U.S. patent application number 14/870824 was filed with the patent office on 2017-03-30 for self-regenerating biofilter.
The applicant listed for this patent is United States of America as Represented by The Secretary of the Army. Invention is credited to Benjamin C. Masters, Andrew J. Nelson, Martin Page.
Application Number | 20170088448 14/870824 |
Document ID | / |
Family ID | 58406460 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170088448 |
Kind Code |
A1 |
Page; Martin ; et
al. |
March 30, 2017 |
SELF-REGENERATING BIOFILTER
Abstract
The present invention is a self-regenerating biofilter. The
biofilter tank receives untreated water through an intake inlet,
filters it through a filtration mass and expels purified water
through an output outlet. The filtration mass includes gravel and
activated carbon layers separated by a mesh screen. A compressed
air line is located below the mesh screen. Periodically, the
biofilter self-cleans by opening a flush valve that expels a flush
water stream carrying debris. The biofilter self-regenerates by
periodically stopping filtration for a time, allowing biological
matter left on the activated carbon to degrade into biomass.
Periodically, the biofilter removes and flushes out biomass by
application of water or a combination of air and water.
Inventors: |
Page; Martin; (Urbana,
IL) ; Nelson; Andrew J.; (Champaign, IL) ;
Masters; Benjamin C.; (Urbana, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
United States of America as Represented by The Secretary of the
Army |
Alexandria |
VA |
US |
|
|
Family ID: |
58406460 |
Appl. No.: |
14/870824 |
Filed: |
September 30, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01D 2101/02 20130101;
C02F 1/42 20130101; C02F 2303/16 20130101; C02F 2209/006 20130101;
C02F 2209/44 20130101; C02F 3/06 20130101; C02F 2003/001 20130101;
C02F 2209/02 20130101; C02F 3/104 20130101; Y02W 10/10 20150501;
C02F 1/283 20130101; C02F 3/006 20130101; C02F 3/106 20130101; Y02W
10/15 20150501 |
International
Class: |
C02F 3/04 20060101
C02F003/04; C02F 1/28 20060101 C02F001/28; C02F 1/42 20060101
C02F001/42; C02F 3/06 20060101 C02F003/06; B01D 24/46 20060101
B01D024/46; B01D 36/02 20060101 B01D036/02 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] The invention described herein was made by an employee of
the United States Government and may be manufactured and used by
the Government of the United States of America for governmental
purposes without the payment of any royalties thereon or therefore.
Claims
1. A self-regenerating biofilter apparatus comprising: a biofilter
tank, wherein said biofilter tank comprises an intake inlet
connected to a first channel, an output outlet connected to a
second channel, and a flush valve; a filtration mass located within
said biofilter tank and at least partially above said intake inlet
and said flush valve, said filtration mass comprising a layer of
gravel and a layer of non-gravel materials, wherein said layer of
non-gravel material comprises activated carbon; a mesh screen
separating said layer of gravel from said layer of non-gravel
material; and a compressed air line located at least partially
within said biofilter tank below said mesh screen.
2. The apparatus of claim 1, wherein said biofilter tank has a
volume ranging from approximately 5 gallons to approximately 5,000
gallons, and wherein said biofilter tank has a daily flow-through
volume ranging from approximately 50 gallons to approximately
50,000 gallons.
3. The apparatus of claim 1, wherein said flush valve is selected
from the group consisting of: a solenoid valve, a butterfly valve,
a ball valve and a pinch valve.
4. The apparatus of claim 1, wherein said filtration mass makes up
approximately 50% to approximately 85% of a volume of said
biofilter tank, wherein said layer of gravel comprises
approximately 3% to approximately 10% of said filtration mass,
wherein said layer of activated carbon comprises approximately 60%
to approximately 97% of said filtration mass.
5. The apparatus of claim 1, wherein said layer of gravel has an
average diameter ranging from approximately 5 mm to approximately
30 mm, wherein said layer of non-gravel material has a mesh size
ranging from approximately 8 to approximately 12.
6. The apparatus of claim 1, wherein said layer of non-gravel
material further comprises a bioculture seed.
7. The apparatus of claim 1, wherein said filtration mass further
comprises a layer of ion exchange material, wherein said layer of
ion exchange material comprises up to approximately 30% of said
filtration mass.
8. The apparatus of claim 1, further comprising a controller
connected to said flush valve and connected to a power source.
9. The apparatus of claim 8, further comprising a timer connected
to said controller.
10. The apparatus of claim 8, further comprising a memory connected
to said controller, wherein said memory is configured with at least
one pre-programmed cycle for opening and closing said flush
valve.
