A kind of composite biological film activated sludge denitrification dephosphorization denitrification method and reactor thereof
Technical field
The present invention relates to saprobia chemical treatment and sewage recycling and utilize the field, be meant a kind of composite biological film activated sludge denitrification dephosphorization denitrification method and reactor thereof especially.
Background technology
The technology of existing sewage water dephosphorization denitrification can be divided into physics method, chemical method and biological process.Comparatively speaking, simple, the non-secondary pollution of few, the operation of biological dephosphorize denitrification technological investment and being widely used.
The ultimate principle of saprobia dephosphorization denitrogenation:
Biological denitrification process is finished by ammonification, nitrification and denitrification three steps.The nitrification and denitrification reaction can be represented by the formula:
Nitration reaction comprises two steps:
(1) NH
4 ++ 1.50
2→ NO
2 -+ 2H
++ H
2O+ Nitrosomas (nitrosation reaction)
(2) NO
2 -+ 0.50
2→ NO
3 -+ Nitromonas (nitration reaction)
The anti-nitration reaction process simply is expressed as follows:
(3)NO
3 -+3H→0.5N
2+H
2O+OH
-
(4)NO
2 -+6H→0.5N
2+H
2O+OH
-
Biological phosphate-eliminating is to utilize dephosphorization bacterial can under anaerobic discharge phosphorus, and aerobic condition is picked-up phosphorus down, and phosphorus is stored at endobacillary characteristic with the form of polymerization phosphorus, forms rich phosphorus sludge, reaches the purpose of dephosphorization from sewage to get rid of rich phosphorus sludge.The biological dephosphorize denitrification technology that has developed at present mainly contains following several: A
2/ O process sequence, SBR process sequence and oxidation ditch process series etc., wherein most typical representative is exactly A
2/ O technology, mostly other technologies are from this technological development.
Traditional denitrogenation dephosphorizing theory thinks that nitrification and denitrification can only be respectively carry out under aerobic and anoxia condition, dephosphorization process then must have aerobic/anaerobic alternate environment could the enrichment dephosphorization bacterial, reaches the purpose of dephosphorization.And some researchs have in recent years shown that not only nitrification and denitrification can take place simultaneously in a reactor, and under the anaerobic/anoxic alternate environment, polyP bacteria (PAOs) can be finished denitrification under anaerobic environment, reinforced phosphor-removing and while nitration denitrification process are realized simultaneously, even some denitrification phosphorus-collecting bacterium (DPB) need not experience the alternate environment of aerobic/anaerobism or anaerobic/anoxic, in anoxic reacter, realize N, remove in the time of P, illustrate that some PAOs have different phosphor-removing effects with DPB under different envrionment conditionss, may exist different dephosphorization mechanism, aerobic/anaerobic or anaerobic/anoxic alternation procedure are not unique biological phosphate-eliminating approach yet.The proposition of denitrification dephosphorization denitrification theory can solve the insurmountable contradiction of traditional dephosphorization and denitrification process self, saves the carbon source and the energy, improves Sewage treatment systems dephosphorization denitrogenation ability.Reduce sludge yield and working cost simultaneously, sewage disposal is developed towards sustainable strategic direction.
