Treatment system suitable for medium-aged and aged organic refuse landfill leachate wastewater

Abstract

The utility model provides a treatment system suitable for medium and old organic refuse landfill leachate wastewater. The treatment system comprises a primary settling regulating tank, a biochemical system, an oxidation adsorption coagulating sedimentation system, an intermediate water tank, a catalytic ozonation tower, an ozone stripping tank, a biological aerated filter and a clean water tank which are connected in sequence, the biochemical system comprises an anoxic tank, an aerobic tank and a membrane bioreactor (MBR) tank which are sequentially connected, a nitrification liquid return pipe is further arranged between the anoxic tank and the aerobic tank and used for returning nitrification liquid at the tail end in the aerobic tank to the front end of the anoxic tank, and a second sludge pipe is arranged between the anoxic tank and the MBR tank and used for returning nitrification liquid at the tail end in the aerobic tank to the front end of the anoxic tank. The anaerobic tank is used for refluxing part / all of sludge deposited in the MBR tank to the front end of the anaerobic tank; the oxidation adsorption coagulating sedimentation system comprises an oxidation pond, an adsorption pond, a mixing pond, a flocculation pond and a sedimentation pond which are connected in sequence, and the oxidation pond is connected with a potassium permanganate adding device. The scheme improves the wastewater treatment process and improves the wastewater treatment efficiency according to the wastewater characteristics.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of sewage treatment, specifically, relate to a kind of processing system suitable for middle-aged organic garbage landfill leachate wastewater. BACKGROUND

[0002] Landfill leachate is a kind of high-concentration organic wastewater, containing aromatic hydrocarbons, heterocyclic compounds, halogenated compounds, alkanes and alkenes and other organic substances, water quantity and water quality change greatly, affected by external environment, garbage composition, garbage disposal method and other factors. Landfill leachate mainly comes from the natural precipitation of the site, the natural moisture contained in the garbage disposal itself and the moisture formed in the garbage degradation process, and its characteristics are complex composition, high content, multiple types, high COD (chemical oxygen demand) concentration, ammonia nitrogen concentration and color, which is a kind of particularly difficult to handle wastewater. The properties of leachate change significantly with the increase of landfill time, and the middle-aged organic landfill site refers to the landfill time more than 5 years or 10 years, and the ammonia nitrogen concentration of its leachate wastewater increases, and the biodegradability decreases, so that the traditional biological treatment method suitable for treating early-stage leachate is difficult to treat middle-aged leachate.

[0003] At present, there are mainly three problems in the treatment of middle-aged leachate wastewater:

[0004] (1) The treatment efficiency of activated sludge

[0005] Activated sludge method is still the most important technology for treating landfill leachate and the most economical method. However, due to the high concentration of pollutants in leachate wastewater and the complex composition, the biodegradability decreases with the increase of landfill time, which reduces the activity of activated sludge in leachate treatment system, and the concentration is not high, so the treatment efficiency of activated sludge is low.

[0006] (2) The treatment problem of high-concentration ammonia nitrogen

[0007] The ammonia nitrogen concentration in leachate increases with the increase of landfill time, and high ammonia nitrogen has a certain inhibitory effect on biochemical system, making it difficult to remove nitrogen.

[0008] (3) The treatment problem of refractory organic matter

[0009] The wastewater itself contains a large amount of refractory macromolecular organic matter, and some refractory metabolites will be produced in the biological treatment process due to the high COD concentration of leachate. For middle-aged landfill leachate wastewater, the waste gradually decays, part of COD is degraded into humus, and it is difficult to proliferate activated sludge.

[0010] The existing landfill leachate wastewater treatment mainly has a combined process of pretreatment physicochemical treatment + biochemical treatment + advanced chemical oxidation treatment or membrane treatment, but all have low biochemical treatment efficiency, large chemical oxidation sludge, and the requirement of effluent COD less than 100 mg / L cannot be met by the deep treatment without using the membrane treatment such as nanofiltration and reverse osmosis; if the nanofiltration and reverse osmosis membrane treatment system is used in the deep treatment, there are problems of difficult treatment of the concentrated liquid of the membrane system, high investment and operation cost of the membrane system. Content of the utility model

[0011] In view of the defects in the prior art, the utility model aims at providing a treatment system suitable for middle-aged and old organic landfill leachate wastewater, improving the wastewater treatment process, improving the wastewater treatment efficiency, reducing secondary pollution, ensuring the safety and reliability of effluent, and reducing the investment and operation cost.

[0012] The utility model provides a treatment system suitable for middle-aged and old organic landfill leachate wastewater, which comprises a primary sedimentation adjusting tank, a biochemical system, an oxidation adsorption coagulation sedimentation system, an intermediate tank, an ozone catalytic oxidation tower, an ozone stripping tank, a biological aerated filter and a clear water tank which are connected in sequence.

[0013] A leachate inlet end is arranged on the primary sedimentation adjusting tank and is used for leachate inlet.

[0014] The biochemical system comprises an anoxic tank, an aerobic tank and a membrane bioreactor (MBR) tank which are connected in sequence, a nitrification liquid return pipe is further arranged between the anoxic tank and the aerobic tank and is used for returning the nitrification liquid at the tail end of the aerobic tank to the front end of the anoxic tank, and a second sludge pipe is arranged between the anoxic tank and the membrane bioreactor (MBR) tank and is used for returning part / whole sludge deposited in the membrane bioreactor (MBR) tank to the front end of the anoxic tank.

