CN105036488B - A kind of sludge water total system - Google Patents

Abstract

The present invention proposes a sludge water comprehensive treatment system, which includes a coagulation reaction tank, one end of the coagulation reaction tank is connected to the concentrated dewatered sludge water, the other end of the coagulation reaction tank is connected to a clarification tank, and the clarification tank and A mixed reaction tank is connected, the mixed reaction tank is connected to a sedimentation tank, the sedimentation tank is connected to the first aerobic tank, the first aerobic tank is connected to the anoxic tank, the anoxic tank is connected to the second aerobic tank, and the mixed reaction tank The other end of the tank is connected to the deep dewatered sludge water through a first pipeline, and one side of the anoxic tank is connected to the deep dewatered sludge water through a second pipeline. The second aerobic tank can be provided with a membrane separation unit in the tank, It can also be connected with the secondary settling tank to realize solid-liquid separation. The present invention realizes the synchronous and efficient removal of organic matter and nitrogen and phosphorus in sludge water through waste treatment inside the sewage treatment plant, saves the cost of adding phosphorus removal agents, alkalinity and carbon sources in sludge water, and greatly reduces the cost of sludge water. Processing costs.

Description

A kind of sludge water comprehensive treatment system

technical field

The invention belongs to the fields of environmental protection and rational utilization of water resources, and relates to a water treatment device, in particular to a sludge water comprehensive treatment system.

Background technique

With the further improvement of China's urbanization construction, the rapid increase of sewage treatment volume has brought about a substantial increase in sludge production. However, due to the increasing shortage of land resources, sludge with a water content of 80% after concentration and dehydration can no longer meet the landfill requirements. The sludge needs to be further conditioned and dehydrated to reach a water content of less than 60% before it can be landfilled. At present, the advanced sludge dewatering technology has been practically applied in Shanghai Bailonggang, Hangzhou Qige, Wuxi Lucun, Xiamen, Jimei and other sewage treatment plants. Deep dewatering sludge water is a kind _of conditioning by adding lime and FeCl3 to the sludge, breaking the cell wall, releasing bound water, adsorbed water and internal water, improving the dehydration performance of the sludge, and then dehydrating under high pressure until the water content is lower than 60% of the wastewater produced in the process. The wastewater produced during the process of sludge concentration, digestion and dehydration until the water content is less than 80% is called concentrated dewatered sludge water. Due to the different conditioning methods, there are significant differences between the two in terms of water quality characteristics.

Concentrated dewatered sludge water has the characteristics of high suspended solids, high orthophosphorus (PO ₄ ^3- ) and high ammonia nitrogen (NH ₃ -N), and direct return to the mainstream biological system will seriously affect the safe and stable operation of the sewage treatment plant. In particular, the anaerobic environment formed during the sludge thickening and dewatering process will cause a large release of phosphorus, so that the phosphorus load in the sludge water usually exceeds 10% of the phosphorus load in the wastewater treatment plant. However, due to the low concentration of available carbon sources in sludge water, traditional enhanced biological phosphorus removal technology is not suitable for sludge water phosphorus removal, while chemical phosphorus removal technology requires high chemical cost. The nitrogen content in sludge water will also reach 5-10% of the influent load. Concentrated treatment of high-concentration nitrogen-containing pollutants in sludge water will help improve reaction efficiency and enrich nitrifying microorganisms. However, the lack of alkalinity and carbon source in concentrated dewatered sludge water will inhibit its nitrogen removal efficiency. The lack of alkalinity will cause the sludge water to accumulate a large amount of H ⁺ during the nitrification process, resulting in a decrease in the pH of the biological system, inhibiting microbial activity, and reducing the pollutant removal effect. The lack of carbon sources will result in insufficient electron donors for denitrification of concentrated dewatered sludge water, and the efficiency of biological nitrogen removal is very low.

