With the granule sludge is two mud technologies of medium short-cut denitrification dephosphorization and device
Technical field
Technical field under the claimed technical scheme is: nitrogenous, phosphorus eutrophication technical field of sewage; relate to a kind of nitrogen efficiently, phosphorus sewage water treatment method; solve sewage denitrification and dephosphorization effect instability, water outlet suspension content height and the lower problem of compliance rate, be applicable to low C/N wastewater treatment.
Background technology
Nitrogen, phosphorus pollute the body eutrophication problem that causes and always are one of subject matter that countries in the world face, and also are the difficult point and the emphasis of water treatment.Denitrogenation dephosphorizing must independently be finished by the denitrifying bacteria of obligate and the polyP bacteria of obligate respectively in traditional denitrogenation dephosphorizing mechanism, and need relate to nitrated, denitrification, releases phosphorus, inhales a plurality of biological processes such as phosphorus.Though obtained some achievements based on the sewage treatment process that traditional denitrogenation dephosphorizing theory is developed, but also exist some drawbacks, mainly show: the requirement that the physiological habit of this three quasi-microorganism of (1), nitrifier, denitrifying bacteria and polyP bacteria reaches envrionment conditions has nothing in common with each other, especially aspect sludge age control, become these three kinds of microorganisms of mix suspending growth under best separately environment, to grow, thereby can't farthest bring into play separately processing power, make process result degrades, simultaneity factor spoil disposal be difficult to control; (2), since sanitary sewage COD/TN low, denitrifying bacteria and polyP bacteria exist competition in the utilization to carbon source; (3), the control problem of anaerobic zone nitrate content, the dephosphorization and denitrification process a great problem that need study and solve synchronously at present especially.Because the existence of anaerobic zone nitrate, denitrifying bacteria can be competed organic substrate in the sewage with polyP bacteria, and has precedence over polyP bacteria and utilize these organic substrates to carry out denitrification; On the other hand, the existence of nitrate also can be carried out denitrification as electron acceptor(EA) by the utilization of part polyP bacteria, thereby influences it to organic fermentation and acid effect; (4), excess sludge production is big.These reasons all make the removal of nitrogen and phosphorus become the aspect of opposition contradiction, make water outlet ammonia nitrogen, TN and TP remove not thorough, nitrogenous, phosphorus eutrophication sewage treating efficiency is low, the treatment time is long, energy consumption is high, and the denitrogenation dephosphorizing effect is unstable and compliance rate is lower.For this reason, forefathers have also done some effort, as add carbon source and change flow process etc., but these methods have increased the waste of the energy.
The proposition of denitrification phosphorus-collecting bacterium theory is that denitrogenation dephosphorizing has been raised new chapter, and synthetic PHB is an internal carbon source during promptly with anaerobism, is electron acceptor(EA) in the anoxic section with nitrate or nitrite, realizes synchronous denitrification dephosphorizing.Compare with traditional denitrification dephosphorization technique and can save the 50%COD consumption, 30% aeration rate, 50% excess sludge production.Therefore denitrifying phosphorus removal technique is regarded as a kind of sustainable sewage treatment technique.The continuous flow double sludge denitrification dephosphorization technique is according to the denitrifying phosphorus removing bacteria theory, taken all factors into consideration the requirement of biological carbon and phosphorous removal to envrionment conditions, made full use of the physiological characteristic of denitrifying bacteria and nitrifier, and a kind of improvement technology that puts forward has solved some problems of above-mentioned single-stage mud technology existence in service.Yet this technology is because reaction carriers is a floc sludge, intermediate sedimentation pond mud-water separation effect is undesirable, mud behind the anaerobic phosphorus release will be back to the oxygen-starved area and participate in inhaling phosphorus reaction, inevitably the part ammonia nitrogen in the sewage together is flowed to the oxygen-starved area, and this part ammonia nitrogen is owing to obtaining the nitrated high shortcoming of ammonia nitrogen concentration in the water outlet that exists.Aeration tank after wanting to remove remaining ammonia nitrogen and need adding one again, so this technology exists the high problem of technical process complexity, capital construction and working cost.