Although also have a lot of disputes about denitrification dephosphorization mechanism, some utilize denitrification dephosphorization phenomenon exploitation and the technology of coming has obtained remarkable progress.Especially mud in the recombining process-film coexistence is easier to realize denitrification dephosphorization denitrogenation (Liu Jinxu etc., 2003) simultaneously.Ren Nanqi etc. mention in China Patent No. 200610009602, and refluxing by nitrification liquid replaces A
2Mixed-liquor return among the O, cultivate the gathering denitrifying polyP bacteria, developed compound active sludge organism film synchronous denitrification dephosphorizing system, obtain stable operating performance, water outlet reaches the one-level B standard-required in the urban wastewater treatment firm pollutant emission standard, but continues to use traditional anaerobic-anoxic-aerobic process, the adding of biologic packing material mainly is in order to improve system's nitrification effect, flow process is relatively complicated, initial cost height, operational administrative difficulty.In fact, direction along liquid to carrier in the compound reactor, constituted the aerobic type that suspends, adhered to aerobic type, adhered to facultative type, adhered to multiple different motion ability, the type of respiration of anaerobic type, the microflora of nutrient type, for nitrifier, denitrifying bacteria and dephosphorization bacterial provide suitable life condition, control suitable operational conditions, utilize microbial film gathering denitrifying polyP bacteria, denitrogenation dephosphorizing is finished in same reactor.Because microbial film has aerobic zone, oxygen-starved area and anaerobic zone simultaneously, its inner denitrifying bacteria is when having phosphorus to exist, the nitrate radical that utilizes microbial film to produce in nitrifying process is made electron acceptor(EA), can realize denitrification dephosphorization denitrification, and denitrification process and dephosphorization process can be mutually promoted.Select rational reinforced phosphor-removing operation scheme, can realize little ecology of inner suitable denitrification phosphorus-collecting bacterium (DPAOs) growth of microbial film, thereby cultivating into dominant bacteria as the DPAOs domestication of final electron acceptor(EA) with nitrate radical, to promote the carrying out of denitrification dephosphorization denitrification (Dephanox) process, overcome polyP bacteria in traditional dephosphorization denitrification process (PAOs) and the competition of denitrifying bacteria, realize effective utilization carbon source in the water inlet to carbon source.
Summary of the invention
Main purpose of the present invention is to overcome the shortcoming of prior art, and a kind of composite biological film activated sludge denitrification dephosphorization denitrification method and reactor thereof are provided.
The present invention is primarily aimed at the defective and the present denitrification dephosphorization denitrification Study on Theory progress of existing technology, be intended to develop a kind of incorporate composite biological film activated sludge denitrification dephosphorization denitrification method and reactor thereof, this reactor can rationally utilize the characteristics of composite biological film-active sludge recombining process, especially utilize the effective gathering denitrifying polyP bacteria of biomembranous special construction, denitrogenation dephosphorizing is finished in a reactor, reduced the quantity of reaction tank; Only make circulating sludge enter anaerobic pond, effectively reduce the anaerobic pond volume,, when overcoming traditional technology denitrogenation and dephosphorization carbon source contradiction, weakened the influence of sludge age phosphor-removing effect by discharging the mode dephosphorization of excess sludge and anaerobic pond supernatant liquor; Finish denitrification dephosphorization in microbial film, denitrogenation and dephosphorization process can be mutually promoted, and realize all good situation of denitrogenation dephosphorizing.In addition,, thereby effectively save floor space, reduce working cost and construction investment because equipment can adopt integrated design.
The present invention adopts following technical scheme:
A kind of composite biological film activated sludge denitrification dephosphorization denitrification method is characterized in that: comprise the steps:
(1) anaerobic phosphorus release: the settling tank bed mud enters the sludge anaerobic pond, and polyP bacteria and denitrification phosphorus-collecting bacterium absorb a large amount of simple low molecule organic matters and store in vivo with the form of poly--beta-hydroxy alkanoic acid ester in the sludge anaerobic pond, discharge phosphorus simultaneously;
(2) denitrification dephosphorization: contain in the Aerobic Pond that the mud through anaerobic phosphorus release enters the anoxic pond that the plaited curtain type soft-filler is installed together with water inlet in the mixed solution of nitrate radical and the anaerobic pond, under the effect of stirring, the denitrification phosphorus-collecting bacterium is at the denitrifying phosphorus that absorbs simultaneously;
(3) aerobic nitrification and denitrification phosphorus-collecting: the anoxic pond water outlet enters the Aerobic Pond that the plaited curtain type soft-filler is installed, the polyP bacteria that microbial film is finished nitrated the time on it is finished suction phosphorus, simultaneously, because biomembranous special construction, a part of phosphorus in the solution is penetrated into microbial film inside, the denitrifying bacteria of microbial film inside utilizes the nitrated nitrate radical that produces, and finishes the further phosphorus that absorbs of denitrifying while, reaches the purpose of denitrification dephosphorization;
(4) solid-liquid separation: the mixed solution of fully finishing nitrated, denitrification, poly-phosphorus enters settling tank, finish solid-liquid separation, the supernatant liquor discharging, the precipitation bed mud enters the sludge anaerobic pond, and further be back to anoxic pond, add circulation next time, excess sludge discharges at post precipitation, and collects phosphorus-rich water at anaerobic pond.
