U.S. patent application number 10/486420 was filed with the patent office on 2004-12-16 for biological water treatment assembly including a bacteria growthdevice and method associated thereto.
Invention is credited to Lord, Garfield R..
Application Number | 20040251198 10/486420 |
Document ID | / |
Family ID | 4170106 |
Filed Date | 2004-12-16 |
United States Patent
Application |
20040251198 |
Kind Code |
A1 |
Lord, Garfield R. |
December 16, 2004 |
Biological water treatment assembly including a bacteria
growthdevice and method associated thereto
Abstract
A bacteria growth device (1) for use with bacteria in a
substantially liquid medium, the device (1) comprising at least one
strip (5) having a surface area shaped and sized for receiving
bacteria present in the substantially liquid medium and for
allowing attachment of said bacteria onto the surface area of the
at least one strip (5) so as to promote growth of the attached
bacteria. The substantially liquid medium may be enclosed in an
aerobic environment, in which case the device (1) is used to
promote the growth of aerobic bacteria. Alternatively, the
substantially liquid medium may be enclosed in an anaerobic and/or
anoxic environment, in which case the device (1) is used to promote
the growth of corresponding anaerobic and/or anoxic bacteria. Also
described are an assembly including the above-mentioned device and
the method associated thereto. Typically, these are used for
promoting growth of bacteria destined for treating and purifying
wastewater effluents which are high in biochemical demand, such as
the wastewater discharges of residential and/or industrial
septic/wastewater tanks for example.
Inventors: |
Lord, Garfield R.;
(Providenciales, TC) |
Correspondence
Address: |
DARBY & DARBY P.C.
P. O. BOX 5257
NEW YORK
NY
10150-5257
US
|
Family ID: |
4170106 |
Appl. No.: |
10/486420 |
Filed: |
August 10, 2004 |
PCT Filed: |
September 26, 2002 |
PCT NO: |
PCT/CA02/01462 |
Current U.S.
Class: |
210/615 |
Current CPC
Class: |
C02F 3/1215 20130101;
C02F 3/2806 20130101; Y02W 10/10 20150501; B01D 2239/0266 20130101;
Y02W 10/15 20150501; C02F 3/10 20130101; C02F 2103/002 20130101;
C02F 3/288 20130101; B01D 39/04 20130101 |
Class at
Publication: |
210/615 |
International
Class: |
C02F 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2001 |
CA |
2 357 907 |
Claims
1. A bacteria growth device (1) for use with bacteria in a
substantially liquid medium, the device (1) comprising at least one
unbound strip (5) introduced and compacted into said substantially
liquid medium so as to present an intertwined and nest-like
configuration in a substantially uniform manner throughout the
substantially liquid medium, the at least one unbound strip (5)
having a surface area etched for receiving bacteria present in the
substantially liquid medium and for allowing attachment of said
bacteria onto the surface area of the at least one unbound strip
(5) so as to promote growth of the attached bacteria.
2. A bacteria growth device (1) according to claim 1, wherein the
bacteria attached onto the surface area of the at least one unbound
strip (5) biologically consume impurities contained in the
substantially liquid medium.
3. A bacteria growth device (1) according to claim 1, wherein the
at least one unbound strip (5) is made of a non-toxic and
non-biodegradable polymeric material.
4. A bacteria growth device (1) according to claims 1, wherein the
surface area of the at least one unbound strip (5) is plasma
etched.
5. A bacteria growth device (1) according to claims 1, wherein the
at least one unbound strip (5) is made of a material containing an
underlying porous substance, said porous substance being exposed to
the bacteria for attachment thereon through corresponding etches of
the plasma etched surface area.
6. A bacteria growth device (1) according to claim 5, wherein the
porous substance is selected from the group consisting of zeolite,
activated carbon, and porous stone.
7. A bacteria growth device (1) according to claims 1, wherein the
at least one unbound strip (5) is made of a polymeric material
selected from the group consisting of high-density polyethylene and
polypropylene.
8. A bacteria growth device (1) according to claims 1, wherein the
at least one unbound strip (5) is made with a manufacturing process
selected from the group of milling, extrusion, molding, machining
and casting.
9. A bacteria growth device (1) according to claims 1, wherein the
substantially liquid medium is enclosed in an aerobic
environment.
10. A bacteria growth device (1) according to claims 1, wherein the
substantially liquid medium is enclosed in an anaerobic
environment.
11. A bacteria growth device (1) according to claims 1, wherein the
substantially liquid medium is enclosed in an anoxic
environment.
12. A bacteria growth device (1) according to claims 1, wherein the
bacteria are selected from the group consisting of nitrosominous
and nitrobacters.
13. A bacteria growth device (1) according to claims 1, wherein the
substantially liquid medium is selected from the group consisting
of grey water, black water, domestic wastewater and industrial
wastewater.
14. A bacteria growth device (1) according to claims 1, wherein the
at least one unbound strip (5) has a substantially rectangular
cross-sectional area having a thickness of about 0.2 mm and a width
of about 3.0 mm.
15. A bacteria growth device (1) according to any one claims 1,
wherein the nest-like configuration of the at least one unbound
strip (5) occupies a volume of about 3 meters cube.
