Biochemical treatment microorganism maintenance and full-quantification treatment method for high-salt landfill leachate

Abstract

The invention provides a high-salt landfill leachate biochemical treatment microorganism maintenance and full-quantification treatment method which comprises the following steps: performing biochemical AO treatment on high-salt landfill leachate through a biochemical AO system, and treating the obtained effluent through an AO microorganism maintenance system to obtain first clear liquid and first concentrated liquid; the first clear liquid flows back to the front end of the denitrification tank through a desalted water backflow system; sludge water obtained through biochemical AO treatment is subjected to sludge water regulation treatment, sludge water separation is completed in a sedimentation tank, second clear liquid and first sludge are obtained, part of the first sludge is subjected to sludge treatment, and part of the first sludge flows back to the front end of denitrification; mixing the obtained first clear liquid and second clear liquid in a buffer pool, pumping the sewage in the buffer pool into an advanced treatment system, and enabling the sewage to flow into a clear water pool after reaching the standard. According to the invention, the desalting function of the system is maintained through microorganisms, the salt concentration of the AO system is reduced, the normal biochemical function of the biochemical AO system is realized, high-salt wastewater recharge is not generated, and the balance of leachate raw water salt production and treated water salt discharge is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of high-salt wastewater treatment, and in particular to a method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate. Background Art

[0002] The treatment of leachate from urban landfills has always been a very difficult problem in landfill design, operation and management. Leachate is the product of gravity flow of liquid in landfills, mainly from precipitation and the water contained in the garbage itself.

[0003] Landfill leachate has characteristics different from those of general urban sewage: high BOD5 and COD concentrations, high metal content, large changes in water quality and volume, high ammonia nitrogen content, imbalanced ratio of microbial nutrient elements, etc. In the past, leachate treatment processes were basically introduced from foreign membrane treatment systems, using pretreatment + biochemical + membrane (UF + RO) system or pretreatment + membrane system (two-stage DTRO membrane). The concentrated solution has a high concentration of chloride ions. If it is recharged into the regulating tank, the salt concentration of the entire system will gradually increase, the difficulty of treatment will increase, the water output will decrease, and a large amount of high-salt leachate will be accumulated; if the MVR evaporation process and cement kiln incineration are used to treat the concentrated solution, it is generally unacceptable due to the high cost; if the high-salt landfill leachate is treated with a biochemical AO system, it is difficult for its microorganisms to survive and it is difficult to achieve biochemical treatment of microorganisms. At present, landfill leachate treatment plants using RO membrane treatment systems have accumulated a large amount of concentrated liquid or recharged the regulating tank, causing the chloride ion concentration in the regulating tank to exceed 5000mg / L, basically between 7000-10000mg / L; these high-salt leachates have become a potential major environmental pollution risk for landfill treatment plants; the reasonable treatment of these high-salt leachates is an important environmental protection task.

[0004] Chloride ion concentration in common sewage is higher than 4000mg / L, which will have a certain toxic effect on the microorganisms in the biochemical treatment system; for example, when the chloride ion concentration in the aqueous solution is above 5000mg / L, the osmotic pressure will increase to about 10 -30 Atmospheric pressure. Under such a large osmotic pressure, a large number of water molecules in the microorganisms will penetrate into the external solution, causing cell dehydration and plasmolysis, and in severe cases, the microorganisms will die. Engineering experience data show that when the chloride ion concentration in the wastewater is greater than 2000mg / L, the activity of microorganisms will be inhibited and the COD removal rate will drop significantly; when the chloride ion concentration in the wastewater is greater than 8000mg / L, it will cause the sludge volume to expand, a large amount of foam will appear on the water surface, and the microorganisms will die one after another. Summary of the invention

[0005] In order to solve the problem of high-salt wastewater or concentrated liquid poisoning the biochemical treatment system in the above-mentioned prior art, the present invention provides a high-salt landfill leachate biochemical treatment microbial maintenance and full-quantity treatment method, which reduces the salt concentration of the AO system through the desalination function of the desalination system, realizes the normal biochemical function of the biochemical AO system, and does not produce high-salt wastewater re-injection to achieve the balance of salt production of leachate raw water and salt discharge of treated water, thereby solving the problem that high-salt landfill leachate or concentrated liquid is difficult to treat using a biochemical AO system.

