Method that a kind of constant water level sequencing batch active sludge is disposed of sewage and system thereof
Technical field
The present invention relates to method and system thereof that a kind of constant water level sequencing batch active sludge is disposed of sewage, belong to technical field of sewage.
Background technology
Existing treatment process simplified summary is as follows:
1, anaerobic-anoxic-aerobic activated sludge process
Anaerobic-anoxic-aerobic process (Anaerobic-Anoxic-Oxic) is the abbreviation of anaerobic-anoxic, aerobic biological denitrification dephosphorization process.Hereinafter to be referred as A
2/ O technology, its general flow chart sees Fig. 1 for details, and wherein 1 is water-in, the 2nd, anaerobic pond, the 3rd, anoxic pond, the 4th, aerobic (nitrated) pond, the 5th, second pond, the 6th, water outlet, the 7th, mixed-liquor return, the 8th, returned sluge, the 9th, excess sludge.
A
2The advantage of/O technology is that the nitre attitude oxygen that makes full use of in denitrification process in the nitrification liquid comes oxidation BOD
5, reclaimed the oxygen requirement of part nitration reaction, the basicity that anti-nitration reaction produced can partly compensate the basicity that nitration reaction consumes, therefore to contain the not high municipal effluent of nitrogen concentration can be not in addition exogenously added alkali regulate PH.This technology is the simplest dephosphorization and denitrification process in system, and total hydraulic detention time is less than other similar technology (as Pu of Baden dephosphorization and denitrification process); Under the condition of anaerobism (anoxic), aerobic alternate run, thread fungus can not breed in a large number, and the anxiety of no sludge bulking, SVI one value be less than 100, is beneficial to handle separating of back sewage and mud; The only light and slow stirring of need in anaerobism and anoxic section in service, working cost is low.Because anaerobism, anoxic, aerobic reaction pond branch are arranged, so its dephosphorization and denitrification effect is higher and stable.
A
2The shortcoming of/O method mainly is this technology itself.Denitrogenation need keep lower sludge loading, so that fully carry out nitrated, reach higher denitrification percent, and biological phosphate-eliminating need be kept higher sludge loading, keep bigger surplus sludge volume, so that reach phosphor-removing effect preferably, therefore in design, also need to take required measure to do further to optimize, to relax both contradiction; Simultaneously, need be provided with that mud refluxes and internal reflux pump house, independent secondary sedimentation basins etc. are handled structures, flow process is comparatively complicated, and power consumption is bigger, and management is inconvenient, and always floor space is bigger.
2, sequencing batch active sludge (Sequencing Batch Activated Sludge Process)
(the Sequencing Batch Reactor of sequencing batch reactor system; hereinafter to be referred as the SBR method) be the pioneer of sewage activated sludge biochemical treatment system; the working method that adopts when Arden in 1914 and Locket propose the notion of activated sludge process first is exactly step; yet up in recent years along with the monitoring and the develop rapidly of measuring technology; a large amount of new installations are developed out; dynamo-electric sequential control problem when particularly the development of computer automatic control system has fundamentally solved System Operation; this technology is just upgraded fully; and be recommended as a low investment by Environmental Protection Agency (US EPA); lower operational cost and maintenance cost, the environment protection novel of high benefit.
SBR method collection aeration, be deposited in a pond, and do not need second pond and mud refluxing unit.In this system, reaction tank is full of sewage at certain time intervals, with the delayed time system operation, handle one section preset time of back mixed solution precipitation after, from the pond, get rid of supernatant liquor.Typical SBR system is divided into: water-filling, reaction, precipitation, draining and leave unused 5 stages, its operation scheme as shown in Figure 2, wherein 10 is water-fillings, the 11st, reaction, the 12nd, precipitation, the 13rd, water port, the 14th, idle, the 15th, sequential, the 16th, water-filling stage, the 17th, step of reaction, the 18th, precipitate phase, the 19th, bleeding stage, the 20th, idle stage.
In the SBR treatment system, can adopt single pond formula and multi-tank type.This mainly decides according to the size of handling the water yield.Single pond formula promptly only has a sbr reactor pond, and with regard to whole process system, its water inlet is step.Multi-tank type, promptly there is two or more sbr reactors pond in total system, and its water inlet can hocket between each reaction tank, and with regard to overall system process, its water inlet is a continous way.
