METHOD AND AN APPARATUS FOR BIOLOGICAL TREATMENT OF WASTE WATERS

METHODE ET APPAREIL POUR LE TRAITEMENT BIOLOGIQUE DES EAUX USEES

English Abstract

A B S T R A C T .
A waste water treatment plant providing biological
oxidation, biological nitrification and denitrification and bio-
logical removal of phosphorus and clarification of the treated
waste water in a single reaction tank in a single suspended growth
sludge system without the use of the traditional compressors,
surface aerators, mixers, recirculation pumps, sludge scrapers,
sludge return pumps, piping and valving.
T I T L E O F I N V E N T I O N
" Method and an Apparatus for Biological
Treatment of Waste Waters. "
- i -

Claims

I claim:
1. A method for treating waste waters comprising mixing the content of a single
reaction tank by single aerating means in three substantially different reac-
tion zones, the first reaction zone being substantially without dissolved
oxygen, the second reaction zone being substantially saturated with dis-
solved oxygen, the third reaction zone being substantially saturated with
dissolved oxygen and with a fluidized bed of sludge therein,
feeding the waste water into said first reaction zone, continuously rotating
by said aerating means the content therein and contacting the waste water
with activated sludge solids in the absence of dissolved oxygen therein,
continuously pumping the anoxic reactor mixed liquor by said aerating means
from said first reaction zone into said second reaction zone and from said
second reaction zone into said third reaction zone,
continuously recirculating the aerobic reactor liquor by said aerating means
from the top of said third reaction zone downward through said second reac-
tion zone, maintaining a fluidized bed of sludge solids in said third reac-
tion zone and contacting the waste water with the fluidized activated sludge
solids in said third reaction zone in presence of dissolved oxygen therein,
continuously flowing by gravity and by said aerating means sludge solids and
the aerobic reactor liquor from said third reaction zone into said first
reaction zone,
continuously pumping air by said aerating means into said second reaction
zone and continuously dispersing the air by said aerating means into the
reactor liquor therein,
continuously flowing the aerobic reactor liquor from said third reaction zone
into a clarifier for separating the sludge solids from the treated waste water,
continuously returning the separated sludge solids from said clarifier back
into said single reaction tank and the clarified waste water flowing out of
said clarifier for further treatment or disposal, and
continuously withdrawing the excess sludge out of the system.
14

2. A method for treating waste waters comprising mixing the content of a bio-
chemical reactor by single aerating means in three substantially different
reaction zones, the first reaction zone being substantially without dis-
solved oxygen, the second reaction zone being substantially saturated with
dissolved oxygen, the third reaction zone being substantially saturated with
dissolved oxygen and having a fluidized bed of sludge solids therein,
feeding the waste water into said third reaction zone, continuously recircu-
lating the aerobic reactor liquor by said aerating means from the top of said
third reaction zone downward through said second aeration zone then upward
through said third reaction zone, maintaining a fluidized bed of sludge
solids in said third reaction zone and contacting the waste water with the
fluidized activated sludge solids in said third reaction zone in presence of
dissolved oxygen therein,
continuously flowing by gravity and by said aerating means sludge solids and
aerobic reactor liquor from said third reaction zone into said first reaction
zone,
continuously rotating by said aerating means the content in said first reac-
tion zone and contacting the reactor liquor with activated sludge solids in
the absence of dissolved oxygen therein,
continuously pumping by said aerating means anoxic reactor mixed liquor from
said first reaction zone into said second reaction zone and from said second
reaction zone into said third reaction zone,
continuously pumping air by said aerating means into said second reaction
zone and continuously dispersing the air by said aerating means into the
reactor liquor therein,
continuously flowing the anoxic reactor mixed liquor from said first reaction
zone into a clarifier for separating the sludge solids from the treated waste
water,

continuously returning the separated sludge solids from said clarifier back
into said biochemical reactor and flowing the clarified waste water out of
said clarifier for further treatment or disposal, and
withdrawing the excess sludge out of the system.
3. A method for treatment of waste waters comprising mixing the content of a
biochemical reactor by single aerating means in two substantially different
reaction zones, the first reaction zone being substantially without dissolved
oxygen, the second reaction zone being substantially saturated with dissolved
oxygen,
feeding the waste water into said first reaction zone, continuously rotating
by said aerating means the content in said first reaction zone and contacting
the waste water with activated sludge solids therein in the absence of dis-
solved oxygen therein,
continuously pumping by said aerating means the anoxic reactor mixed liquor
from said first reaction zone into said second reaction zone and mixing the
content in said second reaction zone and aerating the reactor mixed liquor
by said aerating means therein,
continuously flowing by gravity and by said aerating means the aerobic reactor
mixed liquor from said second reaction zone into said first reaction zone,
continuously flowing the aerobic reactor mixed liquor from said second reac-
tion zone into a clarifier for separating the sludge solids from the treated
waste water,
continuously returning the separated sludge solids from said clarifier back
into said biochemical reactor and the clarified waste water flowing out of
said clarifier for further treatment or disposal, and
withdrawing the excess sludge out of the system.
16