Deeply dewatered sludge water has the characteristics of high alkalinity, high pH, high Ca ²⁺ , high organic matter and high ammonia nitrogen. If it is directly returned to the front end of the mainstream biological treatment system, its high concentration of pollutants will have a great impact on the biological system, and the high concentration of Ca ²⁺ is also prone to fouling and blockage in the return pipeline. If biological methods are used for treatment, the high pH (11-14) and high Ca ²⁺ water quality of deep dewatered sludge water will also inhibit microbial activity and reduce the removal efficiency of organic matter and ammonia nitrogen. If the stripping method is used to remove ammonia nitrogen, it will face the problems of calcium carbonate scaling and stripping tail gas treatment.

Contents of the invention

Aiming at the above-mentioned technical problems in the prior art, the present invention provides a comprehensive sludge water treatment system, which solves the problem of concentrated dewatered sludge water and deep dewatered sewage in the prior art. The technical problem is that muddy water cannot be treated at the same time and the effect of nitrogen and phosphorus removal is not good.

The present invention provides a sludge water comprehensive treatment system, comprising a coagulation reaction tank, one end of the coagulation reaction tank communicates with concentrated dewatered sludge water, the other end of the coagulation reaction tank communicates with a clarifier The tank is connected, the clarifier is connected with a mixed reaction tank, the mixed reaction tank is connected with a sedimentation tank, the sedimentation tank is connected with a secondary biological treatment system, and the secondary biological treatment system consists of A first aerobic tank, an anoxic tank and a second aerobic tank are formed, the sedimentation tank is connected with the first aerobic tank, and the first aerobic tank is connected with the anoxic tank The pool is connected, the anoxic pool is connected with the second aerobic pool, the second aerobic pool is connected with a secondary sedimentation pool, and a second aerobic pool is provided on one side of the second aerobic pool A bypass pipeline, the first bypass pipeline is connected to the anoxic tank, the first bypass pipeline is provided with a first nitrifying liquid return pump, and one side of the secondary sedimentation tank A sludge water discharge pipeline is provided, and a second bypass pipeline is provided on one side of the secondary sedimentation tank, and the second bypass pipeline is connected to the first aerobic tank, and the second bypass pipeline is connected to the first aerobic tank. A first sludge return pump is provided on the second bypass pipeline, and a third pipeline is also provided on one side of the secondary settling tank, and the third pipeline is connected with a biological system aerobic tank, and the The other end of the mixing reaction tank communicates with the deep dewatered sludge water through a first pipeline, and the first pipeline is provided with a first water pump, and the deep dewatered sludge water and the first A grid is arranged between the first pipes, and a second pipe is arranged on one side of the anoxic tank, and the second pipe communicates with the deep dewatered sludge, and the second pipe is A second water pump is provided.

Further, the clarification tank is connected to a chemical sludge discharge pipe, and the sedimentation tank is connected to a phosphorus-containing solid sewage discharge pipe.

The present invention also provides another sludge water comprehensive treatment system, comprising a coagulation reaction tank, one end of the coagulation reaction tank communicates with the concentrated dewatered sludge water, and the other end of the coagulation reaction tank communicates with the A clarification tank is connected, the clarification tank is connected with a mixed reaction tank, the mixed reaction tank is connected with a sedimentation tank, the sedimentation tank is connected with a secondary biological treatment system, and the secondary biological treatment The system consists of a first aerobic tank, an anoxic tank and a second aerobic tank, the sedimentation tank is connected to the first aerobic tank, the first aerobic tank is connected to the The anoxic pool is connected, the anoxic pool is connected to the second aerobic pool, a membrane separation device is arranged in the second aerobic pool, and the membrane separation device includes a membrane for separation, One side of the second aerobic tank is provided with a third bypass pipeline, the third bypass pipeline is connected with the anoxic tank, and the third bypass pipeline is provided with a first Dinitration liquid reflux pump, a fourth bypass pipeline is also provided on one side of the second aerobic tank, the fourth bypass pipeline is connected to the first aerobic tank, and the fourth bypass pipeline is connected to the first aerobic tank. A second sludge return pump is provided on the four bypass pipes, a sludge water discharge pipe is provided at the bottom of the second aerobic tank, and a first sludge discharge pipe is provided on one side of the second aerobic tank Four pipelines, the fourth pipeline is connected to a biological system aerobic tank, the other end of the mixed reaction tank is connected to the deep dewatered sludge water through a first pipeline, and the first pipeline is connected to A first water pump is provided, a grid is provided between the deep dewatered sludge water and the first pipeline, a second pipeline is provided on one side of the anoxic tank, and the first The second pipeline is in water communication with the deep dewatered sludge, and a second water pump is arranged on the second pipeline.