At the Wastewater Treated by Activated Sludge Process technical development initial stage, the operation of this charging and discharging type system has many difficulties, because control techniques prematurity still for step sewage water intake mode, can only be adopted the manually operated alternative, it brings very big inconvenience for the operational management of system.In multi-tank type SBR system, when sewage when a pond switches to another pond, operator note also different working stages.Because the monitoring technique level was lower at that time, batch process only can rely on manpower, because of city and the maximization of Industrial Wastewater Treatment trend, is replaced by continous way gradually in this method of the early stage of development again, intermittent type fails to be applied and develop, but this is absolutely not due to the shortcoming of technology itself.
Along with industrial automatic control technology high speed development, the automatic control system device of being convenient to operate occurs and is tending towards ripe, sewage oxygen supply equipment efficiency of oxygen supply improves, do not produce whipping appts that blocks aerating apparatus, excellent property and the exploitation of straining the water device that can stably discharge primary water, solved the technological difficulties that intermittent activated sludge process is used on engineering, made intermittent activated sludge process on engineering, enter the widespread use stage.
The SBR method is by oxygenation, and alternately changing of anoxic, anaerobism and deposition condition can be carried out dephosphorization denitrogenation and degradation of organic substances simultaneously in a reaction tank, and the multi-task such as solid-liquid separation, do not need to build in addition second pond and mud backflow facility, take up an area of and lack, investment and saving energy; But equipment and utilization rate of tank volume are lower, the dephosphorization and denitrification effect instability, and head loss is also bigger.
Summary of the invention
The objective of the invention is to propose method and the system thereof that a kind of constant water level sequencing batch active sludge is disposed of sewage, shortcoming at prior art, technology to sewage disposal makes improvements, stable to reach treatment effect, floor space is little, equipment and capacity utilization are higher, the purpose of investment and saving energy.
The method that the constant water level sequencing batch active sludge that the present invention proposes is disposed of sewage may further comprise the steps:
(1) make 10%~30% of process grid and settling pit pretreating sewage enter anoxic pond, remove the nitrate that brings in the returned sluge from sequencing batch pond in the anoxic pond, the volume ratio of the total water inlet of sludge back flow quantity and system is that reflux ratio is: 2~3: 1, and the residence time is 1.0~2.0 hours;
(2) make the sewage in the above-mentioned pre-anoxic pond enter anaerobic pond with 70%~90% of process grid and settling pit pretreating sewage, both mix, make polyP bacteria wherein absorb the volatile acid that is produced by the sewage hydrolyzing acidifying and discharge phosphorus, the residence time is 1.5~2.0 hours;
(3) above-mentioned sewage is flowed in the Aerobic Pond, make the organic matter degradation in the sewage, by the ammonia nitrogen in the nitration reaction removal sewage, by the phosphorus in the biological excessive absorption sewage of polyP bacteria, 5.0~7.0 hours reaction times;
(4) in the above-mentioned Aerobic Pond quite 100% of the total water inlet of system mixed solution flow into first sequencing batch pond, to replace in first sequencing batch pond and water outlet up to standard is discharged, during water outlet, excess sludge is discharged through mud-water separation;
(5) 300% of the total water inlet of suitable system mixed solution flows into second sequencing batch pond in the above-mentioned Aerobic Pond, carrying out mud refluxes, the volume ratio of the total water inlet of sludge back flow quantity and system is: 2~3: 1, return time is 1~1.4 hour, carrying out intermittence simultaneously stirs and aeration, reaction times is 1~1.4 hour, last quiescent setting, and the quiet heavy time is 0.6 hour.
The system that the constant water level sequencing batch active sludge that the present invention proposes is disposed of sewage comprises anoxic pond, anaerobic pond, Aerobic Pond, first sequencing batch pond and second sequencing batch pond; Described anaerobic pond is connected with Aerobic Pond, is provided with water-in and diving mixer in the anoxic pond; Described anaerobic pond is connected with Aerobic Pond, is provided with diving mixer in the anaerobic pond; Described Aerobic Pond is connected with first sequencing batch pond and second sequencing batch pond respectively; Described first sequencing batch pond and second sequencing batch pond are connected with anoxic pond by pump respectively, are respectively equipped with reflux pump, diving mixer and water port in first sequencing batch pond and second sequencing batch pond.