4. A method for treatment of waste waters comprising mixing the content of a
biochemical reactor by single aerating means in two substantially different
reaction zones, the first reaction zone being substantially without dis-
solved oxygen, the secondreaction zone being substantially saturated with
dissolved oxygen,
feeding the waste water into said second reaction zone, mixing and aerating
the content in said second reaction zone by said aerating means and contact-
ing the waste water with activated sludge solids therein in the presence of
dissolved oxygen,
continuously flowing by gravity and by said aerating means the aerobic reactor
mixed liquor from said second reaction zone into said first reaction zone,
continuously rotating by said aerating means the content in said first reac-
tion zone and contacting the reactor liquor with activated sludge solids
therein in the absence of dissolved oxygen,
continuously pumping by said aerating means the anoxic reactor mixed liquor
from said first reaction zone into said second reaction zone,
continuously flowing the anoxic reactor mixed liquor from said first reaction
zone into a clarifier for separating the sludge solids from the treated waste
water,
continuously returning the separated sludge solids from said clarifier back
into said biochemical reactor, and flowing the clarified waste water out of
said clarifier for further treatment, and
withdrawing the excess sludge out of the system.
5. A method for treating waste water comprising mixing the content of a bio-
chemical reactor by single aerating means in two substantially different
reaction zones, the first reaction zone being substantially saturated with
dissolved oxygen, the second reaction zone being substantially without dis-
solved oxygen and having a fluidized bed of sludge solids therein,
17

feeding the waste water into said second reaction zone, recirculating the
reactor liquor by said aerating means from top of said second reaction zone
to the bottom and then upward through said second reaction zone, maintaining
a fluidized bed of sludge solids in said second reaction zone and contacting
the waste water with fluidized sludge solids in the absence of dissolved
oxygen therein,
continuously flowing by gravity and by said aerating means the anoxic reactor
liquor and sludge solids from said second reaction zone into said first reac-
tion zone,
continuously rotating the content in said first reaction zone by said aerating
means and contacting the reactor liquor with activated sludge solids in the
presence of dissolved oxygen therein,
continuously pumping by said aerating means the aerobic reactor mixed liquor
from said first reaction zone into said second reaction zone,
continuously pumping air by said aerating means into said first reaction
zone and continuously dispersing the air by said aerating means into the
reactor liquor therein,
continuously flowing the aerobic reactor mixed liquor from said first reac-
tion zone into a clarifier for separating the sludge solids from the treated
waste water,
continuously returning the separated sludge solids from said clarifier back
into said biochemical reactor and flowing the clarified waste water out of
said clarifier for further treatment or disposal, and
withdrawing the excess sludge out of the system.
6. A method for treating waste waters comprising mixing the content of a bio-
chemical reactor by single aerating means in two substantially different
reaction zones, the first reaction zone being substantially saturated with
dissolved oxygen, the second reaction zone being substantially without dis-
solved oxygen and having a fluidized bed of sludge solids therein,
18

feeding the waste water into said first reaction zone, continuously rotating
by said aerating means the content of said first reaction zone and contacting
the waste water with activated sludge solids in the presence of dissolved
oxygen therein,
continuously pumping by said aerating means the aerobic reactor mixed liquor
from said first reaction zone into said second reaction zone,
continuously recirculating by said aerating means the anoxic reactor liquor
from top of said second reaction zone to the bottom and then upward through
said second reaction zone, maintaining a fluidized bed of sludge solids in
said second reaction zone and contacting the reactor liquor with fluidized
sludge solids in the absence of dissolved oxygen therein,
continuously flowing by gravity and by said aerating means sludge solids and
the anoxic reactor liquor from said second reaction zone into said first
reaction zone,
continuously pumping air by said aerating means into said first reaction zone
and continuously dispersing the air by said aerating means into the reactor
liquor therein,
continuously flowing the anoxic reactor liquor from said second reaction zone
into a clarifier for separating the sludge solids from the treated waste
water,
continuously returning the separated sludge solids from said clarifier into
said biochemical reactor and flowing the clarified waste water out of said
clarifier for further treatment or disposal, and
withdrawing the excess sludge out of the system.
7. A method according to claim 1 with said aerating means operating in a cyclic
"on-off" mode.
8. A method according to claim 2 with said aerating means operating in a cyclic
"on-off" mode.
19

9. A method according to claim 3 with said aerating means operating in a cyclic
"on-off" mode.
10. A method according to claim 4 with said aerating means operating in a cyclic
"on-off" mode.
11. A method according to claim 5 with said aerating means operating in a cyclic
"on-off" mode.
12. A method according to claim 6 with said aerating means operating in a cyclic
"on-off" mode.

