in a different manner as the lower portion of the hockey-stick
shaped baffle, when compared to the bottom of the tank.
[0032] In some embodiments, via the baffle configuration comprising
a series of baffles (e.g. hockey stick-shaped, at least one member
and settling promoter) the wastewater stream is forced to flow over
and under the baffles such that the interaction between
microorganisms in the solids and wastewater is increased such that
the removal of Biological Oxygen Demand (BOD) is enhanced.
[0033] In some embodiments, the at least one member comprises a
flow vane configured to slow the flow of wastewater through the
control volume and/or promote settling of solids.
[0034] In some embodiments, the anaerobic settling tank comprises a
plurality of members spaced apart from one another, between the
hockey stick-shaped baffle and the settling promoter.
[0035] In some embodiments, the anaerobic settling tank includes:
at least one member; at least two members; at least three members;
at least four members; at least five members' at least six members;
at least seven members; at least eight members; at least nine
members; or at least ten members.
[0036] In some embodiments, the anaerobic settling tank includes:
not greater than one member; not greater than two members; not
greater than three members; not greater than four members; not
greater than five members' not greater than six members; not
greater than seven members; not greater than eight members; not
greater than nine members; or not greater than ten members.
[0037] In some embodiments, the members are spaced apart from and
are parallel to the angled part of hockey stick. In some
embodiments, the members are equidistant from each other and
comprise the same angled position within the tank, wherein the
three members are located proximate to a lower end of the tank.
[0038] In some embodiments, the anaerobic settling and treatment
tank is configured to remove metals from the wastewater stream. In
some embodiments, the metals include: lead, zinc, cadmium, iron,
molybdenum, and combinations thereof. In some embodiments, via the
anaerobic settling and treatment tank, at least about 90% (e.g. to
approximately 99%) of the metals are removed.
[0039] In some embodiments, the anaerobic tank removes metals
including Zn, Cd, Fe, and Mb to: at least 90%; at least 92% at
least 94% at least 96% at least 98%; or at least 99%.
[0040] In some embodiments, the anaerobic tank removes metals
including Zn, Cd, Fe, and Mb to: not greater than 90%; not greater
than 92% not greater than 94% not greater than 96% not greater than
98%; or not greater than 99%.
[0041] In some embodiments, the anaerobic settling and treatment
tank is configured to remove at least 70% of the phosphate from the
wastewater stream (e.g. as measured in the effluent). In some
embodiments, by adding flocculating media to the anaerobic tank,
the phosphate removal is increased (e.g. above 70%, or above
85%).
[0042] In some embodiments, the anaerobic tank removes: at least
60%; at least 65%; at least 70%; at least 75%; at least 80% of
phosphate from the wastewater stream.
[0043] In some embodiments, the anaerobic tank removes: not greater
than 60%; not greater than 65%; not greater than 70%; not greater
than 75%; not greater than 80% of phosphate from the wastewater
stream.
[0044] In some embodiments, the anaerobic settling and treatment
tank is configured to remove nitrate such that the effluent from
the anaerobic settling and treatment tank comprises at least 70%
removal.
[0045] In some embodiments, the anaerobic tank is configured to
remove: at least 70%; at least 75%; at least 80%; at least 85%; at
least 90%; at least 95%; or at least 99% of nitrate from the
wastewater (e.g. as measured in the effluent).
[0046] In some embodiments, the anaerobic tank is configured to
remove: not greater than 70%; not greater than 75%; not greater
than 80%; not greater than 85%; not greater than 90%; not greater
than 95%; or not greater than 99% of nitrate from the wastewater
(e.g. as measured in the effluent).
[0047] In some embodiments, the anaerobic settling and treatment
tank is configured to remove nitrogen such that the effluent from
the anaerobic settling and treatment tank comprises at least 30%
removal.
[0048] In some embodiments, the anaerobic tank is configured to
remove: at least 30%; at least 35%; at least 40%; at least 45%; at
least 50%; at least 55%; at least 60%; at least 65%; at least 70%;
at least 75%; or at least 80% of nitrogen from the wastewater (e.g.
as measured in the effluent).
[0049] In some embodiments, the anaerobic tank is configured to
remove: not greater than 30%; not greater than 35%; not greater
than 40%; not greater than 45%; not greater than 50%; not greater
than 55%; not greater than 60%; not greater than 65%; not greater
than 70%; not greater than 75%; or not greater than 80% of nitrogen
from the wastewater (e.g. as measured in the effluent).
[0050] In some embodiments, the anaerobic settling and treatment
tank is configured to remove total suspended solids such that the
effluent from the anaerobic settling and treatment tank comprises
at least 90% removal.
[0051] In some embodiments, the anaerobic settling and treatment
tank comprises a solids zone and a mixing zone.
[0052] In some embodiments, the settling and treatment tank
comprises media configured to promote flocculation with bacteria
and settling of solids. Non-limiting examples of media include:
granular activated carbon, powdered activated carbon, clay
particles, bauxite residue; gypsum; and combinations thereof.
[0053] In some embodiments, metal salts are added to the first zone
(e.g. anaerobic settling tank). Some non-limiting examples of metal
salts include: Fe, Ca and/or Al salts. Without being bound to a
particular mechanism or theory, it is believed that adding metal
salts into this anaerobic environment will reduce influent
phosphorous levels less than 0.5 ppm.
[0054] In some embodiments, addition of metal salts into the
anaerobic settling/treatment tank reduces the nitrates amount in a
wastewater stream from about 10 ppm to about 1 ppm.
[0055] In some embodiments, metal salts are added to the anaerobic
settling/treatment tank to achieve <0.1 ppm phosphorous in the
final effluent. In some embodiments when supplemental organics are
added to the engineered wetland, an additional aeration zone or
step is completed. Without being bound to a particular mechanism or
theory, this is believed to reduce the amount/presence of residual
organics added which remain in the wastewater.
[0056] In some embodiments, the engineered wetland is configured to
remove TSS at the influent to less than 60 ppm.
[0057] In some embodiments, the wetland is configured to remove TSS
in the wastewater to: not less than 60 ppm; not less than 55 ppm;
not less than 50 ppm; not less than 45 ppm; not less than 40 ppm;
not less than 35 ppm; not less than 30 ppm; not less than 25 ppm;
not less than 20 ppm; not less than 15 ppm; not less than 10 ppm;
or not less than 5 ppm.
[0058] In some embodiments, the wetland is configured to remove TSS
in the wastewater to: not greater than 60 ppm; not greater than 55
ppm; not greater than 50 ppm; not greater than 45 ppm; not greater
than 40 ppm; not greater than 35 ppm; not greater than 30 ppm; not
greater than 25 ppm; not greater than 20 ppm; not greater than 15
ppm; not greater than 10 ppm; or not greater than 5 ppm.
[0059] In some embodiments, the engineered wetland is configured to
remove BOD from the influent wastewater to less than 50 ppm.
[0060] In some embodiments, the wetland is configured to remove BOD
in the wastewater to: not less than 50 ppm; not less than 45 ppm;
not less than 40 ppm; not less than 35 ppm; not less than 30 ppm;
not less than 25 ppm; not less than 20 ppm; not less than 15 ppm;
not less than 10 ppm; or not less than 5 ppm.
[0061] In some embodiments, the wetland is configured to remove BOD
in the wastewater to: not greater than 50 ppm; not greater than 45
ppm; not greater than 40 ppm; not greater than 35 ppm; not greater
than 30 ppm; not greater than 25 ppm; not greater than 20 ppm; not
greater than 15 ppm; not greater than 10 ppm; or not greater than 5
ppm.
[0062] In some embodiments, the engineered wetland is configured to
remove COD from the wastewater to less than 100 ppm.
[0063] In some embodiments, the wetland is configured to remove COD
(CBOD) in the wastewater to: not less than 100 ppm; not less than
95 ppm; not less than 90 ppm; not less than 85 ppm; not less than
80 ppm; not less than 75 ppm; not less than 70 ppm; not less than
65 ppm; not less than 60 ppm; not less than 55 ppm; not less than
50 ppm; not less than 45 ppm; not less than 40 ppm; not less than
35 ppm; not less than 30 ppm; not less than 25 ppm; not less than
20 ppm; not less than 15 ppm; not less than 10 ppm.
[0064] In some embodiments, the wetland is configured to remove COD
(CBOD) in the wastewater to: not greater than 100 ppm; not greater
than 95 ppm; not greater than 90 ppm; not greater than 85 ppm; not
greater than 80 ppm; not greater than 75 ppm; not greater than 70
ppm; not greater than 65 ppm; not greater than 60 ppm; not greater
than 55 ppm; not greater than 50 ppm; not greater than 45 ppm; not
greater than 40 ppm; not greater than 35 ppm; not greater than 30
ppm; not greater than 25 ppm; not greater than 20 ppm; not greater
than 15 ppm; not greater than 10 ppm.
[0065] In some embodiments, the engineered wetland is configured to
remove nitrogen from the wastewater such that effluent from the
engineered wetland comprises a nitrogen content of less than 40
ppm.
[0066] In some embodiments, the wetland is configured to remove
nitrogen in the wastewater to: not less than 40 ppm; not less than
35 ppm; not less than 30 ppm; not less than 25 ppm; not less than
20 ppm; not less than 15 ppm; not less than 10 ppm; not less than 8
ppm; not less than 6 ppm; not less than 4 ppm; or not less than 2
ppm.
[0067] In some embodiments, the wetland is configured to remove
nitrogen in the wastewater to: not greater than 40 ppm; not greater
than 35 ppm; not greater than 30 ppm; not greater than 25 ppm; not
greater than 20 ppm; not greater than 15 ppm; not greater than 10
ppm; not greater than 8 ppm; not greater than 6 ppm; not greater
than 4 ppm; or not greater than 2 ppm.
[0068] In some embodiments, the engineered wetland is configured to
remove phosphorous from the wastewater to less than 40 ppm (e.g.
comparing the effluent to the influent/as measured in the
effluent).
[0069] In some embodiments, the wetland is configured to remove
phosphorous in the wastewater to: not less than 40 ppm; not less
than 35 ppm; not less than 30 ppm; not less than 25 ppm; not less
than 20 ppm; not less than 15 ppm; not less than 10 ppm; not less
than 8 ppm; not less than 6 ppm; not less than 4 ppm; or not less
than 2 ppm.
[0070] In some embodiments, the wetland is configured to remove
phosphorous in the wastewater to: not greater than 40 ppm; not
greater than 35 ppm; not greater than 30 ppm; not greater than 25
ppm; not greater than 20 ppm; not greater than 15 ppm; not greater
than 10 ppm; not greater than 8 ppm; not greater than 6 ppm; not
greater than 4 ppm; or not greater than 2 ppm.
[0071] In some embodiments, directing the wastewater though an
engineered wetland further comprises aerating the wastewater as it
travels through the engineered wetland.
[0072] In some embodiments, the wetland comprises an aeration
system along the bottom portion. In some embodiments, the aeration
system comprises a series of aeration devices configured to provide
oxygen (e.g. air having oxygen in it, or oxygen gas) to the
microorganisms attached to the growth media (to feed the
microorganisms and promote degradation of organics such as
nitrogen, BOD and COD).
