A kind of method of Sewage Biological Treatment strengthened denitrification and device
Technical field
The present invention relates to a kind of method of Sewage Biological Treatment strengthened denitrification and device, particularly be hydrolyzed acidification to mud after extracellular polymeric dissolves again, part is tamed into without the biological sludge that extracellular polymeric dissolvingization processes and is suitable to decompose extracellular polymeric solute, the high carbon-nitrogen ratio, the material of easily biological-degradable that discharge are back to, as the carbon source of sewage water denitrification, the method that bio-denitrifying sewage processes system, belong to water technology and field of Environment Protection.
Background technology
Along with day by day appearing suddenly of body eutrophication problem, the raising of Public Environmental Awareness, sewage water denitrification problem becomes the focus of extensive concern in water pollution control. The nitrogen discharged standard of strict sewage has been formulated in increasing countries and regions. Typical bio-denitrification technology is by anaerobism, anoxia, the operation such as aerobic, makes to occur in sewage nitrated, the nitrate denitrification of ammonia nitrogen, it is achieved the reduction of water outlet N content, and denitrification process needs to consume certain carbon source. Although this method has removes C, N, P and the advantage such as processing cost is low simultaneously, but < according to practical experience, 20mg/L (urban wastewater treatment firm sewage discharge secondary standard) must assure that in former water, the ratio of dissolubility BOD and total Kjeldahl nitrogen is be more than or equal to 4 to want to reach water outlet total nitrogen content. And organic content is generally relatively low in current China municipal wastewater, denitrifying carbon source deficiency causes that whole system nitric efficiency is not good. Some existing treating methods have problems, and the method as added the additional carbons such as sodium acetate in sewage is also added significantly to operating cost while improving treatment effect, it is difficult in China's penetration and promotion; Setting up primary sludge fermentation pond, needed for utilizing the supernatant after fermentation to supplement denitrification, the method for carbon source is not only consuming time long, it is also difficult to control the stage of reaction. On the other hand, the high cost that excess sludge processes has become the restraining factors that Sewage Biological Treatment is run, and the Sources decreasing of mud receives shows great attention to. Excess sludge is carried out extracellular polymeric (EPS) and dissolves the lysate obtaining high carbon-nitrogen ratio, it is back to sewage biological treatment system and can provide carbon source for anoxic treatment unit denitrification, also mud decrement can be made, but this method exists the extracellular polymeric dissolved mostly is in refractory organic, returned sludge to lack the problems such as the microorganism that is adapted to decompose extracellular polymeric lysate, seriously constrains the universal of this technology.Therefore, explore a kind of efficiently, the municipal sewage biological denitrificaion of low cost and reducing biological sludge new technology very necessary.
The extracellular polymeric lysate of difficult for biological degradation is effectively converted into the organic carbon source of bioavailable by the present invention, and make to be tamed without the biological sludge of EPS solubilization, become and be suitable to decompose extracellular polymeric solute, reach to improve the purpose of backflow utilization of carbon source efficiency, can making reducing biological sludgeization simultaneously and strengthen sewage water denitrification ability, the Technological Economy difficult problem for solving this area provides technological means.
Summary of the invention
The present invention relates to a kind of biological sludge to be hydrolyzed again after EPS dissolves acidification, discharge high carbon-nitrogen ratio, easily biological-degradable material as the carbon source of denitrification denitrogenation, the part processed without EPS dissolvingization in biological sludge is tamed out the microorganism being suitable to decompose EPS solute simultaneously, Material recirculation after hydrolysis acidification is extremely to bio anaerobic or anoxic treatment stage, the method that sewage is carried out denitrogenation.