13. (amended) Apparatus for biological treatment of waste waters including
means defining a reaction tank, waste water inlet means, aerating means, said
aerating means comprising an endless vertical belt means, said belt means being
positioned within said reaction tank with the top portion of said belt means lo-
cated above the liquid level and with the bottom portion of said belt means sub-
merged in the liquid retained within said reaction tank, said belt means having
horizontal chambers equipped with openings for entering of the air into said
chambers and with openings for flowing the air out of said chambers, said belt
means being held in position by belt support means, said belt means and said belt
support means being rotated by motor means and said reaction tank being equipped
with means for discharging of the reactor liquid.
14. (amended) Apparatus according to claim 13 and comprising in addition
clarification means for separating the suspended solids from the reactor mixed
liquor and for clarifying the treated waste water and said clarification means
being equipped with means for returning the separated sludge solids back into said
reaction tank, means for withdrawing the excess sludge and means for flowing the
clarified effluent out of the apparatus.
15. (amended) Apparatus according to claim 13 with said aerating means com-
prising in addition a solid wall partition, said partition being positioned inside
said belt means and being attached to two side walls of said reaction tank, said
partition separating said reaction tank into first and second reaction zones, said
first and second reaction zones being in communication with each other via an open-
ing formed by the bottom of said partition, two side walls and the bottom of said
reaction tank, said belt means moving around said partition dowwardly in said
second reaction zone and upwardly in said first reaction zone, said belt means
pumping and dispersing air into said second reaction zone and mixing the content
therein and rotating the content in said first reaction zone and said belt means
pumping the reactor mixed liquor from said first reaction zone into said second
reaction zone.
21

16. (amended) Apparatus according to claim 13 with said aerating means com-
prising in addition a solid wall partition, said partition being positioned inside
said belt menas and being attached to two side walls of said reaction tank, said
partition separating said reaction tank into first and second reaction zones, said
first and second reaction zones being in communication with each other via an open-
ing formed by the bottom of said partition, two side walls and the bottom of said
reaction tank, said belt means moving around said partition downwardly in said
second reaction zone and upwardly in said first reaction zone, said belt means
pumping and dispersing air into said first reaction zone and rotating the content
therein and mixing the content in said second reaction zone and said belt means
pumping the reactor mixed liquor from said first reaction zone into said second
reaction zone.
17. (amended) Apparatus according to claim 13 with said aerating means com-
prising in addition first solid wall partition and second solid wall partition, said `
first partition being positioned inside said belt means and being attached to two
side walls of said reaction tank separating said reaction tank into first and
second reaction zones, said second partition being positioned in parallel with said
first partition alongside said belt means in said second reaction zone, said second
partition being attached to two side walls of said reaction tank and being submerged
in the liquid held in said second reaction zone, said first and second reaction
zones being in communication with each other via openings formed by the bottoms of
said first and second partitions, two side walls and the bottom of said reaction
tank, said belt means moving around said first partition and downwardly in the space
between said first and second partitions and upwardly in said first reaction zone,
said belt means recirculating the liquid from the top of said second reaction zone
downwardly in the space between said first and second partitions to the bottom of
said reaction tank and then upwardly through said second reaction zone and maintain-
ing a fluidized bed of sludge solids therein and said belt means pumping and dis-
persing air into said first and second reaction zones and rotating the content in
said first reaction zone and pumping the reactor mixed liquor from said first
reaction zone into said second reaction zone.
22