Summary of the invention
The present inventor is through long-term exploration research, in conjunction with granule sludge technology, short distance nitration technology and denitrification dephosphorization technological development a kind of be medium anaerobic/anoxic and nitrated pair of mud short-cut denitrification dephosphorization denitrogenation novel process with the granule sludge.This technology is cultivated short distance nitration granule sludge and denitrification dephosphorization granule sludge respectively by two sbr reactor devices.The short distance nitration granule sludge is controlled at NO with ammonia oxidation
2 -In-N the stage, (DPAO) provides electron acceptor(EA) for the denitrification phosphorus-collecting bacterium; Denitrification granular sludge moves in the anaerobic/anoxic mode, and in the anaerobism section, the synthetic PHB of the organism in the former water is stored in the polyP bacteria body, has stored carbon source for anoxic section denitrification, and promptly " carbon is dual-purpose " realized simultaneously with NO
2 --N is the denitrification denitrogenation of electron acceptor(EA) and inhales phosphorus.
This technology becomes continuous flow double sludge technology and is piston-flow process, simplified technical process, reduced by an intermediate sedimentation pond, also reduced by a cover mud return-flow system and a sludge drainage system, reduce capital construction cost and working cost, also increased the processing power and the operation stability of system simultaneously.Simultaneously microorganism autoflocculation principle is applied in the reactive system; realize granular sludge; give full play to the heavy speed of granule sludge fast, active high, structure is closely knit, microorganism concn and volumetric loading advantages of higher; simplify the separation and the scavenging process of water outlet; increased the processing water yield and draining ratio; make anaerobic/anoxic SBR after anaerobic stages in the DPAO mud remaining ammonia nitrogen amount reduce, ammonia nitrogen can not enter nitrator water outlet ammonia nitrogen problem of higher in two sludge systems of common intermittent type and the continuous flow double sludge system thereby solved.
The present invention is characterized in that:
(1) be medium with the granule sludge, given full play to that the heavy speed of granule sludge is fast, mud-water separation is effective, the reactor draining is than advantages of higher, reaction efficiency improves, reactor volume dwindles;
(2) the denitrification dephosphorization process is with NO
2 --N is as electron acceptor(EA), with two of denitrification denitrogenation and dephosphorization independently process organically combine, utilizing the interior PHB of born of the same parents in " carbon is dual-purpose " mode is that the carbon source and the energy carry out synchronous denitrification dephosphorizing, make DPAO finish excessive suction phosphorus and denitrification simultaneously and reach the dual purpose of denitrogenation dephosphorizing, well realized the saving of the carbon source and the energy and the decrement of excess sludge;
(3) be intermittent type by the operation scheme that changes the continuous flow double sludge denitrification dephosphorization system simultaneously, reduced by an intermediate sedimentation pond, also reduce by a cover mud return-flow system and a sludge drainage system, simplified technical process.
The present invention is the two mud process units of medium short-cut denitrification dephosphorization with the granule sludge, comprises raw water tubes 1, water tank inlet 2 successively, and water intaking valve 3 is characterized in that: also comprise the anaerobic/anoxic sbr reactor device 5 that connects by pipeline successively, intermediate water tank 6; Short distance nitration sbr reactor device 9, reflux tank 10; Intermediate water tank 6 connects short distance nitration sbr reactor device 9, and reflux tank 10 connects anaerobic/anoxic sbr reactor device 5; Be provided with whipping appts in anaerobic/anoxic sbr reactor device and the short distance nitration sbr reactor device, anaerobic/anoxic sbr reactor device is provided with water shoot 4; Be provided with aerating apparatus in the short distance nitration SBR; Throw in the granule sludge with denitrification dephosphorization function of having tamed in the anaerobic/anoxic sbr reactor device 5, throw in the granule sludge with short distance nitration function of having tamed in the short distance nitration sbr reactor device 9.
The principle of work and the process of invention:
The present invention's granule sludge technology that has been coupled, the short distance nitration technology, the denitrification dephosphorization technology adopts two placed in-line sbr reactor devices, has realized that the synchronous high-efficiency of nitrogen, phosphorus is removed.