[0073] In some embodiments, the wetland is sufficiently aerated to
remove contaminants from wastewater. As used herein, "sufficiently
aerated" meet or exceed theoretical oxygen demand (based on COD,
BOD, NH.sub.3) for an influent WW stream. In some embodiments,
sufficiently aerated includes having a dissolved oxygen content of
at least about 80% of saturation (where dissolved oxygen content is
specific to the water temperature of the wastewater).
[0074] In some embodiments, the wetland comprises aerobic portions.
In some embodiments, the wetland comprises anaerobic portions. In
some embodiments, the wetland comprises anaerobic portions. In some
embodiments, the wetland comprises a combination of aerobic and
anoxic portions. In some embodiments, the wetland comprises a
combination of anaerobic and aerobic portions.
[0075] In some embodiments, the rate of aeration to the wastewater
in the engineered wetland is: at least 1 standard cubic feet per
minute (scfmn) air per gallon per minutes (gpm) of wastewater flow.
In some embodiments, the rate of aeration to the wastewater in the
engineered wetland is at least 1 scfm air/gpm wastewater to not
greater than 25 scfm air/gpm wastewater.
[0076] In some embodiments, the rate of aeration to the wastewater
(e.g. a portion of wastewater in the wetland) is: at least 1 scfm
air/gpm wastewater; at least 5 scfm air/gpm wastewater, at least 10
scfm air/gpm wastewater; at least 15 scfm air/gpm wastewater; at
least 20 scfm/gpm wastewater; or at least 25 scfm air/gpm
wastewater.
[0077] In some embodiments, the rate of aeration to the wastewater
(e.g. a portion of wastewater in the wetland) is: not greater than
1 scfm air/gpm wastewater; not greater than 5 scfm air/gpm
wastewater; not greater than 10 scfm air/gpm wastewater; not
greater than 15 scfm air/gpm wastewater; not greater than 20
scfm/gpm wastewater; or not greater than 25 scfm air/gpm
wastewater.
[0078] In some embodiments, the wetland is configured to treat
wastewater at a 0.25 day pore volume hydraulic residence time. In
some embodiments, the wetland is configured to treat wastewater: at
least 0.5 hour pore volume hydraulic residence time; at least a
0.75 hour pore volume hydraulic residence time; at least a 1 day
pore volume hydraulic residence time; at least a 1.25 day pore
volume hydraulic residence time; at least a 1.5 day pore volume
hydraulic residence time; at least a 1.75 pore volume hydraulic
residence time, or at least a 2 day pore volume hydraulic residence
time (e.g. through the wetland).
[0079] In some embodiments, the wetland is configured to treat
wastewater at a 0.25 day pore volume hydraulic residence time. In
some embodiments, the wetland is configured to treat wastewater:
not greater than 0.5 hour pore volume hydraulic residence time; not
greater than a 0.75 hour pore volume hydraulic residence time; not
greater than a 1 day pore volume hydraulic residence time; not
greater than a 1.25 day pore volume hydraulic residence time; not
greater than a 1.5 day pore volume hydraulic residence time; not
greater than a 1.75 pore volume hydraulic residence time, or not
greater than a 2 day pore volume hydraulic residence time (e.g.
through the wetland).
[0080] In some embodiments, the method comprises: directing the
effluent from the engineered wetland to an inlet of at least one
polishing cell having media including bauxite residue, where the
cell is in liquid communication with the engineered wetland,
wherein the polishing cell comprises at least one sidewall, an
inlet and an outlet configured to encase the media within the cell,
wherein the cell is configured to permit water to flow therethrough
via the inlet and outlet, further wherein via the media the cell
removes contaminants from a water stream. Non-limiting examples of
contaminants removed via the bauxite residue cell include (where
present): bacteria, viruses, ammonia, pharmaceuticals, and personal
care products.
[0081] In some embodiments, the bauxite residue cell removes at
least 80% removal of pathogens (e.g. influent averaging 10,000
cfu/100 mL to an effluent averaging 2,000 cfu/100 mL) to 99%
removal of pathogens (e.g. influent averaging 1,000 cfu/100 mL to
effluent averaging 10 cfu/100 mL) (where pathogen removal is
indicated by fecal coliform removal).
[0082] In some embodiments, the bauxite residue cell removes: at
least 60%; at least 65%; at least 70%; at least 75 wt. %; at least
80%; at least 85%; at least 90%; at least 95%; at least 98%; or at
least 99% of pathogens (e.g. by measuring and comparing the
pathogen content in the influent and the effluent streams).
[0083] In some embodiments, the bauxite residue cell removes: not
greater than 60%; not greater than 65%; not greater than 70%; not
greater than 75%; not greater than 80%; not greater than 85%; not
greater than 90%; not greater than 95%; not greater than 98%; or
not greater than 99% of pathogens (e.g. by measuring and comparing
the pathogen content in the influent and the effluent streams).
[0084] In another aspect of the instant disclosure, a method of
treating wastewater is provided, comprising: comprising: removing
solids and organics from a wastewater stream via an anaerobic
settling and treatment tank comprising a baffle configuration
including a hockey stick shaped baffle, a plurality of members
spaced from the hockey stick shaped baffle and the effluent, and a
settling promoter baffle positioned along the effluent end wall of
the tank and configured to provide a surface over flow of at least
0.25 m/hr; removing ammonia from a wastewater stream via an
aerated, engineered wetland, where aeration is at least 1.1
scfm/gpm of wastewater; and removing bacteria from the wastewater
stream via a bauxite residue cell.
[0085] In some embodiments, aerating is sufficient to provide
wastewater having a dissolved oxygen content of at least about 50%
of saturation up to 90% saturation, for that water temperature. In
some embodiments, aerating is sufficient to provide wastewater
having a dissolved oxygen content of at least about 60% of
saturation up to 80% of saturation, for the particular water
temperature. In some embodiments, aerating is sufficient to support
and sustain aerobic bacteria.
[0086] In some embodiments, aeration is sufficient such that the
wastewater in the engineered wetland has a dissolved oxygen content
of: at least 10% of saturation; at least 20% of saturation; at
least 30% of saturation; at least 40% of saturation; at least 50%
of saturation; at least 60% of saturation; at least 70% of
saturation; at least 80% of saturation; at least 90% of saturation;
at least 100% of saturation; or above saturation.
[0087] In some embodiments, aeration is sufficient such that the
wastewater in the engineered wetland has a dissolved oxygen content
of: not greater than 10% of saturation; not greater than 20% of
saturation; not greater than 30% of saturation; not greater than
40% of saturation; not greater than 50% of saturation; not greater
than 60% of saturation; not greater than 70% of saturation; not
greater than 80% of saturation; not greater than 90% of saturation;
not greater than 100% of saturation; or above saturation.
[0088] In one embodiment, aeration devices are set up parallel to
the direction of water flow. In one embodiment, the aeration
devices are set up perpendicular to the wastewater flow. In one
embodiment, the aeration devices are set up angled to the direction
of the water flow. In one embodiment, the aeration devices are set
up in a combination of at least parallel, perpendicular, and angled
with respect to the direction of water flow through the wastewater
treatment stream.
[0089] In another aspect of the instant disclosure, a wastewater
treatment apparatus, is provided, comprising: a unit having at
least one sidewall, an inlet, and an outlet, wherein the sidewall
completely encases an inner void of the unit but for the inlet and
the outlet; at least one distribution plate located in the inner
void and positioned between the inlet and the outlet, where the
distribution plate comprises holes configured to distribute and
direct wastewater through the inner void; and media comprising
bauxite residue located in the inner void between the inlet and the
outlet, wherein the media is configured to treat water and remove
contaminants therefrom.
[0090] In some embodiments, the media consists essentially of
bauxite residue.
[0091] In some embodiments, the media further comprises at least
one of: zero valent iron (ZVI); carbon; organic binder material
(e.g. polymers); inorganic binder material (e.g. water, cement);
and combinations thereof.
[0092] In some embodiments, the media is pelletized. In some
embodiments, the pelletized media comprises an average particle
size of at least 1/8'' to not greater than 3/8''.
[0093] In some embodiments, the pelletized media has comprises an
average particle size of: at least 1/16''; at least 1/8''; at least
1/2''; at least 2/3''; at least %''; or at least 1''. In some
embodiments, the pelletized media has comprises an average particle
size of: not greater than 1/16''; not greater than 1/8''; not
greater than 1/2''; not greater than 2/3''; not greater than %'';
or not greater than 1''.
[0094] In some embodiments, the average particle size of the media
in the bauxite residue cell (non-pelletized or pelletized) is from
about 1/20'' to about 3''.
[0095] In some embodiments, the average particle size of the media
in the bauxite residue cell is: at least 1/16''; at least 1/8''; at
least 1/4'' at least 1/2'' at least 3/4''; or, at least 1''. In
some embodiments, the average particle size of the media in the
bauxite residue is: at least 1''; at least 1.5''; at least 2''; at
least 2.5'' or at least 3''.
[0096] In some embodiments, the average particle size of the media
in the bauxite residue cell is: not greater than 1/16''; not
greater than 1/8''; not greater than 1/4'' not greater than 1/2''
not greater than 3/4''; or, not greater than 1''. In some
embodiments, the average particle size of the media in the bauxite
residue is: not greater than 1''; not greater than 1/5''; not
greater than 2''; not greater than 2.5'' or not greater than
3''.
[0097] In some embodiments, the unit includes two distribution
plates configured in a spaced relation and further wherein the
holes of each distribution plate are off-set from each other (e.g.
to promote distribution/mixing of the water).
[0098] In some embodiments, the holes in the distribution plate are
selected from: concentric holes of the same size, concentric holes
of different sizes, or slits (e.g. spanning nearly the length or
width of the distribution plate).
[0099] In some embodiments, the inlet and the outlet are configured
as connection ports (e.g. disconnect valves, for snap-on
connect/disconnect of the inlet and outlet).
[0100] In some embodiments, the sidewall further comprises an
access door, wherein the access door is configured to cooperate
with the sidewall to completely encase the inner void, further
wherein the access door is configured to open and allow media to be
inserted or removed from the inner void.
[0101] In some embodiments, the apparatus comprises a liner
configured to house the media and retain the media within the at
least one sidewall. In some embodiments, the liner comprises at
least one handle configured to allow removal of the liner and the
media contained within the liner from the BR cell (e.g. via
forklift, tow line, crane, manual operation, etc).
[0102] In some embodiments, the apparatus comprises sand between
the bauxite residue media and the inlet. In some embodiment, the
apparatus comprises sand between the bauxite residue media and the
outlet.
[0103] In some embodiments, the wastewater is aerated at the inlet
(e.g. prior to entry into the media). In some embodiments, the
media retained in the inner void is aerated via aeration devices
(e.g. positioned along the bottom or along the sides or adjacent to
the inlet or next to the distribution plates).
[0104] In some embodiments, the apparatus comprises a transport
device configured to the sidewall (e.g. outer side of the sidewall,
e.g. lowermost end or bottom) where the transport device is
configured to promote mobility of the BR cell. As non-limiting
examples, the transport device includes: wheels, a track and
wheels, a plurality of rollers, a conveyor belt, and combinations
thereof.
[0105] In some embodiments, the apparatus comprises at least one
support (e.g. handle), where the support is configured to allow the
BR cell module to be lifted and adjusted/moved, replaced.