11. The apparatus of claim 8, further comprising a biomass sensor
connected to said controller.
12. The apparatus of claim 8, further comprising a controller
interface connected to said controller.
13. The apparatus of claim 1, further comprising a heating element
located within said biofilter tank.
14. The apparatus of claim 1, further comprising a thermal sensor
at least partially located within said biofilter tank.
15. A self-regenerating biofilter system comprising: at least one
self-regenerating biofilter apparatus, wherein said at least one
self-regenerating biofilter apparatus comprises: a biofilter tank,
wherein said biofilter tank comprises an intake inlet connected to
a first channel, an output outlet connected to a second channel,
and a flush valve; a filtration mass located within said biofilter
tank and at least partially above said intake inlet and said flush
valve, said filtration mass comprising a layer of gravel and a
layer of non-gravel materials, wherein said layer of non-gravel
material comprises activated carbon; a mesh screen separating said
layer of gravel from said layer of non-gravel material; and a
compressed air line located at least partially within said
biofilter tank below said mesh screen; a central controller
connected to said flush valve and connected to a power source.
16. The system of claim 15, further comprising a central timer
connected to said central controller.
17. The system of claim 15, further comprising a central memory
connected to said central controller, wherein said central memory
is configured with at least one pre-programmed cycle for opening
and closing said flush valve.
18. The system of claim 15, further comprising a central interface
connected to said central controller.
19. A method for using a self-regenerating biofilter apparatus
comprising the steps of: iteratively invoking a function n times,
wherein said function comprises the steps of: receiving an
untreated water stream into a biofilter tank through an intake
inlet connected to a first channel, wherein said biofilter tank
comprises said intake inlet connected to said first channel and
receiving said untreated water stream, wherein said biofilter tank
comprises an output outlet connected to a second channel and
expelling a purified water stream, wherein said biofilter tank
comprises a flush valve expelling a flush water stream filtering
said untreated water stream through a filtration mass to transform
said untreated water stream into said purified water stream, said
filtration mass comprising a layer of gravel and a layer of
non-gravel materials, wherein said layer of non-gravel material
comprises activated carbon, wherein said filtration mass is located
within said biofilter tank and at least partially above said intake
inlet and said flush valve, wherein a mesh screen separates said
layer of gravel from said layer of non-gravel material, wherein a
compressed air line is located at least partially within said
biofilter tank below said mesh screen, expelling said purified
water stream through said output outlet connected to said second
channel, stopping receiving said untreated water stream, opening
said flush valve, draining said flush water stream through said
flush valve, closing said flush valve, and waiting for a
predetermined time period before invoking another iteration of said
function; receiving said untreated water stream into said biofilter
tank through said intake inlet; opening said flush valve; draining
said flush water stream through said flush valve; and closing said
flush valve.
20. The method of claim 19, further comprising the step of
receiving an air stream through said compressed air line.
Description
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] This invention relates to the field of liquid purification
or separation and more specifically to a particulate material type
separator with rehabilitation means.
[0004] 2. Description of Related Art
[0005] Aerobic water treatment systems utilize oxygen and microbes
to degrade organic matter and neutralize contaminants, allowing
reuse of the water. Typically, aerobic treatment is a two-step
process. The first phase is physical filtration of larger
particles, which aggregate into a separate biomass. Microbes then
degrade the remaining organic matter until it is stable and/or less
hazardous.
[0006] Fixed-media biological filtration methods rely on either
trickling water over media or submerging the media in water.
Trickling methods involve continual trickling of water over large
filtration media or intermittent trickling of water over large
media. Submersion methods rely on continuous operation of a fully
submerged filter or other media, which is periodically removed for
cleaning or replacement to retain its absorptive capacity.
[0007] Several problems are known in the art with respect to both
trickling and submersion methods. First, both methods require
substantial down time to change filtration media and/or remove the
solid biomass from the system. Both methods also require
substantial energy to maintain continuous trickling of water or
flow through submerged media.
[0008] There is an unmet need in the art for a biofilter capable of
biological regeneration in place (self-cleaning) in a manner that
allows it to restore its adsorptive capacity
[0009] There is a further unmet need in the art for a biofilter
that can facilitate more efficient control of the temperature at
which biological treatment occurs.