18. (amended) Apparatus according to claim 13 with said aerating means com-
prising in addition first solid wall partition and second solid wall partition, said
first partition being positioned inside said belt means and being attached to two
side walls of said reaction tank separating said reaction tank into first and sec-
ond reaction zones, said second partition being positioned in parallel with said
first partition alongside said belt means in said second reaction zone, said second
partition in its lower portion being bent outwardly to form a funnel shaped aeration
zone between said first partition and said second partition for aerating the reactor
liquor, said second partition being attached to two side walls of said reaction tank
and being submerged in the liquid held in said second reaction zone, said first and
second reaction zones being in communication with each other under said funnel shaped
aeration zone via openings formed by the bottoms of said first and second partitions,
two side walls and the bottom of said reaction tank, said belt means moving around
said first partition and downwardly in the space between said first and second
partitions and upwardly in said first reaction zone, said belt means recirculating
the liquid from the top of said second reaction zone downwardly in the space between
said first and second partitions to the bottom of said reaction tank and then upward-
ly through said second reaction zone and maintaining a fluidized bed of sludge solids
therein and said belt means pumping and dispersing air into the reactor liquor in
said funnel shaped aeration zone and rotating the content in said first reaction
zone and pumping the reactor mixed liquor from said first reaction zone into said
second reaction zone.
23

19. Apparatus according to claim 14 with said clarification means being inte-
greated with said reaction tank, said clarification means including means
defining flocculating chamber; means for flowing the reactor liquor into
said flocculating chamber, means for flowing the floating solids back into
said reaction tank, flocculated solids recycling menas, means defining
clear well and clarified effluent discharging means.
24

20. Apparatus according to claim 14 and comprising in addition means for further
treatment of the biologically treated and clarified waste water.
21. Apparatus according to claim 19 and comprising in addition means for further
treatment of the biologically treated and clarified waste water.
22. Apparatus according to claim 14 and comprising in addition a timer switch
means operating said aerating means in a cyclic "on-off" mode.
23. Apparatus according to claim 19 and comprising in addition a timer switch
means operating said aerating means in a cyclic "on-off" mode.

Description

1~1452~3
S P E C I F I C A T I O N
; .
FIELD OF INVENTION
This invention relates to a system for biological removal of carbonaceous,
nitrogenous and phosphorous compounds and suspended solids from waste waters and
has for its object a provision of an apparatus capable of an efficient, reliable
and unattended maintenance free operation at minimum capital, operational costs
and consumption of energy.
BACKGROUND TO THE INVENTION
Overfertilization of surface waters and degradation of potable water sources
in densely populated areas led to pollution control regulations calling for removal
of nutrients in the treatment of municipal and industrial waste waters. Consequent-
ly, in the biological treatment of waste waters attention is being focused on single-
sludge suspended growth system combining the processes of carbon oxidation, nitrifi-
catTon, denitrification and removal of phosphorus in one or more reactors without
the intermediate clarification and without the addition of external carbon source
for denitrification and without addition of chemicals for removal of phosphorus.
It Ts known, that for a high rate biological removal of carbonaceous, nitro-
genous and phosphorous compounds in a single sludge system it is necessary to main-
tain: a) a high concentration of mixed microbial population in the biochemical
reactor, b) an efficient contact of the mixed microbial population with the in-
csming waste water, c) an efficient mixing of the partially treated waste water
with the incoming waste water and with the mixed microbial population for a short
period wTthout the dissolved oxygen being present in the reactor mixed liquor and
for a short period with the dissolved oxygen being present in the reactor mixed
liquor, and d) a controlled withdrawal of the excess sludge.
.~

" 1~14S2~3
To comply with the above process requirements, the current treatment systems
utilize biochemical reactors that require compressors and/or surface aerators for
mixing and aerating the reactor mixed liquor in the aerobic reaction zones, mechani-
cal mixers for mixing of the reactor mixed liquor in the anoxic zones, pumps for re-
circulating the reactor mixed liquor between individual zones and clarifiers thatrequire sludge mixers or sludge scrapers and sludge return pumps, piping and valving,
etc. that make the treatment system opera~ional, but complex and expensive and re-
quiring considerable maintenance.
Therefore, it is the object of this invention to provide an efficient treat-
ment system in which all of the above process requirements could be met and the bio-
logical reactions could be carried out reliably at minimum cost and at minimum con-
sumption of energy.
More particularly, it is the object of this invention to provide a biochemical ~-
reactor and a clarifier that would provide and reliably maintain the conditions re-
quired for a high rate biooxidation of carbonaceous compounds, biological nitrifica-
tion and denitrification and biological uptake of phosphorus in a single reactor and
a single suspended growth sludge system.
It is also the obJect of this invention to provide a simple and maintenance
free biochemical reactor with high energy utilization efficiency in mixing, recircu-
lating and aerating of the reactor mixed liquor without the use of the traditionalcompressors, surface aerators, mixers and recirculation pumps, that could be con-
structed from concrete, steel, fiber glass and or other suitable material.
Another object of this invention is to combine the biochemical reactor with
a clarifier into a sTmple treatment system not requiring compressors, pumps, surface
aerators, mixers, piping, etc. for reliable operation, that could be easy to scale
up or down for use in standardized package plants.
It is another object of this invention to provide a treatment system that
would be capable to operate reliably with high concentration of powerdered minerals,