[0006] In order to achieve the above object, the present invention provides a method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms, comprising the following steps:

[0007] Step 1, the high-salt garbage is infiltrated through the biochemical AO system for denitrification and nitrification treatment in sequence, and part of it is refluxed to the denitrification front end;

[0008] Step 2: The effluent obtained in step 1 is treated by the AO microbial maintenance system to obtain a first clear liquid and a first concentrated liquid. The first clear liquid is returned to the front end of the denitrification tank through the desalted water return system;

[0009] Step 3: The muddy water obtained in step 1 is subjected to muddy water conditioning treatment, and the sedimentation tank completes mud-water separation to obtain a second clear liquid and a first sludge, and part of the first sludge is subjected to sludge treatment, and part of the first sludge is returned to the denitrification front end;

[0010] In step 4, the first clear liquid obtained in step 2 and the second clear liquid obtained in step 3 are mixed in the buffer tank, and the sewage in the buffer tank is pumped into the Fenton system, the filter system, and the activated carbon system in sequence and flows into the clear water tank after meeting the standards.

[0011] Furthermore, before step 1, the method further includes: pre-treating the high-salt garbage infiltration, specifically adjusting the pH value and filtering treatment.

[0012] Furthermore, in step 2, the chloride ion concentration in the first clear solution is lower than that in the first concentrated solution.

[0013] Furthermore, in step 4, the sewage in the buffer tank is sequentially pumped into the Fenton system for Fenton treatment, and the organic pollutants that are difficult to biodegrade in the first concentrated solution and the second clear solution are oxidized by hydroxyl radicals generated by adding ferrous sulfate and hydrogen peroxide to obtain a third clear solution and a second sludge.

[0014] Furthermore, in step 4, the third clear liquid is subjected to filter treatment through a filter system, and the suspended solids SS in the third clear liquid, nitrification and denitrification complete denitrification, and oxidation removes COD to obtain a fourth clear liquid and a third type of sludge; after the fourth clear liquid meets the standards, it is discharged into the standard water discharge system.

[0015] Furthermore, in step 4, the fourth clear liquid is treated with activated carbon through an activated carbon system, and the activated carbon further adsorbs the refractory organic matter in the fourth clear liquid to obtain a fifth clear liquid, and the fifth clear liquid meets the discharge standards.

[0016] Furthermore, the sludge obtained in step 3 is dehydrated by a sludge dehydration system, and specifically, the sludge and water are separated by filter cloth interception to obtain a fourth sludge and a sixth clear liquid. The fourth sludge is disposed of in a sanitary landfill, and the sixth clear liquid is fed back into the sedimentation system for further treatment.

[0017] Furthermore, in step 2, the reflux amount of the desalted nitrification liquid, i.e., the amount of the first clear liquid, is calculated as follows:

[0018] (Q 原水 *m 原水盐浓度 +R 脱盐回流水 *m 脱盐后盐浓度 ) / (Q 原水 +R 脱盐回流水 *Q 原水 )=m 控制盐浓度 Q 原水 ---Amount of raw water inlet to AO system, m 3 / h;

[0019] m 原水盐浓度 ---Original influent salt ion concentration, mg / L;

[0020] R 脱盐回流水 ---Return ratio of wastewater with low salt ion concentration after desalination;

[0021] m 脱盐后盐浓度 --- Wastewater with low ion concentration after desalination, mg / L;

[0022] m 控制盐浓度 ---The salt ion concentration that needs to be controlled in the AO biochemical system.

[0023] Furthermore, the amount of the first concentrated solution in step 2 is calculated as follows:

[0024] 20% = Q 浓液 / Q 清液

[0025] Q 浓液 =20%*Q 清液

[0026] Q 浓液 ---Concentrate water production, m 3 / h;

[0027] Q 清液 ---Clear liquid water output, m 3 / h.

[0028] 80%---The output ratio of clear liquid and concentrated liquid in the desalination unit.