Further, the clarification tank is connected to a chemical sludge discharge pipe, and the sedimentation tank is connected to a phosphorus-containing solid sewage discharge pipe.

The working process of the present invention is: adding polyacrylamide (PAM) to the concentrated dewatered sludge water transported by the pipeline, after being mixed in the coagulation reactor, entering the clarification tank to remove suspended matter, and then entering the sludge water mixing reaction tank;

The deep dewatered sludge water transported from the pipeline, after the large suspended solids and floating solids are removed by the grid, part of the deep dewatered sludge water also enters the mixing reaction tank through the pump;

After the two kinds of sludge water are mixed in the mixing reaction tank to remove most of the phosphorus and part of COD, they enter the sedimentation tank for solid-liquid separation and recovery of phosphorus-containing solid products;

The effluent from the sedimentation tank enters the secondary biological treatment system consisting of the first aerobic tank, the anoxic tank and the second aerobic tank, while another part of the deep dewatered sludge water directly enters the anoxic tank. In the secondary biological treatment system, the first aerobic tank completes the COD degradation and nitrification process of concentrated dewatered sludge water and 30% deep dewatered sludge water, and the anoxic tank completes denitrification and denitrification of the two sludge waters. Second, COD degradation and nitrification of deep dewatered sludge water after anoxic denitrification is completed in the aerobic tank.

The solid-liquid separation unit can be in the form of sedimentation tank (secondary sedimentation tank) or membrane separation.

If a secondary settling tank is used, the mixed solution from the second aerobic tank enters the secondary settling tank, and after solid-liquid separation, the treated sludge water is discharged through the sewage discharge pipe, and part of the concentrated sludge at the bottom of the secondary settling tank is used as residual sewage. The sludge is discharged to the aerobic tank of the mainstream biological system of the sewage treatment plant, and part of it is returned to the first aerobic tank through the sludge return pump to supplement the activated sludge;

If the form of membrane separation is adopted, a membrane separation device is provided in the second aerobic tank, and the membrane separation device includes a membrane for separation. After treatment, the sludge water is discharged after being filtered by the membrane, and the remaining sludge is directly discharged from the second aerobic tank. It is discharged from the second aerobic tank, and a sludge return pump is set up to pump part of the sludge from the second aerobic tank to the first aerobic tank.

The mixed liquid part of the second aerobic tank is returned to the anoxic tank through the reflux pump for denitrification and denitrification.

The present invention aims to combine concentrated dehydration and deep dewatered sludge hydration through reasonable sewage treatment process unit layout, so that the high concentration of ^Ca in deep dewatered sludge water can be combined with Ca in concentrated dewatered sludge water under high pH conditions. PO ₄ ^3- precipitation realizes phosphorus removal. The high content of alkalinity in deep dewatered sludge water can effectively supplement the alkalinity requirements of the nitrification process of the two sludge waters, and the high content of biodegradable organic matter can supply the two kinds of sludge water. Carbon source required for nitrification.