Method and system thereof that constant water level sequencing batch active sludge method of the present invention is disposed of sewage, its characteristics and advantage are:
1, floor space is little: relative A
2/ O technology, adopt constant water level sequencing batch active sludge art breading sewage sewage work's floor space little.Do not build preliminary sedimentation tank, second pond and backflow pumping plant in addition.By being the investigation of sewage work's floor space of 5~100,000 tons, draw following table to some day outputs:
|
City sewage treatment works project construction standard |
Constant water level sequencing batch active sludge technology |
A
2/ O technology
|
Floor space (m
2/m
3.d)
|
0.7~0.85 |
About 0.43 |
1~1.94 |
As can be seen from the above table, adopt the floor space ratio of the sewage work of constant water level sequencing batch active sludge technology to adopt A
2The sewage work of/O technology will lack a lot.The minimizing of floor space directly causes the minimizing of total investment of engineering, and the one, the land acquisition expense reduces, and the 2nd, the ground processing costs reduces.
2, processing efficiency height, stable: for SBR technology, constant water level sequencing batch active sludge technology has the dephosphorization and denitrification effect of efficient stable.The front end of constant water level sequencing batch active sludge process pool has oxygen-starved area one lattice and anaerobic zone one lattice, and the back is aerobic zone and SBR functional zone.The hydraulic detention time of oxygen-starved area and anaerobic zone has 2h respectively, and the reaction times is long, definite functions, and boundary is clearly demarcated.
Constant water level sequencing batch active sludge technology and SBR technology are not all intake and are reacted at precipitate phase, and mud under static state precipitates.And A
2The second pond of/O technology is water outlet while intaking, and mud is dynamically precipitating down, and clearly, the sedimentation effect of SBR technology and constant water level sequencing batch active sludge technology compares A
2/ O technology is good.
3, volume and plant factor height: constant water level sequencing batch active sludge technology and SBR technology all have the rhythmic reaction part, so both capacity utilizations and plant factor are all less than A
2/ O technology.By calculating, the capacity utilization in SBR pond is 50%, and the capacity utilization of constant water level sequencing batch active sludge technology is 75%, so the capacity utilization of constant water level sequencing batch active sludge technology is higher than SBR technology.
Next discusses plant factor, and the utilization ratio of straining wetting system and soil discharging facility of SBR technology is 25%, and the utilization ratio of miscellaneous equipment also has only 50%; And constant water level sequencing batch active sludge technology is lower than 100% except that batch process plant factor partly, and all the other usage ratio of equipment are 100%, so the plant factor of constant water level sequencing batch active sludge technology more is higher than SBR technology.
4, energy-conservation: the single pond of SBR technology is intermittently water outlet of intermittent water inflow, and there is discrepancy in elevation Δ H in the absolute altitude of straining when the water outlet absolute altitude is with water inlet after the water, is generally 1~2m, because this varying head exists, makes the lift height of last stage increase.Because oxygen transfer efficiency is relevant with the depth of water, and the depth of water is dark more, oxygen transfer efficiency is high more simultaneously.The SBR pool inner water strengthens deeply gradually, and oxygen transfer efficiency also is to increase gradually, and water level is constant all the time in the sequencing batch pond of constant water level sequencing batch active sludge technology, so oxygen transfer efficiency is also stable.From this two aspect relatively, the energy loss-rate SBR technology of constant water level sequencing batch active sludge technology is economized.
A
2/ O technology generally comprises two backflows, and the flow of external reflux is Q, (Q is biochemical partial design flow) general 6~7m of lift, and internal reflux is generally 3Q, the general 3~4m of lift; It is that partition wall refluxes that the mud of constant water level sequencing batch active sludge technology refluxes, and flow is 3Q, lift 1m, so constant water level sequencing batch active sludge technology is lower than A at the energy that is consumed aspect the mud backflow
2/ O technology.
5, easy maintenance: the water outlet of constant water level sequencing batch active sludge technology is strained hydrophone by the air weir, and normal dynamic component is the motorized valve on the blast main; The water outlet of SBR technology is by rocker-arm, telescopic and siphonic decant device, and normal dynamic component is the whole hydrophone of straining; A
2The second pond of O technology has scraping and sucking machine, and normal dynamic component also is whole scraping and sucking machine, also comprises the backflow facility.Therefore, aspect maintenance of the equipment, it is much simple that constant water level sequencing batch active sludge technology is wanted.