[0015] The oxidation adsorption coagulation sedimentation system comprises an oxidation tank, an adsorption tank, a mixing tank, a flocculation tank and a sedimentation tank which are connected in sequence, and the oxidation tank is connected with a potassium permanganate dosing device.

[0016] The ozone catalytic oxidation tower is further connected with an ozone generator and an ozone tail gas destruction device respectively.

[0017] A water outlet end is arranged on the clear water tank and is used for effluent discharge meeting the standard.

[0018] The aerobic tank, the membrane bioreactor (MBR) tank, the ozone stripping tank and the biological aerated filter are connected with a blower.

[0019] Preferably, a sludge treatment system is further included; a third sludge pipe is arranged between the membrane bioreactor MBR tank and the sludge treatment system for conveying part / whole of the sludge deposited in the membrane bioreactor MBR tank to the sludge treatment system; a fourth sludge pipe is arranged between the sedimentation tank and the sludge treatment system for conveying the sludge deposited in the sedimentation tank to the sludge treatment system.

[0020] Preferably, a primary sedimentation adjusting tank top cover is arranged on the top of the primary sedimentation adjusting tank, a dewatering machine is arranged on the primary sedimentation adjusting tank top cover, a filtrate outlet of the dewatering machine is connected with a filtrate inlet of the primary sedimentation adjusting tank, and a first sludge pipe is further arranged between the primary sedimentation adjusting tank and the dewatering machine for conveying the sludge deposited in the primary sedimentation adjusting tank to the dewatering machine.

[0021] Preferably, a first enzyme floating filler is arranged in the anoxic tank, and a second enzyme floating filler is arranged in the aerobic tank, wherein the first enzyme floating filler and the second enzyme floating filler are the same or different.

[0022] Preferably, a jet flow device and a microporous aerator are further arranged in the aerobic tank, the jet flow device is located at the water inlet end of the aerobic tank, and the microporous aerator is located at the rear end of the jet flow device.

[0023] Preferably, the adsorption tank is connected with an activated carbon feeding device, the mixing tank is connected with a polyaluminum chloride feeding device, and the flocculation tank is connected with a polyacrylamide feeding device.

[0024] Preferably, an ozone aeration disc is arranged at the bottom of the ozone catalytic oxidation tower, and a catalyst layer is arranged at the middle and lower parts of the ozone catalytic oxidation tower.

[0025] Preferably, a plurality of first sedimentation groove hoppers are arranged at the bottom of the primary sedimentation adjusting tank.

[0026] A inclined plate filler is arranged in the sedimentation tank, at least one second sedimentation groove hopper is arranged at the bottom of the sedimentation tank, and the inclined plate filler is located above the second sedimentation groove hopper.

[0027] Preferably, the sludge treatment system includes a sludge collection tank, a sludge concentration tank and a filter press connected in sequence; the membrane bioreactor MBR tank and the sedimentation tank are respectively connected with the sludge collection tank.

[0028] Preferably, the reverse washing pipe is further connected with the outlet of the clear water tank, the first outlet of the reverse washing water is connected with the reverse washing water inlet pipe of the membrane bioreactor MBR tank, the second outlet of the reverse washing water is connected with the reverse washing water inlet pipe of the ozone catalytic oxidation tower, the third outlet of the reverse washing water is connected with the reverse washing water inlet pipe of the biological aerated filter, the reverse washing water outlet pipe of the membrane bioreactor MBR tank is connected with the primary sedimentation tank, the reverse washing water outlet pipe of the ozone catalytic oxidation tower is connected with the primary sedimentation tank, the reverse washing water outlet pipe of the biological aerated filter is connected with the primary sedimentation tank, and the reverse washing water discharged from the membrane bioreactor MBR tank, the ozone catalytic oxidation tower and the biological aerated filter is transported to the primary sedimentation tank.

[0029] Compared with the prior art, the utility model has the beneficial effects that:

[0030] (1) The primary sedimentation tank has the functions of sedimentation, water storage adjustment, hydrolysis acidification and the like, removes part of organic matters, improves the biodegradability of wastewater, simplifies the process flow, and is convenient for operation, operation and maintenance; the sludge in the primary sedimentation tank contains a large amount of oil, humus organic matter and the like, and is separately treated by using a dewatering machine (such as a stacked screw dewatering machine, which adopts a low-speed mechanical extrusion mode, and does not have filter cloth and sludge injection holes in the whole device, and does not need to borrow the difference between gravity and centrifugal force, so that problems such as separation failure, filter cloth and filter hole blockage do not occur, and oil-containing sludge dewatering is easily realized.

[0031] (2) The anoxic tank and the aerobic tank are both installed with the novel enzyme floating filler, the filler realizes the special structure of a double-membrane and a gap layer through processes such as fiber spinning, needling, raising and heat setting, greatly improves the specific surface area and porosity of the filler, and the effective biological concentration is about 2-5 times that of the conventional activated sludge method and the membrane method, and the biochemical system volume load is improved; the good hydrophilicity and the special enzyme adding process effectively solve the problems of slow adsorption of microorganisms on the surface of the filler, poor affinity between the surface of the filler and the microorganisms and the like in the existing biological membrane method. The food chain of the microorganisms on the enzyme floating filler is long, and the nitrifying bacteria with long sludge age are suitable for growth, so that the enzyme floating filler has good biological denitrification function; the microorganisms are diversified, and have strong adaptability to water quality and water quantity changes.