[0106] In another aspect of the instant disclosure, a method is
provided, comprising: analyzing a wastewater treatment stream to
determine a contaminant profile, the contaminant profile comprising
at least one contaminant; selecting a number of tank modules,
wetland modules, and bauxite residue modules based on the
contaminant profile; configuring a wastewater treatment system
comprising the tank modules, wetland modules, and bauxite residue
modules to define a wastewater flow path; directing a wastewater
influent through the wastewater treatment system via the flowpath;
removing contaminants from the wastewater via the tank modules,
wetland modules, and bauxite residue modules such that the effluent
from the wastewater treatment system comprises an effluent profile,
where the levels of contaminants in the effluent profile are less
than the levels of contaminants in the contaminant profile. In some
embodiments, the effluent profile comprises levels of contaminants
that are less than government regulated permit levels for discharge
of water into the environment.
[0107] In some embodiments, the method comprises: replacing at
least one module of the tank modules, wetland modules, or bauxite
residue modules after a predetermined amount of time. In some
embodiments, the method comprises: replacing at least one module of
the tank modules, wetland modules, or bauxite residue modules after
a predetermined amount of wastewater has been treated.
[0108] In some embodiments, the method further comprises monitoring
each module in the wastewater treatment system to assess the
module's effectiveness. In some embodiments, monitoring comprises
analyzing water samples from the influent and effluent of each
module (e.g. via monitoring wells, monitors, etc) and comparing the
values to a target treatment range for that type of module (e.g.
anaerobic tank, engineered wetland, bauxite residue cell).
[0109] In some embodiments, the water effluent from the system
comprises a pH of: at least 6 to not greater than 9.
[0110] In some embodiments, the hydraulic retention time of the
anaerobic settling and treatment tank is at least 0.25 day; at
least 0.50 day; at least 0.75 day; at least 1 day; at least 1.25
day; at least 1.5 day; at least 1.75 day; or at least 2 days.
[0111] In some embodiments, the hydraulic retention time of the
anaerobic settling and treatment tank is: not greater than 0.25
day; not greater than 0.50 day; not greater than 0.75 day; not
greater than 1 day; not greater than 1.25 day; not greater than 1.5
day; not greater than 1.75 day; or not greater than 2 days.
[0112] In some embodiments, the hydraulic retention time of the
wastewater in the engineered wetland is: at least 0.25 day; at
least 0.50 day; at least 0.75 day; at least 1 day; at least 1.25
day; at least 1.5 day; at least 1.75 day; at least 2 days; at least
2.25 days, at least 2.5 days, at least 2.75 days, at least 3 days,
at least 3.25 days, at least 3.5 days, at least 3.75 days, or at
least 4 days.
[0113] In some embodiments, the hydraulic retention time of the
wastewater in the engineered wetland is: not greater than 0.25 day;
not greater than 0.50 day; not greater than 0.75 day; not greater
than 1 day; not greater than 1.25 day; not greater than 1.5 day;
not greater than 1.75 day; not greater than 2 days; not greater
than 2.25 days, not greater than 2.5 days, not greater than 2.75
days, not greater than 3 days, not greater than 3.25 days, not
greater than 3.5 days, not greater than 3.75 days, or not greater
than 4 days.
[0114] In some embodiments, the hydraulic retention time of the
wastewater in the bauxite residue cell is: at least 30 minutes; at
least an hour, at least 2 hours; at least 4 hours; at least 6
hours; at least 8 hours; at least 10 hours; or at least 12
hours.
[0115] In some embodiments, the hydraulic retention time of the
wastewater in the bauxite residue cell is: not greater than 30
minutes; not greater than an hour, not greater than 2 hours; not
greater than 4 hours; not greater than 6 hours; not greater than 8
hours; not greater than 10 hours; or not greater than 12 hours.
[0116] In some embodiments, the hydraulic retention time of
wastewater in the system is at least about 3 to about 8 days. In
some embodiments, the hydraulic retention time of wastewater in the
system is at least 121/2 hours to 61/2 days.
[0117] In some embodiments, the hydraulic retention time of the
wastewater is: at least 121/2 hours; at least 18 hours; at least 24
hours; at least 30 hours; at least 36 hours; at least 40 hours; at
least 48 hours; at least 52 hours; at least 56 hours; at least 60
hours; at least 64 hours; or at least 72 hours.
[0118] In some embodiments, the hydraulic retention time of the
wastewater is: not greater than 121/2 hours; not greater than 18
hours; not greater than 24 hours; not greater than 30 hours; not
greater than 36 hours; not greater than 40 hours; not greater than
48 hours; not greater than 52 hours; not greater than 56 hours; not
greater than 60 hours; not greater than 64 hours; or not greater
than 72 hours.
[0119] In one embodiment, the first zone (e.g. anaerobic
settling/treatment tank) removes at least about 50% to not greater
than 90% of the BOD/COD/TSS. With this embodiment, in the second
zone (e.g. aerated wetland(s)) any remaining biodegradable organics
are removed up to about 99%. Furthermore, up to 99% of the ammonia
is removable via this second zone, as the second zone is configured
to convert ammonia to nitrate and, by regulating air flow/aeration
(and/or supplemental organics) convert nitrate to nitrogen gas. In
some embodiments, the nitrate is taken up by the plants growing in
the media. Further, in the third zone (e.g. mixed metal oxide media
cell) the wastewater is polished to further remove contaminants
(e.g. phosphorous removal to less than 0.1-1 ppm and residual
ammonia to less than 0.2 ppm) and disinfected to remove pathogens
(e.g. as indicated by measuring non-limiting, examples of
pathogens: fecal/total coliform, e-coli, viruses, and water-borne
organisms such a giardia).
[0120] In some embodiments, off-gas including methane is captured
and used to operate/run a generator to power the system pumps
and/or aeration system. In some embodiments, the pumps and/or
aeration system are operated by power generated via solar power
generated with solar panels. In some embodiments, the pumps and/or
aeration systems are operated by wind power generated via wind
turbines. In some embodiments, the pumps and or aeration systems
are operated with hydraulic power from the water flow through the
system. In some embodiments, the wastewater treatment system is a
zero energy system, requiring no external power sources to operate
the components which require power (e.g. aeration system,
pumps).
[0121] In some embodiments, by utilizing a three zone system as
articulated herein, a smaller footprint (e.g. size) of the wetland
is needed to achieve contaminant removal. In some embodiments,
"smaller footprint" is quantifiable by a smaller total bed volume
per a given surface area of media in the bed.
[0122] As used herein, "inlet" means: a location where something
enters. In one embodiment, wastewater enters each zone through an
inlet in liquid communication with the zone.
[0123] As used herein, "outlet" means: a location where something
exits. In one embodiment, wastewater exits each zone through an
outlet in liquid communication with the zone.
[0124] As used herein, "first zone" means: the zone which is
closest to the inlet of the system. In some embodiments, the first
zone comprises at least one anaerobic tank (sometimes called a
settling and treatment tank). In one embodiment, the first zone
comprises a plurality of anaerobic tanks. In one embodiment, the
anaerobic tank is modular (e.g. mobile, interchangeable).
[0125] As used herein, "anaerobic tank" (also called an anaerobic
settling/treatment tank) means: a tank in an anaerobic environment
where sludge and/or particulates settle from a material and where
contaminants are removed (e.g. organics, including BOD, COD). In
some embodiments, anaerobic degradation occurs in this tank. In
some embodiments, the anaerobic settling tank comprises an
anaerobic zone.
[0126] In some embodiments, the anaerobic settling tank does not
have any media therein.
[0127] In some embodiments, the anaerobic tank comprises media.
[0128] In some embodiments, the anaerobic tank comprises at least
one baffle, which is configured to deflect the flow of water and/or
direct the water through a water flow path from the inlet of the
tank to the outlet of the tank. In some embodiments, the baffles
are integral to the tank. In some embodiments, the baffles are
adjustable and/or removable from the tank.
[0129] In some embodiments, the wastewater is directed through the
sludge (zone or area of high concentration of solids or suspended
solids) which forms in the bottom of the tank. Without being bound
to a particular mechanism or theory, this is believed to improve
the treatment process (e.g. removal of metals, nitrates,
phosphates, TSS, VSS, COD, and BCOD). In some embodiments, the
anaerobic settling/treatment tank is configured to allow
particulates and sludge to settle out from the wastewater (e.g. it
was suspended in the water) to the bottom of the tank.
[0130] In some embodiments, the tank includes at least one vent to
direct off-gases out of the tank and/or maintain pressure within
the tank.
[0131] In some embodiments, the tank is constructed of non-porous
materials or porous materials that have a surface coating of a
non-porous material.
[0132] As used herein, "baffle" means: an obstruction for
deflecting the flow of a material. In some embodiments, the baffles
are constructed of various non-reactive (non-degrading) materials.
In some embodiments, the baffles comprise a vertical configuration,
a horizontal configuration, a curved (arcuate) configuration, or an
angled configuration. In some embodiments, the baffle comprises an
angled configuration (e.g. hockey stick or dog leg configuration).
In some embodiments, the baffles are the same configuration. In
some embodiments, the baffles include different configurations. In
one or more embodiments, the dimension and shape of the baffles can
be varied as desired.
[0133] As used herein, "hockey stick-shaped baffle" means a baffle
with a straight portion and an angled, lower portion. In some
embodiments, the hockey stick-shaped baffle is located closest to
the inlet of the anaerobic settling/treatment tank, where the
hockey stick-shaped baffle directs wastewater into the tank. In
some embodiments, the hockey stick-shaped baffle directs the
incoming wastewater through a sludge zone, the area having a high
concentration of sludge (particulates, settled solids) in the
anaerobic tank.
[0134] In some embodiments, the hockey stick-shaped baffle is at an
acute angle when compared to the plane created by the bottom of the
tank. In some embodiments, the end of the hockey stick-shaped
baffle is angled from greater than 0 degrees (where 0 degrees
indicates that the member is parallel to the bottom surface of the
tank) to not greater than 90 degrees (where 90 degrees indicates
that the hockey stick-shaped baffle is perpendicular to the bottom
of the tank, or in a straight line with the rest of the body of the
baffle). In some embodiments, the hockey-stick shaped baffle
comprises an angle of between 30 to 80 degrees. In some
embodiments, the hockey stick shaped baffle comprises an angle of
between 45 and 60 degrees.
[0135] In some embodiments, the hockey stick-shaped baffle as an
angle that is: at least 5 degrees; at least 10 degrees; at least 15
degrees; at least 20 degrees; at least 25 degrees; at least 30
degrees; at least 35 degrees; at least 40 degrees; at least 45
degrees; at least 50 degrees; at least 55 degrees; at least 60
degrees; at least 65 degrees; at least 70 degrees; at least 75
degrees; at least 80 degrees; or at least 85 degrees.
[0136] In some embodiments, the hockey stick shaped baffle has an
angle that is: not greater than 5 degrees; not greater than 10
degrees; not greater than 15 degrees; not greater than 20 degrees;
not greater than 25 degrees; not greater than 30 degrees; not
greater than 35 degrees; not greater than 40 degrees; not greater
than 45 degrees; not greater than 50 degrees; not greater than 55
degrees; not greater than 60 degrees; not greater than 65 degrees;
not greater than 70 degrees; not greater than 75 degrees; not
greater than 80 degrees; or not greater than 85 degrees.
