Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
T I T L E O F I N V E N T I O N
"Apparatus for On-site Renovation of Sanitary Waters"
S P E C I F I C A T I O N
This invention relates to an apparatus for on-site
renovation of sanitary waters and has for it's object a
provision of an improved apparatus capable of unattended
an reliable operation when purifying sanitary waters to a
high quality effluent suitable for limited reuse.
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BACKGROUND TO THE INVENTION
It has become evident that nitrogen and phosphorus affect the
productivity of aquatic life - nitrogen being the limiting nut-
rient in eutrophic waters and phosphorus in oligotrophic waters.
It is also known that domestic waste waters contain from 10 to
100 times the nutrient concentration of agricultural or forest
drainage. COnsequently in densely populated areas overfertil-
ization of surface waters, algae growth and chemical pollution
have been noticed along with degradation of potable water sources
and the need for more efficient removal of all pollutants from
waste waters has become more obvious.
While removal of phosphorus can be achieved reliably by chemical
precipitation and removal of organics by biological followed by
physical-chemical processes, removal of nitrogen is more comp-
licated.
The biological transformations of nitrogenous compounds occur
through biological processes of ammonification, nitrification
and denitrification. The first two require presence of oxygen,
the denitrification require absence of oxygen. The two distinct
mechanisms responsible for removal of nitrogen and reduction of
nitrite and nitrate are (a) - formation of ammonia followed by
transfer of ammonia into the anabolic cell metabolism which is
of minor importance since C:N ratio in cell tissue is 5 - 6,
whereas in domestic wasteiwaters only 2 to 2.5 and (b) -
microbial denitrification, which is a respiratory reduction in
which nitrite and nitrate replace oxygen as the final electron
acceptors in the respiration chain.
Bio-oxidation of organic matter, ammonification and nitrification
cause no problem. Nitrification is efficient and reliable if
organic loadings are maintained below 0.3 lb BOD per lb of
mixed liquor suspended solids per day, sludge age is maintained
above 3 -4 days and dissolved oxygen in the mixed liquor is
maintained above 1.0 - 2.0 mg/lit. The higher is the concent-
ration of mixed liquor suspended solids, the more efficient is
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the transformation of ammonia to nitrite and nitrate. The
overall rate of denitrification is a function of the concent-
ration of the heterotrophic facultative bacteria present in
mixed liquor suspended solids and their activity in the absence
of oxygen. To maintain the activity the denitrifying bacteria
must be supplied with suitable organic material - source of
energy.
From the process point of view to accommodate the different
food and oxygen requirements of bio-oxidation of organic matter,
ammonification and nitrification of nitrogenous compounds and
decomposition of nitrite and nitrate by microbial respiration
and to achieve acceptable reaction rates and efficiencies, the
various biochemical reactions are currently being carried out
in separate process stages. While the conventional activated
sludge process is capable of removing nitrogen with efficiency
of 50 -60 per cent, the current multistage processes can achieve
the removal of nitrogen with efficiency of up to 80 -90 per cent.
The multistage processes currently in use in large municipal
treatment plants require treatment facilities that are too com-
plex to be scaled down to small package pla~ts to serve small
developments or single family dwellings. Because of the number
of process steps required for removal of the various pollutants
renovation and reuse of domestic waste waters at present seems
feasible only if practiced on a large scale.
A large waste water treatment -renovation plant however requires
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large underground sewage collection -transportation network, and
in case the renovated water is to be reused also a large under-
ground water distribution networ~. Such networ~s are expensive
to build and even more expensive to maintain and to operate.
It is therefore obvious that on-site renovation and reuse of
waste water would be economically more attractive than renovat-
ion and reuse of waste waters via central collection-treatment
distribution. However because of the complexity of the involved
treatment on-site renovation and reuse of domestic waste waters
as yet can't be practiced.
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Although at present small package sewage treatment plants are
available, they do not provide the required degree of purific-
ation that would permit reuse of the purified effluent and in
general they also lack the required mechanical reliability.
It is therefore the prime object of this invention to provide
an apparatus in which the various processes to remove all poll-
utants present in sanitary waters could be carried out reliably,
unattended and at acceptable cost when serving.single or multiple
family dwellings.
More particularly it is the object of this invention to provide
an apparatus that would reliably maintain all conditions required
for efficient bio-oxidation of organic mat`ter, biological nitrif-
ication, biological denitrification, chemical precipitation of
soluble phosphates, chemical oxidation of the residual and ref-
ractory organics and toxic compounds, efficient kill of bacteria
and viruses and efficient removal of the residual chemical oxid-
izing agents so as to render the effluent non-toxic to aquatic
life and suitable for reuse.