[0029] Furthermore, the sludge return flow is calculated as follows:

[0030] Q 污泥 =100%*Q 原水

[0031] Q 污水 ---Raw water inflow, m 3 / h;

[0032] Q 污泥 ---Sludge return flow, m 3 / h.

[0033] The present invention has the following beneficial effects:

[0034] (1) The salt ions in the raw water are temporarily extracted to create a sewage environment with low salt concentration (3500 mg / L chloride ion) for the AO system, so that the water in the microbial cells of Bacillus, nitrifying bacteria, denitrifying bacteria, actinomycetes and other microorganisms in the biochemical system does not actively diffuse into the sewage. The microorganisms survive in large numbers and then oxidize and decompose organic matter such as COD, obtain phosphorus pollutants and synthesize cells; the total nitrogen is removed through nitrification and denitrification.

[0035] (2) Temporarily reducing the salt concentration (removing chloride ions from the AO system) can treat high-concentration landfill leachate wastewater. The current RO membrane process makes it impossible to treat high-salt landfill water in the regulating pond and reservoir area to meet the discharge standards. If it continues to be stored, there will be an environmental risk of overflow. The use of MVR evaporation will greatly consume energy and is economically unreasonable. The use of a high-salt landfill leachate biochemical treatment microbial maintenance and full-scale treatment method provided by the present invention will solve the high-salt sewage treatment cost and overflow risk.

[0036] (3) The AO microbial maintenance system in the high-salt landfill leachate biochemical treatment microbial maintenance and full-scale treatment method provided by the present invention will create a low-salt environment (chloride ion) environment for the AO system, realize the function of biochemical treatment of pollutants, reduce the pressure on subsequent deep treatment, and realize the Fenton oxidation reagent cost and activated carbon replacement frequency in deep treatment.

[0037] (4) The present invention mainly intercepts the salt ions (chloride ions) of the AO system by setting up a disk filter AO microbial maintenance system, reduces the salt concentration (chloride ions) of the AO system, activates the activity of microorganisms, and converts high-salt leachate wastewater that cannot be biochemically treated into wastewater that can be biochemically treated, greatly reducing the cost of physical treatment. In addition, the present invention adopts a full-quantity treatment method. After the high-salt leachate enters the AO biochemical system, the salt is separated by the AO microbial maintenance system into two parts. One part is the separated low-salt wastewater that flows back to the front end of the AO system to dilute the high-salt leachate and protect the microorganisms of the AO system. The biochemical effluent is then mixed with the other separated high-salt wastewater for deep treatment to meet the discharge standards. There is no reinjection of high-salt concentrated wastewater, and the balance of the inflow and outflow of wastewater and the balance of the inflow and outflow of salt ions in the wastewater is achieved.

[0038] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 A simplified flow chart of a method for maintaining microorganisms and fully quantifying the biochemical treatment of high-salt landfill leachate provided by the present invention;

[0041] Figure 2 A detailed flow chart of a method for maintaining microorganisms and fully quantified treatment of high-salt landfill leachate biochemical treatment provided by the present invention. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the invention clearer, the process scheme of the embodiments of the invention is clearly and completely described below in conjunction with the drawings in the embodiments of the invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0044] The present invention provides a method for biochemical treatment of high-salt landfill leachate, microbial maintenance and full-scale treatment, and the device used includes a pretreatment system, a biochemical AO system, a mud water regulation system, an AO microbial maintenance system, a buffer tank, a deep treatment system, a clear water tank, a sludge dewatering system and other connected components. Among them, the biochemical AO system includes a denitrification system, a nitrification system, and an internal reflux system; the AO microbial maintenance system includes a biological maintenance pretreatment system, a microbial maintenance system, and a mud water regulation system; the deep treatment system includes a Fenton system, a filter tank system, an activated carbon adsorption system and other components.