The beneficial technical effect of the present invention is:

(1) In the high pH environment of the mixed reaction tank, the high concentration of Ca ²⁺ in the deep dewatered sludge water reacts with PO ₄ ^3- in the concentrated dewatered sludge water to form a precipitate and remove it, saving the cost of phosphorus removal chemicals;

(2) The high content of alkalinity in deep dewatered sludge water can supplement the alkalinity required for nitrification of concentrated dewatered sludge water, strengthen the nitrification effect of sludge water, and save the cost of alkalinity dosing;

(3) The deep dewatered sludge water with a high carbon-nitrogen ratio can supplement the carbon source required for the denitrification process of the concentrated dewatered sludge water with a carbon-nitrogen ratio, improve the denitrification and denitrification effect of the sludge water, and save the cost of adding carbon sources.

(4) Through the optimized combination of the reaction modules of the process system, the organic matter and nitrogen and phosphorus pollutants in the two kinds of sludge water can be removed simultaneously and efficiently at low cost.

The invention develops a sludge water reaction-sedimentation-aerobic-anoxic-aerobic (RSOAO) process, realizes the synchronous and efficient removal of organic matter and nitrogen and phosphorus pollutants in the sludge water of sewage treatment plants, and ensures the safe and stable operation of sewage treatment plants .

Compared with the prior art, the technical progress of the present invention is remarkable. The present invention realizes the synchronous and efficient removal of organic matter and nitrogen and phosphorus pollutants in sludge water through waste treatment in sewage treatment plants, saves the cost of adding phosphorus removal agents, alkalinity and carbon sources in sludge water, and greatly reduces The cost of sludge water treatment ensures the safe and stable operation of the sewage treatment plant.

Description of drawings

Fig. 1 is a schematic process flow diagram of a sludge water comprehensive treatment system of the present invention.

Fig. 2 is another schematic flow chart of a sludge water comprehensive treatment system of the present invention.

Among them, 1 is the grid, 2 is the coagulation reaction tank, 3 is the clarification tank, 4 is the mixed reaction tank, 5 is the sedimentation tank, 6 is the first aerobic tank, 7 is the anoxic tank, and 8 is the second aerobic tank , 9 is the secondary settling tank; 10 is the first water pump (deeply dewatered sludge water is used as the pump for phosphorus removal agent dosing), 11 is the second water pump (deeply dehydrated sludge water is used as the denitrification carbon source dosing pump), 12 is The first nitrification liquid return pump; 13 is the first sludge return pump; 14 is the chemical sludge sewage pipeline, 15 is the phosphorus-containing solid sewage pipeline, 16 is the remaining sludge discharge pipe; 17 is the sludge water discharge pipeline after treatment; 18 is the second nitrification liquid return pump; 19 is the second sludge return pump, and 20 is the membrane separation device.

detailed description

The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings, but the present invention is not limited.

Example 1

As shown in Figure 1, the present invention is a sludge water comprehensive treatment system, the 7m ³ /d deep dewatered sludge water is processed through the grid 1, and the 10m ³ /d concentrated dewatered sludge water is passed through the coagulation reaction tank 2 and the clarification tank 3 treatment, the hydraulic retention time of the coagulation reaction tank 2 and the clarification tank 3 are 20 and 15 min respectively, and the sludge discharge cycle of the clarification tank ³ is 3 h; The concentrated dewatered sludge water enters the mixing reaction tank 4 and the sedimentation tank 5, the hydraulic retention time of the reaction tank 4 and the sedimentation tank 5 are 60 and 15 min respectively, and the sludge discharge period of the sedimentation tank 5 is 1.5 h; The biological treatment unit composed of an aerobic pool 6, anoxic pool 7, and the second aerobic pool 8 enters the secondary sedimentation pool 9; the hydraulic retention time of the first aerobic pool 6, the anoxic pool 7, and the second aerobic pool 8 8, 4 and 16 hours respectively; at the same time, the remaining 5m ³ /d of deep dewatered sludge water is fed into the anoxic tank 7 through the pump 11 .