Another object of this invention is to provide an inexpensive
and reliable method for storing and proportioning of the various
chemicals to the unsteady or batchwise flow of the incoming
waste water.
Another object of this invention is to provide an apparatus in -~
which efficient separation of suspended solids from the effluent
is achieved inside the reactor so that a separate clarifier and
the associated sludge return pumping is not required.
A~other object of this lnvention is to provide an apparatus
capable of reliable and unattended operation when processing
waste waters on ships under condition of ship motion and vib-
ration.
Another object of the invention is to provide an improved
suspended solids separator that would not be affected by
"sloshing" that normally occurs on ships during heavy roll and
pitch conditions.
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1090~t88
Another object of this invention is to provide an apparatus
that would require only once per year replenishment of the used
chemicals and only once per year withdrawal of the excess sludge
when serving single family or multiple damily dwellings.
It is also an object of this invention to provide an apparatus
capable of reliable and unattended operation when operating with
wood particles such as saw dust, powdered minerals, powdered
activated carbon, powdered charcoal or their mixtures in reaction
chambers.
Another object of the invention is to provide an apparatus that
would be easy to scale up or down to use as standardized waste
water renovation system to serve small communities, camps, air-
ports, commercial developments, recreation centers, parks and
industrial plants either as a permanent or temporary install-
ations.
Other objects and features of the invention will be set orth
; fully hereinafter.
The full nature of the invention will be understood from the
accompanying drawing and the following description of claims.
SUMMARY OF THE INVENTION - ~-
The present invention provldes an apparatus permitting the
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various biological, chemical and physical processes required to
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remove the various pollutants from raw sanitary waste water to
be carried out within a single tank.
The tank is divided by partitions into three bio-reaction
chambers and two chemical reaction chambers and in a preferred
embodiment the tank is made of steel and equipped with manways
permitting entrance into each individual chamber.
The tank may be located below or above the ground when serving
single or multiple family dwellings or installed on ships as a
marine.sanitation deviae.
The first bio-reaction chamber contains a suspension of pro-
cessed waste water,nonbiodegradable suspended solids and mixed
microbial population, the suspension being recirculated within
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the first reaction chamber by a mechanical mixer without
addition of oxygen.
The second bio-reaction chamber contains a suspension of
partially processed waste water, non-biodegraaable suspended
solids and mixed microbial population, the-suspension being
recirculated in this chamber by a mechanical mixer which sim-
ultaneously injects into the suspension atmospheric air to
keep the liquid in this chamber saturated with oxygen.
The third bio-reaction chamber contains a submerged multi-
channel suspended solids separator and the suspension contain- -
ing purified waste water, nonbioaegradable suspended solids and
mixed microbial population in this chamber is recirculated
over and under the multichannel suspended solids separator to
maintain the suspended solids in suspension and to enhance
flocculation. The recirculation of the suspension in this
chamber is by mechanical mixer without addition of oxygen.
The fourth reaction chamber is a chemical oxidation-clarification
chamber and contains a submerged multichannel chemical reactor
~; ~ to prevent shortcutting of the chemically treated effluent with-
in the fourth reaction chamber, to provide the required contact
time for chemical oxidation of the residual organics and/or
toxic chemicals, to provide the required contact time for effic-
ient kill of bacteria and viruses and to simultaneously separate
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the formed precipitate and the residual suspended solids from
`~ 25 ~the chemically purified effluent.
The fifth reaction chamber is for~ final polishing of the purif-
ied waste water and contains charcoal or activated carbon to de-
compose the residual oxidizing agents and to render the effluent
~ nontoxic to aquatic life and suitable for reuse.
-~ 30 The dosage of the various chemical agents is by disolution o~
granulated chemicals into the recirculated liquor, the level of
which is rising in bioreaction chambers when the waste water is
fed into the system and then slowly falling to normal operating
level when there is no flow of the incoming waste water.
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BRIEF DESCRIPTION OF DRAWING:
Fig. 1 is an overall view through a preferred embodiment of the
apparatus of the present invention.