1$14S~
activated carbon, sawdust, or their mixtures present in the system.
Another object of this invention is to provide a system for biological
treatment of waste waters capable of cyclic "on-off" operation to permit optimum
utilization of energy at batch-wise flow conditions occuring in small package
plants and particularly in a single house sewage treatment systems.
Other objects and features of the invention will be understood from the
accompanying drawings and the following description of claims.
SUMMARY OF THE INVENTION
The present invention provides a biochemical reactor with a new type of
~mixing of the reactor content permitting operation of the reactor with high concen-
tration of mixed liquor suspended solids, permitting formation of anoxic and aerobic
zones within a single reaction tank and providing a!l process conditions required
for biooxidation of carbonaceous material, biological nitrifica~ion and denitrifica-
tion and biological ùptake of phosphorus in a single suspended growth sludge system.
The present invention provides a new type of transport of the reactor mixed
liquor between the anoxic and aerobic zones automatically formed tn the reactor,
provides a new type of delivery and dispersion of the air into the reactor mixed
liquor, provides a new type of mixing in the formed anoxic and oxic zones thus eli-
minating the need for the traditional compressors, air diffusers, surface aerators,
Z mixers, pumps and the associated pip;ng and valving.
.
The present invention permits integration of the biochemical reactor with a
clarifier into a treatment system that does not require the traditional sludge re-
turn pumps, air lifts, sludge mixers or scrapers, mechanical or air operated skimmers
and the associated piping and valving. The treatment system of this invention is
therefore simple, its operation reliable, the capital and operational costs reduced
and the traditional maintenance eltm;nated.
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`` ~114S23
~ .
The biochemical reactor of this invent;on with minor adjustment can also be
used with the various activated sludge process modifications and the existing acti-
vated sludge treatment plants can be modified to utilize the benefits of this in-
vention to reduce maintenance and operational costs, to improve the treatment
efficiency and to increase the plant performance.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the present invention will
become apparent from the following detailed description which proceeds with refer-
ence to the accompanying drawings wherein:
Fig. 1 is a vertical view through one prefered embodiment of the biochemical
reactor of thTs invention.
Fig. 2 is a plan view of the biochemical reactor of Fig. 1.
Fig. 3 ;s a vert;cal view of one prefered embodiment of an integrated system
of-this ;nvent;on.
F;g. 4 is a plan view of the integrated system of Fig. 3.
Fig. 5 is a vertical view through another prefered'embodiment of a biochemi-
cal reactor of this invention.
DESCRIPTION OF THE PREFERED EMBODIMENTS
Before explaining the present invention in detail it is to be understood that
the invention is not limited in its application to the details of construction and
arrangement of parts illustrated in the accompanying drawings, since the invention
is capable of other embodiments and of being practiced or carried out in various
ways. Also it is to be understood that'the phraseology or terminology employed here-
in is for the purpose of description and not of limitation.
Reference is made first to Fig. 1, 2, for an explanation of one prefered
modification of a biochemical reactor of the present invention. As is there shown,
the biochemical reactor comprises a react;on tank 10 and a multi unctional device 20.

11145Z~
The multifunctional device 20 performs the following functions: a) it mixes the
reactor content, b) it permits formation and separation of the anox;c zone from
the aerobic zone in a single reaction tank, c) it pumps the reactor mixed liquor
from the anoxic zone into the aerobic zone, d) it recycles the sludge solids from
the aerobic zone into the anoxic zone, e) it pumps and transports the air into
the reactor, f) it permits control and it disperses the air into the reactor
mixed liquor, g) it recirculates the reactor liquor through the aerobic zone, and
h) it maintains a fluidized bed of sludge in the aerobic zone, and i) it creates
hydraulic head of the anoxic reactor mixed liquor.
As is shown in Fig. 1, 2, the waste water enters the biochemical reactor 10
via pipè 13 and the reactor liquor discharges via pipe 14. However, it is also
feasible to operate the reactor in a mode in which the waste water enters via pipe 14
and the reactor liquor dTscharges via pipe 13. As shown in Fig. 1, 2, the multifunc-
tional device 20 comprises a belt 21 with horizontal chambers 22, a drum 23, and an
air dispersion chamber 24 equipped with a throat 24.4 and a standpipe 24.5 with valve
24.6, and throat 50.
When the drum 23 rotates in the direction shown by the arrow 25, the belt 21 with
chambers 22 moves in the direction shown by arrows 26. The rotation of the drum 23
can be by an electric motor and is such that the upward and/or downward speed of the
belt 21 is in the range between 5 to 100 cm/sec. Preferably the velocity of the
belt 21 is maintained in the range from 10 to 50 cmisec. The belt 21 can be con-
structed from chaTn or from rope and the horizontal chambers 22 from pipes, ducts,
or other elements. Chambers 22 have openings 22.2 located on the top side when
chambers 22 are on the left from drum 23 and on the bottom side when on the right
side from the drum and when movlng in the direction shown by arrows 26. As chambers
22 on the left from the drum 23 move upward, they force to rotate the reactor content
kept in the anoxic zone 11 in the direction shown by arrows 27 thus mix;ng the sludge
solids with the reactor liquor kept in the anoxic zone 1! in the absence of dissolved
oxygen therein. At the same time, chambers 22 are filled with the anoxic mixed
liquor and as they pass to the right side on the drum 23 at position 23.3 the content
of chambers 22 is empti~d v7a openings 22.2 into the throat 24.4 of the air dispersion
chamber 24. At position 23.4 as chambers 22 and openings 22.2 change position the en-
-- 6 --
.