The present invention is the two mud technologies of medium short-cut denitrification dephosphorization with the granule sludge, it is characterized in that: be divided into following 3 steps:
(1) cultivates denitrification dephosphorization granule sludge and short distance nitration granule sludge;
(2) throw in the granule sludge with denitrification dephosphorization function of having tamed in the anaerobic/anoxic sbr reactor device 5, throw in the granule sludge with short distance nitration function of having tamed in the short distance nitration sbr reactor device 9.
(3) coupling of denitrification dephosphorization granule sludge and short distance nitration granule sludge:
3.1 the anaerobic phosphorus release stage: adopt instantaneous water intake mode to add sanitary sewage in anaerobic/anoxic sbr reactor device, stir simultaneously, control pH value is 7.5-8.5; This stage is finished the removal of COD, the release of phosphorus and the storage of PHB, behind the anaerobic phosphorus release, and precipitation, the sewage that contains ammonia nitrogen and rich phosphorus is pumped in the short distance nitration sbr reactor device through intermediate water tank;
3.2 the short distance nitration stage: the control dissolved oxygen is 7.5-8.0 at 1.0mg/L and pH value, the sewage that contains ammonia nitrogen and rich phosphorus from anaerobic/anoxic sbr reactor device is further degraded and the short distance nitration effect in short distance nitration sbr reactor device generation residual organic substances, and ammonia nitrogen is oxidized to nitrite.After the short distance nitration effect finished, precipitation was carried out mud-water separation, contains rich phosphorus and nitrite in the supernatant liquor.
3.3 anoxic denitrification is inhaled the phosphorus stage: the supernatant liquor of short distance nitration sbr reactor device pumps in the anaerobic/anoxic sbr reactor device through reflux tank.In this stage, the denitrification phosphorus-collecting bacterium utilizes the nitrite in the supernatant liquor to inhale phosphorus as the intracellular PHB of electronics oxidation from waste water, finishes synchronous denitrification dephosphorizing, after reaction finishes, and sedimentation and drawing.
The present invention design with the granule sludge be medium short-cut denitrification dephosphorization denitrogenation sewage treatment process compared with prior art, have following advantage:
(1) synchronous denitrification dephosphorizing is effective, the water outlet ammonia nitrogen is less than 3mg/L, total nitrogen is less than 10mg/L, total phosphorus is less than 0.5mg/L, in the pollution exhaust criteria of country's promulgation in 2002, to the strict emission control standards of town sewage be the water outlet ammonia nitrogen less than 5mg/L, total nitrogen less than 15mg/L, water outlet ammonia nitrogen of the present invention, total nitrogen and total phosphorus are far below the pollution exhaust criteria of country's promulgation.
(2) this technology is medium with the granule sludge; microorganism autoflocculation principle is applied in the reactive system; realize granular sludge; give full play to the heavy speed of granule sludge fast, active high, structure is closely knit, microorganism concn and volumetric loading advantages of higher; simplify the separation and the scavenging process of water outlet; increase the processing water yield and draining ratio, can remedy the deficiency of traditional cotton-shaped active sludge to a certain extent.
(3) this technology change continuous flow double sludge technology is piston-flow process, has simplified technical process, has reduced capital construction cost and working cost, thereby has increased the processing power and the operation stability of system.
(4) the COD consumption is few.COD farthest is used for the synthetic of PHB by DPAO in the anaerobism section, because the special arrangement of this technology, synthetic PHB is used to finish denitrification simultaneously and inhales phosphorus by DPAOB, has realized the denitrogenation dephosphorizing of system by the mode of " carbon is dual-purpose ";
(5) power consumption of saving oxygen supply aeration.Short distance nitration and denitrification dephosphorization technology are combined characteristics such as on the one hand short-cut denitrification has the oxygen requirement of reduction, reduces the carbon source dosage, technical process is short, reaction efficiency improves, reactor volume dwindles; On the other hand, the electron acceptor(EA) that nitrite serves as dephosphorization carries out denitrification dephosphorization, have the cycle of operation short, inhale phosphorus and put advantages such as phosphorus speed is fast.