DETAILED DESCRIPTION OF THE APPARATUS
A cut away perspective view of the complete apparatus of the
present invention is shown in Fig. 1. The apparatus comprises
of first bio-reaction chamber 100 formed by partition 112 and
the outside walls and the floor of the tank 10 and equipped with ~-
a submerged mechanical mixer 117 and containing a suspension of
purified waste water, non-biogradable suspended solids and mixed
microbial population 103; the second bio-reaction chamber 200
formed by partitions 112, 212 and 412 and one outside wall and
floor of the tank 10 and equipped with a submerged mechanical
mixer with an air injector 217 and containing a suspension of
purified waste water, non-biodegradable suspended solids and
mized microbial population; the third bio-reaction chamber 300 --
formed by partitions 112, 212 and 412 and the second outside
wall and floor of the tank 10 and equipped with a submerged
mechanical mixer 317 and~a submerged multichannel suspended
~ solids separ~ator 310; the flow equalizer 402; a chemical oxid-
izing agent storage-dispensing chamber 410; a mineral storage-
dispen~sing container 101; an organic material storage-dispensing~
container 201; chemical oxidation-clarification chamber 400
formed by partitions 412 and 413 and the side walls and floor of
the tank 10 and equipped with a submerged multichannel reactor
415; and polishing chamber 420 containing charcoal or activated
carbon formed by partitions 412, 413 and the side walls and
floor of the tank 10.
Referring to the system's hydraulics, at periods of zero flow
:
of the incoming waste water the height of the suspension in the
first 100, second 200 and third 300 bio-reaction chambers is at
103, 203 and 303 levels with the suspension containing waste
water non-biodegradable suspended solids and mixed microbial
population being continuously recirculated within the three bio-
reaction chambers by submerged mechanical mixers 117, 217 and 317
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100 and 300 and with injection of the atmospheric air into
the suspension in chamber 200, the suspension being also con-
tinuously circulated from the third ~ioreaction chamber via
channel 340 located in partition 112 into the first bioreaction
S chamber 100, from first bioreaction chamber 100 via a screened
opening 115 in partition 112 into the second bioreaction chamber
200 and from second bioreaction chamber 200 via restricted open-
ing 205 in parti~ion 212 back into third bioreaction chamber 300.
Under conditions of zero flow of the incoming waste water the
mineral storage dispensing container 101 located in second bio-
reaction chamber 200 and the organic material storage dispensing
container 201 located in third bioreaction chamber 300 are just
above the liquid levels 203, 303, the mineral and the organic
material not being in contact with the rerirculated suspension
maintained in bioreaction chambers 200 and 300 and therefore
not being dissolved into the recirculated liquid. As the waste
water enters via opening 104 into first bioreaction chamber 100
the liquid level in first, second and third bioreaction chambers
rises, the increase in the height of the recirculated suspension
being proportional to the difference between the flow of incoming
: waste water and the flow of the clarified waste water from theflow equalizer 402. The higher the flow rate of the incoming
waste water, the higher is the liquid level in the three bio-
reaction chambers and consequently more of the mineral and the
organic material is submerged into the recirculated suspension ~ -
and dissolved.
As the incoming waste water is mixed in the first bioreaction
chamber 100 with the suspension containing purified waste water,
non-biodegradable suspended solids and mixed microbial populat-
ion, the activity of the mixed microbial population rises and
the nitrite and/or nitrate present in the suspension are removed
by respiration of the mixed microbial population. At the same
time, portion of the organic matter from the waste water is bio-
ozidized, portion of organic matter is adsorbed on the non bio-
degradable suspended soilds and the nitrogenous compounds trans-
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formed to ammonia. The suspension containing partially
purified waste water, suspended solids and mixed microbial
population then flows from the first bioreaction chamber 100
via screened opening 115 located in partition 112 into second
bioreaction chamber 200 to be mixed with diffused air supplied
by mechanical mixer 217, mixed microbial population, non bio-
degradable suspended solids and mineral dissolved into the re-
circulated suspension to precipitate phosphates. Enough contact
time is provided in second bioreaction chamber 200 to completely
bio-oxidize the dissolved bio-degradable organic matter and to
transform the an~nonia present in the waste water to nitrite and/
- or nitrate and a portion of nitrite and/or nitrate to nitrogenous
gas and to precipitate phosphates.
The suspension containing the treated waste water, the ramaining
nitrite ana/or nitrate, suspended solids and mixed microbial
population is then flown from second bioreaction chamber 200
through restricted opening 205 located in partition 212 into
third bioreaction chamber 300 to be mixed with the suspension
present in bioreaction chamber 300 and containing nondegradable
suspended solids, mixed microbial population and zero dissolved
oxygen ln the liquid, the suspension being continuously recir-
culated by a submerged mechanical mixer 317. The activity of
the mixed microbial population in third bioreaction chamber 300 ;
is~ maintained by suspended organic matter and by soluble organic
;~ 25 matter adsorbed on non-biodegradable suspended solids present in
this chamber and by ~the added soluble organix material and by the
nitrite and/or nitrate entering into bioreaction chamber 300 from
bioreaction chamber 200. Due to the activity of the mixed micro-
`~ bial population present in third bioreaction chamber 300 in the
absence of dissolved oxygen, the remaining dissolved bio degrad-
able organic matter is bio-oxidized with the nitrite and/or
nitrate being transformed by the respiration of the mixed microbia;
population to nitrogen gas. The mixture of purified waste water
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and suspended solids then enters into the submerged multi-
channel suspended solids separator 310 via openings 320 located
at the lower end of the separator 310, then flows upward in
channels 321 in direction of arrows 309, then into a centrally
located collection line 323-and out of bioreaction chamber 300
into flow equalizer 402 located in chamber 410. On the way up
in channels 321 suspended solids are settled out on the walls
of the inclined channels, then continuously slid down into the
recirculated liquor.