[0032] (3) The aerobic tank adopts the mixed aeration mode of micro-porous aeration and jet aeration, has high mass transfer efficiency, and greatly reduces energy consumption; the novel enzyme floating filler installed in the aerobic tank constructs the violent mixing and mass transfer of gas, liquid and solid three phases, and supplements the oxygen supply of the air blowing aeration, so that the mixing effect is good.

[0033] (4) The aerobic tank provided by the utility model is arranged on the pool shape, the water inlet side of the aerobic tank starts to adopt the jet aeration mode to fully mix and stir the water, the jet aeration accounts for about 1 / 4 of the total aeration amount; the subsequent part of the pool adopts the microporous aeration mode, and the water flow is relatively stable. The arrangement forms a gas-liquid-solid three-phase turbulent flow area in the water inlet area of the aerobic tank, can efficiently and quickly mix and disperse the toxic and harmful substances in the aerobic tank, is resistant to impact load; the microporous aeration is adopted in the main body area of the aerobic tank, good hydraulic conditions are provided, on the basis of good mixing of the gas-liquid-solid three phases, the hydraulic scouring to the filler is reduced, so that the biological membrane of the unaged filler is prevented from falling off, the filler coating effect is ensured; meanwhile, the stable water flow can ensure that the waste water flows into the subsequent membrane bioreactor MBR tank in a stable manner.

[0034] (5) The utility model discloses a biochemical effluent adopts potassium permanganate / ozone composite oxidation technology, plays the synergistic oxidation effect, simultaneously, the potassium permanganate reduction intermediate valence manganese oxide can produce catalytic oxidation effect to ozone, further improves the ozone processing efficiency, the oxidation object of potassium permanganate and ozone is different, and the potassium permanganate can oxidize mercaptan, aldehyde and phenol substance, and ozone often acts on heterocyclic macromolecular compound, and the potassium permanganate and ozone are two types of complementary water treatment reagents, through the treatment of different types of organic matter, finally improve the biodegradability of waste water, and reduce the COD of waste water.

[0035] (6) The utility model discloses a potassium permanganate is reduced and generates manganese dioxide under neutral condition. Manganese dioxide has low solubility in water, and can form hydrated manganese dioxide colloid with large specific surface area, and can also adsorb other organic matters. The dual action of oxidation of potassium permanganate and adsorption of manganese dioxide can not only remove the oxidized organic matter, but also remove the unoxidized organic matter; the effluent after oxidation of potassium permanganate is adsorbed by activated carbon, which plays a synergistic effect, and the oxidation and decomposition of macromolecular organic matter by potassium permanganate and the generation of manganese dioxide colloid are beneficial to the adsorption of activated carbon, and then removed by subsequent coagulation and sedimentation. BRIEF DESCRIPTION OF DRAWINGS

[0036] Other features, objects and advantages of the utility model will become more apparent through reading the following detailed description of non-restrictive embodiments with reference to the accompanying drawings:

[0037] Figure 1 A structure schematic view of a treatment system suitable for middle-aged and old organic landfill leachate wastewater is provided for the utility model embodiment.

[0038] In the drawings:

[0039] 1, primary sedimentation conditioning tank; 1-1, dewatering machine; 2, biochemical system; 201, anoxic tank; 202, aerobic tank; 203, membrane bioreactor MBR tank; 201-1, first enzyme floating filler; 202-1, second enzyme floating filler; 202-2, jet device; 3, oxidation adsorption coagulation sedimentation system; 301, oxidation tank; 302, adsorption tank; 303, mixing tank; 304, flocculation tank; 305, sedimentation tank; 4, intermediate water tank; 5, ozone catalytic oxidation tower; 6, ozone stripping tank; 7, biological aerated filter; 8, clean water tank; 9, sludge collection tank; 10, sludge concentration tank; 11, filter press. DETAILED DESCRIPTION

[0040] The utility model will be explained in detail below in combination with specific embodiments. The following embodiments will help the person skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for the person skilled in the art, on the premise of not departing from the utility model concept, a number of changes and improvements can be made. These all belong to the protection scope of the utility model.

[0041] Embodiment:

[0042] Please refer to Figure 1 The utility model embodiment provides a kind of for middle-aged and old organic landfill leachate wastewater treatment system, using biochemical treatment as main process, cooperate with the optimization combination process of pretreatment and depth treatment, including sequentially connected primary sedimentation conditioning tank 1, biochemical system 2, oxidation adsorption coagulation sedimentation system 3, intermediate water tank 4, ozone catalytic oxidation tower 5, ozone stripping tank 6, biological aerated filter 7, clean water tank 8, sludge treatment system and backwash pipe;

[0043] Primary sedimentation conditioning tank 1 is provided with leachate inlet end, for leachate inlet;Primary sedimentation conditioning tank 1 is provided with primary sedimentation conditioning tank top cover on top, for collecting odor, and primary sedimentation conditioning tank top cover is provided with dewatering machine 1-1, and the filtrate outlet end of dewatering machine 1-1 is connected with the filtrate inlet end of primary sedimentation conditioning tank 1, so that the filtrate outlet of dewatering machine 1-1 is discharged into primary sedimentation conditioning tank 1, and first sludge pipe is further provided between primary sedimentation conditioning tank 1 and dewatering machine 1-1, for conveying the sludge deposited in primary sedimentation conditioning tank 1 to dewatering machine 1-1;Preferably, the inside bottom of primary sedimentation conditioning tank 1 is provided with multiple first sedimentation tank hoppers, and the hopper inclination is 60 °, uses perforated pipe to regularly pump mud discharge, and dewatering machine 1-1 uses stacked screw dewatering machine, and the oil-containing dry sludge obtained after stacked screw dewatering machine treatment is transported for disposal;Because primary sedimentation conditioning tank stays for a long time, water storage regulation, sedimentation and hydrolysis acidification can be realized simultaneously;