16. An assembly (3) for treating a liquid containing impurities,
the assembly (3) comprising a reactor (7) having: an inlet (17)
through which the liquid containing impurities is introduced into
the reactor (7) and an outlet (19) through which the liquid removed
of certain impurities is discharged from the reactor (7); and at
least one bacteria growth device (1) as defined in claim 1, the
device (1) being operatively positioned inside the reactor (7)
between the inlet (17) and the outlet (19) thereof so that the
bacteria attached onto the surface area of the at least one unbound
strip (5) of said device (1) are used to biologically eliminate
impurities from the liquid present in the reactor (7).
17. An assembly (3) according to claim 16, wherein the reactor (7)
further comprises neighboring first and second chambers (9), the
chambers (9) being in fluid connection with each other between the
inlet (17) and the outlet (19) of the reactor (7), each of said
chambers (9) comprising at least one of said bacteria growth device
(1), the first chamber (9) being an aerobic chamber (9a) for
eliminating impurities from the liquid with aerobic bacteria, and
the second chamber (9) being an anaerobic chamber (9b) for
eliminating other impurities from the liquid with anaerobic
bacteria.
18. An assembly (3) according to claim 17, wherein the first
chamber (9) has a volume which is twice that of the second chamber
(9).
19. An assembly (3) according to claim 17, wherein the assembly (3)
further comprises a septic tank (13) having an inlet (21), and an
outlet (23) connected to the inlet (17) of the reactor (7) so that
a liquid containing impurities being discharged from the septic
tank (13) is introduced into the reactor (7).
20. An assembly (3) according to claim 19, wherein the septic tank
(13) further comprises neighboring first and second chambers (9),
said chambers (9) being in fluid connection with each other between
the inlet (21) and the outlet (23) of the septic tank (13), the
first chamber (9) of the septic tank (13) acting as a settling
chamber (15), the second chamber (9) of the septic tank (13)
comprising at least one of said device (1) and being an anaerobic
chamber (9b) for eliminating impurities from the liquid with
anaerobic bacteria.
21. An assembly (3) according to claim 20, wherein the first
chamber (9) of the septic tank (13) has a volume which is twice
that of the second chamber (9) of the septic tank (13).
22. An assembly (3) according to claim 19 wherein the outlet (19)
of the reactor (7) is connectable to the inlet (21) of the septic
tank (13) so that liquid containing impurities discharged from the
reactor (7) may be re-circulated through the septic tank (13) and
the reactor (7).
23. A method for treating a liquid containing impurities, the
method comprising the steps of: a) introducing the liquid
containing impurities into a reactor (7); b) providing a bacteria
growth device (1) as defined in claim 1 in the reactor (7) of step
a); c) allowing the bacteria attached onto the surface area of the
at least one unbound strip (5) of the device (1) to grow and
eliminate impurities from the liquid present in the reactor (7);
and d) evacuating the liquid removed of certain impurities from the
reactor (7).
24. A method according to claim 23, wherein step a) comprises the
step of discharging a liquid containing impurities from a septic
tank (13) into the reactor (7).
25. A method according to claim 24, wherein step d) further
comprises the step of re-circulating the liquid removed of certain
impurities back into the septic tank (13).
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a bacteria growth device,
hereinafter referred to also as a "bionest". More particularly, the
present invention relates to a bacteria growth device for use with
bacteria in a substantially liquid medium, as well as to an
assembly including such a device and the method associated thereto.
Typically, the device, assembly, and method are used for treating
and purifying wastewater effluents which are high in biochemical
oxygen demand, such as the wastewater discharges of residential
and/or industrial septic/wastewater tanks for example.
BACKGROUND OF THE INVENTION
[0002] Known in the art are several filtering apparatuses used for
treating and purifying wastewater. For instance, the North American
Filter Corporation has developed a filter known as the Waterloo
Biofilter.TM., which comprises an open cell foam wherein little
blocks are cut into dimensions of about 3 inches by 3 inches.
Typically, grey water is poured over the top of the blocks and
flows down as air is blown up through the bottom of the open cell
foam. By keeping the media wet with re-circulating grey water, the
bacteria grow inside the foam. However, such a system is fairly
expensive to maintain, as it constantly needs air blowing to
generate aerobic bacteria in the foam and because a mechanical pump
is required to continuously re-circulate the grey water over the
foam.
[0003] Also known in the art are other filtering/purifying
apparatuses used for treating and purifying wastewater. These
include the following: leaching fields attached to septic tanks,
biodisks (rotating disks), multimedia sand filters, fluidized beds
(sand suspended in water), Zenon Zeeweed.RTM. filters, ECO
FLOW.RTM. (peat moss) and plastic spheres, balls, stars,
honeycombs, and the like.
[0004] A major problem with the devices that use peat moss and
other similar substances for filtering/purifying applications is
that these substances are biodegradable, and thus get eaten by
bacteria with time and turn into mock, which is very undesirable,
as is known in the art.
[0005] Known to the Applicant are the following US patents which
describe different purifying apparatuses and methods: 4,615,803;
5,206,206; 5,618,414; 5,811,002; 5,913,588; 6,063,276; 6,110,374;
and 6,162,020.
[0006] Also known to the Applicant are the following international
patent applications which also describe different purifying
apparatuses and methods: WO 87/05593; WO 91/16496; WO 01/04060; WO
01/12563; WO 01/56936; and WO 01/66475.