(6) this technology is two sludge systems, grow in each comfortable own adapt circumstance of nitrifier and denitrification phosphorus-collecting bacterium, this has created a stable environment not only for the slower nitrifier of growth velocity, increase the biomass of nitrifier in the system and improved nitrated rate, also shortened hydraulic detention time and reduced the volume of reactor, nitration reaction no longer has been the restrictive factor of technology operation; On the other hand, both separation have solved the polyP bacteria requirement different to sludge age with nitrifier in the traditional technology, two kinds of floras are all grown in best separately environment, help keeping the stability of dephosphorization denitrogenation system operation more, and the controllability of system also is improved;
(7) sludge yield is low, reduces mud subsequent disposal expense.
Description of drawings
Fig. 1 is that the present invention is the pilot system synoptic diagram of the short-cut denitrification dephosphorization denitrogenation sewage water treatment method of medium with the granule sludge.
Embodiment
Describe this technology in detail below in conjunction with drawings and Examples:
The cultivation of stage i denitrification dephosphorization granule sludge.
Culturing sludge is in three stages: in the 1st stage, inoculation actual sewage treatment plant phosphorus removal property is mud preferably, adds simulated wastewater, moves in the mode of aerobic/anaerobic (A/O) alternate run, realizes automatic control to operational process by program timer.Move 4 cycles every day, each cycle 6h, each cycle comprises 8min water inlet, and the 2.5h anaerobism stirs, the 3h aerobic aeration, sedimentation time is successively decreased and 2min idle mixing time step by step from 20-1min.Each cycle draining 7L, water inlet 7L, the draining ratio is 7/10, sludge age 9d, hydraulic detention time is approximately 8.5h, and temperature is 25 ± 0.5 ℃, and the water inlet pH regulator is at 7.5-8.0, and aerobic stage dissolved oxygen (DO) is controlled at 4-6mg/L.Through 120 cycles (30 days), system finishes granulating, and dephosphorizing rate remains on more than 90%, thinks that the granule sludge with dephosphorization ability cultivates successfully.The 2nd stage, granule sludge is induced the granule sludge that becomes to have the denitrification dephosphorization ability, promptly finish the back and add a certain amount of nitric nitrogen (KNO in anaerobism
3), aerobic section is become the anoxic section, only stir, aeration not, other operating parameters are constant.Move 11 days, total nitrogen remove reach more than 85%, tp removal rate reaches more than 95%, thinks that promptly the denitrification dephosphorization granule sludge induces successfully.The 3rd stage became real life sewage with manual simulation's waste water, tamed 20 cycles (5 days), the condition of water quality of the basic real life sewage of denitrification phosphorus-collecting granule sludge.Between domestication, regularly detect influent quality and microorganism and release, put the phosphorus situation, in time adjust operating parameter (as load according to these data, C/P, C/N, sludge age etc.), as the COD of intaking is low can't satisfy polyP bacteria and release the phosphorus needs time, can suitably add carbon sources such as acetate or propionic acid and replenish COD.
The operating parameter in this stage is: water inlet COD is controlled at 400-600mg/L, PO
4 3-Between-P control the 6-10mg/L, sludge concentration (MLSS) is controlled between the 2.0-2.5g/l, and pH regulator is between 7.5-8.0, and temperature is controlled at 25 ± 0.5 ℃.Hydraulic detention time is approximately 8.5h, sludge age 9d, and the draining ratio is 7/11.Aerobic stage dissolved oxygen (DO) is controlled at 4-6mg/L.