The outlet of the second aerobic tank 8 is provided with a bypass, and the nitrified sludge from the second aerobic tank 8 is returned to the front end of the anoxic tank 7 through the sludge return pump ₁₂ , and the return ratio R1 is 300%. The secondary settling tank 9 is provided with two outlets, one is the discharge outlet 17 of the treated sewage, and the other is the discharge outlet 16 of the excess sludge to be discharged to the aerobic pool of the mainstream biological system of the sewage treatment plant, and the discharge of the excess sludge There is a bypass on the mouth, and after the first sludge return pump 13, the remaining sludge discharged from the secondary sedimentation tank 9 is returned to the front end of the aerobic tank ₆ , and the return ratio R2 is 50%.

The working process of the above-mentioned sewage treatment system is as follows:

The deep dewatered sludge water transported from the pipeline removes large suspended solids and floating solids through the grid 1; the concentrated dewatered sludge water transported from the pipeline is added with PAM, undergoes coagulation reaction in the coagulation reaction tank 2, and enters the clarification tank 3 After removing the sludge and suspended matter, 30% of the deep dewatered sludge water passes through the pump 10, and enters the mixed reaction tank 4 to react with the concentrated dewatered sludge water to remove phosphorus and some organic matter, and then enters the sedimentation tank 5 for solid-liquid separation and recovery Phosphorous solid product.

The effluent from sedimentation tank 5 then enters the secondary biological treatment system consisting of aerobic tank 6, anoxic tank 7, and aerobic tank 8. The COD degradation and nitrification process is completed in aerobic tank 6, and the reaction is completed in anoxic tank 7. For nitrification and denitrification, 70% of deep dewatered sludge water is added through the pump 11 to supplement the carbon source required for denitrification, and the process of nitrification and COD degradation of the newly added deep dewatered sludge water containing high concentration of ammonia nitrogen is completed in the aerobic pool 8 .

The mixed liquid from the aerobic tank 8 is divided into two parts, one part is transported to the anoxic tank 7 by the first sludge return pump 12 for denitrification and denitrification of 70% deep dewatered sludge water supplemented after completion, and the other part enters the secondary sedimentation tank 9. After solid-liquid separation, the treated sludge is discharged through the sludge water discharge pipeline 17, and part of the concentrated sludge at the bottom of the secondary sedimentation tank 9 is discharged through the remaining sludge discharge pipeline 17, and can be discharged to the aerobic pool of the mainstream biological system of the sewage treatment plant for strengthening Part of the nitrification is transported to the first aerobic tank 6 through the first sludge return pump 13 .

If the form of membrane separation is adopted, a membrane separation device 20 is placed in the second aerobic tank 8, and the membrane separation device 20 includes a membrane for separation. After treatment, the sludge water is discharged after membrane filtration, and the remaining sewage The mud is directly discharged from the second aerobic tank 8, and the outlet of the second aerobic tank 8 is provided with a bypass, and the nitrification sludge from the second aerobic tank 8 is returned to the anoxic tank through the second sludge return pump 18. At the front end of pool ₇ , the reflux ratio R1 is 300%. A second sludge return pump 19 is also provided to pump part of the sludge from the second aerobic tank 8 to the first aerobic tank 6 .

Run continuously for 100 days according to the above process. The average concentration of soluble COD, BOD ₅ , ammonia nitrogen, total nitrogen and total phosphorus in influent concentrated dewatered sludge water is 152.2, 27.5, 105.8, 145.2 and 69.4 mg/L, and the soluble COD, BOD ₅ , ammonia nitrogen in deep dewatered sludge water , The average concentrations of total nitrogen and total phosphorus were 3480.4, 1052.1, 341.6, 347.6 and 17.4mg/L. After being treated by the above RSOAO process proposed by the present invention, the pH of the reactor is 6.5-7.5, and the average concentrations of COD, ammonia nitrogen, total nitrogen and total phosphorus in the effluent are 225.1, 35.8, 67.4 and 3.2 mg/L respectively. Compared with the water quality after mixing the two kinds of sludge water according to the amount of water, the removal rates of COD, ammonia nitrogen, total nitrogen and total phosphorus were 85.2%, 82.3%, 70.5% and 93.3%, respectively.