[0007] These different apparatuses and methods are disadvantageous
because they tend to be elaborate in design; require a substantial
amount of energy input for operating; are fairly expensive and/or
difficult to manufacture/assemble/install; require considerable
maintenance; etc.
SUMMARY OF THE INVENTION
[0008] The object of the present invention is to provide an
improved device for promoting the growth of bacteria, which
satisfies some of the above-mentioned needs and which is thus an
improvement over the devices known in the prior art.
[0009] In accordance with the present invention, the above object
is achieved with a bacteria growth device for use with bacteria in
a substantially liquid medium, the device comprising at least one
strip having a surface area shaped and sized for receiving bacteria
present in the substantially liquid medium and for allowing
attachment of said bacteria onto the surface area of the at least
one strip so as to promote growth of the attached bacteria.
[0010] Preferably, the at least one strip is intertwined and has a
nest-like configuration, and the bacteria attached onto the surface
area of the at least one strip are used for biologically consuming
impurities contained in the substantially liquid medium.
[0011] Preferably also, each strip of the device is made of a
non-toxic and non-biodegradable polymeric material.
[0012] According to another aspect of the present invention, there
is also provided an assembly for treating a liquid containing
impurities, the assembly comprising a reactor having:
[0013] an inlet through which the liquid containing impurities is
introduced into the reactor and an outlet through which the liquid
removed of certain impurities is discharged from the reactor;
and
[0014] at least one bacteria growth device such as the
above-mentioned, the device being operatively positioned inside the
reactor between the inlet and the outlet thereof so that the
bacteria attached onto the surface area of the at least one strip
of said device are used to biologically eliminate impurities from
the liquid present in the reactor.
[0015] Preferably, the reactor further comprises neighboring first
and second chambers, the chambers being in fluid connection with
each other between the inlet and the outlet of the reactor, each of
said chambers comprising at least one of said bacteria growth
device, the first chamber being an aerobic chamber for eliminating
impurities from the liquid with aerobic bacteria, and the second
chamber being an anaerobic chamber for eliminating other impurities
from the liquid with anaerobic bacteria.
[0016] According to yet another aspect of the present invention,
there is also provided a method for treating a liquid containing
impurities, the method comprising the steps of:
[0017] a) introducing the liquid containing impurities into a
reactor;
[0018] b) providing a bacteria growth device such as the
above-mentioned in the reactor of step a);
[0019] c) allowing the bacteria attached onto the surface area of
the at least one strip of the device to grow and eliminate
impurities from the liquid present in the reactor; and
[0020] d) evacuating the liquid removed of certain impurities from
the reactor.
[0021] Preferably, step a) comprises the step of discharging a
liquid containing impurities from a septic tank and/or settling
tank into the reactor.
[0022] Preferably also, step d) further comprises the step of
re-circulating the liquid removed of certain impurities back into
the septic tank and/or settling tank.
[0023] The objects, advantages and other features of the present
invention will become more apparent upon reading of the following
non-restrictive description of preferred embodiments thereof, given
for the purpose of exemplification only with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic representation of the bacteria growth
device according to the present invention, the device being shown
with at least one strip intertwined into a nest-like configuration
according to the preferred embodiment of the invention.
[0025] FIG. 2 is a fragmentary enlarged plan view of the surface
area of the strip shown in FIG. 1 according to a preferred
embodiment of the invention.
[0026] FIG. 3 is a fragmentary enlarged plan view of the surface
area of the strip shown in FIG. 1 according to another preferred
embodiment of the invention.
[0027] FIG. 4 is a fragmentary enlarged plan view of the surface
area of the strip shown in FIG. 1 according to yet another
preferred embodiment of the invention.
[0028] FIG. 5 is a fragmentary enlarged plan view of the surface
area of the strip shown in FIG. 1 according to yet another
preferred embodiment of the invention.
[0029] FIG. 6 is a schematic cross-sectional view of an assembly
for treating a liquid containing impurities according to a first
preferred embodiment of the invention.
[0030] FIG. 7 is a schematic cross-sectional view of an assembly
for treating a liquid containing impurities according to a second
preferred embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0031] In the following description, the same numerical references
refer to similar elements. The embodiments shown in the figures are
preferred.
[0032] Furthermore, although the present invention was primarily
designed for promoting the growth of attached bacteria destined to
clean wastewater discharged from a septic tank, it may be used for
promoting the growth of attached bacteria capable of interacting
with other various types of liquids employed in other technical
fields, as apparent to a person skilled in the art. For this
reason, expressions such as "waste", "water", "septic" and the like
should not be taken as to limit the scope of the present invention
and include all other kinds of liquids or technical applications
with which the present invention may be used and could be
useful.
[0033] Moreover, in the context of the present invention, the
expressions "water", "liquid", "effluent", "discharge", and any
other equivalent expression known in the art used to designate a
substance displaying liquid-like features, as well as any other
equivalent expressions and/or compound words thereof, may be used
interchangeably. Furthermore, expressions such as "polluted",
"contaminated" and "soiled" for example, may also be used
interchangeably in the context of the present description. The same
applies for any other mutually equivalent expressions such as
"septic" and "settling", as well as "reactor", "assembly" and
"clarifier" for example, as also apparent to a person skilled in
the art. Moreover, in the context of the present invention,
"anaerobic" may also be used to designate and include "anoxic", as
apparent to a person skilled in the art.