[0137] As used herein, "member" means an object positioned in the
anaerobic tank. In some embodiments, the member is a baffle which
is placed in the path of the wastewater so that the wastewater is
deflected, slows, and solids settle out from the wastewater. In
some embodiments, the member is positioned between the hockey
stick-shaped baffle and the outlet, in the control volume of the
tank.
[0138] In some embodiments, the member is at an acute angle when
compared to the plane created by the bottom of the tank. In some
embodiments, the member is angled from greater than 0 degrees
(where 0 degrees indicates that the member is parallel to the
bottom surface of the tank) to not greater than 90 degrees (where
90 degrees indicates that the member is perpendicular to the bottom
of the tank). In some embodiments, the member comprises an angle of
between 30 to 80 degrees. In some embodiments, the member comprises
an angle of between 45 and 60 degrees.
[0139] In some embodiments, the member has an angle that is: at
least 5 degrees; at least 10 degrees; at least 15 degrees; at least
20 degrees; at least 25 degrees; at least 30 degrees; at least 35
degrees; at least 40 degrees; at least 45 degrees; at least 50
degrees; at least 55 degrees; at least 60 degrees; at least 65
degrees; at least 70 degrees; at least 75 degrees; at least 80
degrees; or at least 85 degrees.
[0140] In some embodiments, the member has an angle that is: not
greater than 5 degrees; not greater than 10 degrees; not greater
than 15 degrees; not greater than 20 degrees; not greater than 25
degrees; not greater than 30 degrees; not greater than 35 degrees;
not greater than 40 degrees; not greater than 45 degrees; not
greater than 50 degrees; not greater than 55 degrees; not greater
than 60 degrees; not greater than 65 degrees; not greater than 70
degrees; not greater than 75 degrees; not greater than 80 degrees;
or not greater than 85 degrees.
[0141] In some embodiments, the anaerobic tank comprises at least
one member. In some embodiments, the anaerobic tank comprises
several members spaced apart from each other. In some embodiments,
the member is a baffle which deflects the water flow (e.g. to
prevent short circuiting and/or dead zones in the anaerobic tank
and/or to promote mixing).
[0142] In some embodiments, the members are angled in the same way
that the lower portion of the hockey stick-shaped baffle is angled.
In some embodiments, the members comprise a different angle from
the hockey stick-shaped baffle. In some embodiments, the members
comprise the same angled configuration (e.g. with reference to the
bottom of the tank). In some embodiments, the members comprise
different angles from each other (e.g. with reference to the bottom
of the tank). In some embodiments, the members are spaced
equidistant from each other. In some embodiments, the members are
spaced at different distances from each other (e.g. distance
between member 1 and member 2 is different from the distance
between member 2 and member 3, where members 1-3 are located
sequentially and adjacent to each other between the inlet and the
outlet of the anaerobic tank).
[0143] As used herein, "settling promoter" (sometimes called a
prism baffle or angle baffle) means a baffle configured to promote
settling of solids from a wastewater stream. In some embodiments,
the settling promoter is configured to deflect wastewater towards
the center of the tank (e.g. promote mixing and settling of
solids). In some embodiments, the settling promoter is a
discontinuous portion of the sidewall, angled outward from the
sidewall towards the inside of the tank. In some embodiments, the
settling promoter is a baffle which is attached to the sidewall
proximate to the outlet.
[0144] In some embodiments, the settling promoter is at an acute
angle when compared to the plane created by the bottom of the tank.
In some embodiments, the settling promoter is angled from greater
than 0 degrees (where 0 degrees indicates that the member is
parallel to the bottom surface of the tank) to not greater than 90
degrees (where 90 degrees indicates that the settling promoter is
perpendicular to the bottom of the tank). In some embodiments, the
settling promoter comprises an angle of between 30 to 80 degrees.
In some embodiments, the settling promoter comprises an angle of
between 45 and 60 degrees.
[0145] In some embodiments, the settling promoter has an angle that
is: at least 5 degrees; at least 10 degrees; at least 15 degrees;
at least 20 degrees; at least 25 degrees; at least 30 degrees; at
least 35 degrees; at least 40 degrees; at least 45 degrees; at
least 50 degrees; at least 55 degrees; at least 60 degrees; at
least 65 degrees; at least 70 degrees; at least 75 degrees; at
least 80 degrees; or at least 85 degrees.
[0146] In some embodiments, the settling promoter has an angle that
is: not greater than 5 degrees; not greater than 10 degrees; not
greater than 15 degrees; not greater than 20 degrees; not greater
than 25 degrees; not greater than 30 degrees; not greater than 35
degrees; not greater than 40 degrees; not greater than 45 degrees;
not greater than 50 degrees; not greater than 55 degrees; not
greater than 60 degrees; not greater than 65 degrees; not greater
than 70 degrees; not greater than 75 degrees; not greater than 80
degrees; or not greater than 85 degrees.
[0147] As used herein, "mixing zone" refers to the upper region of
the anaerobic settling and treatment tank, located generally above
the solids zone, where the solids zone comprising a high
concentration of solids. In some embodiments, wastewater is
directed/deflected to the mixing zone in order to promote contact
(e.g. maximize reaction/contact time) with the organic material and
inorganic material of the wastewater stream with the microorganisms
located in the tank.
[0148] As used herein, "solids zone" refers to the lower region of
the anaerobic settling tank, where the solids, organic material,
and inorganic material generally settle out and/or flocculate from
the wastewater as it travels through the tank.
[0149] As used herein, "second zone" means: the zone which is
between the first zone and the third zone. In some embodiments, the
second zone includes at least one engineered wetland. In some
embodiments, the second zone includes a plurality of engineered
wetlands. In some embodiments, the engineered wetlands are modular
(e.g. mobile, interchangeable units).
[0150] As used herein, "engineered wetland" means: a non-naturally
occurring wetland. In some embodiments, the engineered wetland
comprises an impermeable barrier (liner) which retains a media
therein. In some embodiments, the engineered wetland comprises a
tank. In some embodiments, the engineered wetland comprises a tank
which is portable (e.g. a module). In some embodiments, the wetland
comprises an inlet and an outlet in liquid communication with the
main body of the wetland. In some embodiments, the wetland
comprises an aeration system, which is configured to provide
aeration to the water present in the wetland. In some embodiments,
the wetland is a horizontal subsurface flow wetland. In some
embodiments, the wetland retains media. In some embodiments, the
wetland supports vegetation, which grows in the wetland and/or is
rooted in the media retained in the wetland.
[0151] As used herein, "aeration" means: the process of directing
(e.g. circulating) air through something. In some embodiments, the
wetland cell comprises aeration to provide air (including oxygen,
or dissolved oxygen) to the water present in the wetland. In some
embodiments, aeration comprises bubbling oxygen gas into the water.
In some embodiments, aeration comprises bubbling air, which
includes oxygen gas (along with nitrogen gas and carbon dioxide)
into the water.
[0152] As used herein, "aeration system" means: a system for
producing aeration in a material. In some embodiments, the aeration
system aerates the wastewater after it leaves the first zone and
before it gets into the second zone (e.g. at the piping/first zone
outlet to second zone inlet). In some embodiments, the aeration
system aerates the wastewater as it travels through the second zone
or portions of the second zone.
[0153] In some embodiments, the aeration system includes the
following components: a pump, a gauge, an inlet, an outlet (e.g. in
the wetland), and piping (to direct the air from the pump through
the inlet to the outlet). In some embodiments, the outlet comprises
the open end of the piping. In some embodiments, the outlet
comprises a plurality or perforations which allow the air to bubble
there through. In some embodiments, the outlet is configured with a
diffuser, which is configured to diffuse the large air bubbles into
smaller air bubbles. In some embodiments, the aeration is
adjustable (e.g. coarse bubbles, fine bubbles), such that aeration
in a portion or all of a component is configured to be increased,
decreased, or varied from one portion of a component (e.g.
engineered wetland) to another portion of the component.
[0154] In some embodiments, the components of the aeration system
which are located within the wetland (e.g. piping, outlet) are
referred to as the aeration device. In some embodiments, the
aeration device is located in the inlet of the wetland. In some
embodiments, the aeration device is located proximate to a portion
of the wetland. In some embodiments, the aeration device is located
throughout the wetland. In some embodiments, the aeration system is
located along the bottom portion of the wetland. In some
embodiments, the aeration device is located proximate to the outlet
of the wetland.
[0155] As used herein, "media" means: a substance having a surface
area. In some embodiments, the wetland comprises media (e.g. media
retained within the wetland) to provide an area for vegetation to
root. In some embodiments, the media within the wetland provides a
surface area for bacteria to adhere to and/or a habitat for
bacteria to live in. Some non-limiting examples of media include:
aggregate (e.g. rocks), sand, lava rocks, ceramic (e.g. beads),
plastics (e.g. BioRings.TM.), polymers, compost, mulch, and the
like. Further, it is noted that the size and shapes of the media
are variable in accordance with one or more embodiments of the
instant disclosure in order to provide a desired surface area of
media per unit volume of material.
[0156] As used herein, "third zone" means: the zone which is
closest to the outlet of the system. In some embodiments, the third
zone includes at least one cell having bauxite residue therein. In
some embodiments, the third zone comprises a plurality of bauxite
residue cells. In some embodiments, the bauxite residue cells are
modular (e.g. adjustable, movable, interchangeable).
[0157] As used herein, "mixed metal oxide media" means a media
including two or more metal oxides. One non-limiting example of a
mixed metal oxide media includes bauxite residue.
[0158] As used herein, "bauxite residue cell" means a cell having
bauxite residue media therein. In some embodiments, the wastewater
is flowed through the cell in: a downward flow (e.g. gravity), an
upward or up-flow (e.g. reverse gravity), a substantially
horizontal flow, or combinations thereof. In some embodiments, the
cell is constructed of a non-porous material or a porous material
with a non-porous coating to retain wastewater therein. In some
embodiments, the bauxite residue cell is configured to operate as a
filter to remove contaminants from a wastewater stream.
[0159] Without being bound to a particular mechanism or theory, it
is believed that the bauxite residue cell removes pollutants
through one or more mechanisms including: filtration, predation,
adsorption, absorption, ion exchange, nitrification, oxidation,
chemical degradation, and free radical reduction.
[0160] As used herein, "bauxite residue" means: a particulate
alkaline clay. Bauxite residue includes a plurality of metals and
metal oxides therein. As a non-limiting example, raw alkaline clay
includes alkaline clay which has transformed/changed due to
neutralization (e.g. the prolonged exposure to atmospheric carbon
dioxide and/or contact with anthropogenic carbon dioxide, and as a
result, is generally free from draining liquids and is more neutral
than its original, alkaline form.
[0161] As used herein, "ZVI" means: zero valent iron (e.g. iron
metal). Some non-limiting examples of ZVI include: iron filings,
iron balls, iron particles, iron fibers, and the like.
[0162] In some embodiments, the cell includes a ratio of bauxite
residue to zero valent iron (ZVI).