The foregoing is only an example of the embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and Modifications should also be regarded as the scope of protection of the present invention.

Claims (4)

1. a kind of sludge water total system, including a coagulation reaction tank it is characterised in that：Described coagulation reaction tank One end connects with thickening sludge water, and the described other end of coagulation reaction tank and a depositing reservoir connect, and described is clear Qing Chi and mixed reaction pond connects, and described mixed reaction pond and a sedimentation tank connect, described sedimentation tank and one Two stage biological processing system connects, and described two stage biological processing system is by first Aerobic Pond, an anoxic pond and one Second Aerobic Pond composition, described sedimentation tank and described the first Aerobic Pond connection, the first described Aerobic Pond and described lacking Oxygen pond connects, and described anoxic pond and the second described Aerobic Pond connect, and the second described Aerobic Pond and a second pond connect, The side of the second described Aerobic Pond is provided with first bypass duct, the first described bypass duct and described anoxic pond Connect, the first described bypass duct is provided with a first nitrification liquid reflux pump, the side of described second pond is provided with One sludge water discharge tube, the side of described second pond is additionally provided with second bypass duct, described the second bypass Pipeline and the first described Aerobic Pond connect, and the second described bypass duct is provided with first sludge reflux pump, described The side setting of second pond also have the 3rd pipeline, the 3rd described pipeline and biosystem Aerobic Pond to connect, institute The other end of the mixed reaction pond stated is connected with deep dehydration sludge water by first pipeline, on the first described pipeline It is provided with first water pump, between described deep dehydration sludge water and the first described pipeline, be provided with a grid, institute The side of the anoxic pond stated is provided with a second pipe, and described second pipe connects with described deep dehydration sludge water, One the second water pump is provided with described second pipe.

2. a kind of sludge water total system according to claim 1 it is characterised in that：Described depositing reservoir and one Chemical sludge blow-off pipe connects, and described sedimentation tank and a phosphorous solid blow-off pipe connect.

3. a kind of sludge water total system, including a coagulation reaction tank it is characterised in that：Described coagulation reaction tank One end connects with thickening sludge water, and the described other end of coagulation reaction tank and a depositing reservoir connect, and described is clear Qing Chi and mixed reaction pond connects, and described mixed reaction pond and a sedimentation tank connect, described sedimentation tank and one Two stage biological processing system connects, and described two stage biological processing system is by first Aerobic Pond, an anoxic pond and one Second Aerobic Pond composition, described sedimentation tank and described the first Aerobic Pond connection, the first described Aerobic Pond and described lacking Oxygen pond connects, and described anoxic pond and the second described Aerobic Pond connect, and be provided with a film and divide in the second described Aerobic Pond From device, described membrane separation device includes a separation film, and the side of the second described Aerobic Pond is provided with one the 3rd Bypass duct, the 3rd described bypass duct and described anoxic pond connect, and the 3rd described bypass duct is provided with one Second nitrification liquid reflux pump, the side of the second described Aerobic Pond is additionally provided with the 4th bypass duct, by the of the described 4th Road pipeline and the first described Aerobic Pond connect, and the 4th described bypass duct is provided with second sludge reflux pump, institute The bottom of the second Aerobic Pond stated is provided with a sludge water discharge tube, and the side of the second described Aerobic Pond is additionally provided with one Individual 5th pipeline, the 5th described pipeline and biosystem Aerobic Pond connect, the other end of described mixed reaction pond Connected with deep dehydration sludge water by first pipeline, the first described pipeline is provided with first water pump, described Deep dehydration sludge water and the first described pipeline between be provided with a grid, the side of described anoxic pond is provided with one Individual second pipe, described second pipe connects with described deep dehydration sludge water, and described second pipe is provided with one Individual second water pump.

4. a kind of sludge water total system according to claim 3 it is characterised in that：Described depositing reservoir and one Chemical sludge blow-off pipe connects, and described sedimentation tank and a phosphorous solid blow-off pipe connect.