[0034] In addition, although the preferred embodiment of the
present invention as illustrated in the accompanying drawings
comprises various components, such as small pumps, air returns,
etc., and although the preferred embodiment of the present
invention as shown consists of certain geometrical configurations
and arrangements, not all of these components, geometries and/or
arrangements are essential to the invention and thus should not be
taken in their restrictive sense, i.e. should not be taken as to
limit the scope of the present invention. It is to be understood,
as also apparent to a person skilled in the art, that other
suitable components and cooperations thereinbetween, as well as
other suitable geometrical configurations and arrangements may be
used for the bacteria growth device 1 and corresponding assembly 3
according to the present invention, as will be briefly explained
hereinafter, without departing from the scope of the invention.
[0035] Broadly described, the device 1 according to the present
invention, as illustrated in the accompanying drawings, is a
bacteria growth device 1 for use with bacteria in a substantially
liquid medium, the device 1 comprising at least one strip 5 having
a surface area shaped and sized for receiving bacteria present in
the substantially liquid medium and for allowing attachment of said
bacteria onto the surface area of the at least one strip 5 so as to
promote growth of the attached bacteria. The substantially liquid
medium may be enclosed in an aerobic environment, in which case the
device 1 is used to promote the growth of aerobic bacteria.
Alternatively, the substantially liquid medium may be enclosed in
an anaerobic environment, in which case the device 1 is used to
promote the growth of anaerobic bacteria. The bacteria according to
the present are preferably selected from the group consisting of
nitrosominous, nitrobacters, and the like. It is worth mentioning
however that other suitable bacteria (and corresponding enzymes),
whether naturally occurring in the fluid medium or introduced
therein from an outside source, may be used according to the
present invention, depending on the particular applications for
which the bacteria growth device 1 is intended and the particular
liquid medium with which it is intended to interact, as apparent to
a person skilled in the art.
[0036] Preferably, at least one strip 5 is intertwined and has a
nest-like configuration, as better shown in FIG. 1. It is to be
understood, as apparent to a person skilled in the art, that
according to the present invention, the bacteria growth device 1
may comprise one single elongated strip 5 or a plurality of strips
5 bundled up together so as to obtain a desired nest-like
configuration, such as the one illustrated in FIG. 1, or any other
suitable geometrical configuration (whether one-, two-, or
three-dimensional configuration; whether orderly or random spatial
disposition; and/or whether tightly packed or loosely fitted; etc),
depending on the particular applications for which the bacteria
growth device 1 is intended and the particular liquid medium with
which it is intended to interact, as apparent to a person skilled
in the art. Indeed, among other considerations, the geometrical
configuration of the bionest 1 according to the present invention
should be intended to allow an appropriate flow rate of the liquid
medium therethrough, as also apparent to a person skilled in the
art.
[0037] Preferably, the bacteria attached onto the surface area of
each strip 5 of the device 1 are used for biologically consuming
impurities which may be contained in the substantially liquid
medium, such as waste products contained in wastewater for example.
Preferably, the substantially liquid medium is selected from the
group consisting of grey water, black water, domestic wastewater,
industrial wastewater, and the like. Consequently, each strip 5 is
preferably made of a non-toxic and non-biodegradable polymeric
material, which is preferably selected from the group consisting of
high-density polyethylene, polypropylene, and the like, as apparent
to a person skilled in the art. The strip(s) 5 of the device 1 are
preferably made with a suitable and cost-effective manufacturing
process selected from the group of milling, extrusion, molding,
machining, casting, and the like, as also apparent to a person
skilled in the art.
[0038] It is worth mentioning here that the strip(s) 5 of the
device 1 can be made of any type of suitable material that is not
bioacidal in its nature, i.e. that will not be detrimental to the
attachment and growth of bacteria, unlike polyvinyl chloride for
example. Preferably, the material used for the strip(s) 5 of the
device 1 is a plastic that is compatible to bacteria growth rather
than a plastic that may disintegrate in time and leach toxic
chemical that would kill the bacteria, as apparent to a person
skilled in the art.
[0039] As aforementioned, the plastic that is used for the strip(s)
5 of the bionest 1 may be selected from the group consisting of
high-density polyethylene, polypropylene or any other plastic that
can be heated, extruded, molded, milled, cast and/or made in a way
that will allow them to be loosely packed together. The strip(s) 5
of the device 1 should be constructed and arranged so as to not
compress or collapse or disintegrate over time and/or stop the flow
of the fluid medium passing through the device 1.
[0040] When considering the geometrical and dimensional features of
the strip(s) 5 of the bionest 1, these strip(s) 5 should be
manufactured as small and as thin as possible while being
structurally sound and rigid at the same time. The rigidity is,
among other factors, provided by the nature of the material used as
well as the cross-section of the strip 5. It is important not to
manufacture the strip(s) 5 of the device 1 too thin since it will
become like a frail sheet that will collapse together and won't
allow proper passage of the liquid medium there between the
strip(s) 5.