6, flexible operation: constant water level sequencing batch active sludge technology can be adjusted following parameter according to actual needs: 1) water entry; 2) sludge back flow quantity; 3) aeration time; 4) reaction time; 5) tolerance; It can be according to coming BOD in the water
5, TN, TP situation adjust running status, improve operating performance, reduce energy expenditure.
7, be convenient to fairly large sewage disposal: single pond processing power maximum of constant water level sequencing batch active sludge technology can reach 50,000 m
3/ d compares with SBR technology, can obviously reduce pond body quantity, thereby equipment and automatic control number of spots reduce, and running maintenance is easy.
8, can satisfy the requirement of subsequent disposal Continuous Flow: because therefore constant water level sequencing batch active sludge technology compare its easier can linking with follow-up advanced treatment for intaking continuously and continuous effluent with SBR technology.
Description of drawings
Fig. 1 is A in the prior art
2/ O general flow chart.
Fig. 2 is SBR operational mode figure in the prior art.
Fig. 3 is the constant water level sequencing batch active sludge process schematic representation of the Sewage treatment systems that proposes of the present invention.
Among Fig. 1~Fig. 3, the 1st, water-in, the 2nd, anaerobic pond, the 3rd, anoxic pond, the 4th, aerobic (nitrated) pond, the 5th, second pond, the 6th, water outlet, the 7th, mixed-liquor return, the 8th, returned sluge, the 9th, excess sludge, the 10th, water-filling, the 11st, reaction, the 12nd, precipitation, the 13rd, water port, the 14th, idle, the 15th, sequential, the 16th, water-filling stage, the 17th, step of reaction, the 18th, precipitate phase, the 19th, bleeding stage, the 20th, in the idle stage, 21 is first sequencing batch pond (straining the water stage), 22 is second sequencing batch pond (returned sluge/rhythmic reactions/quiescent setting stage), the 23rd, reflux pump, the 24th, residual sludge pump, the 25th, diving mixer.
Embodiment
The method that the constant water level sequencing batch active sludge that the present invention proposes is disposed of sewage, at first make through 10%~30% of grid and settling pit pretreating sewage and enter anoxic pond, remove the nitrate that brings in the returned sluge from sequencing batch pond in the anoxic pond, the volume ratio of the total water inlet of sludge back flow quantity and system is that reflux ratio is: 2~3: 1, and the residence time is 1.0~2.0 hours; Make the sewage in the anoxic pond enter anaerobic pond with 70%~90% of process grid and settling pit pretreating sewage, both mix, and make polyP bacteria wherein absorb the volatile acid that is produced by the sewage hydrolyzing acidifying and discharge phosphorus, and the residence time is 1.5~2.0 hours; Sewage is flowed in the Aerobic Pond, make the organic matter degradation in the sewage, by the ammonia nitrogen in the nitration reaction removal sewage, by the phosphorus in the biological excessive absorption sewage of polyP bacteria, 5.0~7.0 hours reaction times; In the Aerobic Pond quite 100% of the total water inlet of system mixed solution flow into first sequencing batch pond, to replace in first sequencing batch pond and water outlet up to standard is discharged, during water outlet, excess sludge is discharged through mud-water separation; 300% of the total water inlet of suitable system mixed solution flows into second sequencing batch pond in the Aerobic Pond, carrying out mud refluxes, the volume ratio of the total water inlet of sludge back flow quantity and system is: 2~3: 1, return time is 1~1.4 hour, carrying out intermittence simultaneously stirs and aeration, reaction times is 1~1.4 hour, last quiescent setting 0.6 hour.
The system that the constant water level sequencing batch active sludge that the present invention proposes is disposed of sewage, its flow process comprises anoxic pond 3, anaerobic pond 2, Aerobic Pond 4, first sequencing batch pond 21 and second sequencing batch pond 22 as shown in Figure 3.Anoxic pond 3 is connected with Aerobic Pond 2, is provided with water-in 1 and diving mixer 25 in the anoxic pond.Anaerobic pond 2 is connected with Aerobic Pond 4, is provided with diving mixer 25 in the anaerobic pond.Aerobic Pond 4 is connected with first sequencing batch pond 21 and second sequencing batch pond 22 respectively.First sequencing batch pond 21 and second sequencing batch pond 22 are connected by reflux pump with anoxic pond 3 respectively, are respectively equipped with reflux pump 23, diving mixer 25 and water port 13 in first sequencing batch pond and second sequencing batch pond.