[0045] like Figure 1 and Figure 2 As shown, the embodiment of the present invention provides a method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate microorganisms, and the process includes the following steps:

[0046] Step 1: pre-treat the high-salt garbage leachate to adjust the physicochemical properties of the high-salt garbage leachate and remove suspended matter and large particle pollutants in the leachate (suspended matter and large particle pollutants with density less than water are intercepted by the screen, and suspended matter and large particle pollutants with density greater than water are precipitated in the regulating tank, and the sludge at the bottom of the regulating tank is cleaned regularly).

[0047] Specifically, the physical and chemical properties of high-salt garbage leachate can be adjusted in the pretreatment; for example, the pH value can be adjusted to 7-9. In this embodiment, impurities such as suspended matter and large particle pollutants in the high-salt garbage leachate can be removed by filtering with a blue filter, and at the same time, the regulating tank uses a large volume to mix sewage with different pH values ​​before and after to reduce the large fluctuation of the pH value, thereby ensuring the water quality requirements of the high-salt garbage leachate when it enters the next stage of treatment.

[0048] Step 2: The pretreated high-salt garbage leachate is sequentially subjected to denitrification and nitrification treatments through a biochemical AO system, and part of the waste is returned to the denitrification front end.

[0049] Denitrification treatment can decompose some COD pollutants, ammoniation of organic nitrogen, and reflux of nitrification liquid to complete the denitrification function. Specifically, denitrifying bacteria reduce nitrates to nitrogen gas under the condition of providing carbon source to achieve denitrification function; at the same time, organic pollutants are decomposed into CO2 and H2O or some low molecular weight organic matter under the action of anaerobic bacteria.

[0050] Nitrification treatment can oxidize and decompose part of COD, ammoniation of organic nitrogen, and nitrification of ammonia nitrogen; the nitrification products are nitrates and nitrites, etc. Specifically, nitrifying bacteria, with the assistance of O2, convert ammonia nitrogen into nitrates; at the same time, organic pollutants are decomposed into CO2 and H2O or some low molecular weight organic matter under the action of aerobic bacteria; the reflux of nitrification liquid provides a large amount of nitrates and other substances for denitrification.

[0051] The pretreated leachate reacts in a multi-stage AO system to remove pollutants such as COD, ammonia nitrogen, total nitrogen, and phosphorus in the high-salt garbage leachate. Specifically, after a multi-stage anoxic aerobic tank reaction, organic nitrogen is converted into ammonia nitrogen through ammoniation, and then ammonia nitrogen is nitrified into nitrate, and then nitrate is denitrified into nitrogen gas to achieve denitrification; part of the COD is converted into inorganic substances such as CO2 and H2O through anoxic aerobic tank oxidation reaction; phosphorus is released through anaerobic dilution to achieve sewage phosphorus removal. Not only can the nitrification liquid be refluxed, but the sludge reflux can also be achieved to maintain the sludge concentration of the system, and the excess sludge is discharged from the sludge tank through a pump. The specific return volume is based on the sewage quality and formula: nitrification liquid return volume calculation and sludge return volume calculation.

[0052] Step 3: The effluent obtained in step 1 is treated by the AO microbial maintenance system to obtain a first clear liquid (a small amount of chloride ions) and a first concentrated liquid (a large amount of chloride ions). The first clear liquid is refluxed to the front end of the denitrification tank through the desalted water reflux system. The biological maintenance pretreatment system and the microbial maintenance system are used to separate large particle impurities and intercept chloride ions by the physical membrane to obtain a first concentrated liquid and a first clear liquid. The first clear liquid is injected into the denitrification tank through the desalted water reflux system, which can reduce the salt ion concentration of the AO system.

[0053] Specifically, the leachate treated by the biochemical AO system achieves the removal of most of the organic matter, nitrogen, phosphorus and other inorganic substances, and then enters the biological maintenance pretreatment system again to meet the influent water quality requirements of the biological maintenance system; the sewage flowing through the biological maintenance pretreatment system is pumped into the RO membrane, the main equipment of the biological maintenance system, and the separation of concentrated brine and clean water is achieved through the physical separation principle of reverse osmosis, thereby obtaining the first clear liquid (a small amount of chloride ions) and the first concentrated liquid (a large amount of chloride ions); the first clear liquid is returned to the front end of the denitrification system through the desalination nitrification liquid return system, and the return volume is approximately 100%-200% of the influent volume through conversion, which can dilute the chloride ions of about 10000 mg / L to less than 5000 mg / L. The specific calculated value is calculated based on the water quality and the return volume of the desalination nitrification liquid.