[0041] Preferably, each strip 5 has a substantially rectangular
cross-sectional area having a thickness of about 0.2 mm and a width
of about 3.0 mm. Typically, for domestic applications, e.g. for a
single-family household having three bedrooms, the nest-like
configuration of the device 1 should occupy a volume of about 3
meters cube, for example. It should be understood that, according
to the present invention, other suitable cross-sectional
configurations may used for the strip(s) 5 of the bionest 1, as
well as other volumetric dimensions, depending on the particular
applications for which the bacteria growth device 1 is intended and
the particular liquid medium with which it is intended to interact,
as apparent to a person skilled in the art. However, it is worth
mentioning that a structurally sound and very thin substantially
rectangular cross-section is preferred in that it offer a greater
surface area exposed for the amount of material used. Indeed, the
greater the surface area of the strip 5, the greater the rate of
bacteria attachment (and growth), which is very advantageous, as
will be explained hereinafter. Furthermore, the less material used
for the strip(s) 5 of the device 1, the less the resulting
manufacturing costs, which is also advantageous.
[0042] Further to the geometrical and dimensional features of the
strip(s) 5 which are preferably devised to increase the surface
area thereof, it is worth mentioning that the peripheral surface of
the strip(s) 5 of the device 1 according to the present invention
may also be surface treated in various forms so as to further
increase the effective surface area of the strip(s) 5, and thus
increase the attachment and growth of the bacteria thereon, as will
be briefly explained hereinbelow.
[0043] For example, FIGS. 2-5 show various strip(s) 5 which may be
used for the device 1 according to the present invention and whose
respective surfaces having been treated differently. For example,
FIG. 2 illustrates a strip 5 as it is first produced from virgin or
recycled polymer. FIG. 3 illustrates the same strip 5 of FIG. 2
after its surface area has been plasma etched. FIG. 4 shows a strip
5 made of polymeric material blended with a porous material prior
to its final processing. FIG. 5 show the strip 5 of FIG. 4 after it
has been plasma etched so as to expose the surfaces of the porous
material trapped in the polymeric material to the bacteria so that
they may better attach thereon, as apparent to a person skilled in
the art.
[0044] As aforementioned, the strip(s) 5 of the device 1 may
consist of a simple elongated polymeric strip 5, such as shown in
FIG. 2. The surface area of each strip 5 may be etched, as better
shown in FIG. 3. Preferably, the surface area of each one strip 5
of the device 1 is plasma etched. Preferably also, each strip 5 is
made of a material containing an underlying porous substance, as
better shown in FIG. 4. The porous substance is preferably exposed
to the bacteria for attachment thereon through corresponding etches
of the plasma etched surface area, as better shown in FIG. 5.
Preferably also, the porous substance is selected from the group
consisting of zeolite, activated carbon, porous stone/rock, and the
like, as apparent to a person skilled in the art.
[0045] As shown in FIG. 5, the plasma etched strip 5 has superior
adhesive qualities than the strip 5 of FIG. 1. Indeed, the adhesive
qualities of the strip(s) 5 of the device 1 can be improved thanks
to a known technology that allows processing of the plastic strip 5
that will in turn increase its adhesive properties. This technology
is called Plasma Etch Technology, and essentially uses a gas in a
vacuum with a high frequency RF or microwave. The surface of any
plastic media can thus be appropriately etched to create a much
larger effective surface area for the bacteria to attach thereto.
This preferably includes all synthetic media that are presently
being used to support bacteria growth, as apparent to a person
skilled in the art.
[0046] As shown in FIGS. 4 and 5, the polymer strips 5 of the
device 1 may comprise a porous substance blended inside of the
plastic. Such porous substance may be zeolyte or activated carbon
or any other porous-like material which is preferably non-toxic to
bacterial growth. This porous substance is preferably blended into
the strip 5 in such a way that it lies just below the surface of
the plastic. Once the strips 5 are formed, the surface is etched
off so as to create an opening on the surface to expose the porous
substance and thereby creating a larger surface for bacteria
growth. Therefore, any inert porous material that is preferably
heat resistant may be used for the strip(s) 5 of device 1 according
to the present invention.
[0047] Preferably also, the porous material is not affected by heat
if the plastic is molded, cast, machined, extruded and/or formed by
any other suitable manufacturing process in which heat may be
generated. Furthermore, as can be easily understood by a person
skilled in the art, the porous material should not have holes that
are so big that the plastic will impregnate it and the plastic can
be etched off easily from the surface with plasma etching.
[0048] The above-described material used for the strip(s) 5 of the
device 1 is preferably manufactured by a suitable process after
having been blended with the porous substance such as activated
carbon, any zeolyte or other porous material that could be mixed
into the plastic before the manufacturing phase of the strip(s) 5.
The porous substance sould be uniformly blended inside the plastic
of the strip(s) 5 when completed. This blended composite material
should then be machined or plasma etched as above-described, to
etch the surface of the strip(s) 5 and thereby expose the porous
substance trapped inside the plastic so as to thus increase
substantially the effective surface area of the finished strip(s)
5.