BRIEF SUMMARY OF THE INVENTION
[0010] In one embodiment of the present invention, a
self-regenerating biofilter apparatus includes a biofilter tank, a
filtration mass and a compressed air line. The biofilter tank
includes an intake inlet connected to a first channel and receiving
an untreated water stream. The biofilter tank also includes an
output outlet connected to a second channel and expelling a
purified water stream. The biofilter tank also includes a flush
valve expelling a flush water stream. The filtration mass includes
a layer of gravel and a layer of non-gravel materials. The layer of
non-gravel material includes activated carbon. The filtration mass
is located within the biofilter tank and at least partially above
the intake inlet and the flush valve. A mesh screen separates the
layer of gravel from the layer of non-gravel material. The
compressed air line is located at least partially within the
biofilter tank below the mesh screen.
[0011] In another embodiment of the present invention, a
self-regenerating biofilter system includes at least one
self-regenerating biofilter apparatus, as above, and a central
controller connected to the flush valve and connected to a power
source.
[0012] In another embodiment of the present invention, a method for
using a self-regenerating biofilter apparatus, as above, includes
iteratively invoking a function n times. The function includes the
steps of: receiving an untreated water stream into a biofilter tank
through an intake inlet; filtering the untreated water stream
through the filtration mass to transform the untreated water stream
into the purified water stream; expelling the purified water stream
through the output outlet connected to the second channel; stopping
receiving the untreated water stream; opening the flush valve;
draining the flush water stream through the flush valve; closing
the flush valve and waiting for a predetermined time period before
invoking another iteration of the function. The method also
includes the steps of receiving the untreated water stream into the
biofilter tank through the intake inlet, opening the flush valve,
draining the flush water stream through the flush valve and closing
the flush valve.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING(S)
[0013] FIG. 1 illustrates a side view of an exemplary embodiment of
a self-regenerating biofilter.
[0014] FIG. 2 illustrates an exemplary embodiment of a
self-regenerating biofilter system.
[0015] FIGS. 3a and 3b illustrate an exemplary embodiment of a
method for using a self-regenerating biofilter.
TERMS OF ART
[0016] As used herein, the term "channel" means a structure used to
convey fluids.
[0017] As used herein, the term "ion exchange media" means media
that can exchange ions with a solution of electrolytes.
[0018] As used herein, the term "mesh" means a material having
apertures.
[0019] As used herein, the term "mesh size" means the number of
apertures per square inch in a mesh through which a particle can
pass. The higher number a mesh size has, the smaller a particle
must be to pass through the mesh.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 illustrates a side view of an exemplary embodiment of
a self-regenerating biofilter 100. Self-regenerating biofilter 100
includes a biofilter tank 10, a filtration mass 20, an optional
controller 30, a compressed air line 40, an optional heating
element 50, and at least one vent 60.
[0021] Biofilter tank 10 houses filtration mass 20, compressed air
line 40 and heating element 50. Biofilter tank 10 has a volume
ranging from approximately 5 gallons to approximately 5,000
gallons, with a daily flow-through volume ranging from
approximately 50 gallons to approximately 50,000 gallons. Intake
inlet 11 provides influent of an untreated water stream 14, while
output outlet 12 removes a purified water stream 15. Intake inlet
11 is located on a level below filtration mass 20 to ensure capture
of large particulates below filtration mass 20.
[0022] Flush valve 13 permits draining of biofilter tank 10 to
allow air to enter filtration mass 20 to aid microorganisms in
breaking down any biodegradable contaminants adsorbed from
untreated water stream 14 and turn them into biomass. In the
exemplary embodiment, flush valve 13 is a solenoid valve. In other
embodiments, flush valve 13 is a pinch valve, solenoid valve, or
ball valve. In various embodiments, operation of flush valve 13 may
occur automatically or manually.
[0023] The capture of large particulate occurring on a level below
filtration mass 20 permits easily removal of the same large
particulates in a flush water stream 16 traveling through flush
valve 13. At least one of biofilter tank 10 and the channels 17a
and 17b connected to intake inlet 11 and output outlet 12,
respectively, includes at least one vent 60 for pressure
equalization. Optionally, at least one of intake inlet 11, output
outlet 12, channel 17a or channel 17b includes a flow meter sensor
18 to measure flow volume of untreated water stream 14 or purified
water stream 15.
[0024] Filtration mass 20 removes water contaminants by straining,
adsorption and/or biological remediation. Biodegradable
contaminants in untreated water stream 14 provide food for
microorganisms in filtration mass 20 and become biomass. Filtration
mass 20 adsorbs these contaminants, which has an impact on
filtration mass 20.
[0025] Filtration mass 20 is made up of separate layers of gravel
21 and non-gravel material. In the exemplary embodiment, non-gravel
material is activated carbon 22 and optional ion exchange material
23. Gravel 21 is crushed rock having an average diameter ranging
from approximately 5 mm to approximately 30 mm. Activated carbon 22
is granular activated carbon having a mesh size ranging from
approximately 8 to approximately 12.Ion exchange material 23 also
has a mesh size ranging from approximately 8 to approximately
12.