4S2~ ~
trapped air is released from chambers 22, rises through the reactor liquor and accu-
mulates in the top portion of the air dispersion chamber 24. The velocity of thechambers 22 being in the range from 10 to 50 cm/sec, and the recirculated liquorflowing downwardly in the throat 24.4 prevent the air collected in the top portion
of the air d;spersion chamber 24 to escape through the throat 24.4 out from the air
dispersion chamber 24 and the valve 24.6 prevents the air to escape through the
standpipe 24.5. The motion of chambers 22 and the velocity of the recirculated
reactor liquor causes the air collected in the air dispersion chamber 24 to be con-
tinuously dispersed into small bubbles and distributed into the reactor liquor flow-
ing through the air dispersion chamber 24. As the downward velocity of the reactor
liquor drops due to increased cross-sectional area of the air dispersion chamber 24
the air bubbles tend to stay within the air dispersion chamber 24 until all of the
air is absorbed Into the recirculated liquor. In this way substantially all of the
oxygen present in the a7r delivered ;nto the air dispersion chamber 24 by chambers
22 is utilized in the process and therefore none of the used energy is wasted. To
control the amount of the oxygen dissolved in the liquor a small portion of the air
collected in the air dispersion chamber 24 may be continuously bled off via standpipe
24.5 and valve 24.6
As chambers 22 move downward through the throat 24.4 they force to flow the
reactor liquor from the top of the aerobic zone 12 through the throat 24.4 downward
through the air disperston chamber 24 and upward through the aerobic zone 12 in the
direction shown by arrows 28. Consequently a fluidized bed of sludge solids is auto-
matically formed in the aerobic zone 12 which permits a build up of high concentration
of sludge soltds in the aerobic zone 12 and subsequently also in the anoxic zone 11.
Thus the present invention creates conditions permitting operation of the reactor at
high concentration of the activated sludge solids in the reactor liquor.
The anoxic reactor mixed liquor delivered into the aerobic zone 12 by chambers
22 is mixed by the recirculated liquor with the fluidized sludge solids and simultan-
eously equivalent volume of the fluidized sludge is replaced from the aerobic zone 12
through the opening 30 formed between the open bottom of the air dispérsion chamber
24 and the floor of the reactor 10 into the anoxic zone 11.
_ 7 _