[0044] The biochemical system 2 comprises an anoxic tank 201, an aerobic tank 202 and a membrane bioreactor MBR tank 203 connected in sequence; the first enzyme floating filler 201-1 is arranged in the anoxic tank 201, the second enzyme floating filler 202-1 is arranged in the aerobic tank 202, the first enzyme floating filler 201-1 is the same as or different from the second enzyme floating filler 202-1, and the sludge concentration is improved; the jet device 202-2 and the microporous aerator are further arranged in the aerobic tank 202, the jet device 202-2 is located at the water inlet end of the aerobic tank 202, and the microporous aerator is located at the rear end of the jet device 202-2, that is, the microporous aeration and the jet aeration are mixed in the aerobic tank 202, the jet aeration is used at the water inlet end of the aerobic tank 202 to fully mix and stir the water, and then the microporous aeration is used, and the water flow is relatively stable; the membrane bioreactor MBR tank 203 separates the sludge and water, and the PVDF flat membrane is used in the membrane bioreactor MBR tank 203, and the membrane pore size is less than 0.1 μm; the nitrification liquid reflux pipe is further arranged between the anoxic tank 201 and the aerobic tank 202, used for refluxing the nitrification liquid at the tail end of the aerobic tank 202 to the front end of the anoxic tank 201 to perform the denitrification reaction; the second sludge pipe is arranged between the anoxic tank 201 and the membrane bioreactor MBR tank 203, used for refluxing part / whole sludge deposited in the membrane bioreactor MBR tank 203 to the front end of the anoxic tank 201 to ensure the sludge concentration; the third sludge pipe is arranged between the membrane bioreactor MBR tank 203 and the sludge treatment system, used for conveying part / whole sludge deposited in the membrane bioreactor MBR tank 203 to the sludge treatment system; wherein the proportion of the sludge deposited in the membrane bioreactor MBR tank 203 refluxing to the anoxic tank 201 and the sludge treatment system depends on the sludge concentration requirement of the anoxic tank 201, and the priority of the conveying is that the anoxic tank 201 is higher than the sludge treatment system;

[0045] The oxidation adsorption coagulation sedimentation system 3 comprises an oxidation tank 301, an adsorption tank 302, a mixing tank 303, a flocculation tank 304 and a sedimentation tank 305 connected in sequence, the oxidation tank 301 is connected with a potassium permanganate adding device, the adsorption tank 302 is connected with a powdered activated carbon adding device, the mixing tank 303 is connected with a polyaluminum chloride adding device, the flocculation tank 304 is connected with a polyacrylamide adding device, under neutral conditions, the potassium permanganate oxidizes macromolecular organic matter into small molecular organic matter, the effluent flows into the adsorption tank 302 by itself, which is beneficial to the adsorption of organic matter and colority by activated carbon and improves the decontamination effect, meanwhile, coagulation is carried out in the subsequent mixing tank 303 and flocculation tank 304, the dispersed small flocculation bodies are destabilized and aggregated into large flocculation bodies, which is beneficial to the removal by sedimentation; the sedimentation tank 305 is provided with a fourth sludge pipe between the sedimentation tank 305 and the sludge treatment system, which is used for conveying the sludge deposited in the sedimentation tank 305 to the sludge treatment system; preferably, the activated carbon adding device is used for adding powdered activated carbon, the sedimentation tank 305 is provided with a inclined plate filler at a position 1.2 meters below the water surface, and the sedimentation tank 305 is provided with at least one second sedimentation tank hopper at the bottom, the inclined plate filler is located above the second sedimentation tank hopper, the sedimentation efficiency is improved and the land occupation is reduced by adopting the inclined plate sedimentation form;

[0046] The ozone catalytic oxidation tower 5 is also connected with an ozone generator and an ozone tail gas destruction device respectively; the bottom of the ozone catalytic oxidation tower 5 is provided with an ozone aeration disc made of titanium alloy, which disperses ozone gas into small bubbles through micropores, the bubbles fully contact with water during the rising process, the gas-water mixing effect is good, and the ozone utilization rate is high; the middle and lower part of the ozone catalytic oxidation tower 5 is provided with a catalyst layer, the active material of which is nanoscale transition metal ions such as iron, nickel, manganese and cobalt, which can provide active sites for the reaction of ozone and organic matter in wastewater, further accelerate the reaction process, and at the same time, the catalyst layer can increase the gas-liquid contact area and promote gas-liquid mixing, so that the ozone catalytic oxidation efficiency is high; the ozone catalytic oxidation tower 5 realizes regular backwashing through a backwashing pipe, removes the suspended solids and impurities in the ozone catalytic oxidation tower 5, maintains the activity of the catalyst, and thus improves the treatment efficiency;

[0047] The clear water tank 8 is provided with a water outlet end for effluent discharge up to standard;

[0048] The sludge treatment system comprises a sludge collection tank 9, a sludge concentration tank 10 and a filter press 11 connected in sequence; the membrane bioreactor MBR tank 203 and the sedimentation tank 305 are connected with the sludge collection tank 9; preferably, the filter press is a plate and frame filter press, and the dry sludge after the dehydration treatment by the plate and frame filter press is transported out for disposal;