[0049] As aforementioned, the present invention broadly relates
also to an assembly 3 for treating a liquid (not shown) containing
impurities. The assembly employs at least one bacteria growth
device 1 such as the above-discussed for increasing bacterial
growth thereon and also preferably employs a multi-chamber reactor
7 (or "clarifier") used after a settling tank 9 such as a domestic
multi chamber septic tank for example, as shown in FIGS. 6 and 7,
or a solids removal apparatus such as a screen, a filter, a screw
or any other type of press, and the like, as apparent to a person
skilled in the art. Preferably, the assembly 3 is used for
increasing attached growth bacteria in aerobic/anaerobic chamber(s)
9 of a multi-chamber biological clarifier 7, typically attached to
a settling tank 13, such as a septic tank for example, as shown in
FIGS. 6 and 7. According to the preferred embodiments of the
invention as shown in the accompanying drawings, the assembly 3 is
mainly intended to carry out a process for purifying wastewater
from a residential or community septic tank.
[0050] FIGS. 6 and 7 show the various general stages of
decontamination of effluent, the first stage essentially consisting
in the separation of the solids from the wastewater, in one or more
settling chambers 15, the next stage essentially consisting in the
remediation of the wastewater by bacteria growth device(s) in the
various aerobic/anaerobic chambers 9 of the assembly 3.
[0051] Indeed, according to a particular aspect of the present
invention, there is also provided an assembly 3 for treating a
liquid containing impurities. The assembly comprises a reactor 7
having a) an inlet 17 through which the liquid containing
impurities is introduced into the reactor 7; b) at least one
bacteria growth device 1 as explained hereinabove, the bacteria
attached onto the surface area of the at least one strip 5 of said
device being used to biologically eliminate impurities from the
liquid present in the reactor 7; and c) an outlet 19 through which
the liquid removed of certain impurities is discharged from the
reactor 7.
[0052] Preferably, the reactor 7 further comprises neighboring
first and second chambers 9, the chambers 9 being in fluid
connection with each other between the inlet 17 and the outlet 19
of the reactor 7, each of said chambers 9 comprising at least one
of said device 1, the first chamber 9 being an aerobic chamber 9a
for eliminating impurities from the liquid with aerobic bacteria,
and the second chamber 9 being an anaerobic chamber 9b for
eliminating other impurities from the liquid with anaerobic
bacteria.
[0053] Preferably also, the assembly 3 further comprises a septic
tank 13 having an inlet 21, and an outlet 23 connected to the inlet
17 of the reactor 7 so that a liquid containing impurities being
discharged from the septic tank 13 is introduced into the reactor
7.
[0054] Referring particularly to the assembly 3 according to the
first preferred embodiment of the invention as shown in FIG. 6, the
assembly 3 comprises a multi-chamber container, the chambers 9
being separated by baffles so that air can access the first chamber
9 and provide aerobic biological treatment while the next chamber
is deprived of air or oxygen so as to provide anaerobic treatment.
Indeed, according to this embodiment, a series of subsequent
chambers 9, preferably three chambers as shown, are alternately
aerated and deprived of air or oxygen. Alternatively, it is worth
mentioning that air could be turned on and off at varying intervals
in each chamber 9 of the reactor 7 (or a single chamber 9 which
could constitute the entire reactor for that matter) to promote the
growth of both aerobic and anaerobic bacteria in the same
chamber(s) 9 or reactor(s) 7. That is, it should be understood that
instead of having the liquid to be treated flow continuously from
one chamber 9a, 9b to another neighboring chamber 9b, 9a, from the
inlet 17 to the outlet 19 of the reactor 7, in alternating
aerobic/anaerobic conditions, the liquid being treated could be
processed in a single chamber 9 of the reactor 7 by varying the
aerobic/anaerobic conditions of the given chamber 9, i.e. the
liquid being treated may be processed in "batches", as also
apparent to a person skilled in the art.
[0055] Referring now particularly to the assembly 3 according to
the second preferred embodiment of the invention as shown in FIG.
7, the septic tank 13 preferably comprises neighboring first and
second chambers 15, 9, said chambers being in fluid connection with
each other between the inlet 21 and the outlet 23 of the septic
tank 13, the first chamber 15 of the septic tank 13 acting as a
settling chamber 15, the second chamber 9 of the septic tank 13
comprising at least one of said device 1 and being an anaerobic
chamber 9b for eliminating impurities from the liquid with
anaerobic bacteria.
[0056] As better shown in FIG. 7, the first chamber 9a of the
reactor 7 has a volume which is preferably twice that of the second
chamber 9b, and the the first chamber 15 of the septic tank 13 has
a volume which is preferably twice that of the second chamber 9b of
the septic tank 13.
[0057] Preferably also, the outlet 19 of the reactor 13 is
connectable to the inlet 21 of the septic tank 13 so that liquid
containing impurities discharged from the reactor 7 may be
re-circulated through the septic tank 13 and the reactor 7.
[0058] Preferably also, whether for the assembly 3 shown in FIG. 6
or FIG. 7, each chamber 9 which is not acting as a settling chamber
15 is filled with a loose bundle of non-toxic thin and narrow
strips of elongated virgin or recycled polymer, i.e. the bionest 1,
that allows for the free circulation of the wastewater through the
attached growth bacteria (either nitrosominous or nitrobacters)
completing the natural nitrogen cycle treatment or process in a
controlled environment.
[0059] Preferably also, the polymer strips 5 of the device 1 serve
to vastly increase the area on which bacteria can attach themselves
and grow in the reaction chambers 9, thereby providing for faster
and more efficient treatment for the liquid.