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The continuous recirculation of the reactor liquor and of the sludge solids
between the anoxic zone 11 and aerobic zone 12 can be controlled by the rotating
drum 23.
It should be apparent that an efficient biochemical reactor can be constructed
also without using the air dispersion chamber 24. The throat 50 on the left from
drum 23 may be also excluded, or may be used to establish a hydraulic head for
flowing the anoxic mixed liquor where needed.
It should be also apparent to those skilled in the art that the biochemical
reactor of the present invention can be combined with any standard clarifier into
a plant capable of an efficient biological treatment of waste waters.
It should also be apparent that a cyclic operation of the biochemical reactor
of the present invention is feasible and can be arranged by a single timer switch
controlling the operation of the electric motor rotating the drum 23.
Reference is now made to Fig. 3, 4 for explanation of one prefered embodiment
of the present invention wherein the biochemical reactor of this invention is com-
bined with a clarifier into an integrated system for the treatment of waste waters.
To achieve efficient separation of floatable and settleable solids present
in the reactor mixed liquor from the treated waste water It is necessary to maintain
a continuous flow of the two types of solids through the clarifier. In the current
art systems these conditions are met by: a) continuously scraping the settled
sludge solids by mechanical sludge scrapers, ~b) continuously recirculating the
sludge solids between the clar;fier and the reactor by sludge return pumps or by
airlifts and c) by continuous skimming of the floatable solids in the clarifters
by mechanical or air lift operated skimmers.
In the treatment system of the present invetion all process conditions for
efficient biological treatment and clar7fication of the treated waste water are
met without the need for any such auxiliary equipment. As shown in Fig. 3, 4 in
.. .. . .
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L14~2~
one prefered embodiment of th;s invention the clarifier 100 is located on the out-
side of the aerobic zone 12-utilizing one side wall of the reactor 10. It should
be apparent to those skilled in the art that such a clarifier can be located also
inside the aerobic zone 12 or inside the anoxic zone 11 or outside the anoxic
zone 11.
As shown in Fig. 3 4 waste water enters into the reactor via pipe 13 and the
treated waste water discharges from the clarifier via pipe 114. A continuous recir-
culation of floatable and settleable solids through clarifier 100 is insured by con-
tinuously flowing a small portion of the reactor liquor withdrawn from the aerobic
zone 12 via pipe 107 into the flocculation chamber 120 of the clarifier 100. Com~
pressed air collected in standpipe 24.5 may be fed by line 105 into pipe 107 if
control of the treated waste water through the clarifier 100 is desired and a baffle
108 is provided to prevent mixing of the fiocculated sludge solids in chamber 120
formed by the side wall of the reactor 10 walls 102 104 and partition 101 of the
clarifier 100. Most of the floatable solids present in the mixed liquor are separ-
ated in chamber 120 and are continuously returned back into
the reactor 13 with a small portion of the liquor via openings 110 located in
channel 115 of the clarifier 100. As the aerobic liquor-moves downward in chamber
120 the biologTcal solids flocculate and the formed flocc entraps the colloidal
particles present in the treated waste water. Baffle 116 maintalns a bed of
floccùlated sludge soltds under partition 101 under which the treatèd waste water
flows together with the formed flocc into chamber t30 formed by walls 102 103 and
104 and partition 101 of the clarTfier 100. The treated waste water flows through
~ the continuously moving bed of flocculated sludge solids then upward in chamber
130 to be collected in the weir 112. Baffle 113 prevents floatable solids to enter
~. . .. .
the weir 112 and opening 111 located ;n channel 115 permits to recycle the floating
solTds from chamber 130 back into reactor 10. The flocculated sludge solids move
horizontally across chamber 130 to wall 103 then slide on the wall 103 downward
and finally flow out of chamber 130 with a small portion of the liquor via opening
3 109 located in the side wall of the reactor 10 into the aerobic zone 12.