Further, return current ratio of the mixed liquid is 100-200% in the described Aerobic Pond, and return sludge ratio is 50-100% in the anaerobic pond.
Further, the water temperature in each reaction tank is 20-30 ℃, and pH is 7-9.
Further, the activated sludge concentration in the described Aerobic Pond is 3-5g/l, and the activated sludge concentration in the sludge anaerobic pond is 5-10g/l.
A kind of composite biological film activated sludge denitrification dephosphorization denitrification reactor, this reactor is an integral structure, separate successively by three dividing plates and to be anoxic pond, Aerobic Pond, settling tank and sludge anaerobic pond, anoxic pond is provided with sewage import, mixed-liquor return inlet and mud reflux inlet, Aerobic Pond is provided with the mixed-liquor return outlet, settling tank is provided with supernatant liquor exhaust outlet and bed mud relief outlet, is provided with mud bypass outlet, phosphorus-rich water outlet and excess sludge discharge outlet in the sludge anaerobic pond; And, be provided with agitator by motor drives, rotating speed is adjustable in the middle part in sludge anaerobic pond, between mixed-liquor return outlet and mixed-liquor return inlet, be provided with CD-ROM drive motor, between mud bypass outlet and mud reflux inlet, be provided with CD-ROM drive motor, bottom in Aerobic Pond and anoxic pond is provided with aerator, the plaited curtain type soft-filler is installed on aerator, and its filling is than being 50%-70%.
Further, anoxic pond forward upper end is located in described sewage import, the bottom of Aerobic Pond is located in described mixed-liquor return outlet, and described supernatant liquor exhaust outlet and bed mud relief outlet are located at the top and the bottom of settling tank respectively, and the upper end at rear portion, sludge anaerobic pond is located in described phosphorus-rich water outlet.
Further, above described supernatant liquor exhaust outlet and phosphorus-rich water outlet, be respectively equipped with overflow groove.
Further, at the front end of described anoxic pond, Aerobic Pond and settling tank one flow deflector is installed all, this flow deflector is a flat board, and its upper end is equal with the top, pond, the lower end apart from the pond at the bottom of certain distance, this calculates definite apart from size according to the overcurrent water yield.
Further, this reactor is the integral type rectangular vessel.
Further, described aerator is along the pool wall single-sided arrangement of Aerobic Pond and anoxic pond.
By the above-mentioned description of this invention as can be known, compare with prior art, the present invention has following advantage:
1, structure of reactor compactness of the present invention, structure is succinct, and operation is very simple with maintenance, and manual request is few, easily is automated control.
2, the present invention forms independently anoxic pond, Aerobic Pond, settling tank and sludge anaerobic pond in a reactor, and can realize the collection of solid-liquid separation and phosphorus-rich water, has effectively saved floor space.