----- - The separated suspended solids are circulated in the
third bioreaction chamber downwardly in the space formed between
partition 112 and the wall of the suspended solids separator 310
and upwardly in the space formed between partition 412 and the
other wall of the suspended solids separator 310. Portion of
the separated suspended solids is continuously recycled into bio-
reaction chamber 100 via channel 340 located in partition 112.
The flow equalizer 402 located in the chemical oxidizing agent
dispensing chamber 410 consists of a vertical pipe with a
narrow opening 403. The flow equalizer maintains the flow of
the processed waste water through the three bioreaction chambers
and through the suspended solids separator within the designedrange by means of the opening 403 and relatively independent of
the flow of the incoming waste water. At a surge flow of the
incoming waste water, the flow equalizer causes to rise the
liquid level in bioreaction chambers 100, 200 and 300 to a level
which is limited only by the height of equalizer pipe 402,
accumulating the surge of the waste water in bioreaction cham- -
bers and then slowly at relatively constant rate, releasing the
p~ocessed waste water through the submerged suspended solids
separator via opening 403 into chemical oxidizing agent dispen-
sing chamber 410. In this way, the detrimental effects of the
surge of the incoming waste water on the involved biological
processes and on the separation of suspended solids is eliminated. `
The clarified effluent containing the residual refractory organ-
ics, bacteria and viruses and residual suspended solids, over-
flows from opening 403 of the flow equalizer 402 into the chcm-
ical ozidizing agent dispensing chamber 410. To flow out from
chamber 410, the effluent must pass through a narrow opellin-~ ~l4
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in one wall of chamber 410 which controls the flowrate out of
ch~mber 410 into the chemical o~idation -clarification chamber
400. At the varying flow of the effluent from the flow equal-
izer 402, the level of the liquid in chamber 410 rises and
varies within the height of the opening 414. A mixture of gran-
ulated chemical oxidizing agents is stored in perforated cont-
ainer 430 located in chamber 410 with the container's bottom
touching the level of the li~uid in the chamber 410 at zero
flow of the effluent through flow equalizer 402. The liquid
level in chamber 410 rises proportionally to the flow rate
of the effluent fxom this chamber submerging the perforated
container 430 contalning chemical oxidizing agents into the
liquid and dissolving the oxidizing agents into the effluent
through chamber 410. Thus the amount of chemical oxidizing
agents dissolved into a unit volume of the effluent~in the
apparatus of this invention is constant and is controlled by
the dimensions of the opening 414.
The effluent containing~dissolYed chemical oxidi~zing agents
; then flows into the lower portion;of the chemical oxi~dation
~ - clarification chamber 400 and via opening 425 into~a~sub-
merged~multlchannel reactor 410.~ The multichannel reactor
prevents short-cutting of the chemically~pxidized effluent
within the chemical oxidation-clar~ificatlon chamber thus pro-
viding~condltions~for efficient oxidation of the residual
mpurlties, efficient kill of bacteria and viruses and si~mul-
taneously also efficient removal~f the formed precipitate and
residual suspended sollds entrained from the third bioreaction
chamber. In~channels 421 the chemically oxidized effluent
flows upwardly into a centrally located collection line 422 and
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then out of chamber 400 into chamber 420 for final purification
and decomposition of the remaining oxidizing agents. In chamber
420 the purified effluent flows by gravity through a bed of char-
coal, then via opening 423 and pipe 424 out of the apparatus for
surface disposal or for reuse.
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While the described apparatus is particularly useful for stand-
ardized single or multiple family waste water renovation units,
or as a marine sanitation device, it has application to sewage
treatment systems and sewage renovation systems of various
sizes. It is particularly useful as a standardized package
plant for use on l,and or off-shore in various permanent or
temporary installations.
While the apparatus of the present invention has been described
for use with steel, it is obvious that the apparatus may be
constructed of any convenient material such as reinforced con-
crete or fiber glass.
Although the present invention has been described in part with
reference to specific example, modifications may be constructed
or used without departing from the scope of the invention which
; 20 is defined in the following claims.
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