[0163] In some embodiments, the ZVI is present in: not greater than
about 15 wt. %; not greater than about 13 wt. %; not greater than
about 11 wt. %; not greater than about 10 wt. %; not greater than
about 7 wt. %; not greater than about 5 wt. %; not greater than
about 3 wt. %; not greater than about 2.5 wt. %; not greater than
about 1 wt. %; or not greater than about 0.5 wt. %. In some
embodiments, the ZVI is present in: at least about 15 wt. %; at
least about 13 wt. %; at least about 11 wt. %; at least about 10
wt. %; at least about 7 wt. %; at least about 5 wt. %; at least
about 3 wt. %; at least about 2.5 wt. %; at least about 1 wt. %; or
at least about 0.5 wt. %.
[0164] In some embodiments, the bauxite residue and ZVI are mixed
to commingle the media. In some embodiments, the BR and ZVI are
mixed to thoroughly disperse the ZVI within the BR. In some
embodiments, the combined/mixed BR and ZVI is pelletized, to
provide a pelletized media.
[0165] Without being bound to a particular mechanism or theory, it
is believed that the pelletized media may provide an improved
hydraulic conductivity through the cell by eliminating potential
plugging due to degradation (rusting) of pockets of ZVI.
[0166] As used herein, "module" means: a self-contained component,
which can be installed as a unit. In some embodiments, the bauxite
residue cell comprises a module comprising an outer sidewall which
contains (e.g. completely encases) the media therein. In some
embodiments, the anaerobic tank comprises a module. In some
embodiments, the engineered wetland comprises a module (e.g. tank
wetland).
[0167] As used herein, "pathogen" means: a disease causing agent.
Some non-limiting examples of pathogens include: bacteria (e.g. as
indicated by fecal coliform, E. coli, fecal streptococcous),
protozoa (e.g. Giardia and Cryptosporidium), and
microorganisms.
[0168] As used herein, "bacteria" means: a single-celled or
non-cellular spherical or spiral or rod-shaped organisms (lacking
chlorophyll) that reproduce by fission.
[0169] As used herein, "anaerobic zone" means: a region which has
the capability to supports anaerobic bacteria.
[0170] As used herein, "aerobic zone" means: a region which has the
capability to support aerobic bacteria.
[0171] As used herein, "anoxic zone" means: a region which has the
capability to support microaerophilic bacteria.
[0172] As used herein, "wastewater" means: water having impurities
and/or contaminants therein. In some embodiments, wastewater
includes: sanitary wastewater, industrial (or process) wastewater,
storm water (e.g. run-off) and/or combinations thereof. As some
non-limiting examples, wastewater treated in accordance with one or
more embodiments of the instant disclosure can include the
following contaminants/impurities: viruses, bacteria, protozoa,
algae, oil, grease, pharmaceuticals, personal care products,
ammonia, phosphorous, heavy metals (e.g. arsenic, mercury,
chromium), and others.
[0173] As used herein, "cleaned water" means: water meeting the
purity limits as set by regulations set by various government
and/or regulatory bodies. In some embodiments, the systems and
methods of the instant disclosure transform wastewater into cleaned
water. In some embodiments, cleaned wastewater is discharged to a
holding tank for reuse (recycle). In some embodiments, cleaned
wastewater is discharged to a drainage field, into a body of water,
or used for irrigation purposes.
[0174] As used herein, "dissolved oxygen" (also called DO) means:
the amount of oxygen dissolved in water, measured in ppm. Oxygen
saturation for a wastewater stream is dependent upon the
temperature of the wastewater.
[0175] As used herein, "average particle size of media" refers to
the average particle size of the media.
[0176] As used herein, "average particle diameter of media" refers
to the average diameter of the media, when the media is in
circular/spherical form.
[0177] As used herein, "hydraulic conductivity" means: the
quantitative measure of a saturated material's ability to transmit
water when subjected to a hydraulic gradient. As a non-limiting
example: hydraulic conductivity is the ease with which pores of a
saturated material permit water movement. In some embodiments,
hydraulic conductivity is a function of the materials or the
mixture of materials, and relates to the permeability
characteristics of the material (e.g. particle size of the
material/media). In some embodiments, hydraulic conductivity is a
function of velocity and pressure drop across the media/cell.
[0178] As used herein, "hydraulic gradient" means: the difference
in total hydraulic head per unit distance.
[0179] As used herein, "hydraulic loading rate" means: the rate at
which the wastewater loads onto the substrate (media) and this rate
may vary based on the media particle size and/or contaminant being
removed. As used herein, "surface over flow rate" means the volume
flow of water per hour (m.sup.3/hr) as a function of the surface
area of the treatment tank (m.sup.2), such that surface over flow
rate is measured in m/hr.
[0180] As used herein, "hydraulic retention time" means: the amount
of time the water spends moving through a volume of material.
[0181] As used herein, "field capacity" (or "in situ moisture
content) means: how much moisture a particulate material can
hold.
[0182] As used herein, "pH in zone" means: the average pH of water
in a zone (e.g. first zone, second zone, or third zone). In some
embodiments, the pH in the wastewater treatment system is between
about 4 and about 11. In some embodiments, the pH of the effluent
is 6 to not greater than 9.
[0183] Various ones of the inventive aspects noted hereinabove may
be combined to yield a wastewater treatment system or method of
using such system to remove contaminants and impurities from a
wastewater stream.
[0184] These and other aspects, advantages, and novel features of
the invention are set forth in part in the description that follows
and will become apparent to those skilled in the art upon
examination of the following description and figures, or may be
learned by practicing the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0185] FIG. 1 depicts and flow chart of an embodiment of a
wastewater treatment system in accordance with the instant
disclosure.
[0186] FIG. 2A depicts a top plan view of an embodiment of a second
zone, or an engineered wetland, in accordance with the instant
disclosure.
[0187] FIG. 2B depicts a side plan view of the engineered wetland
of FIG. 2A.
[0188] FIG. 2C depicts a close-up cut-away side plan view of the
engineered wetland of FIG. 2B.
[0189] FIG. 3A depicts an embodiment of a perforated aeration pipe
usable in accordance with an embodiment of a second zone of the
instant disclosure.
[0190] FIG. 3B depicts an embodiment of an aeration system of an
engineered wetland, including several aerations lines anchored via
grating (e.g. grating supports).
[0191] FIG. 4 depicts a cut-away perspective view of an embodiment
of a portion of an aeration system in a second zone of a wastewater
treatment system in accordance with the instant disclosure.
[0192] FIG. 5 depicts a close-up cut away perspective view of the
embodiment depicted in FIG. 4.
[0193] FIGS. 6A-6C depicts various perspective side views of
portions of the aeration system depicted in FIG. 5. FIG. 6A is a
cut-away perspective view of an embodiment of the drop down
aeration lines stemming from the piping. FIG. 6B is a partial
cut-away perspective view of FIG. 6A, showing a close-up of the
upper portion of the drop down aeration lines stemming from the
piping. FIG. 6C is a partial cut-away perspective view of FIG. 6A,
showing a close-up of the upper portion of the drop down aeration
lines stemming from the piping, depicting a different perspective
than that depicted in FIG. 6B.
[0194] FIG. 7A depicts an embodiment of a third zone (e.g. bauxite
residue cell) in accordance with the instant disclosure.
[0195] FIG. 7B depicts a cut away side view of an embodiment of a
bottom portion of the third zone (e.g. bauxite residue cell) of
FIG. 7A.
[0196] FIG. 8 depicts a top plan view of an embodiment of the third
zone of the instant disclosure, including a plurality of bauxite
residue cells configured in parallel to one another and connected
to receive wastewater and disperse cleaned water.
[0197] FIG. 9 depicts a top plan view of one embodiment of the
system of the instant disclosure.
[0198] FIG. 10 depicts a cut-away side view of the embodiment of
the wastewater treatment system depicted in FIG. 9.
[0199] FIG. 11A depicts a cut-away side view an embodiment of an
anaerobic settling tank in accordance with the instant disclosure
(e.g. referenced as Tank 3 in the Examples section).
[0200] FIGS. 11B through 11G depict alternative embodiments of the
baffle configuration of the anaerobic settling and treatment tank
in accordance with the instant disclosure.
[0201] FIG. 11B depicts a hockey stick-shaped baffle, a single
member angled in the same manner as the hockey stick shaped baffle,
and a settling promoter (e.g. angle baffle attached to the
sidewall).
[0202] FIG. 11C depicts a hockey stick shaped baffle, two members
angled in the same manner as the lower end of the hockey stick
shaped baffle, and spaced equidistant from each other, with a third
member located above the first two members (e.g. in the "mixing
zone" and angled in an obtuse direction when compared to the plane
of the bottom of the tank), and a settling promoter that is a
baffle positioned in an angled direction (e.g. acute angle).
[0203] FIG. 11D depicts a hockey stick shaped baffle adjacent to
the inlet, followed by two members positioned at different heights
from each other relative to the depth of the tank, with a settling
promoter attached to the sidewall and positioned in an obtuse angle
when compared to the plane created by the bottom of the tank.
[0204] FIG. 11E depicts a hockey stick shaped baffle, a very large
member (lengthwise) having a different angle than the lower portion
of the hockey stick shaped baffle, where the member crosses a
substantial portion of the mixing volume of the tank, and a
settling promoter angled in an acute angle from the sidewall with a
top portion having an angle close to 0 degrees.
[0205] FIG. 11F depicts a hockey stick shaped baffle, with two
members having an angle close to 0 degrees (e.g. .about.5 degrees,
and spaced equidistantly from each other), with a settling promoter
located on the effluent sidewall adjacent to the outlet.
[0206] FIG. 11G depicts a hockey stick shaped baffle, with two
members having an angle close to 0 degrees (e.g. .about.5 degrees,
and spaced equidistantly from each other), with a settling promoter
located on the effluent sidewall adjacent to the outlet, where this
embodiment depicts larger-sized members and larger-sized settling
promoter than in the embodiment depicted in FIG. 11F.
[0207] FIG. 12A depicts a series of columns having different media
which were run in accordance with an experimental example.
[0208] FIG. 12B depicts the measured characteristics of each
column, including porosity, empty bed contact time (EMCT), and
hydraulic retention time (HRT). FIG. 13 is a graphical result of
the measured effluent fecal coliform over time for the five
different column experiments depicted in FIG. 12A over a span of
151 days, where the measure fecal coliform is an indicator of
pathogen presence/pathogen removal.
[0209] FIG. 13 shows the effluent fecal coliform concentrations for
each column versus time through the course of the study. The sand
control column exhibited a lag in disinfection performance, as
indicated by the high effluent concentration in the first six data
points (to the left of the first dotted line); the remaining
columns performed more consistently over the course of the pilot,
exhibiting no low-removal startup period. When the flow rate was
doubled, (i.e. the right side of the second dotted line) fecal
coliform effluent concentration tended to increase slightly in all
columns, as empty bed contact time was reduced from about 624
minutes to about 300 minutes per column.
[0210] FIG. 14 is a graphical result depicting the average effluent
fecal coliform at various concentrations (e.g. all data, 20 mL/min,
and 10 mL/min (with sand lag removed), where fecal coliform values
are indicators for pathogen contaminants.
[0211] FIG. 15 depicts the average % removal of pathogens (as
indicated by fecal coliform) for the different media columns of
FIG. 12A. Sand had an average of 83.1% removal of pathogens;
bauxite residue had an average of 94.2% removal of pathogens;
bauxite residue and 2.5 wt. % zero valent iron had an average of
94.5% removal of pathogens; compost, followed by sand with 2.5 wt.