[0054] Step 4: The muddy water obtained in step 1 is subjected to muddy water conditioning treatment, and the sedimentation tank completes mud-water separation to obtain a second clear liquid and a first sludge, and part of the first sludge is subjected to sludge treatment, and part is returned to the denitrification front end.

[0055] The first clear liquid obtained in step 5 and step 2 and the second clear liquid obtained in step 3 are mixed in the buffer tank, and the sewage in the buffer tank is pumped into the deep treatment system (including the Fenton system, filter system, and activated carbon system connected in sequence) in sequence and flows into the clear water tank after meeting the standards.

[0056] The sewage in the buffer tank is pumped into the Fenton system for Fenton treatment in turn. The organic pollutants that are difficult to biodegrade in the first concentrated liquid and the second clear liquid are oxidized by hydroxyl radicals generated by adding ferrous sulfate and hydrogen peroxide to obtain the third clear liquid and the second sludge.

[0057] The third clear liquid is treated by the filter system, and the suspended solids SS in the third clear liquid, nitrification and denitrification are completed, and COD is oxidized to remove, so as to obtain the fourth clear liquid and the third sludge; the fourth clear liquid meets the standards and can be discharged into the qualified water discharge system.

[0058] The fourth clear liquid is treated with activated carbon through an activated carbon system, and the activated carbon further adsorbs the difficult-to-degrade organic matter in the fourth clear liquid to obtain a fifth clear liquid, and the fifth clear liquid meets the discharge standards.

[0059] Specifically, the first clear liquid and the second clear liquid are mixed in a mixing tank and pumped into the Fenton treatment system through a pump group (flow meter and valve). The Fenton system oxidizes the difficult-to-degrade organic matter through hydroxyl radicals generated by the added ferrous sulfate and hydrogen peroxide. The mud-water mixture is separated from the water under the action of PAM coagulation when the pH value is adjusted by alkali. The sludge is discharged into the sludge tank, and the sewage flows into the filter system by gravity to further remove COD, ammonia nitrogen, total nitrogen, SS and other pollutants. The sewage treated in the filter enters the activated carbon to further adsorb pollutants through the gaps in the carbon, and flows into the clear water tank for discharge after meeting the standards.

[0060] Step 6, the excess AO sludge and Fenton chemical sludge are dehydrated by the sludge dehydration system, the sludge is dehydrated by the plate and frame, and the sixth clear liquid after the plate and frame filter is returned to the first stage of the multi-stage AO system. The mud and water can also be separated by filter cloth interception to obtain the fourth sludge (low water content) and the sixth clear liquid. The fourth sludge is disposed of in sanitary landfill, and the sixth clear liquid is returned to the sedimentation system for further treatment.

[0061] In the method for biochemical treatment of high-salt landfill leachate by microbial maintenance and full-quantity treatment provided by the invention, the calculation of the reflux volume is as follows:

[0062] ① Calculation of total reflux volume:

[0063] Q 回流泥水 =Q 原水 *R 总

[0064] R 总 =(TN 进水 -TN 出水 ) / TN 出水

[0065] Q 回流泥水 ---The sum of the three types of mud and water: the returned sludge, the returned nitrification liquid, and the returned desalted nitrification liquid, m 3 / h;Q 污水---Raw water inflow, m 3 / h;

[0066] TN 进水 ---Total nitrogen in the raw water of biochemical pool A, mg / L;

[0067] TN 出水 ---Total nitrogen in the effluent from the biochemical O2 pool, mg / L;

[0068] ②Calculation of desalination nitrification liquid reflux volume (first clear liquid volume):

[0069] (Q 原水 *m 原水盐浓度 +R 脱盐回流水 *m 脱盐后盐浓度 ) / (Q 原水 +R 脱盐回流水 *Q 原水 )=m 控制盐浓度 Q 原水 ---Amount of raw water inlet to AO system, m 3 / h;

[0070] m 原水盐浓度 ---Original influent salt ion concentration, mg / L;

[0071] R 脱盐回流水 ---Return ratio of wastewater with low salt ion concentration after desalination;

[0072] m 脱盐后盐浓度 --- Wastewater with low ion concentration after desalination, mg / L;

[0073] m 控制盐浓度 ---The salt ion concentration that needs to be controlled by the AO biochemical system can be set to 3500mg / L, 4000mg / L, and 5000mg / L.