3, reactor of the present invention exists microbial film and active sludge simultaneously in anoxic pond and Aerobic Pond, thereby can improve biomass greatly, and then improves sewerage dephosphorization and denitrification effect, reduces construction investment and working cost.Simultaneously owing to the constructional feature of microbial film self in the recombining process and the restriction of oxygen diffusion, direction along liquid to carrier in the compound reactor, constituted the aerobic type that suspends, adhered to aerobic type, adhered to facultative type, adhered to multiple different motion ability, the type of respiration of anaerobic type, the microflora of nutrient type, for nitrifier, denitrifying bacteria and dephosphorization bacterial provide suitable life condition, control suitable operational conditions, utilize microbial film gathering denitrifying polyP bacteria, denitrogenation dephosphorizing is finished in same reactor.Because microbial film has aerobic zone, oxygen-starved area and anaerobic zone simultaneously, its inner denitrifying bacteria is when having phosphorus to exist, the nitrate radical that utilizes microbial film to produce in nitrifying process is made electron acceptor(EA), can realize denitrification dephosphorization denitrification, and denitrification process and dephosphorization process can be mutually promoted.The simultaneously biomembranous microorganism that can make the part anaerobic zone of coming off enters the aerobic environment of active sludge, and biomembranous attaching process also can make the microorganism in a part of aerobic environment enter the hypoxic/anaerobic environment.This shows, distinctive microorganic adhesion in the recombining process-process that comes off and biomembranous special construction, for the various microorganism species relevant with dephosphorization denitrogenation provide suitable living environment, impelling simultaneously, dephosphorization denitrogenation becomes possibility.Select rational reinforced phosphor-removing operation scheme, the dissolved oxygen of control treating processes, water inlet nutrition such as compares at factor, can realize the transition of inner anoxic of microbial film and anaerobic zone, can realize little ecology of inner suitable denitrification phosphorus-collecting bacterium (DPAOs) growth of microbial film, thereby cultivating into dominant bacteria as the DPAOs domestication of final electron acceptor(EA) with nitrate radical, to promote the carrying out of denitrification dephosphorization denitrification (Dephanox) process, overcome polyP bacteria in traditional dephosphorization denitrification process (PAOs) and the competition of denitrifying bacteria, realize effective utilization carbon source in the water inlet to carbon source.
4, the present invention compares with being both the technology of utilizing the denitrification dephosphorization principle to develop, has made full use of biomembranous special construction gathering denitrifying polyP bacteria, and flow process is simple relatively, is easy to control, can guarantee effluent quality preferably simultaneously.Existing technology based on the exploitation of denitrification dephosphorization principle, mostly belong to improvement to traditional dephosphorization and denitrification process, therefore all followed the dephosphorization pattern of anaerobic-aerobic and the denitrogenation pattern of anoxic denitrification to a great extent, just in the partial reaction device or the partial portion of reactor utilized the synchronous dephosphorization denitrogenation effect of denitrification phosphorus-collecting bacterium.Compare with traditional dephosphorization and denitrification process, these technologies are not simplified on flow process; On the contrary, for the function of painstakingly embodiment denitrification phosphorus-collecting bacterium and be provided with nitric nitrogen supernatant liquor tripping device, or many internal reflux measures, make flow process and operation become more complicated.In the compound denitrifying phosphorus removal technique of biological film activated sludge, only add biofilm packing at aerobic zone, its purpose mainly is to improve nitrification effect, and traditional aerobic-anoxic-anaerobic technique has still been continued to use in its technical process, and increased contact tank and nitrification liquid and refluxed, made flow process become complicated.The present invention utilizes biomembranous special construction gathering denitrifying polyP bacteria, strengthen the denitrification dephosphorization function of anoxic pond by mixed-liquor return, and the backflow of passing through anaerobic phosphorus release mud increases the quantity of anoxic pond denitrification phosphorus-collecting bacterium, simultaneously, only make precipitating sludge enter anaerobic pond, the volume of anaerobic pond be can save, construction investment and working cost reduced greatly.
5,, strengthen the denitrification dephosphorization function of anoxic pond by mixed-liquor return.
6, increase the quantity of anoxic pond polyP bacteria by the backflow of anaerobic phosphorus release mud.
7, only precipitating sludge is entered anaerobic pond, dwindle the anaerobic pond volume greatly, be beneficial to the collection of phosphorus-rich water.