[0026] In the exemplary embodiment, ion exchange material 23 is
zeolite. In other embodiments, ion exchange material 23 is a
synthetic material specifically selected to target a particular
contaminant of interest that can be biodegraded or bioaccumulated.
By way of non-limiting example, in one embodiment, ion exchange
material 23 is a tannin anion resin targeting humic acids and
tannins. Certain embodiments may use multiple different ion
exchange materials 23 to target multiple contaminants of
interest.
[0027] In certain embodiments, at least one of activated carbon 22
and ion exchange material 23 includes a bioculture seed. Bioculture
seeds may include custom cultures generated for the particulate
contaminant stream of interest by mixing an environmental source
(i.e., soil, sludge) with a growth media containing nutrients and
the desired target contaminants. Bioculture seeds may include
commercial aerobic cultures such as those used for the aquarium
industry, or pure cultures of microbes with desired physiological
attributes for the desired biodegradation process or
environment.
[0028] A mesh screen 24 separates gravel 21 from activated carbon
22 and ion exchange material 23. In the exemplary embodiment,
filtration mass 20 makes up approximately 50% to approximately 85%
of the volume of biofilter tank 10. Gravel 21 makes up
approximately 3% to approximately 10% of filtration mass 20.
Activated carbon 22 makes up approximately 60% to approximately 97%
of filtration mass 20. Ion exchange material 23 makes up to
approximately 30% of filtration mass 20.
[0029] In the exemplary embodiment, self-regenerating biofilter 100
includes controller 30. Controller 30 connects to flush valve 13,
allowing it to control when self-regenerating biofilter 100 drains
and regenerates. In the exemplary embodiment, controller 30
includes a timer 31, a memory 32, a biomass sensor 33, at least one
power source 34 and a controller interface 35. Timer 31 allows
flush valve 13 to open and close according to a pre-programmed
cycle, which may be located in memory 32. The duty cycle for flush
valve 13 may range from approximately 10% to approximately 90%,
depending on the contaminant loading rate on a given volume and
geometry of filter mass 20 and the adsorptive capacity of filter
mass 20 for the contaminant. In the exemplary embodiment, flush
valve 13 has an approximately 50% duty cycle, open for
approximately four hours and closed for approximately four hours,
allowing degradation of biodegradable contaminants on activated
carbon 22 and ion exchange material 23.
[0030] Biomass sensor 33 provides a user or controller 30 with
information about the level of biomass in self-regenerating
biofilter 100. This allows automated or manual triggering of a
biomass removal cycle when biomass in self-regenerating biofilter
100 has reached a critical level. In one embodiment, biomass sensor
33 senses a head differential across filter mass 20. In another
embodiment, biomass sensor 33 senses UV light absorbance across
filter mass 20. Power source 34 may be a DC or AC voltage source.
Power source 34 couples to controller 30 and other parts of
self-regenerating biofilter 100 that might require power. In
certain embodiments, each part of self-regenerating biofilter 100
that might require power has a separate power source 34. Controller
30 optionally includes a controller interface 35, which may permit
a user to enter commands to and receive output information from
controller 30.
[0031] Compressed air line 40 is located just below mesh screen 24.
An air source 41, such as, but not limited to an air compressor or
compressed air cylinder, provides an air stream 42 through
compressed air line 40. Controller 30 may connect to air source 41,
allowing controller 30 to control the flow of air through
compressed air line 40. During a biomass removal cycle, air stream
42 travels through compressed air line 40 and enters biofilter tank
10 through at least one air line aperture 43. Air stream 42 can
also enter into filtration mass 20 after draining self-regenerating
biofilter 100 to further increase oxygen concentrations. A
resistive heater may pre-warm air stream 42 to increase the
temperature of filtration mass 20 during regeneration.
[0032] Combined with an influx of untreated water stream 14 from
intake inlet 11, air stream 42 fluidizes and tumbles activated
carbon 22 and ion exchange material 23, removing biomass from
activated carbon 22 and ion exchange material 23. In the exemplary
embodiment, biomass removal occurs every two days. This frequency
may increase for untreated water streams 14 having high amounts of
biodegradable contaminants. The frequency of biomass removal may
likewise decrease for untreated water streams 14 having low amounts
of biodegradable contaminants. In certain embodiments, use of air
stream 42 may not be necessary for untreated water streams 14
having low amounts of biodegradable contaminants.