[0074] ③ Calculation of sludge return flow:

[0075] Q 污泥 =100%*Q 原水

[0076] Q 污水 ---Raw water inflow, m 3 / h;

[0077] Q 污泥 ---Sludge return flow, m 3 / h.

[0078] ④ Calculation of nitration liquid reflux volume:

[0079] Q 硝化液回流量 =(R 总 -100%-R 脱盐回流水 )*Q原水

[0080] ⑤ Calculation of the first concentrated liquid volume:

[0081] 20% = Q 浓液 / Q 清液

[0082] Q 浓液 =20%*Q 清液

[0083] Q 浓液 ---Concentrate water production, m 3 / h;

[0084] Q 清液 ---Clear liquid water output, m 3 / h.

[0085] 80%---The output ratio of clear liquid and concentrated liquid in the desalination unit.

[0086] The present invention is described in detail below with reference to specific embodiments.

[0087] The leachate treatment plant of a landfill has a treatment capacity of 100m 3 / d, originally there was a box-type DTRO membrane to treat the leachate, which reinjected a large amount of concentrated solution with high concentration of chloride ions; now after the transformation, the high-salt leachate wastewater is treated according to the process of multi-stage AO biochemical system + MBR ultrafiltration membrane system + AO microbial maintenance system (desalting device) + buffer tank + deep treatment system (two-stage Fenton + filter tank + activated carbon). The influent water quality is shown in Table 1.

[0088] Table 1:

[0089] Serial number Water quality indicators Total water inflow value Total water output value unit 1 PH 6.8-8.5 6.0-9.0 2 COD 1500-2000 ≤100 mg / L 3 BOD 200-600 ≤25 mg / L 4 Chloride ion 10000 ≤10000 mg / L 5 Ammonia nitrogen 1200-1500 ≤25 mg / L 6 Total Nitrogen 1300-1600 ≤40 mg / L

[0090] The present invention adopts a high-salt garbage leachate biochemical treatment microbial maintenance and full-quantity treatment method to treat 100m 3 / d high-salt landfill leachate is treated as follows:

[0091] 1) Pretreatment: A large-volume regulating tank is used to adjust the pH of the water so that the pH of the sewage is between 6 and 9, which is beneficial to AO microorganisms. A blue filter intercepts large particles in the sewage to protect subsequent sewage pumps and pipelines.

[0092] 2) Two-stage AO (chloride concentration is set to 3500mg / L) + MBR device + AO microbial maintenance system (chloride concentration of desalination water is set to 50mg / L). The pre-treated high-salt leachate wastewater enters the two-stage AO + MBR device + AO microbial maintenance system for treatment.

[0093] The reflux is calculated as follows:

[0094] a.Total reflux ratio of primary AO:

[0095] R 总 =(TN 进水 -TN 出水 ) / TN 出水 =(1600-229) / 219=6.3

[0096] b. Secondary AO total reflux ratio:

[0097] R 总 =(TN 进水 -TN 出水 ) / TN 出水 =(219-30) / 30=6.3

[0098] Take the total reflow ratio of the MBR device as R 总 =6.3

[0099] c. Sludge return ratio:

[0100] R 污泥 =100%=1.0

[0101] d. Calculation of desalination nitrification liquid reflux ratio:

[0102] (Q 原水 *C 原水盐浓度 +Q 原水 *R 脱盐回流水 *C 脱盐后盐浓度 ) / (Q 原水 +R 脱盐回流水 *Q 原水 )=C 控制盐浓

[0103] Spend

[0104] (4.166*10000+4.166*R 脱盐回流水 *50) / (4.166+R 脱盐回流水 *4.166)=3500

[0105] Launch R 脱盐回流水 =1.88

[0106] e. Calculation of nitration liquid reflux:

[0107] R 硝化液回流量 =R 总 -100%-R 脱盐回流水 =6.3-1.0-1.88=3.42

[0108] f. The first concentrated solution water production:

[0109] Q浓液 =20%*Q 清液 =0.2*1.88*4.16=1.56m3 / h

[0110] g. Calculate the chloride ion concentration of the concentrated solution based on the chloride ion balance:

[0111] 10000*(1.88*4.16+1.88*4.16*0.2)=1.88*4.16*50+C 浓液 *1.88*4.16*0.2

[0112] Launch C 浓液 =59750mg / L

[0113] According to the high-salt landfill leachate biochemical treatment microbial maintenance and full-quantity treatment method of the present invention, the high-salt landfill leachate sewage with upper surface water quality is treated, and the two-stage AO sludge return volume is 4.16m 3 / h, desalination nitrification liquid reflux is 7.82m 3 / h, nitration liquid reflux 14.22m 3 / h, the first concentrated liquid water output is 1.56m 3 / h. The chloride ion concentration of the first clear solution is 50 mg / L, and the chloride ion concentration of the first concentrated solution is 59750 mg / L.

[0114] The water quality of MBR effluent is shown in Table 2:

[0115] Table 2:

[0116]

[0117]

[0118] The water output of MBR is 11.98m 3 / h; 2.6m 3 / h sewage enters the buffer tank, 9.38m 3 / h sewage enters the desalination device for treatment, the first concentrated liquid is 1.56m 3 / h, the first clear liquid (desalting nitrification liquid) is 7.82m 3 / h.

[0119] The mixed water quality of the buffer tank is shown in Table 3: (2.6m of water entering the MBR in the buffer tank 3 / h, and the first concentrated liquid entering at the same time is 1.56m 3 / h)

[0120] Table 3:

[0121]

[0122] 3) Deep treatment system (two-stage Fenton + filter + activated carbon)

[0123] The effluent from the buffer tank is pumped into a two-stage Fenton system, and after adding ferrous sulfate, hydrogen peroxide, caustic soda flakes, and PAM, it flows into the filter tank to remove SS and some pollutants. The pollutants that cannot be removed by Fenton advanced oxidation can be adsorbed by the activated carbon filter tank to meet the emission standards.

[0124] The water quality of each level of effluent is shown in Table 4:

[0125] Table 4:

[0126]

[0127]

[0128] It can be seen from Table 4 that the water quality after deep treatment by the deep treatment system (specifically two-stage Fenton + filter + activated carbon) meets the discharge standards.

[0129] In summary, the present invention provides a method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate by microorganisms, which solves the toxic effects of high-salt wastewater or concentrated liquid on the microorganisms of the biochemical treatment system, reduces the salt concentration of the AO system through the desalination function of the desalination system, realizes the normal biochemical function of the biochemical AO system, and does not produce high-salt wastewater re-injection to achieve the balance of salt production of the leachate raw water and salt discharge of the treated water. The present invention adopts a fully quantified treatment method. After the high-salt leachate enters the AO biochemical system, the salt is separated into two parts by the AO microbial maintenance system. One part is the separated low-salt sewage that flows back to the front end of the AO system to dilute the high-salt leachate and protect the microorganisms of the AO system. The biochemical effluent is then mixed with the other separated high-salt sewage for deep treatment to meet the discharge standards. There is no re-injection of high-salt concentrated sewage, which achieves the balance of sewage water inflow and outflow and the balance of salt ions in sewage inflow and outflow. The present invention intercepts salt ions (chloride ions) of the AO system by setting up a disk filter AO microbial maintenance system, reduces the salt concentration (chloride ions) of the AO system, activates the activity of microorganisms, converts high-salt leaching wastewater that cannot be biochemically treated into wastewater that can be biochemically treated, and greatly reduces the cost of physical treatment.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate, characterized in that: The following steps are involved: Step 1, the high-salt garbage is infiltrated through the biochemical AO system for denitrification and nitrification treatment in sequence, and part of it is refluxed to the denitrification front end; Step 2: The effluent obtained in step 1 is treated by the AO microbial maintenance system to obtain a first clear liquid and a first concentrated liquid. The first clear liquid is returned to the front end of the denitrification tank through the desalted water return system; Step 3: The muddy water obtained in step 1 is subjected to muddy water conditioning treatment, and the sedimentation tank completes mud-water separation to obtain a second clear liquid and a first sludge, and part of the first sludge is subjected to sludge treatment, and part of the first sludge is returned to the denitrification front end; In step 4, the first clear liquid obtained in step 2 and the second clear liquid obtained in step 3 are mixed in the buffer tank, and the sewage in the buffer tank is pumped into the Fenton system, the filter system, and the activated carbon system in sequence and flows into the clear water tank after meeting the standards.