% ZVI had an average of 94.9% removal of pathogens; and compost
followed by bauxite residue having 2.5 wt. % ZVI had an average
removal of 99.1% removal of pathogens.
[0212] FIG. 16 depicts a graph of Pathogen Removal (indicated by
Fecal Coliform Removal (%)) in three different columns, showing
that the column having pelletized BR with 2.5 wt. % ZVI had 78.52%
removal; the column having bauxite residue had 77.97% removal; and
the column having bauxite residue and 2.5 wt. % ZVI had 80.52%
removal.
[0213] FIG. 17 depicts a schematic of a cut-away sideview of a
bauxite residue module, in accordance with the instant
disclosure.
[0214] FIG. 18 depicts the computational flow dynamics of an
anaerobic tank having a baffle configuration of the instant
disclosure compared to a tank having conventional baffle
configuration, where the dashed lines are representative of a
velocity profile of water through the tanks, illustrative of the
water movement through the tank and dead zones or static areas.
DETAILED DESCRIPTION
[0215] The present disclosure provides systems and methods of
effectively treating a wastewater stream to disinfect the water and
remove other contaminants from the water. Removal of contaminants,
other than microorganisms, may include the removal of ammonia,
biodegradable organics (e.g. BOD, CBOD), TSS, VSS, oils, greases,
phosphorus, metals, pharmaceuticals, and personal care products.
Reference will now be made in detail to the accompanying drawings,
which at least assist in illustrating various pertinent embodiments
of the present invention.
[0216] Referring to FIG. 1, a schematic of an embodiment of the
wastewater treatment system 10 of the instant disclosure is
depicted. The system 10 depicts an inlet 12, an outlet 14, and a
first zone 40, second zone 60, and third zone 100, which are in
liquid communication with each other, as depicted via arrows
between zones. Wastewater 26 is directed into the system via inlet
12.
[0217] Then, the wastewater 26 travels from the inlet 12 into the
first zone 40, which is at least one anaerobic settling and
treatment tank 42. The anaerobic settling/treatment tank 42 is
configured to remove particulates and sludge from the wastewater
and remove/reduce biodegradable organics. Next, the wastewater 26
is directed from the outlet 58 of the first zone 40 to the inlet 66
of the second zone 60, which is at least one engineered wetland
62.
[0218] The engineered wetland 62 includes media 68 and vegetation
(plants) 70 retained in the wetland and/or rooted in the media 68.
Also, the engineered wetland 62 is aerated via an aeration system
90 in communication with the engineered wetland 62 via piping 84.
In some embodiments, the engineered wetland 62 is configured to
receive organics (e.g. methanol, woodchips, molasses, etc.) from an
organic feed chamber 78 (depicted, e.g. in FIG. 9). In some
embodiments, the organic feed chamber 78, which is adapted to be in
liquid communication with the engineered wetland 62. (see, e.g.
FIG. 9, 10.) In the second zone 60, the wastewater 62 is
disinfected and contaminants are removed therefrom. The wastewater
26 is then directed out of the second zone 60 via the outlet 74 and
into the third zone 100 via the inlet 114.
[0219] The third zone 100 comprises at least one bauxite residue
cell 102. The bauxite residue cell 102 includes media 108 therein.
In some embodiments, the media 108 comprises bauxite residue. In
some embodiments, the media consists essentially of bauxite
residue. In some embodiments, the media 108 comprises bauxite
residue and ZVI in a particular weight ratio. In some embodiments,
the media 108 comprises a mixture of bauxite residue and ZVI.
[0220] In some embodiments, in the bauxite residue cell 102, the
wastewater 26 is disinfected and is treated to remove (if present),
as non-limiting examples, contaminants including: ammonia,
phosphorous, heavy metals, pharmaceuticals, and personal care
products. Cleaned water is then directed out of the bauxite residue
cell 102 via outlet 116. Cleaned water then exits the system 10 via
the outlet 14. In some embodiments, the outlet 116 from the bauxite
residue cell 102 is the same as the outlet 14 from the wastewater
treatment system.
[0221] FIGS. 2A through 3B are directed towards an embodiment of
the second zone 60, at least one engineered wetland 62. Referring
to FIGS. 2A-2C, wastewater 26 enters the wetland 62 via inlet 66,
and is aerated by air directed into the engineered wetland via
piping 84, which is located along the bottom portion of the vessel
64. While wastewater 26 is retained in and travels through the
wetland 62, it is aerated via air coming through the piping 84 and
it is directed through the media 68 and plant roots of the plants
rooted in the media 68.
[0222] Referring to the aeration system 90, the piping 84 is
located along the bottom portion of the wetland 62, and is
configured with a plurality of perforations to distribute air into
the wastewater 26. Diffusers 88 cover the perforations in the
piping 84 and are configured to diffuse the gaseous air into the
wastewater 26. A grate 76 (including the grate and support)
supports the piping 84 to prevent the media 68 from crushing the
piping 84. FIG. 3A shows a close-up of a curved portion of piping
84 having perforations 86 therein. FIG. 3B depicts the portions of
piping 84 anchored via grate 76 into the bottom of the vessel
64.
[0223] Referring to FIGS. 4-6C, another embodiment of an engineered
wetland 62 is depicted. As shown in FIGS. 4 and 5, the
configuration of the vessel 64, inlet 66 and outlet 74 are similar,
while the aeration system 90, including the piping 84 and diffusers
88, are in a different configuration. Here, the piping 84 is
directed across the top of the vessel 64, with individual aeration
lines which are retained into secondary pipes 92. The secondary
pipes 92 are connected to the piping 84 via plugs 94 to prevent
water from flowing into the secondary pipes 92 and pipes 84. In
some embodiments, the pipes 84 are removable and/or the incoming
air supply/level of aeration is variable to adjust the amount of
aeration in the wetland. FIGS. 6A, 6B, and 6C each depict close-up
perspective views of the drop down aeration lines stemming from the
piping 84.
[0224] FIGS. 7A and 7B depict an embodiment of the third zone,
comprising at least one bauxite residue cell 102. Referring to
FIGS. 7A and 7B, a modular bauxite residue cell is depicted. In
some embodiments, the sidewall of the module completely encases the
inner void of the bauxite residue cell 102, where the media 108 is
housed. Wastewater 26 is directed into and out of the cell 102 via
inlet and outlet, which are in liquid communication with the inner
void. In some embodiments, the cell 102 is equipped with supports
(e.g. on each side) to enable the module to be moved/adjusted. In
some embodiments, supports comprise wheels, a wheel and track
configuration, a stand (e.g. which allows for a lift to move/remove
the cell 102), and combinations thereof. Referring to FIG. 7A, the
bauxite residue cell 102 includes distributor plates (e.g. baffles)
110 towards the bottom portion of the cell 102, where each
distributor plate 110 includes perforations therein 112 to permit
wastewater 26 to flow there through. In some embodiments, the
distributor plates are configured to disperse wastewater as it
enters the bauxite residue cell via the inlet 114. In some
embodiments, the distributor plates are off-set from each other
such that the perforations do not line up. FIG. 7B depicts the
inlet 114 at the base of the cell 102 vessel 104, illustrating that
this embodiment is for an up-flow configuration (e.g. reverse
gravity). Also depicted in FIG. 7B is the connection port 122,
which is configured to allow for a quick connect/disconnect of the
bauxite residue cell module from the inlet 114 and outlet 116 (e.g.
so that another module can replace it).
[0225] Referring to FIG. 8, a plurality of bauxite residue cells
102 are arranged in parallel to one another on top of a support 118
to enable wastewater 26 to be fed from an inlet 114 at the base of
each module (see, e.g. FIG. 7B). Further, a pump 120 is depicted,
for pumping the wastewater 26 in an up-flow configuration. Once the
water is cleaned, it exits the cells 102 via piping and is directed
to the outlet 116 of the third zone of the bauxite residue
cell/module system.
[0226] Without being bound to a particular mechanism or theory, the
function of the anaerobic settling tank (e.g. septic tank) is
believed to be the breaking down/removal of organic matter by
anaerobic bacteria contained in the tank sludge. Settling of
suspended solids, organic and inorganic solids are removed in this
first zone.
[0227] Without being bound by a particular mechanism or theory, it
is believed that the function of engineered wetland A is for
additional removal of BOD, using aerobic bacteria (e.g. the wetland
is aerated) and to provide nitrification (conversion of ammonia to
nitrate), via the aerobic bacteria. Without being bound to a
particular mechanism or theory, the function of the engineered
wetland portion of the treatment is believed to be BOD removal,
nitrification/denitrification, and additional TSS removal from the
wastewater.
Example 1
Example of a Wastewater Treatment System
[0228] Referring to FIGS. 9 and 10, schematics for an embodiment of
a wastewater treatment system is depicted. This schematic was
constructed and operated as a pilot for this Example. In each tank
(three shown), the design HRT is 0.25 to 1 day at an influent flow
rate.
[0229] Within each tank, there is an upflow region and a down flow
region. Each tank contains 3 chambers (1 chamber consisting of a
down flow section followed by an up flow section). The separate
chambers and baffles direct the flow of water, allowing for better
contact between the wastewater and the anaerobic bacteria in the
sludge (i.e. high concentration sludge zone located proximate to
the bottom of the tank.) The up flow chambers are sized so that the
up flow velocity is 0.25 m/hr at an influent flow rate of 1
gpm.
[0230] Tank 1&2 each contain a baffle configuration which is a
`hockey stick` design (i.e. two baffles, each with a generally
straight portion and each straight portion having an angled section
at its end). Tanks 1 &2 are piped in series, so that the
effluent from Tank 1 is the influent to Tank 2, testing removal
efficiency of 6 total chambers.
[0231] Referring to FIG. 11, Tank 3 is depicted, which includes a
baffle configuration including a hockey stick-shaped baffle, three
members (vane baffles) and a settling promoter (e.g. located on the
sidewall closest to the outlet). The baffle configuration was based
upon computer modeling experiments (see, e.g. Example 5). This tank
has 3 different types of baffles that cooperate as one structure.
The suspended baffle is closest to the inlet and is configured to
separate the down flow from the up flow section. The suspended
baffle comprises a hockey-stick shape, with a straight portion
(e.g. generally vertical, perpendicular to the bottom of the tank)
and a bottom portion which is curved. Also, there are three
separate members that are configured to act as turning vane
baffles. The members direct the path of water downward to promote
the settling of solids and the mixing of water in the tank (e.g.
prevent short circuiting). Next, there is a settling promoter (e.g.
prism shaped baffle) configured to promote current density
throughout the tank. The settling promoter is configured to direct
the flow of water to the center of the up flow chamber (e.g. in a
uniform manner). This baffle design is depicted in greater detail
in FIG. 11.
[0232] Referring to FIGS. 9 and 10, each engineered wetland tank
contains a different media, where the depth of the media within
each wetland is approximately four feet deep. Also, each engineered
wetland is configured accept aeration from an aeration system (or
portions thereof) which extends beneath (under) the media towards
the bottom portion of the engineered wetland. Each wetland includes
two types of aeration systems: an aquarium tubing-based aeration
system and a diffuser tubing-based aquarium system. Each engineered
wetland is designed for 1 day HRT under normal operating
conditions.
[0233] Engineered wetland 1A includes plastic media in an elongated
ring shape (e.g. BioRings.TM.) (SA=32 ft.sup.2/ft.sup.3).