Sewage treatment plant produces large number of biological mud every day, biological sludge is made up of microorganism and EPS etc., it is 50-60% that EPS accounts for mud, it it is organic key component in biological sludge, wherein 70%~80% is be made up of protein and polysaccharide, remaining 20%~30% comes from humic acid, nucleic acid and lipid etc., and the carbon of these materials and the ratio of nitrogen are much higher than biological cell, and the lysate after dissolving has significantly high carbon-nitrogen ratio. EPS source one is the high molecular polymer secreted by bacterial cell metabolism, and two come from the compound in stain disease, i.e. matrix environment residing for mud. There are some researches show, mud EPS is made up of the 40% not biodegradable EPS of biodegradable EPS and 60%, and biodegradable part mostly then is recalcitrant substance, and biodegradability is poor. Simultaneously conventional biological denitrificaion processes and lacks the microorganism that can utilize EPS in system and equipment anaerobic bio-treatment of wastewater, sewage anoxia biological treatment device and sewage aerobic biological treatment device, limits the utilization ratio of EPS. The biological sludge discharged is carried out EPS and dissolves the biological sludge lysate that can obtain high carbon-nitrogen ratio; It can be used as carbon source to be back to biological denitrificaion and process system, anaerobism or anoxic treatment unit arrival end such as Sewage Biological Treatment, the carbon source in the former water of sewage can be supplemented, improve denitrification denitrogenation effect, the consumption of this some residual mud is achieved reducing biological sludge simultaneously; In order to improve the bio-degradable of backflow lysate and avoid process system lacks the microorganism adapted, this invention to biological sludge through EPS dissolvingization process after, be hydrolyzed acidification again, the Organic substance of difficult for biological degradation can be effectively made to decompose further, it is converted into easily biological-degradable material, and make to be tamed without liquefiable biological sludge, the microorganism after domestication is more suitable for the product after degraded EPS dissolves, and decreases cost of investment.
The present invention adopts the following technical scheme that realization:
A kind of method of Sewage Biological Treatment strengthened denitrification, is at least made up of following process:
(1) in the sewage disposal system that or Anoxic/Aerobic biological treatment process aerobic by anaerobic/anoxic form, the biological sludge discharged after Aerobic biological process and precipitate and separate is through extracellular polymeric solubilization;
(2) lysate after extracellular polymeric solubilization is hydrolyzed acidification with the biological sludge dissolved without extracellular polymeric;
(3) lysate after hydrolysis acidification processes and biological sludge is returned to the anaerobism of Sewage Biological Treatment or anoxic treatment unit arrival end processes.
Described hydrolysis acidification pool hydraulic detention time is 24 28h, and sludge retention time is 1.5 2d, and basicity is at 700 750mg/L.
Described hydrolysis acidification processes the biological sludge without extracellular polymeric dissolving added and derives from one or more selections of the returned sludge of sedimentation tank and the mud mixture of anoxic pond.
The device of the sewage water treatment method of the present invention, at least includes bio-denitrifying sewage and processes device, sedimentation tank, EPS dissolver and hydrolysis and acidification treater; The sludge outlet of sedimentation tank is connected with the sludge inlet of EPS dissolver, the sludge outlet of EPS dissolver is connected with hydrolysis and acidification treater sludge inlet, and clarifier sludge outlet is connected with anaerobic biological treatment apparatus or anoxia biological treatment device sludge inlet.
Described bio-denitrifying sewage processes device and includes the equipment anaerobic bio-treatment of wastewater of series connection, sewage anoxia biological treatment device and sewage aerobic biological treatment device; Or sewage anoxia biological treatment device and the sewage aerobic biological treatment device of series connection.
Hydrolysis and acidification treater sludge inlet includes following 3 kinds of connected modes:
The biological sludge source that hydrolysis and acidification treater dissolves without extracellular polymeric is connected with hydrolysis and acidification treater sludge inlet for clarifier sludge outlet.
Mud mixture outlet after the sewage anoxia biological treatment that the biological sludge source that hydrolysis and acidification treater dissolves without extracellular polymeric is sewage anoxia biological treatment device is connected with the sludge inlet of hydrolysis and acidification treater.
The biological sludge source that hydrolysis and acidification treater dissolves without extracellular polymeric is connected with hydrolysis and acidification treater sludge inlet for the mud mixture outlet after the sewage anoxia biological treatment of clarifier sludge outlet and sewage anoxia biological treatment device simultaneously.