[0060] Minimal maintenance is required according to the present
invention in that excess residue from bacterial action which falls
off the device 1 becomes a source of carbon for further biological
processing of the liquid and/or can be sucked away by appropriate
vacuums placed at the bottom of the reactor. Alternatively, excess
residue from bacterial action which falls off the device 1 can also
be pumped out after an extended period of time, such as five years
for example, through one or more of the container's covers.
[0061] The size of the container and its polymer strip bundle
filled chambers 9 can be varied to allow for different retention
times and meet specific goals for effluent discharge, as apparent
to a person skilled in the art.
[0062] Treated effluent is preferably decontaminated to a quality
level that meets national and local requirements for water being
discharged either into the ground or for irrigation use, as also
apparent to a person skilled in the art.
[0063] An important advantage of such a clarifying system is that
it replaces a leaching field or bed and is sized according to the
amount of wastewater produced by the septic tank 13 or community
effluent discharge as well as it's specific biochemical oxygen
demande ("b.o.d."). Water thus treated is decontaminated to a
quality level that easily allows for its discharge either into the
ground or surface discharge for irrigation.
[0064] Another important advantage of such a clarifying system
comes from the fact that it is now possible to create a very large
surface area for bacteria growth in a fairly delimited volume.
Indeed, because attached growth bacteria need a surface to attach
to and to grow, the greater the surface area one can create for a
given volume possible, the greater the efficiency of the treatment,
which is very advantageous.
[0065] Furthermore, the overall cost to produce the above-mentioned
system is fairly low when compared to other prior art systems.
[0066] As aforementioned, the bacteria growth device 1 according to
the present invention preferably comprises a non-toxic (virgin or
recycled) polymer that is manufactured into thin strips 5 of
various lengths and gathered in a loose bundle. The loose
conformation of the polymer strips 5 is important in that allows
unhindered wastewater to circulate through the device 1.
Furthermore, this conformation allows the device 1 to fit within
each of the multiple chambers 9 of an aerobic and anaerobic
clarifier 7 that is fed with a residential or community domestic
effluent (or any waste water source high in b.o.d.) from a settling
tank 13 or multi-chambered septic tank 13. Moreover, the
conformation of the polymer increases the surface area on which
attached growth bacteria can proliferate and thus increases the
efficiency and the treatment capacity of the clarifier 7.
[0067] After being manufactured by an appropriate process, the
strip(s) 5 are preferably put into an irregular form either by
putting them through a gear or spinning them or blowing them as
they are growing so that they will adopt an irregular form, as
better shown in FIG. 1. This is mainly to prevent them from
substantially touching together and compacting together, because,
as mentioned hereinabove, it important that the water flows through
the device 1 without an excessive restriction carrying through the
pollutants in the wastewater that the bacteria will remove, as
apparent to a person skilled in the art.
[0068] According to another example of the present invention, there
is also provided a method for treating a liquid containing
impurities, the method comprising the steps of a) introducing the
liquid containing impurities into a reactor 7; b) providing a
bacteria growth device 1 such as the above-described in the reactor
of step a); c) allowing the bacteria attached onto the surface area
of the at least one strip 5 of the device 1 to grow and eliminate
impurities from the liquid present in the reactor 7; and d)
evacuating the liquid removed of certain impurities from the
reactor 7.
[0069] Preferably, step a) comprises the step of discharging a
liquid containing impurities from a septic tank 13 into the reactor
7.
[0070] Preferably also, step d) further comprises the step of
re-circulating the liquid removed of certain impurities back into
the septic tank 13.
EXAMPLES
[0071] The following examples are illustrative of the wide range of
applicability of the present invention and is not intended to limit
its scope. Modifications and variations can be made therein without
departing from the spirit and scope of the invention. Although any
method and material similar or equivalent to those described herein
can be used in the practice for testing of the present invention,
the preferred methods and materials are described.
[0072] The following are the results of the analysis of various
parameters of water at the inlet 17 and at the outlet 19 of an
assembly 3 including bacteria growth devices 1 according to the
present invention, such as the one illustrated in FIG. 7.