The cultivation of stage ii short distance nitration granule sludge
The cultivation of short distance nitration granule sludge divides 2 stages: in the 1st stage, inoculation sewage work nitrification effect is active sludge preferably, adopts manual simulation's waste water to start the sbr reactor device, by the automatic control of program timer realization to operational process.Move 6 cycles every day, each cycle 4h comprises 8min water inlet, the 3.5h aerobic aeration, and sedimentation time is successively decreased and 2min idle mixing time from 15-1min.Aeration rate is constant in 0.3m
3/ h, each cycle draining 7L, water inlet 7L, the draining ratio is 7/11, and hydraulic detention time is approximately 6h, and temperature remains on 25 ± 0.5 ℃, and pH is controlled between the 7.5-8.5.Between incubation period, influent ammonia nitrogen progressively is increased to 200mg/L from 50, improves constantly ammonia nitrogen loading, and purpose is to improve the ratio that nitrobacteria accounts for full bacterium, in time stops aeration with time control after the ammonia nitrogen oxidation finishes, and ammonia oxidation is controlled at NO
2 -In the stage, realize short distance nitration.By the settling time of progressively successively decreasing, outside the mud discharge system that settling property is bad, impel the formation of granule sludge.In time observe the kenel of mud change with microscope, detect effluent quality and nitrite accumulation rate, cultivate through 180 cycles (30 days), ammonia-N removal rate reaches more than 90% and the accumulation rate of nitrite reaches more than 85%, and stable, think that the short distance nitration granule sludge cultivates successfully.The 2nd stage, to manually join simulated wastewater and change real life sewage into, through 30 cycles (5 days) domestication, ammonia nitrogen removal frank reaches more than 98% and the accumulation rate of nitrite reaches more than 90%, and stable, think that the short distance nitration granule sludge of processing real life sewage is cultivated successfully.
The operating parameter in this stage is: water inlet COD is about 400mg/L, and ammonia nitrogen progressively is increased to 200mg/L from 50, and sludge concentration (MLSS) is controlled between the 2.0-2.5g/l, and pH regulator is between 7.5-8.5, and temperature is controlled at 25 ± 0.5 ℃, and aeration rate is constant in 0.3m
3/ h.Hydraulic detention time is approximately 5.7h, sludge age 7d, and the draining ratio is 7/11.
The coupling of stage iii denitrification dephosphorization granule sludge and short distance nitration granule sludge describes in detail below in conjunction with accompanying drawing:
The at first former water of I water inlet enters into water tank inlet 2 through raw water tubes 1, opens water intaking valve 3, starts water pump pending waste water is injected anaerobic/anoxic sbr reactor device 5, and when reaching liquid level, water pump is out of service;
The II anaerobism stirs water inlet and finishes, and agitator starts, and carries out anaerobic reaction.The denitrification phosphorus-collecting bacterium absorbs a large amount of organism, and is stored in the body with the form of PHB, discharges a large amount of phosphorus simultaneously;
Stop to stir after III precipitation anaerobism finishes, precipitate, precipitation obtains to be rich in the supernatant liquor of ammonia nitrogen and phosphorus.Opening water discharge valve is added to supernatant liquor in the intermediate water tank 6;
The reaction of IV short distance nitration starts water pump, and the supernatant liquor that is rich in ammonia nitrogen and phosphorus is injected in the short distance nitration sbr reactor device 9, and gas blower 8 starts, the beginning aeration, and remaining organism is further degraded, and ammonia nitrogen is oxidized to nitrite;
After V precipitates nitrated end, stop aeration, stirring, precipitate, contain rich phosphorus and nitrite in the supernatant liquor that precipitation obtains, enter reflux tank 10 through water discharge valve;
The VI anoxic denitrification reacts the sewage that contains rich phosphorus and nitrite in the reflux tank 10, is injected into through water pump and carries out the anoxia stirring reaction in the anaerobic/anoxic sbr reactor device 5, and DPAO is an electron donor with the PHB that stores in the body, with the NO in the nitrification liquid
2 -Be electron acceptor(EA), finish denitrification denitrogenation and the effect of excessive suction phosphorus;
When the VII precipitin reaction finishes, discharge a certain amount of mud mixed liquid and keep suitable sludge age, then precipitation;
The supernatant liquor of the final post precipitation of VIII draining is discharged from water shoot 4 as treat effluent;
The idle draining of IX finishes to begin to be defined as lay-up period to next cycle.