It is described as follows:
Biological sludge is carried out EPS dissolution process after separating in sedimentation tank by the mud mixture that bio-denitrifying sewage process system is discharged. owing to biological sludge is made up of microorganism and EPS etc., account for the EPS composition that mud is 50-60% and mainly include the polysaccharide of high carbon-nitrogen ratio, protein and a small amount of humus, the carbon of these materials and the ratio of nitrogen are much higher than biological cell, lysate after dissolving has significantly high carbon-nitrogen ratio, but mud EPS is made up of the 40% not biodegradable EPS of biodegradable EPS and 60%, biodegradable part mostly then is recalcitrant substance, and biodegradability is poor. and the biological denitrificaion of routine processes and lacks the microorganism that can utilize EPS in system and equipment anaerobic bio-treatment of wastewater, sewage anoxia biological treatment device and sewage aerobic biological treatment device, the utilization ratio of EPS is low. be hydrolyzed further acidification by the biological sludge dissolved through EPS, the Organic substance of difficult for biological degradation can be effectively made to decompose further, it is converted into easily biological-degradable material, improve biodegradability, and make to be tamed without the biological sludge of EPS solubilization, microorganism after domestication is more suitable for the product after degraded EPS dissolves, anaerobism or anoxic treatment unit arrival end that lysate is back to biological processing unit process with sewage, can be anoxia section denitrification process biological respinse supplementary carbon source and acclimated microorganism, reach the purpose of sludge reduction simultaneously.
The dissolving EPS invented, acclimation sludge with the idiographic flow of the method that promotes sewage water denitrification for: the sewage through pretreatment enters bio-denitrifying sewage and processes device, mud mixture entrance sedimentation tank separation through denitrification process, supernatant qualified discharge, the sludge part produced is back to biological denitrification system to maintain the microorganism overall balance of biological treatment system, partial sludge enters EPS dissolver and carries out solubilization, produce high-carbon and compare lysate, treated lysate and the mud mixture from the mud of sedimentation tank or mud anoxia biological treatment device enter hydrolysis acidification device, the lysate of the high carbon-nitrogen ratio after decomposing further enters biological denitrificaion together with the biological sludge tamed and processes anaerobism or the anoxia section of system, for denitrification biological respinse supplementary carbon source and acclimated microorganism.Outside excess sludge, row processes. The method that EPS dissolves can adopt ultrasound wave, ozone oxidation, centrifugal or addition alkaline reagent such as sodium bicarbonate, sodium carbonate, Calx, sodium hydroxide etc.
The sludge source of described hydrolysis acidification device has three kinds. Source one: when the biological sludge amount that sedimentation tank is discharged is more, namely, when enough the total biomass of maintenance sewage disposal system balances and has excess sludge to produce, part biological mud is directly discharged into hydrolysis acidification device to provide the biological sludge without EPS solubilization; Source two: when the biological sludge amount that sedimentation tank is discharged is less, when namely not having excess sludge or excess sludge less, entering hydrolysis and acidification treater from the part mud mixture of sewage anoxia biological treatment device discharge can by acclimated microorganism with offer; Source three: when the biological sludge amount that sedimentation tank is discharged is moderate, a mud part for hydrolysis acidification device comes from the biological sludge that sedimentation tank is discharged, and a part comes from the mud mixture that sewage anoxia biological treatment device is discharged.
Described biological denitrificaion processes device and is divided into two kinds. One includes equipment anaerobic bio-treatment of wastewater, sewage anoxia biological treatment device and sewage aerobic biological treatment device, and another kind includes sewage anoxia biological treatment device and sewage aerobic biological treatment device. Two kinds of device all energy strengthened denitrifications, according to the corresponding device of the different choice of the difference of influent quality and investment, operation operating cost.