1TABLE 3 Results of the suspended matter. Date of sampling
28-05-2002 18-06-2002 26-06-2002 09-07-2002 Inlet 24 mg/L 23 mg/L
22 mg/L 8 mg/L Outlet <3 mg/L <3 mg/L 5 mg/L <3 mg/L
[0073]
2TABLE 5 Results of the stercoraceous coliforms. Date of sampling
18-06-2002 26-06-2002 09-07-2002 Inlet 88000 UFC/100 mL 40000
UFC/100 mL 1000 UFC/100 mL Outlet 1400 UFC/100 mL 180 UFC/100 mL
150 UFC/100 Ml
[0074]
3TABLE 7 Results of the DBO 5 days. Date of sampling 14-05-2002
28-05-2002 18-06-2002 26-06-2002 Inlet 69 mg O.sub.2/L 78 mg
O.sub.2/L 27 mg O.sub.2/L 34 mg O.sub.2/L Outlet 5 mg O.sub.2/L
<3 mg O.sub.2/L <3 mg O.sub.2/L <3 mg O.sub.2/L
[0075]
4TABLE 9 Results of the turbidity. Date of sampling 28-05-2002
18-06-2002 26-06-2002 09-07-2002 Inlet 24 UTN 10 UTN 18 UTN 13 UTN
Outlet 2.2 UTN 0.7 UTN 2.9 UTN 0.8 UTN
[0076]
5TABLE 10 Summary of the various parameters analyzed. Performance
of the system during winter five months after installation Apparent
color 90% Turbidity 98% Suspended matter >99% DBO 5 days 99%
Stercoraceous coliforms >99% Total coliforms >99% Total
nitrogen kjeldahl 71% Total phosphorus 34%
[0077]
6TABLE 11 Comparative overview between the results obtained and the
norms required. Result Norm Ammoniacal nitrogen 0.24 mg N/L Total
nitrogen kjeldahl 1.12 mg N/L Stercoraceous coliforms 150 50 000
(UFC/100 mL) Total coliforms 50 000 (UFC/100 mL) Apparent color
23.7 UCA DBO 5 days <3 mg O.sub.2/L DCO 25 mg O.sub.2/L
Suspended matter <3 mg/L 15 mg/L Total phosphorus 3.02 mg P/L
Turbidity 0.8 UTN 5 UTN *for drinking water DBO 5 carbonaced <3
mg O.sub.2/L 15 mg O2/L Nitrites/Nitrates 5.57
[0078] Thus, the above table indicates that the water treated by
the present invetion presents a much greater quality than that of
most government standards. Furthermore, a very appreciable
turbidity may be achieved, in that it is inferior to that of
drinking water. Moreover, there is a remarkable absence of
coliforms in the water treated with the present invetion: 300 times
less than that of the required norm.
[0079] As may now be appreciated, the present invention is a
substantial improvement over the prior art in that the water
treated by the bacteria growth device 1 and corresponding assembly
3 reaches, as demonstrated from the results herein, an exceptional
quality enabling its reuse after minor disinfection, namely for
residential needs (such as: showers, pools, washing and irrigation)
or its rejection into water courses without adverse effect for the
fauna and the flora.
[0080] Other advantages of the present invention, as can be easily
understood from the above-discussed, are that the system enables a
greater volume of nitrification/denitrification when compared to
what is possible the majority of apparatuses and methods known in
the art. Indeed, the great area covered by the bacteria growth
device 1 enables to reduce the toxic concentrations of
ammonia/nitrite/nitrate very rapidly. In addition, the shape and
size of the surface area of the device 1, as well as the surface
treatment thereof, enables a more rapid growth of the bacterial
mass, even when the flow of the water being treated is high, by
favouring adhesion, attachment and growth of the bacteria onto the
strip(s) 5. Moreover, per meter squared, the present invention is
one of the less costly water treatment devices on the market. Its
high productivity translates into a greater infiltration for a
smaller volume. Thus, the present invention is a low cost solution
for any type of wastewater treatment application, whether
residential or commercial.
[0081] Furthermore, the present invention is also advantageous in
it results in a step forward with respect to the protection of the
environment and the battle against the contamination of water
resources by enabling to transform wastewater into an evacuated
water of superior quality which may cleanse the phreatic surface
into which it may be discharged by dilution effect. Indeed, the
present secondary treatment system (device 1 and corresponding
assembly/method) of wastewater is capable of purifying water at an
exceptional rate of 95% and more, as shown hereinabove.
[0082] Other advantages that are possible with the present
invention: it maintains the septic tank 13 but decreases of a third
the surface used for the discharge field by replacing it by a
biological reactor 7 preferably fed by gravity and by a polishing
field; this treatment link acts independently of soil conditions;
the present invention can act as a secondary treatment system which
rejects a quality effluent enabling the maintenance of a healthy
environment for the generations to come; the casing of the reactor
7 is of a dimension similar to that of the septic tank 13 and
contains a medium enabling the bacterial attachment responsible for
the purification of the water; the materials used with the present
invention are non-biodegradable and thus requires no replacement
over time; and installed underground, the biological reactor 7 does
not modify at all the appearance of the land.
[0083] The present invention is also an improvement of the devices
of the prior art, in that it also has the following advantages: the
exceptional quality of the effluent rejected into the environment;
a compact, efficient, and easy-to-install system; the maintenance
is minimal, given the fact that it consists of a passive system,
which may be entirely activated by gravity; permanent installation:
the media is non-biodegradable, and thus requires no replacement;
minimal costs of energy (approximately $5 per month for a
single-family household with 3 bedrooms); capability to monitor at
a distance; reduction of the pollution of the phreatic surface by
dilution effect; reduces considerably the surface of the
purification field; removes 99% of the E. Coli bacteria before that
the effluent reaches the soil; efficient all throughout the season
independent of weather conditions; possible use of the effluent for
irrigation purposes following an additional ozone or sterilizing
UV-ray treatment or the like.
[0084] As may now also be appreciated, the present invention is
also advantageous in that it may be is used in various technical
fields of nitrification/denitrification, namely in sewage
treatment, aquaculture, aquariums and ponds, water processing,
wastewater remediation, and the like.
[0085] While several embodiments of the invention have been
described herein, it will be understood that the present invention
is capable of further modifications, and this application is
intended to cover any variations, uses, or adaptations of the
invention, following in general the principles of the invention and
including such departures from the present disclosure as to come
within knowledge or customary practice in the art to which the
invention pertains, and as may be applied to the essential features
hereinbefore set forth and falling within the scope of the
invention as defined in the appended claims.
* * * * *