8, by the circulation of anoxic, anaerobic and aerobic, can effectively improve sludge settling and dewatering.
9, dephosphorization of the present invention is to realize that by releasing phosphorus and getting rid of high phosphorous water therefore be not subjected to the influence of sludge age, high phosphorous water is easy to reclaim phosphorus by chemical method simultaneously.
In a word, a kind of composite biological film activated sludge denitrification dephosphorization denitrification method of the present invention and reactor thereof organically combine organic matter removal and biological denitrification dephosphorization denitrogenation, utilize biomembranous unique texture to realize denitrification dephosphorization denitrification, have unique structures and operation operation scheme, effectively overcome in the traditional technology denitrogenation and dephosphorization about the contradiction of mud age and carbon source competition, make the effect of denitrogenation and dephosphorization reach best simultaneously, be particularly useful for the municipal sewage treatment of low ratio of carbon to ammonium, phosphor-removing effect is splendid, and helps realizing the recycling of phosphorus.A kind of composite biological film activated sludge denitrification dephosphorization denitrification method of the present invention and reactor thereof both can be used for municipal sewage treatment separately and reach national comprehensive discharge standard; Also can use, realize the utilization again of municipal effluent with other technical combinations such as filtration, reverse osmosis; Not only be suitable for newly-built sewage work, especially be beneficial to the transformation of existing activated sludge process.
Description of drawings
Fig. 1 is the cross-sectional schematic of a kind of composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention;
Fig. 2 is the schema of a kind of composite biological film activated sludge denitrification dephosphorization denitrification method of the present invention.
Embodiment
A kind of composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention, with reference to Fig. 1, this reactor is the integral type rectangular vessel, by three dividing plates 5,8,15 separate successively and are anoxic pond a, Aerobic Pond b, settling tank c and sludge anaerobic pond d, anoxic pond a is provided with sewage import 1, mixed-liquor return inlet 3 and mud reflux inlet 26, Aerobic Pond b is provided with mixed-liquor return outlet 7, settling tank c is provided with supernatant liquor exhaust outlet 17 and bed mud relief outlet 11,12, be provided with mud bypass outlet 28 in the d of sludge anaerobic pond, phosphorus-rich water outlet 19 and excess sludge discharge outlet 25; And, be provided with agitator 22 by motor 18 drives, rotating speed is adjustable in the middle part of sludge anaerobic pond d, between mixed-liquor return outlet 7 and mixed-liquor return inlet 3, be provided with CD-ROM drive motor, between mud bypass outlet 28 and mud reflux inlet 26, be provided with CD-ROM drive motor, be provided with aerator 29 in the bottom of Aerobic Pond and anoxic pond, plaited curtain type soft-filler 30 is installed on aerator 29, and its filling is than being 50%-70%.Aerator 29 is respectively equipped with overflow groove 16,20 along the pool wall single-sided arrangement of Aerobic Pond b and anoxic pond a above supernatant liquor exhaust outlet 17 and phosphorus-rich water outlet 19.Front end at anoxic pond a, Aerobic Pond b and settling tank c is separately installed with flow deflector 4,6,27, is respectively equipped with dividing plate 9,10,13,14 in the bottom of settling tank c, is provided with dividing plate 23,24 in the bottom of anaerobic pond d, is convenient to the shunting of mud.
With reference to Fig. 2, adopt above-mentioned reactor simultaneously, a kind of composite biological film activated sludge denitrification dephosphorization denitrification working method of the present invention is as follows:
Embodiment 1:
Utilize intake pump, by the sewage import, to anoxic pond a, sewage enters Aerobic Pond b then with sewage transport; Aerobic Pond b is provided with the mixed-liquor return device, with a part of mixed-liquor return to anoxic pond a, remaining mixed solution enters settling tank c and carries out solid-liquid separation, supernatant liquor is discharged, bed mud enters anaerobic pond d, and a part of mud is discharged with the form of excess sludge, and a part of mud is back to anoxic pond a, mix with water inlet, and carry out phosphorus-rich water at anaerobic pond d and collect.Can after chemical treatment, mix after phosphorus-rich water is collected, reenter reactor with water inlet.