The invention has the beneficial effects as follows, the biological sludge that sewage treatment process is produced carries out EPS dissolving, the method that sewage is carried out denitrogenation by the further hydrolysis acidification of lysate backflow; The further hydrolysis acidification of lysate through solubilization is processed can make the Organic substance of difficult for biological degradation decompose further, it is converted into easily biological-degradable material, improve biodegradability, and make to be tamed without the biological sludge of EPS solubilization, it is more suitable for the product after degraded EPS dissolves, is back to sewage biological treatment system, can be that anoxic treatment unit denitrification increases carbon source, therefore both enhance the effect of sewage water denitrification, biological sludge can be carried out minimizing recycling again; Improve mud utilization ratio, compare other technique, decrease cost of investment.
Accompanying drawing explanation
Fig. 1: embodiment 1 device flow chart
Fig. 2: embodiment 2 device flow chart
Fig. 3: embodiment 3 device flow chart
Fig. 4: embodiment 4 device flow chart
Fig. 5: embodiment 5 device flow chart
Fig. 6: embodiment 6 device flow chart
Wherein: the former water of 1-; 2-equipment anaerobic bio-treatment of wastewater; Mud mixture after the biological treatment of 3-anerobic sowage; 4-backflow mixed liquor; 5-sewage anoxia biological treatment device; Mud mixture after the biological treatment of 6-sewage anoxia; 7-sewage aerobic biological treatment device; Mud mixture after the biological treatment of 8-sewage aerobic; 9-sedimentation tank; 10-permitted discharge; 11-returned sludge; 12-excess sludge; 13-EPS dissolver; 14-lysate; 15-hydrolysis and acidification treater; 16-backflow mixed liquor; 17-air.
Detailed description of the invention
After the excess sludge that the present invention is applicable to that sewage treatment plant is produced carries out mud EPS dissolving, hydrolysis acidification decomposes further, being back to biological anoxic unit is denitrification denitrogenation process supplementary carbon source and acclimated microorganism, increase denitrification effect, realize sludge reduction, improve biological sludge utilization ratio. The method not only provides requisite degradable carbon source and acclimated microorganism for biological processing unit, also achieves the utilization to sludge reduction resource, substantially reduces cost under the premise of satisfied process target.
The device of the sewage water treatment method of the present invention at least includes: bio-denitrifying sewage processes device, EPS dissolver 13, hydrolysis and acidification treater 15 and sedimentation tank 9; Bio-denitrifying sewage processes device and includes equipment anaerobic bio-treatment of wastewater 2, sewage anoxia biological treatment device 5, sewage aerobic biological treatment device 7 or sewage anoxia biological treatment device 5, sewage aerobic biological treatment device 7; The sludge outlet of sedimentation tank 9 is connected with the sludge inlet of EPS dissolver 13, the sludge outlet of EPS dissolver 13 is connected with hydrolysis and acidification treater 15 sludge inlet, and sedimentation tank 9 sludge outlet is connected with anaerobic biological treatment apparatus 3 or anoxia biological treatment device 5 sludge inlet.
Bio-denitrifying sewage processes device and includes equipment anaerobic bio-treatment of wastewater 2, sewage anoxia biological treatment device 5, sewage aerobic biological treatment device 7 or sewage anoxia biological treatment device 5, sewage aerobic biological treatment device 7.
There are three kinds of selections in the biological sludge source that hydrolysis and acidification treater 15 dissolves without extracellular polymeric: source one: sedimentation tank 9 sludge outlet is connected with hydrolysis and acidification treater 15 sludge inlet; Source two: mud mixture 6 outlet after the sewage anoxia biological treatment of sewage anoxia biological treatment device 5 is connected with the sludge inlet of hydrolysis and acidification treater 15; Source three: mud mixture 6 outlet after the sewage anoxia biological treatment of sedimentation tank 9 sludge outlet and sewage anoxia biological treatment device 5 is connected with hydrolysis and acidification treater 15 sludge inlet simultaneously.