Engineered wetland 1A houses the control aquarium tubing aeration
system, and ten (10) fine bubble diffusers which are 20 inches
long.
[0234] Engineered wetland 2A includes lava rocks (porous rock) as
the media, with an average size 1''-2''. Wetland 2A includes the
aquarium tubing aeration system, and eight sections of weighted
bubble tubing which are each 69'' in length. The aeration tubing
includes a fiberglass grating which rests on concrete blocks to
prevent the media from causing the aeration tubing.
[0235] Wetland 3A includes ASTM No 3 stone (aggregate) as the
media, with an average size of 1''-2''. Wetland 3A contains the
control aquarium tubing aeration system, and eight weighted bubble
tubing which are each 69'' in length. The aeration tubing includes
a stainless steel wire mesh which rests on concrete blocks to
prevent the media from causing the aeration tubing.
[0236] In wetland B, each tank in this portion is divided into two
sections, and water flows sequentially through each sections. The
function of the first section is denitrification (i.e. conversion
of nitrate to nitrogen gas by anaerobic and/or anoxic bacteria).
The first section includes a carbon source (e.g. molasses,
methanol, wood chips) to `feed` the bacteria. The function of the
second chamber is additional aeration and removal of any residual
BOD from the carbon source added in the first chamber. The second
chamber contains a growth media for bacteria to grow on (e.g. and
for plants, cattails to root in) and is aerated (e.g. configured to
an aeration device).
[0237] Engineered wetland 1B includes wood chips as the carbon
source in section 1 and contains BioRings as the media in section
2. The aeration system in section 2 includes both aquarium tubing,
and eight sections of weighted bubble tubing which are each 47'' in
length.
[0238] Engineered wetland 2B includes rocks as the media in section
1. Prior to entering section 1, the influent will be mixed (e.g. in
line) with a water/molasses mixture (e.g. at low concentration) as
the carbon source. Engineered wetland 2B includes No 3 stone media
in section 2 and the aeration system in section 2 includes both
aquarium tubing, and nine weighted bubble tubing sections which are
each 47'' in length. A stainless steel wire mesh rests on concrete
blocks to protect the aeration tubing (e.g. from the weight of the
media). Without being bound to particular mechanism or theory, the
mixed metal oxide cell (e.g. bauxite residue cell) is believed to
function to provide (if needed) final polishing (TSS removal) and
disinfection (pathogen removal, e.g. indicated via fecal coliform,
e. coli removal) to the wastewater, resulting in cleaned water. The
cell will use two separate modules. One module includes bauxite
residue (e.g. alkaline clay) "as received" from the storage
facility. The other module includes bauxite residue with 2.5 wt. %
ZVI in pelletized form (e.g. pellets).
[0239] The following tables provide data obtained via the pilot
system.
TABLE-US-00001 Conventional Baffle Baffle Configuration Min % Avg.
% Max % Min % Avg. % Max % removal removal removal removal removal
removal Total COD 39 72 94 42 75 96 BOD5 74 86 97 77 88 99 NH3--N
-- 33 62 -- 34 75 NO3--N -- 77 95 -- 72 91 PO4 -- 58 65 -- 70 72
TSS -- 92 97 -- 90 98 VSS -- 92 97 -- 91 99
TABLE-US-00002 Wetland Influent Min Max Avg. Total 48 395 292 COD
Soluble 30 179 90 COD BOD 5 29 759 170 NH3--N 13 48 28 values in
mg/L
TABLE-US-00003 Wetland 1A Wetland 2A Wetland 3A Min Max Avg Min Max
Avg Min Max Avg Total COD 35 92 54 12 58 30 11 70 36 Soluble COD 20
66 39 8 51 24 2 50 25 BOD 5 6 7 6.5 3 3 3 n/a n/a n/a NH3--N 2.2 44
15 0.15 25 8.5 0.32 40 17 values in mg/L
[0240] In some embodiments, the hydraulic loading rate of the
anaerobic settling/treatment tank is at least about 0.008
gal/min/ft.sup.2 to not greater than about 0.143
gal/min/ft.sup.2.
[0241] In some embodiments, the hydraulic loading rate of the
anaerobic tank is: at least 0.01 gal/min/ft.sup.2; at least 0.025
gal/min/ft.sup.2; at least 0.05 gal/min/ft.sup.2; at least 0.075
gal/min/ft.sup.2; at least 0.1 gal/min/ft.sup.2; at least 0.125
gal/min/ft.sup.2; at least about 0.140 gal/min/ft.sup.2.
[0242] In some embodiments, the hydraulic loading rate of the
anaerobic tank is: not greater than 0.01 gal/min/ft.sup.2; not
greater than 0.025 gal/min/ft.sup.2; not greater than 0.05
gal/min/ft.sup.2; not greater than 0.075 gal/min/ft.sup.2; not
greater than 0.1 gal/min/ft.sup.2; not greater than 0.125
gal/min/ft.sup.2; not greater than about 0.140 gal/min/ff.
[0243] In some embodiments, the hydraulic loading rate of the
engineered wetland is at least about 0.002 to about 0.072
gal/min/ft.sup.2.
[0244] In some embodiments, the hydraulic loading rate of the
wetland is: at least 0.002 gal/min/ft.sup.2; at least 0.005
gal/min/ft; at least 0.01 gal/min/ft.sup.2; at least 0.03
gal/min/f; at least 0.05 gal/min/ft; or at least 0.07
gal/min/ft.sup.2.
[0245] In some embodiments, the hydraulic loading rate of the
wetland is: not greater than 0.002 gal/min/ft.sup.2; not greater
than 0.005 gal/min/ft.sup.2; not greater than 0.01
gal/min/ft.sup.2; not greater than 0.03 gal/min/ft.sup.2; not
greater than 0.05 gal/min/ft; or not greater than 0.07
gal/min/ft.sup.2.
[0246] In some embodiments, the hydraulic loading rate of the mixed
metal oxide media cell is at least about 0.011 galmin/ft.sup.2 to
not greater than about 0.444 gal/min/ft.sup.2.
[0247] In some embodiments, the hydraulic loading rate of the BR
cell is: at least 0.05 gal/min/ft; at least 0.1 gal/min/ft; at
least 0.2 gal/min/ft.sup.2; at least 0.3 gal/min/ft.sup.2; or at
least 0.4 gal/min/ft.sup.2.
[0248] In some embodiments, the hydraulic loading rate of the BR
cell is: not greater than 0.05 gal/min/ft.sup.2; not greater than
0.1 gal/min/ft.sup.2; not greater than 0.2 gal/min/ft.sup.2; not
greater than 0.3 gal/min/ft.sup.2; or not greater than 0.4
gal/min/ft.sup.2.
[0249] In some embodiments, the flow rate of water into the system
is at least about 1 gpm to about 10 gpm. In some embodiments, the
flow rate of water into the system is: at least 2 gpm; at least 4
gpm; at least 6 gpm; or at least 8 gpm. In some embodiments, the
flow rate of wastewater into the system is not greater than 2 gpm;
not greater than 4 gpm; not greater than 6 gpm; or not greater than
8 gpm.
[0250] In some embodiments, the hydraulic conductivity of the mixed
metal oxide cell is at least about 0.0009 cm/s to not greater than
about 0.19 cm/s.
[0251] In some embodiments, the hydraulic conductivity of the
pelletized media in the mixed metal oxide cell is: at least about
10.sup.-1 cm/s to about 10.sup.-4 cm/s.
[0252] In some embodiments, the porosity of the engineered wetland
is at least about 35% (e.g. aggregate) to not greater than about
95% (e.g. plastic media or hollow cylindrical form).
[0253] In some embodiments, the field capacity of the mixed metal
oxide media cell is at least about 50% to not greater than about
60%.
[0254] In some embodiments, the anaerobic settling/treatment tank
is configured to remove at least about 50% to not greater than
about 99% of BOD/COD from a wastewater stream.
[0255] In some embodiments, the engineered wetland is configured to
remove at least about 40% to not greater than about 99.9% of
pathogens (e.g. indicated by fecal coliform).
[0256] In some embodiments, the mixed metal oxide medial bed is
configured to remove at least about 60% to not greater than about
100% (e.g. below detection limit) of pathogens (e.g. indicated by
fecal coliform).
[0257] In some embodiments, the mixed metal oxide media bed is
configured to remove at least about 30% to not greater than about
99% of pharmaceuticals and personal care products.
Example 2
Column Study
[0258] A pilot was run to test bauxite residue and ZVI media
disinfection. Five columns were constructed, and each was 30-inches
tall with a 4-inch diameter. The column influent water was pumped
from a front portion of an existing wastewater treatment system
(wastewater had solids removed via a septic system, but had
otherwise undergone limited, if any, treatment).
[0259] Each column contained a different media, including: sand
(control), BR only, BR with 2.5 wt % ZVI; two columns, BR with 2.5
wt % ZVI and sand with 2.5 wt %/ZVI, each had a compost
pretreatment column to remove dissolved oxygen from the influent
water. Without being bound to a particular mechanism of theory, it
is believed that by adding a small amount of ZVI to the BR media,
wastewater disinfection would be enhanced without reducing the
hydraulic conductivity of the column (e.g. due to accumulation of
iron oxides in the filter bed).
[0260] The columns were constructed to operate in up-flow mode.
Each column contained 6.35 cm (2.5 inches) of gravel on the bottom
to ensure the influent water dispersed evenly throughout the
column. After the gravel was placed, 76.2 cm (30 inches) of media
was put into the column. The top of the column was connected to a
smaller column, where the pH, dissolved oxygen, and temperature
were measured with a Fischer Scientific Accument AP63 pH Probe, and
a Hach HQ40d Dual-Input Multi-Parameter Digital Meter LD0101
Dissolved Oxygen/Temperature Probe. The columns were run for a 151
day period from spring through fall in an outdoor setting.
[0261] In the pilot-scale BR and ZVI disinfection columns, the BR
and ZVI columns removed pathogens (e.g. indicated via fecal
coliform) more effectively than the control (sand) column. The data
showed that the column containing 2.5 wt %/ZVI performed better
than the BR only column, but analysis of the data showed no
statistically significant difference was achieved by adding the
ZVI. Without being bound to a particular mechanism or theory, since
it consistently outperformed sand, BR's mechanism of action is
thought to be a combination of filtration and another
mechanism;
[0262] The five (5) disinfection media scenarios run in seven (7)
columns are illustrated in FIG. 12A. The first column was a
control, containing only sand. The second column contained BR only.
The third scenario consisted of a pretreatment column containing
spent mushroom compost with 2.5 wt % ZVI, followed by a column
containing sand with 2.5 wt % ZVI (i.e. this scenario had two
columns in series). The fourth column contained bauxite residue
with 2.5 wt % ZVI. The fifth scenario consisted of a pretreatment
column containing spent mushroom compost with 2.5 wt % ZVI followed
by a column containing bauxite residue with 2.5% ZVI (i.e. this
scenario had two columns in series). The bauxite residue was taken
from a Residue Storage Area in Texas, USA.