The system that above-mentioned constant water level sequencing batch active sludge is disposed of sewage is the modified version SBR technology of a kind of continuous water inlet, continuous effluent, permanent water level.This technology is made up of placed in-line anoxic, anaerobism, aerobe reaction tank (being called for short continuous pond) and two the mud backflows that hocket, rhythmic reaction, quiescent settings in the middle of being positioned at of a series of continuous water inlets, continuous effluent, permanent water level and the sequence batch (reaction tank (abbreviation sequencing batch pond) that replaces the both sides symmetric arrangement of water outlet, with Continuous Flow A
2/ O technology and intermittent flow SBR technology organically combine, and by anoxic in the continuous pond, anaerobism, aerobic alternation procedure, remove organism and nitrogen phosphorus, main further denitrogenation and the solid-liquid separation process of realizing in the sequencing batch pond.Water outlet is mainly discharged by water inlet displacement overflow in the sequencing batch pond, therefore keeps the sequencing batch pond water level constant.In reaction process, sequencing batch pond is constantly to continuous pond returned sluge, with the mud that keeps the entire reaction system to have equilibrium concentration.Each reaction member has two sequencing batch ponds, and in each reaction time, the sewage of handling is alternately discharged from two sequencing batch pond overflows, realizes continuous effluent.
In the said system, be positioned at the continuous pond of intermediary and be respectively anoxic pond, anaerobic pond and Aerobic Pond.This 3 pond series operation, similar improvement inversion A
2/ O Sludge System, wherein all operations continuously of all devices.The effect of anoxic pond is to remove the nitrate that is mainly brought by returned sluge, enters anaerobic cell to prevent nitrate, and what influence PAOs releases the phosphorus effect.Simultaneously, the sewage that enters removes small part (general 20%) and enters anoxic pond to provide denitrification required carbon source, and most of raw waste water (general 80%) then enters anaerobic pond, provides PAOs to release the required volatile acid of phosphorus by acidication.In main aeration tank, most of organic matter degradation, nitration reaction and biological excessive suction phosphorus are all finished at this.This technology is arranged symmetrically in first and second sequencing batch ponds of both sides, continuous pond, the functional cycle exchange: straining water during the stage when a pond wherein, another pond is then carried out mud backflow, rhythmic reaction and quiescent setting (finishing the solid-liquid separation of treat effluent and active sludge) successively; Vice versa.When sequencing batch pond was strained water, treat effluent was replaced discharge continuously by this pond.Displacement is strained the water time and is generally 2hr; This moment, an other sequencing batch pond then carried out mud backflow, rhythmic reaction and quiescent setting.When carrying out returned sluge, reflux pump in this sequencing batch pond, mixing equipment and aerating system start, a cycle of operation on the inherence, pond is back to anoxic pond as straining water lattice time institute cumulative sludge pump, return time is generally 1.2hr, and maximum reflux ratio is generally 3: 1. returned sluge the time, the aerating system in this pond can be opened and can close, or the time close when opening, carry out rhythmic reaction, the reaction times is generally 1.4hr, with the nitric efficiency of optimization system.After returned sluge finishes, the reflux pump shutdown this pond in, after rhythmic reaction is finished, aeration and mixing equipment shutdown, thereby for treat effluent with created one and the similar quiescent setting condition of typical SBR separating of active sludge, the quiet heavy time is generally 0.6hr.During straining water, regularly excess sludge is discharged with pump.Quiescent setting is strained the water lattice and is got ready for this pond was transformed in next cycle of operation.
The process design parameter of embodiments of the invention is as follows:
Mud age: θ c=10~12d, overall yield coefficient: Yt=0.8~1.1kgTSS/kgBOD
5, sludge loading: Ls=0.1~0.15kgBOD
5/ (kgMLSSd), reflux ratio: R=300%, sludge concentration (MLSS): X=2.5~4.5g/L, oxygen requirement: O
2=1.3~1.8kgO
2/ kgBOD, preface is criticized lattice long-width ratio 〉=3: 1, the depth of water between 5~6 meters, processing efficiency: BOD
5: 85~95% TP:60~80% TN:60~80%.