Embodiment 1
The present embodiment is for the process process modification of certain sewage treatment plant, as it is shown in figure 1, this sewage treatment plant adopts A2O (anaerobic-anoxic-oxic) technique carries out synchronous denitrification dephosphorizing. former water 1 flows into equipment anaerobic bio-treatment of wastewater 2, mud mixture 3 after anerobic sowage biological treatment flows into sewage anoxia biological treatment device 5, mud mixture 6 after the biological treatment of sewage anoxia flows into sewage aerobic biological treatment device 7, continue to sewage aerobic biological treatment device 7 aeration (passing into air 17), backflow mixed liquor 4 is back to anoxia biological treatment device 5, mud mixture 8 after sewage aerobic biological treatment flows into sedimentation tank 9, last permitted discharge 10 discharges, the partial reflux mud 11 discharged from sedimentation tank 9 is back to equipment anaerobic bio-treatment of wastewater 2, partial reflux mud 11 enters EPS dissolver 13 and adopts supercritical ultrasonics technology to carry out solubilization, adding sodium bicarbonate adjustment pH value is 9, ultrasonic density is 15W/cm2, the process time is 30 minutes. It is easily biological-degradable material that lysate 14, partial reflux mud 11 and the part mud mixture 6 discharged from sewage anoxia biological treatment device 5 enter the further decomposition and inversion of hydrolysis and acidification treater 15, and make to be tamed without liquefiable biological sludge, the backflow mixed liquor 16 discharged from hydrolysis and acidification treater 15 is back to equipment anaerobic bio-treatment of wastewater 2 provides degradable carbon source and acclimated microorganism for denitrification, and excess sludge 12 is outer to be arranged. Through to the carbon-nitrogen ratio in backflow carbon source and the monitoring of total nitrogen in water outlet, in backflow carbon source, carbon-nitrogen ratio is higher than 20, and in water outlet, total nitrogen content is lower than 15mg/L (one-level A standard).
Embodiment 2
The present embodiment is substantially the same manner as Example 1, as in figure 2 it is shown, be different in that, when the biological sludge amount that sedimentation tank is discharged is less, clipped returned sludge 11 is directly entered hydrolysis and acidification treater 15 sections.
Idiographic flow is as follows: former water 1 flows into equipment anaerobic bio-treatment of wastewater 2, mud mixture 3 after anerobic sowage biological treatment flows into sewage anoxia biological treatment device 5, mud mixture 6 after the biological treatment of sewage anoxia flows into sewage aerobic biological treatment device 7, continue to sewage aerobic biological treatment device 7 aeration (passing into air 17), backflow mixed liquor 4 is back to anoxia biological treatment device 5, mud mixture 8 after sewage aerobic biological treatment flows into sedimentation tank 9, last permitted discharge 10 discharges, the partial reflux mud 11 discharged from sedimentation tank 9 is back to equipment anaerobic bio-treatment of wastewater 2, partial reflux mud 11 enters EPS dissolver 13 and adopts supercritical ultrasonics technology to carry out solubilization, adding sodium bicarbonate adjustment pH value is 10, ultrasonic density is 10W/cm2, the process time is 30 minutes. It is easily biological-degradable material that lysate 14 and the part mud mixture 6 discharged from sewage anoxia biological treatment device 5 enter the further decomposition and inversion of hydrolysis and acidification treater 15, and make to be tamed without liquefiable biological sludge, the backflow mixed liquor 16 discharged from hydrolysis and acidification treater 15 is back to equipment anaerobic bio-treatment of wastewater 2 provides degradable carbon source and acclimated microorganism for denitrification, and excess sludge 12 is outer to be arranged. Through to the carbon-nitrogen ratio in backflow carbon source and the monitoring of total nitrogen in water outlet, in backflow carbon source, carbon-nitrogen ratio is higher than 20, and in water outlet, total nitrogen content is lower than 15mg/L (one-level A standard).
Embodiment 3
The present embodiment is substantially the same manner as Example 1, as it is shown on figure 3, be different in that, when the biological sludge amount that sedimentation tank is discharged is more, omits the part mud mixture 6 discharged from sewage anoxia biological treatment device and enters hydrolysis and acidification treater 15 sections.