[0263] The flow rate to all of the columns was 10 mL/min, with an
empty bed contact time of 624 minutes; the flow rate to the columns
was increased to 20 mL/min towards the end of the test, as
indicated in FIG. 13. After the increase in flow rate, the empty
bed contact time was reduced to about 300 minutes. The hydraulic
residence time varied with the porosity of the various media, and
ranged from 3.8 hours for column 5b with bauxite residue and ZVI,
to 5.1 hours for columns 3a and 5a with spent mushroom compost and
ZVI, as shown in FIG. 12B.
[0264] Fecal coliform (FC) concentration was the focus of the data
analysis for the pilot columns. Other parameters, including
dissolved oxygen, oxidation reduction potential, chemical oxygen
demand, total organic carbon, nitrate, ammonia, and phosphate were
also monitored; however, FC concentration showed no correlation
with any of these data. Concentration of dissolved ferric and
ferrous iron in column effluents were also analyzed; however, most
results were below method detection limit.
[0265] The effluent from each column was generally sampled
twice/week for three months. The table below summarizes the
analytical methods used for analyzing the samples during this
period. Prior to day 50, only one influent sample was taken,
generally at column 4 (BR+ZVI), and it was assumed that other
influents were the same since they were taken from the same source;
however, the influent FC concentrations for each column were
starting on day 50, individual fecal coliform samples were taken at
the influent to each column. For the next two and a half months,
columns were sampled once per week for influent and effluent FC
concentration.
TABLE-US-00004 Pilot Study Parameters Measured and Analytical
Methods Used Parameter Analytical Method or Instrument Used
Pressure Pressure Gage (Inches of Water) pH Fischer Scientific
Accument AP63 pH Probe Dissolved Hach HQ40d Dual-Input
Multi-Parameter Digital Meter Oxygen LD0101 Dissolved
Oxygen/Temperature Probe Temperature Hach HQ40d Dual-Input
Multi-Parameter Digital Meter LD0101 Dissolved Oxygen/Temperature
Probe Chemical Method 8000 Reactor Digestion Method Oxygen Demand
Nitrate EPA 300.0 (1.sup.st two weeks of pilot operation) Cadminum
Reduction Method (after 1.sup.st two weeks of pilot operation)
Ortho- EPA 300.0 (1.sup.st two weeks of pilot operation) Phosphate
PhosVer3 (Ascorbic Acid) Method (after 1.sup.st two weeks of pilot
operation) Ammonia 4500 NH3--N--C 20th Edition (1.sup.st two weeks
of pilot operation) Salicylate Method (after 1.sup.st two weeks of
pilot operation) ICP Metals Inductively Coupled Plasma Scan Fecal
Coliform Standard Method 9222D Membrane Filtration Total Iron EPA
Method 6010B Ferric Iron Standard Method 3500-Fe B (Phenanthroline
Method) Ferrous Iron Standard Method 3500-Fe B (Phenanthroline
Method) Dissolved Iron Inductively Coupled Plasma Total Organic
USEPA SW-846 III Ed., Method 9060 Carbon
[0266] FIG. 13 below shows the effluent FC concentrations for each
column versus time through the course of the study. During the
first 6 weeks of monitoring, an effluent sample was taken at each
column, but only one sample was taken at the influent and assumed
to be the same for all columns. After week 4, samples were taken at
the influent and effluent of each column, and it was discovered
that FC concentration varied between the columns. Because influent
concentrations for each column were not sampled for the duration of
the experiment, effluent FC concentration was the focus of the data
analysis, though average percent removal was examined. Average FC
influent concentration was approximately 5000 CFU/100 mL. The sand
control column exhibited a lag in performance, as indicated in FIG.
13; the remaining columns performed more consistently over the
course of the pilot. When the flow rate was doubled (as indicated
by the dashed vertical line on the graph), FC effluent
concentration tended to increase slightly, as empty bed contact
time was reduced from about 600 minutes to about 300 minutes per
column.
[0267] The right-most bars in FIG. 14 below shows each column's
effluent concentration, averaged over the course of the pilot
study. The columns with a compost pretreatment step consisting of
two columns in series were considered a single entity, with the
influent as the influent to the "A" compost column, and the
effluent as the effluent from the "B" sand, BR, or ZVI media
column. The method detection limit for FC concentration was 10
CFU/100 mL, and results below the detection limit were reported as
<10; in the following analysis, any values reported <10 were
assumed to be 5 CFU/100 mL.
[0268] Looking at all the data, the control sand column had the
highest average FC effluent; this high concentration may be because
the sand column exhibited a lag in performance for several weeks as
indicated in FIG. 13. The columns with compost pretreatment
performed slightly better than the single columns, most likely
because they had a hydraulic residence time approximately double
that of the single columns. Much of the data for the columns with
compost pretreatment was below detection limit.
[0269] The BR+2.5% ZVI column had lower effluent concentration than
the BR only column, and the BR+2.5% ZVI column with compost
pretreatment had lower effluent concentration than the sand+2.5%
ZVI with compost pretreatment column; these results indicate not
only that BR improves disinfection compared to sand, but also that
the addition of ZVI seems to enhance BR disinfection.
[0270] Referring to FIG. 14, the graph depicts the average pathogen
effluent concentration (indicated by fecal coliform, where the
influent average is 5030 CFU/100 mL).
[0271] The centered bars for each column in FIG. 14 show the
average FC effluent concentration with data from the sand column
startup period and the 20 mL/min flowrate period removed. Data from
the first 30 days of monitoring (typical sand filter startup
period) and the last 42 days of monitoring were removed from the
set. Even accounting for the sand column startup period, all
columns showed lower average effluent FC concentration
[0272] The right-most bars in FIG. 14 show the average effluent FC
concentration with only data from the last 42 days of monitoring,
the 20 mL/min period, removed. The center columns show that the
columns containing sand were affected by the startup period, having
effluent concentration higher than the red bars. The columns not
containing sand performed about the same when data from the startup
period was and was not included. The BR+2.5% ZVI column with
compost pretreatment did not seem to follow this trend; however,
most data points were at or below detection limit except for one
high value that may have skewed the results.
[0273] FIG. 15 is a graph depicting the average percent removal of
pathogens (e.g. indicated as fecal coliform) for the five different
columns tested. For this data, influent and effluent FC
concentrations were measured at each column and data from the first
6 weeks of monitoring was removed. Percent FC removal is measured
as (CFU inf-CFU eff)/CFU inf. Outliers or unreliable data were
considered any data points below two standard deviations below the
mean and any data points below zero (indicating that the effluent
FC concentration was higher than the influent). Data reported below
the detection limit (<10 CFU/100 mL) were assumed to be 5, so
average percentages did not skew high or low.
[0274] Like the average effluent concentration, the average percent
removal shows that all treatment columns performed better than
sand, and that the columns with the compost pretreatment step
performed better than the columns without the additional residence
time. The column with BR+2.5% ZVI performed slightly better than
the BR only column, and the BR+2.5% ZVI column with compost
pretreatment performed better than all other treatment columns.
[0275] Because it was believed that due to experimental error,
reliable data for the influent concentration was not available for
a large portion of the study, effluent FC concentration only was
considered in the statistical analysis. In the BR/ZVI column tests,
all treatment columns performed statistically significantly better
than sand at a 90% confidence level; even after the `startup
period` during which the sand column developed its biological
disinfection layer, all treatment columns performed statistically
significantly better than sand at an 86% confidence level.
[0276] Without being bound to a particular mechanism or theory,
filtration is still believed to play a role in disinfection in the
bauxite residue cell. The data in the column experiments showed
that BR removes FC more effectively than the simple granular
filtration mechanism seen in sand. These results indicate that
another mechanism in addition to granular filtration is at work in
disinfection by BR.
Example 3
Media Pelletizing Experiments
[0277] In order to pelletize the BR with 2.5 wt. % ZVI, the BR was
first dried to remove the excess moisture content of the BR (e.g.
25-30% moisture content in as-received form). Once dried, the BR
and ZVI were both ground into a powder (e.g. fine powder),
completed via a cone mill (e.g. which ground and mixed the
components). Once the media were ground and commingled, water was
added to the mixture (e.g. to act as a binding agent). The media
with binding agent was mixed in a Simpson mixer until the media
formed into balls/pellets. The pelletized media was allowed to air
dry. The average size of the pellets varied. D.sub.25 was 3/8''.
D.sub.50 for the pelletized BR/ZVI material was 0.187 in (standard
US mesh size 4).
[0278] In some embodiments, the pelletized media (BR and ZVI) is
from about 1/20 of an inch to about 3 inches.
Example 4
Pelletized Vs. Non-Pelletized Media
[0279] Column experiments were carried out to compare pathogen
removal (e.g. indicated via fecal coliform removal) of pelletized
and unprocessed (non-pelletized) BR. Three columns were tested, and
contained the following media: pelletized BR with 2.5 wt % ZVI, BR
hand mixed with 2.5 wt % ZVI, and BR only. Each column had an HRT
of 4 hours. The columns drew influent with an average fecal
coliform concentration of 143 CFU/100 mL. The pelletized BR with
2.5 wt % ZVI began running 37 days before the BR only column began
running and 101 days before the hand-mixed BR with 2.5 wt % ZVI;
samples were collected from each column approximately weekly.
[0280] Influent and effluent samples were analyzed for fecal
coliform concentration using Standard Method 9222D; samples were
analyzed by Microbac, a certified outside lab. Data was analyzed
for percent removal, C.sub.inf-C.sub.eff/C.sub.inf. This data set
included 9 or fewer samples per column. Results indicate that the
pelletized BR with 2.5 wt % ZVI works about as well as the
unprocessed (non-pelletized) BR.
Example 5
Computational Flow Dynamics Modeling
[0281] Computational fluid dynamics (CFD) modeling of various
baffle configurations was completed to understand the velocity
profile of different configurations. Modeling was done on Ansys
Fluent Software Version 13.0. Each model run assumed influent flow
of 1 gallon per minute (gpm) plain water into one chamber plus half
of another chamber, where the chamber is depicted as
two-dimensional chambers (consisting of a 60'' water depth, 6''
wide downflow section, and 24'' wide up flow section, and the 6''
wide down flow section of the subsequent chamber). Each chamber
includes: one down flow section (before hockey stick shaped baffle
to direct flow of water down) and one up flow section (after hockey
stick or `suspended` baffle to direct the flow of water up).
[0282] Referring to FIG. 18, the resulting models depicts a
two-dimensional velocity vector profile between the baffles in the
system, where the velocity profile is indicative of the water
velocity through the chamber and displays "dead zones", or areas of
slow velocity/no mixing, if any.
[0283] Referring to FIG. 18, the model on the left was of the
baffle configuration depicted in FIG. 11 (e.g. hockey stick-shaped
baffle and the three spaced members (e.g. vane baffles)), while the
model on the right was of the conventional baffle design. The dead
zones perceived through visual observation of the resulting CFD
models are circled in each model in FIG. 18. In contrast with the
conventional baffle configuration, the baffle configuration of the
instant disclosure as a much smaller "dead zone" area. Without
being bound by a particular mechanism or theory, it is believed
that this may attribute to a higher degree of mixing, improved
treatment as compared to the conventional system (e.g. promote
solids retention, removal of inorganic solids, organic solids).
[0284] While various embodiments of the present invention have been
described in detail, it is apparent that modifications and
adaptations of those embodiments will occur to those skilled in the
art. However, it is to be expressly understood that such
modifications and adaptations are within the spirit and scope of
the present invention.
* * * * *