In the whole service process, keeping the water temperature in the composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention is 20-30 ℃, pH is 7-9, and wherein the activated sludge concentration in the Aerobic Pond b is 3-5g/l, and the activated sludge concentration in the anaerobic pond d is 5-10g/l.According to certain sludge loading and dephosphorization and denitrification effect, take a certain amount of flooding velocity and return sludge ratio.
Aerator by being laid in Aerobic Pond b and anoxic pond a bottom constantly circulates through aerobic, anoxic and anaerobic to Aerobic Pond b and anoxic pond a oxygen supply, reaches the purpose of removing organism and dephosphorization denitrogenation.
Enter that COD is 120-480mg/L in the sewage of composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention, TN (water outlet total nitrogen) concentration is 47~108mg/l, NH3-N (water outlet ammonia nitrogen) concentration is 42-95mg/l, TP (water outlet total phosphorus) concentration is 2-18mg/l, COD is 5-18mg/L in the sewage after the processing, TN concentration is 15~25mg/l, NH3-N concentration is 0-7mg/l, TP concentration is 1-4mg/l, average removal rate has reached 92% respectively, 67%, 92% and 64%, dephosphorization and denitrification effect is remarkable.
Embodiment 2
Utilize intake pump, by the sewage import, to anoxic pond a, sewage enters Aerobic Pond b then with sewage transport; Aerobic Pond b is provided with the mixed-liquor return device, with a part of mixed-liquor return to anoxic pond a, remaining mixed solution enters settling tank c and carries out solid-liquid separation, supernatant liquor is discharged, bed mud enters anaerobic pond d, and a part of mud is discharged with the form of excess sludge, and a part of mud is back to anoxic pond a, mix with water inlet, and carry out phosphorus-rich water at anaerobic pond d and collect.Can after chemical treatment, mix after phosphorus-rich water is collected, reenter reactor with water inlet.
In the whole service process, keeping the water temperature in the composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention is 20-30 ℃, pH is 7-9, and wherein the activated sludge concentration in the Aerobic Pond b is 3-5g/l, and the activated sludge concentration in the anaerobic pond d is 5-10g/l.According to certain sludge loading and dephosphorization and denitrification effect, take a certain amount of flooding velocity and return sludge ratio.
Aerator by being laid in Aerobic Pond b and anoxic pond a bottom constantly circulates through aerobic, anoxic and anaerobic to Aerobic Pond b and anoxic pond a oxygen supply, reaches the purpose of removing organism and dephosphorization denitrogenation.
Enter that COD is 110-580mg/L in the sewage of composite biological film activated sludge denitrification dephosphorization denitrification reactor of the present invention, TN concentration is 45~118mg/l, and NH3-N concentration is 38-96mg/l, and TP concentration is 2-20mg/l, COD is 5-20mg/L in the sewage after the processing, TN concentration is 20~30mg/l, and NH3-N concentration is 0-8mg/l, and TP concentration is 1-5mg/l, average removal rate has reached 95% respectively, 68%, 90% and 63%, dephosphorization and denitrification effect is remarkable.After connect the quartz sand filtration device, COD is 3-15mg/L in the water outlet, TN concentration is 15~240mg/l, NH3-N concentration is 0-5mg/l, TP concentration is 0.5-3mg/l.
Above-mentioned only is a specific embodiment of the present invention; but design concept of the present invention is not limited thereto; such as; sewage can be sent into simultaneously anoxic pond a and anaerobic pond b; other steps are the same; in a word, allly utilize this design that the present invention is carried out the change of unsubstantiality, all should belong to the behavior of invading protection domain of the present invention.