Idiographic flow is as follows: former water 1 flows into equipment anaerobic bio-treatment of wastewater 2, mud mixture 3 after anerobic sowage biological treatment flows into sewage anoxia biological treatment device 5, mud mixture 6 after the biological treatment of sewage anoxia flows into sewage aerobic biological treatment device 7, continue to sewage aerobic biological treatment device 7 aeration (passing into air 17), backflow mixed liquor 4 is back to anoxia biological treatment device 5, mud mixture 8 after sewage aerobic biological treatment flows into sedimentation tank 9, last permitted discharge 10 discharges, the partial reflux mud 11 discharged from sedimentation tank 9 is back to equipment anaerobic bio-treatment of wastewater 2, partial reflux mud 11 enters EPS dissolver 13 and adopts supercritical ultrasonics technology to carry out solubilization, adding sodium bicarbonate adjustment pH value is 11, ultrasonic density is 12W/cm2, the process time is 20 minutes. It is easily biological-degradable material that lysate 14 and partial reflux mud 11 enter the further decomposition and inversion of hydrolysis and acidification treater 15, and make to be tamed without liquefiable biological sludge, the backflow mixed liquor 16 discharged from hydrolysis and acidification treater 15 is back to equipment anaerobic bio-treatment of wastewater 2 provides degradable carbon source and acclimated microorganism for denitrification, and excess sludge 12 is outer to be arranged. Through to the carbon-nitrogen ratio in backflow carbon source and the monitoring of total nitrogen in water outlet, in backflow carbon source, carbon-nitrogen ratio is higher than 20, and in water outlet, total nitrogen content is lower than 15mg/L (one-level A standard).
Embodiment 4
The present embodiment is substantially the same manner as Example 1, as shown in Figure 4, is different in that, in order to reduce investment, reduces operating cost, adopts anoxic-aerobic process, omits equipment anaerobic bio-treatment of wastewater 2.
Idiographic flow is as follows: former water 1 flows into sewage anoxia biological treatment device 5, mud mixture 6 after the biological treatment of sewage anoxia flows into sewage aerobic biological treatment device 7, continue to sewage aerobic biological treatment device 7 aeration (passing into air 17), backflow mixed liquor 4 is back to anoxia biological treatment device 5, mud mixture 8 after sewage aerobic biological treatment flows into sedimentation tank 9, last permitted discharge 10 discharges, from the partial reflux sludge reflux of sedimentation tank 9 discharge to sewage anoxia biological treatment device 5, partial reflux mud 11 enters EPS dissolver 13 and adopts supercritical ultrasonics technology to carry out solubilization, adding sodium bicarbonate adjustment pH value is 13, ultrasonic density is 15W/cm2, the process time is 10 minutes.It is easily biological-degradable material that lysate 14, partial reflux mud 11 and the part mud mixture 6 discharged from sewage anoxia biological treatment device 5 enter the further decomposition and inversion of hydrolysis and acidification treater 15, and make to be tamed without liquefiable biological sludge, the backflow mixed liquor 16 discharged from hydrolysis and acidification treater 15 is back to sewage anoxia biological treatment device 5 provides degradable carbon source and acclimated microorganism for denitrification, and excess sludge 12 is outer to be arranged. Through to the carbon-nitrogen ratio in backflow carbon source and the monitoring of total nitrogen in water outlet, in backflow carbon source, carbon-nitrogen ratio is higher than 20, and in water outlet, total nitrogen content is lower than 15mg/L (one-level A standard).
Embodiment 5
The present embodiment is substantially the same manner as Example 4, as it is shown in figure 5, be different in that, when the biological sludge amount that sedimentation tank is discharged is less, clipped returned sludge 11 is directly entered hydrolysis and acidification treater 15 sections.
Embodiment 6
The present embodiment is substantially the same manner as Example 4, as shown in Figure 6, is different in that, when the biological sludge amount that sedimentation tank is discharged is more, omits the part mud mixture 6 discharged from sewage anoxia biological treatment device and enters hydrolysis and acidification treater 15 sections.
Embodiment 7
The present embodiment is substantially the same manner as Example 1, as it is shown in figure 1, be different in that employing Ozonation carries out solubilization.
Embodiment 8
The present embodiment is substantially the same manner as Example 1, as it is shown in figure 1, be different in that employing centrifuging carries out solubilization.