X repeats above water inlet, anaerobism stirring, precipitation, short distance nitration, precipitation, anoxic denitrification, precipitation and drainage procedure, make total system be in anaerobism, aerobic, anoxic alternative state all the time, intermittent water inflow and water outlet, and when each end cycle, regularly discharge remaining granule sludge.The operating parameter that with the granule sludge is the short-cut denitrification dephosphorization denitrogenation Sewage treatment systems of medium is: water inlet COD=260-600mg/L, NH
4 +-N=20~80mg/L, TP=5.0-20.0mg/L, water inlet pH is controlled between the 7.5-8.0, and sludge concentration MLSS is controlled at 2.0-2.5g/L, and the DO of short distance nitration granule sludge SBR is controlled at about 1.0mg/L.When being the electron acceptor(EA) denitrification dephosphorization denitrification with the nitrite, should note the concentration of nitrite in the anaerobic/anoxic sbr reactor device solution and the relation of pH, can add suitable acid-alkali accommodation pH, the concentration of the free nitrous acid of control is at 0.002HNO
2Below-N the mg/L, guarantee that the nitrite that enters among the anaerobic/anoxic SBR can not produce inhibition to denitrifying phosphorus uptake, therefore anaerobism the control of the pH of anoxic SBR when anoxic is moved can not be low excessively, should remain between the 7.5-8.5, suppress to prevent that too high free nitrous acid from producing denitrifying phosphorus uptake.
Embodiment 1:
With the real life sewage of certain university dependents' district discharging as former water, water inlet pH=7.8-8.0, COD=260~350mg/L, NH
4 +-N=20~40mg/L, TP=5.0-10.0mg/L.The operating parameter of anaerobic/anoxic sbr reactor device and short distance nitration sbr reactor device is identical when cultivating.Raw waste water enters in the anaerobic/anoxic sbr reactor device, finishes the release of phosphorus, and post precipitation enters and carries out nitration reaction in the short distance nitration SBR.Short distance nitration SBR nitrite accumulation rate remains on 80-90%, and nitrite concentration is at 12-30mg/L after the nitrated end.The supernatant liquor that contains nitrite is back in the anaerobic/anoxic sbr reactor device and carries out the denitrification synchronous denitrification dephosphorizing.Under 25 ℃ of the room temperatures, pH maintains 7.7-8.0 when utilizing pH transmitter control anaerobic/anoxic SBR denitrifying phosphorus uptake, and its free nitrous acid concentration is 0.44 * 10
-3-1.7 * 10
-3N mg/L is less than inhibition concentration 2.0 * 10
-3N mg/L can not produce restraining effect to denitrifying phosphorus uptake.Whole process water inlet 7L, draining 7L, the draining ratio is 7/11, the SRT of anaerobic/anoxic sbr reactor device is 9-10d, COD, NH
4 +The clearance of-N and TP can maintain about 95%, 95% and 90%.
Embodiment 2:
, add an amount of tap water dilution or add glucose, NH as former water with the real life sewage of certain university dependents' district discharging
4Cl or K
2HPO
4To reach different COD, ammonia nitrogen and total phosphorus value (COD=400-600mg/L, NH
4 +-N=50~80mg/L, TP=10.0-20.0mg/L).The operating parameter of anaerobic/anoxic sbr reactor device and short distance nitration sbr reactor device is identical when cultivating.Raw waste water enters in the anaerobic/anoxic sbr reactor device, finishes the release of phosphorus, and post precipitation enters and carries out nitration reaction in the short distance nitration SBR.Short distance nitration SBR nitrite accumulation rate remains on 80-90%, nitrated end back nitrite concentration is at 42-70mg/L, pH maintains about 8.0-8.2 when utilizing pH transmitter control anaerobic/anoxic SBR denitrifying phosphorus uptake, and under 25 ℃ of the room temperatures, its free nitrous acid concentration is 1.0 * 10
-3-1.6 * 10
-3N mg/L is less than inhibition concentration 2.0 * 10
-3N mg/L can not produce restraining effect to denitrifying phosphorus uptake.Water inlet 7L, the SRT of poly-phosphorus sludge is 9-10d, COD, NH
4 +The clearance of-N and TP can maintain about 90%, 92% and 93%.