[0049] The water inlet end of the backwashing pipe is connected with the water outlet end of the clean water pool 8, the first water outlet end of the backwashing water is connected with the backwashing water inlet pipe of the membrane bioreactor MBR pool 203, the second water outlet end of the backwashing water is connected with the backwashing water inlet pipe of the ozone catalytic oxidation tower 5, the third water outlet end of the backwashing water is connected with the backwashing water inlet pipe of the biological aerated filter 7, the backwashing water outlet pipe of the membrane bioreactor MBR pool 203 is connected with the primary sedimentation adjusting pool 1, the backwashing water outlet pipe of the ozone catalytic oxidation tower 5 is connected with the primary sedimentation adjusting pool 1, the backwashing water outlet pipe of the biological aerated filter 7 is connected with the primary sedimentation adjusting pool 1, and the backwashing water discharged from the membrane bioreactor MBR pool 203, the ozone catalytic oxidation tower 5 and the biological aerated filter 7 is transported to the primary sedimentation adjusting pool 1;

[0050] The aerobic tank 202, the membrane bioreactor MBR pool 203, the ozone stripping tank 6 and the biological aerated filter 7 are all connected with the air blower.

[0051] In the embodiment, the leachate wastewater treatment process is as follows:

[0052] The wastewater is firstly introduced into the primary sedimentation adjusting tank 1 to adjust the water quantity and remove the oily sludge and the like for a long time, and has a hydrolysis acidification effect, thereby removing part of the COD and improving the biodegradability of the wastewater. The wastewater is lifted by a pump to the high-efficiency composite biochemical system 2, and the wastewater flows through the anoxic tank 201, the aerobic tank 202 and the membrane bioreactor MBR tank 203 in sequence; the anoxic tank 201 and the aerobic tank 202 are both provided with the new enzyme floating filler, the aerobic tank 202 adopts the composite aeration mode, the sludge concentration is maintained at about 6-8 g / L, the organic matter and ammonia nitrogen and the like in the wastewater are maximally reduced by the metabolism of the microorganisms; the effluent of the aerobic tank 202 is introduced into the membrane bioreactor MBR tank 203, the MBR membrane has a microfiltration effect, and almost all of the suspended matter, activated sludge and the like are removed, and the wastewater is greatly cleaned; the nitrification liquid at the end of the aerobic tank 202 is back-flushed to the front end of the anoxic tank 201 to perform denitrification; the sludge of the membrane bioreactor MBR tank 203 is back-flushed to the front end of the anoxic tank 201 to ensure the sludge concentration. The effluent of the membrane bioreactor MBR tank 203 is introduced into the oxidation adsorption coagulation sedimentation system 3, the effluent is firstly introduced into the reaction tank 301 (potassium permanganate reaction tank), under the neutral condition, the potassium permanganate transmits oxygen to the reducing agent to generate manganese dioxide, and the macromolecular organic matter is oxidized into small molecular organic matter, and the generated manganese dioxide has the adsorption effect on the pollutants; the effluent is introduced into the adsorption tank 302 (powdered activated carbon adsorption tank), the mixing tank 303 and the flocculation tank 304 in sequence, the powdered activated carbon, PAC (polyaluminum chloride) and PAM (polyacrylamide) agents are added respectively to perform the adsorption destabilization coagulation effect, the effluent is introduced into the sedimentation tank 305 to further remove the pollutants; the effluent of the sedimentation tank 305 is introduced into the intermediate water tank 4, and is lifted to the ozone catalytic oxidation tower 5 to oxidize and decompose the refractory organic matter, change the structure and characteristics of the organic matter, improve the water quality and the biodegradability; the effluent is introduced into the ozone stripping tank 6 by itself, and after the air stripping, the wastewater is introduced into the biological aerated filter 7 to further remove the organic matter and the suspended matter and the like by the biochemical degradation and filtration double effects, thereby ensuring the wastewater treatment effect.

[0053] In one specific embodiment, the water treatment system of the utility model is further described in the order of water treatment:

[0054] (1) The raw landfill leachate first enters the primary sedimentation tank 1. The organic matter and suspended solids in the landfill leachate wastewater have high concentrations, and the water quality and quantity vary greatly. The primary sedimentation tank 1 is used for pretreatment. On the one hand, the water quantity is stored and adjusted in the tank. On the other hand, after a long period of sedimentation, most of the suspended solids are precipitated, and at the same time, a long residence time causes hydrolysis and acidification, removing part of the COD, improving the B / C ratio, and reducing the load of subsequent treatment. The primary sedimentation tank 1 is covered at the top to deodorize, and a sedimentation tank hopper is arranged at the bottom. The hopper has an inclination of 60°, and a perforated pipe is used to periodically pump and discharge sludge. The sludge in the primary sedimentation tank 1 contains a large amount of oil, humus organic matter, etc. A stacked screw dewatering machine 1-1 is used for separate treatment. The stacked screw dewatering machine 1-1 is placed on the top cover of the primary sedimentation tank 1. The sludge press filtrate flows into the primary sedimentation tank 1 for treatment, and the dry sludge is transported and disposed.