[0033] In the exemplary embodiment, self-regenerating biofilter 100
includes heating element 50. Although self-regenerating biofilter
100 does not require heat in many environments, certain biological
degradation processes may accelerate due to application of heat
creating an optimal temperature for biodegradation rates and
biomass production. Heating element 50 is located within biofilter
tank 10 and couples to controller 30. A thermal sensor 51 coupled
to controller 30 takes temperature readings to ensure that the
temperature does not increase or decrease to undesired levels.
[0034] FIG. 2 illustrates an exemplary embodiment of a
self-regenerating biofilter system 200. Self-regenerating biofilter
system 200 includes at least one self-regenerating biofilter 100
and a central controller 210. Self-regenerating biofilter system
200 is a scalable system. The exemplary embodiment shows a
self-regenerating biofilter system 200 with a single
self-regenerating biofilter 100 having a volume of 5 gallons, with
a daily flow-through volume of approximately 50 gallons. Another
embodiment incorporates twelve self-regenerating biofilters 100,
each having a volume of 210 gallons. This self-regenerating
biofilter system 200 has a daily flow-through volume of
approximately thirty thousand gallons.
[0035] Central controller 210 connects to controller 30 and flush
valve 13, allowing it to both send commands to controller 30 and
override controller 30 to open flush valve 13. Certain embodiments
of self-regenerating biofilter system 200 replace controller 30
with central controller 210. Central controller 210 may also
directly connect to any sensors of self-regenerating biofilter 100,
such as, but not limited to, flow meter sensor 18, biomass sensor
32 or thermal sensor 51.
[0036] Central controller 210 optionally includes a central timer
211, which allows flush valve 13 to open and close according to a
pre-programmed cycle that may be stored in central memory 212. In
embodiments incorporating multiple self-regenerating biofilters
100, central timer 211 allows coordination between
self-regenerating biofilters 100. This ensures that at least one
self-regenerating biofilter 100 is available for use at all times.
This also allows self-regenerating biofilter system 200 to operate
at peak capacity during peak gray water generation or demand times,
such as, but not limited to, business hours in an office building
or morning and evening in a residence, while reserving a smaller
capacity for times when predicted demand is not as great. Central
controller 210 optionally includes a central interface 213, which
may permit a user to enter commands to and receive output
information from central controller 210 and/or controller 30.
[0037] FIGS. 3a and 3b illustrate an exemplary embodiment of a
method 300 for using self-regenerating biofilter 100.
[0038] In step 302, self-regenerating biofilter 100 receives an
influx of untreated water stream 14 through intake inlet 11.
[0039] In step 304, self-regenerating biofilter 100 filters
untreated water stream 14 through filtration mass 20, transforming
it into purified water stream 15.
[0040] In step 306, self-regenerating biofilter 100 expels purified
water stream 15 through output outlet 12.
[0041] In step 308, self-regenerating biofilter 100 stops receiving
the influx of untreated water stream 14 through intake inlet
11.
[0042] In step 310, self-regenerating biofilter 100 opens flush
valve 13.
[0043] In step 312, self-regenerating biofilter 100 drains flush
water stream 16 through flush valve 13.
[0044] In step 314, self-regenerating biofilter 100 closes flush
valve 13.
[0045] In step 316, self-regenerating biofilter 100 waits for a
predetermined time period before continuing method 300.
[0046] In step 318, method 300 repeats steps 302-316 n times, until
method 300 meets a preselected condition. This condition may be for
elapsed time, volume of water treated or amount of biomass in
self-regenerating biofilter 100.
[0047] In step 320, self-regenerating biofilter 100 receives an
influx of untreated water stream 14 through intake inlet 11.
[0048] In optional step 322, self-regenerating biofilter 100
receives air stream 42 through compressed air line 40. Steps 318
and 320 may be performed simultaneously.
[0049] In step 324, self-regenerating biofilter 100 opens flush
valve 13.
[0050] In step 326, self-regenerating biofilter 100 drains flush
water stream 16 through flush valve 13.
[0051] In step 328, self-regenerating biofilter 100 closes flush
valve 13.
[0052] It will be understood that many additional changes in the
details, materials, procedures and arrangement of parts, which have
been herein described and illustrated to explain the nature of the
invention, may be made by those skilled in the art within the
principle and scope of the invention as expressed in the appended
claims.
[0053] It should be further understood that the drawings are not
necessarily to scale; instead, emphasis has been placed upon
illustrating the principles of the invention. Moreover, the terms
"substantially" or "approximately" as used herein may be applied to
modify any quantitative representation that could permissibly vary
without resulting in a change in the basic function to which it is
related.
* * * * *