2. A method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate according to claim 1, characterized in that: Before step 1, the method also includes: pre-treating the high-salt garbage infiltration, specifically adjusting the pH value and filtering.

3. The method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 1, characterized in that: In step 2, the chloride ion concentration in the first clear solution is lower than that in the first concentrated solution.

4. A method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate according to claim 1, characterized in that: In step 4, the sewage in the buffer tank is sequentially pumped into the Fenton system for Fenton treatment, and the organic pollutants that are difficult to biodegrade in the first concentrated solution and the second clear solution are oxidized by hydroxyl radicals generated by adding ferrous sulfate and hydrogen peroxide to obtain a third clear solution and a second sludge.

5. A method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 4, characterized in that: In step 4, the third clear liquid is subjected to filter treatment through a filter system, and the suspended solids SS in the third clear liquid, nitrification and denitrification complete denitrification, and COD is oxidized to remove, thereby obtaining a fourth clear liquid and a third type of sludge; after the fourth clear liquid meets the standards, it is discharged into the standard water discharge system.

6. A method for maintaining and fully quantifying the biochemical treatment of high-salt landfill leachate according to claim 5, characterized in that: In step 4, the fourth clear liquid is treated with activated carbon through an activated carbon system, and the activated carbon further adsorbs the refractory organic matter in the fourth clear liquid to obtain a fifth clear liquid, and the fifth clear liquid meets the discharge standards.

7. The method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 1, characterized in that: The sludge obtained in step 3 is dehydrated by a sludge dehydration system, and specifically the sludge and water are separated by filter cloth interception to obtain the fourth sludge and the sixth clear liquid. The fourth sludge is disposed of in a sanitary landfill, and the sixth clear liquid is fed back into the sedimentation system for further treatment.

8. The method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 1, characterized in that: In step 2, the reflux rate of desalted nitrification liquid, i.e., the first clear liquid volume, is calculated as follows: (Q 原水 *m 原水盐浓度 +R 脱盐回流水 *m 脱盐后盐浓度 ) / (Q 原水 +R 脱盐回流水 *Q 原水 )=m 控制盐浓度 Q 原水 ---Amount of raw water inlet to AO system, m 3 / h; m 原水盐浓度 ---Original influent salt ion concentration, mg / L; R 脱盐回流水 ---Return ratio of wastewater with low salt ion concentration after desalination; m 脱盐后盐浓度 --- Wastewater with low ion concentration after desalination, mg / L; m 控制盐浓度 ---The salt ion concentration that needs to be controlled in the AO biochemical system.

9. The method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 1, characterized in that: The amount of the first concentrated solution in step 2 is calculated as follows: 20%=Q 浓液 / Q 清液 Q 浓液 =20%*Q 清液 Q 浓液 ---Concentrate water production, m 3 / h; Q 清液 ---Clear liquid water output, m 3 / h; 80%---The output ratio of clear liquid and concentrated liquid in the desalination unit.

10. The method for maintaining and fully treating high-salt landfill leachate by biochemical treatment of microorganisms according to claim 1, characterized in that: The sludge return flow rate is calculated as follows: Q 污泥 =100%*Q 原水 Q 污水 ---Raw water inflow, m 3 / h; Q 污泥 ---Sludge return flow, m 3 / h.

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