[0055] (2) The effluent of the primary sedimentation tank 1 is lifted to the A / O / MBR biochemical system 2 for degradation of organic matter and denitrification treatment. The wastewater flows through the anoxic tank 201, the aerobic tank 202, and the membrane bioreactor MBR tank 203 in turn. The sludge in the membrane bioreactor MBR tank 203 is returned to the front end of the anoxic tank 201, and the nitrified liquid at the end of the aerobic tank 202 is returned to the front end of the anoxic tank 201. Enzyme floating fillers 201-1 and 202-1 are installed in the anoxic tank 201 and the aerobic tank 202, respectively. The fillers have the characteristics of large specific surface area and high porosity, large amount of microorganisms, high unit volume load of the biochemical system, and good impact load resistance. At the same time, the good hydrophilicity of the filler surface makes the microbial biofilm form rapidly, the biological adhesion force is strong, the long generation cycle of microorganisms is relatively easy to form dominant flora, and the removal efficiency of nitrification reaction and refractory organic matter is improved. In the aerobic tank 202, the biofilm attached to the enzyme floating filler 202-1 forms an aerobic, anoxic, and anaerobic environment from the outside to the inside, which is conducive to the simultaneous existence of nitrosation bacteria and denitrification bacteria, and can form simultaneous nitrification and denitrification. NO2 - can be directly denitrified without being converted to NO3 - , speeding up the denitrification reaction process and saving the biochemical reaction volume. At the same time, the product of the nitrosation bacteria can be used as the substrate of the denitrification bacteria, and part of the COD in the wastewater is utilized during denitrification, thereby saving energy consumption. The alkalinity produced by the denitrification reaction also makes up part of the alkalinity required for nitrification, thereby reducing the dosage of alkalinity.

[0056] The aerobic tank 202 adopts a combination of micro-porous aeration and jet aeration. In the pool arrangement, the jet aeration is used at the water inlet side of the aerobic tank 202. The pump sucks the mud-water mixture at the end of the aerobic tank 202 into the jet device 202-2, and air is also continuously sucked into the jet device. After the gas-liquid-solid three phases are fully mixed, they are sprayed out to fully mix and stir the water. The jet aeration accounts for about 1 / 4 of the total aeration amount. The micro-porous aeration is used in the subsequent part of the tank. The water flow is relatively stable. This arrangement forms a gas-liquid-solid three-phase turbulent flow area at the water inlet area of the aerobic tank, which can efficiently and quickly mix and disperse the toxic and harmful substances entering the aerobic tank, and can resist impact load. The micro-porous aeration is used in the main body area of the aerobic tank to provide good hydraulic conditions. On the basis of good mixing of the gas-liquid-solid three phases, the hydraulic scouring on the filler is reduced to prevent the aging of the biological membrane from falling off and to ensure the effect of the filler film. At the same time, the stable water flow can ensure that the waste water flows into the subsequent membrane bioreactor MBR tank 203 treatment unit.

[0057] (3) The effluent from the membrane bioreactor MBR tank 203 enters the oxidation adsorption coagulation sedimentation system 3. Potassium permanganate, powdered activated carbon, PAC and PAM are added respectively in the potassium permanganate oxidation tank 301, the powdered activated carbon adsorption tank 302, the mixing tank 303 and the flocculation tank 304 for oxidation adsorption coagulation reaction. Under neutral conditions, potassium permanganate oxidizes the functional groups and complex bonds of organic matter, thereby reducing COD. The products generated after potassium permanganate oxidation generally do not have biological toxicity, so the biodegradability of the wastewater is improved. After the oxidation of organic matter by potassium permanganate, new hydrated manganese dioxide is generated. The solubility of manganese dioxide in water is very small. When it precipitates from water, it can generate fine manganese dioxide colloid. The manganese dioxide colloid has a large specific surface area and a large number of hydroxyl groups, which can form hydrogen bonds with organic matter containing hydroxyl groups and amino groups, thereby adsorbing and removing organic matter from water. The manganese dioxide generated by the oxidation of potassium permanganate increases the color of the water. The oxidation effluent is added with powdered activated carbon for adsorption. Potassium permanganate and activated carbon are used together, and the synergistic effect of the two is exerted. During the oxidation of potassium permanganate, large molecular organic matter is oxidized into small molecular organic matter, which is more conducive to adsorption by activated carbon and improves the pollution removal effect. After oxidation and adsorption, the wastewater is subjected to coagulation and sedimentation to cause the micro-impurities to be destabilized and aggregated into larger flocculation bodies. The wastewater flows into the sedimentation tank 305 for solid-liquid separation.

[0058] (4) The effluent of the sedimentation tank 305 flows into the intermediate water tank 4 by itself, and then enters the ozone catalytic oxidation tower 5 and the ozone stripping tank 6 in turn after being lifted. The ozone, by the action of the catalyst, significantly improves the oxidation ability of the ozone, and generates hydroxyl radicals (·OH) with stronger oxidation ability. The hydroxyl radical ·OH is very active and can react with most organic matters. The degradation process of the organic matters is controlled by the radical reaction, and the reaction speed is significantly accelerated, so as to efficiently degrade the organic pollutants in the water. The ozone can oxidize and decompose pollutants such as alkyl benzene sulfonate sodium (ABS), protein, amino acid, organic amine, lignin, humus, heterocyclic compound and chain unsaturated compound in the wastewater, break the double bond, and destroy the cyclic compounds such as benzene, naphthalene and anthracene, so as to improve the B / C of the wastewater. In this project, the intermediate valence manganese oxides reduced by potassium permanganate also have catalytic oxidation effect on the ozone, and the two can play a synergistic oxidation effect, so that the treatment efficiency is obviously improved. The oxidation objects of potassium permanganate and ozone are different. The potassium permanganate can oxidize mercaptan, aldehyde and phenol compounds, while the ozone often acts on heterocyclic macromolecular compounds. The potassium permanganate and the ozone are two types of complementary water treatment agents. Through the treatment of different types of organic matters, the biodegradability of the wastewater is finally improved, and the COD of the wastewater is reduced. After the wastewater is subjected to the ozone catalytic oxidation, it enters the ozone stripping tank 6, and the residual ozone in the water is dispersed by aeration.