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. .
Sloping of the walls of the clarifier 100 is such that a continuous reliable move-
ment of the sludge solids through the clarifier is insured without the need for a
mechanical sludge scraper.
The excess sludge may be withdrawn from the reactor 10 for further treatment
and disposal via opening lS located in the side wall of the reactor 10, pipe 16 and
valve 17.
Operation
The operation of the aforedescribed treatment system and the method of the
biological treatment used therein cons7sts of the following:
a) feeding the waste water vTa inlet 13 into the anoxic zone 11 of the
reactor 10, continuously rotating the content in this zone by the multifunctional
device 20, and continuously contacting the waste water with the rotating sludge
: solids in the absence of dissolved oxygen there;n,
b) continuously pumping a predetermined volume of the mixed liquor from
: 15 the anoxic zone 11 by chambers 22 into the a;r d;spersion chamber 24 and from there
into the aerobic zone 12 and simultaneously continuously flowing by gravity an
equivalent volume of sludge from the aerobic zone 12 back into the anoxtz zone 1i
via opening 30,
c) cont7nuously recirculating the reactor liquor from the top of the aero-
bic zone 12 downward through the air dispers;on chamber 24 then upward through the
aerobic zone 12 to maintain a fluidized bed of sludge solids in an aerobic zone 12.
and contacting the waste water with the fluidized activated sludge solids in the
presence of dissolved oxygen therein,
d) cont7nuously pumping air by chambers 22 into the air dispersion chamber
24, continuously dispersing the air in the air dispersion chamber and aerating the
reactor liquor recirculating therethrough,
e) continuously flowing via pipe 107 a portion of the reàctor liquor with-
drawn from the aerobic zone 12 into the clarifier 100,
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f) continuously flocculating the sludge solids in the clarifier and separ-
ating the sludge solids from the treated waste water therein by filtration through
a continuously moving bed of flocculated sludge solids,
g) continuously flowing the flocculated sludge solids by gravity via open-
ing 109 and the floating solids with small portion of the clarified waste water viaopenings 110 and 111 back into the reactor 10 to maintain the biological activity
in the reactor to insure high degree of biological treatment of waste water,
h~ continuously withdrawing the excess biological solids out of the reactor
via opening 15, pipe 16 and valve 17, and,
i) continuously flowing the biologically treated and clarified waste
water via weir 112 and pipe 114 out of the treatment system.
It should be also apaprent to those skilled in the art that eliminating the
air dispersion chamber 24 and modifying the openings 22.2 of chambers 22 the oper-
ating conditions in the biochemical reactor would also substantially change. In
such a situation it is possible to maintain the reaction zone 12 aerobic but with
the content being completely mixed and without the fluidized bed of sludge solids
therein. Consequently the oeprating method of such a system could be considered
as substantially different from that described above.
It should be also apparent to those skilled in the art that the incoming
waste water could be fed into the reactor into the aerobic zone 12 via pipe 14
with the clarifier receiving the reactor mixed liquor from anoxic zone 11 via pipe
13. Such treatment could be also considered as different from those described above.
It should be also apparent to those skilled in the art that all of the above
described treatment methods'could be further modified by operating the multifunc-
tional device 20 in a cyclic "on-off" mode.
Reference is now made to Fig. 5 showing another prefered embod;ment of the
present invention in which the air dispersion chamber 24 is excluded and the throat
24.4 Ts extended. This modification of the multifunctional device 20 w;ll provide
a biochemical reactor with two reaction zones, the first reaction zone 11 being
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substantially saturated with dissolved oxygen with the content in this zone rotating
in the direction shown by arrows 27 the second reaction zone 12 being substantially
without dissolved oxygen present in the reactor liquor with the reactor liquor circu-
lating from top of reaction zone 12 downward through throat 24.4 and upward through
zone 12 as shown by arrows 28 and maintaining a fluidized bed of sludge solids there-
in. The openings 22.2 in chambers 22 may be modified to improve dispersion of the
entrapped air at point 23.4 where chambers 22 and openings 22.2 change position and
where the air is released from chambers 22 and dispersed into the rotating liquor.
The incoming waste water may be fed into the aerobic zone 11 via pipe 13 and
the reactor liquor may be discharged from the anoxic zone 12 via pipe 14. It is also
apparent that it is feasible to feed the incoming waste water into the fluidized bed
maintained in the anoxic zone 12 via p7pe 14 and discharge the reactor effluent from
the aerobic zone 11 via pipe 13.
It should be also apparent that the described embodiment of the biochemical
reactor of this invention can be combined with any clarifier into a plant capable of
efficient biochemical treatment of waste waters with the clarifier receivng the
reactor effluent either from the aerobic zone 11 or from the anoxic zone 12.
It should be also apparent to those skTlled in the art that such a plant
could be oeprating with the belt 21 moving either contTnuously or in a cyclic on-
off mode.
It should be also apparent to those skilled in the art that the treatmentmethods utilizing the above described embodiments of this invention could be con-
sidered as substantially different from those described previously.
Although all the above described embodiments of this invention relate to a
system utilizing a biochemical reactor with two or three substantially different
reaction zones it should be apparent to those sk;lled in the art that by excluding
the throat 24.4 and modifying the shape and/or location of openings 22.2 of chambers
22 or changing the direction of rotation of the drum 23 it is feasible to provide
also a biochemical reactor with a single reaction zone with completely mixed and
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aerated content therein for use with the established activated sludge process and/
or the various activated sludge process modifications.
All of the described suspended growth systems and the associated treatments
do not require the traditional compressors and air diffusers or surface aerators
for aeration of the reactor content, do not require the traditional mixers to main-
tain the biological activity in the denitrifying stages of the treatment, do not
require the traditional pumps for recirculation of the reactor liquor between the
aerobic and anoxic zones, do not requ;re the traditional sludge return pumps, sludge
scrapers, mechanical or air lift operated skimmers, etc. as common in all current
art systems. In the described treatment systems there is no equipment or parts to
faTl and therefore the described treatment systems and the associatèd treatment
methods are exceptTonally reliable. It is also apparent to those skilled in the art
that due to the simplicity of the invented apparatus the capital costs and the oper-
ational costs for such described biological treatments will be considerably below
the cost of the current art treatments.
It is also apparent that if further treatment of the clarified waste water is
required such can be provided by existing tertiary treatments.
Having described the prefered embodiments of my invention, it should be
apparent to those skilled In the art that the same permits of modificatlon in
arrangement and detatl. I claim as my invention all such modifications as come
within the true spirit and scope of the following claims.