[0059] (5) The effluent of the ozone stripping tank 6 enters the biological aerated filter 7. By using the improved biodegradability, the subsequent biological aerated filter 7 can be used for biochemical degradation and filtration, so that the discharge standard of COD concentration less than 100 mg / L can be realized.

[0060] The biological aerated filter 7 is filled with a new type of granular material with small particle size as filter material. The filter material is immersed in water, and an aeration system is installed at the bottom of the tank to provide sufficient oxygen, so that the wastewater can be stably aerated.

[0061] ① Biochemical degradation process: when the wastewater passes through the filter material layer in the vertical direction from top to bottom, the oxidation and degradation ability of the high-concentration biofilm brought by the high specific surface area of the filter material is used to quickly purify the wastewater.

[0062] ② Interception and filtration process: when the wastewater flows, the filter material is in a compact state. By using the characteristics of small particle size of the filter material and the bioflocculation of the biofilm, the suspended solids in the wastewater are filtered and intercepted, and the detached biofilm is prevented from being carried out of the water.

[0063] ③ Backwashing process: after a period of operation, the water head loss increases. The treated effluent is used to backwash the filter tank to release the intercepted suspended solids and update the biofilm, and the proliferated activated sludge is removed.

[0064] The effluent of the biological aerated filter 7 flows into the clean water tank 8 by itself, and the wastewater is discharged up to the standard.

[0065] The treatment system for middle-aged and old organic landfill leachate wastewater is provided, and the traditional process and emerging technology are combined to solve the problems of high ammonia nitrogen concentration, poor biodegradability, complex pollutant composition and difficult degradation of the middle-aged and old landfill leachate wastewater, and organic combination is performed from the aspects of pretreatment, biochemical treatment and advanced treatment.

[0066] (1) The pretreatment adopts primary sedimentation adjustment treatment, has the effects of sedimentation, water storage adjustment and hydrolysis acidification, and simultaneously, oil-containing sludge is pretreated, oil stains and part of insoluble pollutants can be removed, the biodegradability of the wastewater is improved, and the subsequent biochemical load is reduced;

[0067] (2) The biochemical treatment adopts A / O / MBR as the main process, contact oxidation process is adopted for biochemical treatment, the special structure of the double membrane layer and the gap layer of the high-efficiency enzyme floating filler is used to fix and attach microorganisms, the effective biological concentration is improved, the sludge age of the system is long, and the nitrification and denitrification denitrification reaction is promoted; the jet and the micro-pore mixed aeration is adopted for the aerobic tank, the oxygenation efficiency is high, the wastewater can be rapidly and uniformly mixed, local accumulation of toxic and harmful substances will not be caused, the impact load resistance is good, and meanwhile, the aeration mode is matched with the enzyme floating filler to construct the violent mixing and mass transfer of the gas, liquid and solid three phases, so that the high-quality mixing effect is achieved; the MBR system realizes the separation of the sludge retention time and the hydraulic retention time, the sludge concentration and the solid-liquid separation efficiency are improved, the emergence of the target dominant flora is promoted, and the biochemical reaction efficiency is improved. The biochemical system of the project is organically combined through the enzyme floating filler, the mixed aeration and the MBR membrane, the biochemical sludge concentration is ensured, the purposes of efficient denitrification and removal of refractory organic matter are achieved.

[0068] (3) The advanced treatment adopts the combined process of synergistic advanced oxidation, adsorption mixed sedimentation and aeration biology, the combined process is optimized through the combined oxidation of potassium permanganate and ozone, the adsorption mixed sedimentation of activated carbon and the biochemical filtration effect, and the combined process is mutually promoted and supplemented; the oxidation objects of potassium permanganate and ozone have complementary effects; the manganese generated by the reduction of potassium permanganate is helpful to the ozone catalytic oxidation effect; potassium permanganate has the dual effects of oxidation and adsorption, and is more conducive to promoting the subsequent powdered activated carbon adsorption to remove refractory pollutants. After the combined oxidation of potassium permanganate and ozone, the improved biodegradability is used to perform biochemical filtration treatment through the aeration biological filter, and finally, the purpose of stably discharging the wastewater up to the standard is achieved. The advanced treatment adopts the new combined advanced oxidation technology, constructs the synergistic advanced oxidation process, and exhibits the high efficiency of potassium permanganate and ozone in the synergistic oxidation process.

[0069] The treatment process can ensure the wastewater treatment effect, can realize the discharge standard that the effluent COD concentration is less than 100 mg / L, the sludge amount generated by the system is less, the problem that concentrated liquid is difficult to handle due to the application of membrane systems such as nanofiltration and reverse osmosis is not generated, the investment operation cost is lower, and the garbage leachate wastewater treatment has more obvious advantages.

[0070] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific implementation described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A treatment system for leachate wastewater from middle-aged and old organic waste landfills, characterized in that, It comprises sequentially connected primary sedimentation adjusting tank (1), biochemical system (2), oxidation adsorption coagulation sedimentation system (3), intermediate water tank (4), ozone catalytic oxidation tower (5), ozone stripping tank (6), biological aerated filter (7) and clear water tank (8); The primary sedimentation adjusting tank (1) is provided with a leachate inlet end for leachate inlet; The biochemical system (2) comprises sequentially connected anoxic tank (201), aerobic tank (202) and membrane bioreactor MBR tank (203), and a nitrification liquid reflux pipe is further arranged between the anoxic tank (201) and the aerobic tank (202) for refluxing the nitrification liquid at the tail end of the aerobic tank (202) to the front end of the anoxic tank (201), and a second sludge pipe is arranged between the anoxic tank (201) and the membrane bioreactor MBR tank (203) for refluxing part / whole sludge deposited in the membrane bioreactor MBR tank (203) to the front end of the anoxic tank (201); The oxidation adsorption coagulation sedimentation system (3) comprises sequentially connected oxidation tank (301), adsorption tank (302), mixing tank (303), flocculation tank (304) and sedimentation tank (305), and the oxidation tank (301) is connected with a potassium permanganate dosing device; The ozone catalytic oxidation tower (5) is further connected with an ozone generator and an ozone tail gas destruction device respectively; The clear water tank (8) is provided with a water outlet end for water outlet standard discharge; The aerobic tank (202), the membrane bioreactor MBR tank (203), the ozone stripping tank (6) and the biological aerated filter (7) are all connected with a blower.

2. The system for treating leachate wastewater from a middle-aged or aged organic landfill site according to claim 1, wherein It further comprises a sludge treatment system, a third sludge pipe is arranged between the membrane bioreactor MBR tank (203) and the sludge treatment system for conveying part / whole sludge deposited in the membrane bioreactor MBR tank (203) to the sludge treatment system, and a fourth sludge pipe is arranged between the sedimentation tank (305) and the sludge treatment system for conveying sludge deposited in the sedimentation tank (305) to the sludge treatment system.

3. The system for treating leachate wastewater from a middle-aged or aged organic landfill site according to claim 1, wherein A primary sedimentation adjusting tank top cover is arranged on the top of the primary sedimentation adjusting tank (1), a dewatering machine (1-1) is arranged on the primary sedimentation adjusting tank top cover, a filtrate outlet end of the dewatering machine (1-1) is connected with a filtrate inlet end of the primary sedimentation adjusting tank (1), and a first sludge pipe is further arranged between the primary sedimentation adjusting tank (1) and the dewatering machine (1-1) for conveying sludge deposited in the primary sedimentation adjusting tank (1) to the dewatering machine (1-1).

4. The system for treating leachate waste water from a middle-aged or aged organic waste landfill site according to claim 1, wherein A first enzyme floating filler (201-1) is arranged in the anoxic tank (201), and a second enzyme floating filler (202-1) is arranged in the aerobic tank (202), and the first enzyme floating filler (201-1) is same as or different from the second enzyme floating filler (202-1).

5. The system for treating leachate wastewater from a middle-aged or aged organic landfill site according to claim 4, wherein The jet flow device (202-2) is located at the water inlet end of the aerobic tank (202), and the microporous aerator is located at the rear end of the jet flow device (202-2).

6. The system for treating leachate waste water from a middle-aged or aged organic waste landfill site according to claim 1, wherein The adsorption tank (302) is connected with an activated carbon feeding device, the mixing tank (303) is connected with a polyaluminum chloride feeding device, and the flocculation tank (304) is connected with a polyacrylamide feeding device.

7. The system for treating leachate waste water from a middle-aged or aged organic waste landfill site according to claim 1, wherein The bottom of the ozone catalytic oxidation tower (5) is provided with an ozone aeration disc, and the middle and lower parts are provided with a catalyst layer.

8. The system for treating leachate waste water from a middle-aged or aged organic waste landfill site according to claim 1, wherein The bottom of the primary sedimentation adjusting tank (1) is provided with a plurality of first sedimentation tank hoppers. The sedimentation tank (305) is provided with a inclined plate filler, and the bottom of the sedimentation tank (305) is provided with at least one second sedimentation tank hopper, and the inclined plate filler is located above the second sedimentation tank hopper.

9. The system for treating leachate waste water from a middle-aged or aged organic waste landfill site according to any one of claims 2 to 8, characterized in that, The treatment system comprises a sludge collection tank (9), a sludge concentration tank (10) and a filter press (11) connected in sequence; the membrane bioreactor MBR tank (203) and the sedimentation tank (305) are connected with the sludge collection tank (9).

10. The system for treating leachate wastewater from a matured organic landfill site according to claim 9, wherein It also includes a backwashing pipe, the water inlet end of the backwashing pipe is connected with the water outlet end of the clean water tank (8), the backwashing water first outlet is connected with the backwashing water inlet pipe of the membrane bioreactor MBR tank (203), the backwashing water second outlet is connected with the backwashing water inlet pipe of the ozone catalytic oxidation tower (5), the backwashing water third outlet is connected with the backwashing water inlet pipe of the biological aerated filter (7), the backwashing water outlet pipe of the membrane bioreactor MBR tank (203) is connected with the primary sedimentation adjusting tank (1), the backwashing water outlet pipe of the ozone catalytic oxidation tower (5) is connected with the primary sedimentation adjusting tank (1), and the backwashing water outlet pipe of the biological aerated filter (7) is connected with the primary sedimentation adjusting tank (1), which is used for conveying the backwashing water discharged by the membrane bioreactor MBR tank (203), the ozone catalytic oxidation tower (5) and the biological aerated filter (7) to the primary sedimentation adjusting tank (1).

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