Device for treating landfill leachate by combining mineralized refuse reactor with short-cut nitrification-anaerobic ammonia oxidation

Abstract

The utility model discloses a device for treating landfill leachate by combining a mineralized refuse reactor with short-cut nitrification-anaerobic ammonia oxidation. A mineralized refuse reactor A, a short-cut nitrification reactor B and an anaerobic ammonium oxidation reactor C are arranged to be an integrated device, the mineralized refuse reactor A is arranged to be an anoxic reactor by adjusting the aeration rate and operation parameters, the concentration of organic matter is reduced as much as possible, the inhibition effect on follow-up anaerobic ammonium oxidation bacteria is reduced, and the high ammonia nitrogen concentration value of landfill leachate is guaranteed; the landfill leachate discharged from the mineralized refuse reactor A enters a reactor B for short-cut nitrification treatment, part of ammonia nitrogen is converted into nitrite nitrogen, and sufficient nitrite nitrogen is provided for anaerobic ammonium oxidation bacteria; and the landfill leachate which is discharged from the reactor B and contains a certain proportion of ammonia nitrogen and nitrite nitrogen enters the reactor C to be subjected to anaerobic ammonia oxidation reaction, so that denitrification is realized, and the aim of improving the denitrification efficiency of the anaerobic ammonia oxidation system is finally achieved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of environmental protection and new energy, and particularly relates to a device for treating landfill leachate by combining a mineralized waste reactor with shortcut nitrification-anaerobic ammonium oxidation. Background Art

[0002] Landfill leachate is a by-product of sanitary landfills, which is characterized by high concentrations of organic pollutants and ammonia nitrogen. If not properly treated, it poses a major threat to the ecological environment and human health. Usually, the removal of ammonia nitrogen in leachate mostly adopts the nitrification-denitrification nitrogen removal process. However, the traditional nitrification-denitrification process has always had drawbacks. For example, a large amount of aeration is required in the nitrification stage, and an organic carbon source (such as methanol) is required in the denitrification stage, resulting in an increase in operating costs. In order to overcome the disadvantages of traditional nitrogen removal technologies, many researchers have begun to focus on developing new biological technologies.

[0003] Compared with traditional nitrogen removal technologies, anaerobic ammonium oxidation has received attention in the field of landfill leachate treatment due to the advantages of almost no need to supplement carbon sources and less sludge production. The anaerobic ammonium oxidation process is to convert ammonia nitrogen into nitrogen molecules by anaerobic ammonium oxidizing bacteria using nitrite nitrogen as an electron acceptor in an anaerobic or anoxic environment. Among them, the shortcut nitrification-anaerobic ammonium oxidation process can save 60% of the aeration volume and 100% of the carbon source, achieving economic and efficient nitrogen removal. Since high concentrations of ammonia nitrogen are beneficial to inhibiting the activity of nitrite-oxidizing bacteria and promoting the growth of anaerobic ammonium oxidizing bacteria, the shortcut nitrification-anaerobic ammonium oxidation nitrogen removal process is particularly suitable for high-concentration ammonia nitrogen wastewater. Landfill leachate is a high-concentration ammonia nitrogen wastewater, so it is suitable to use the shortcut nitrification-anaerobic ammonium oxidation technology to treat landfill leachate. However, landfill leachate also contains high concentrations of organic matter, which will affect the anaerobic ammonium oxidation process and reduce the total nitrogen removal efficiency.

[0004] Therefore, in order to reduce the impact of high concentrations of organic matter on the anaerobic ammonium oxidation system, it is necessary to dilute the leachate or pre-treat the leachate to reduce the organic matter concentration. The biological reactor filled with mineralized waste has a good treatment effect on landfill leachate and can effectively reduce the organic matter and harmful toxic substances in landfill leachate. Therefore, this utility model patent uses a mineralized waste reactor to pre-treat landfill leachate to reduce the impact of organic matter in landfill leachate on anaerobic ammonium oxidizing bacteria, and combines the shortcut nitrification-anaerobic ammonium oxidation process to achieve efficient nitrogen removal. Summary of the Utility Model

[0005] The purpose of the present utility model is to improve the nitrogen removal efficiency of the anaerobic ammonium oxidation system by reducing the impact of high concentrations of organic matter, chromaticity and toxic substances in landfill leachate on anaerobic ammonium oxidizing bacteria, and thus provides a device for treating landfill leachate by combining a mineralized waste reactor with shortcut nitrification-anaerobic ammonium oxidation.

[0006] Idea of the present invention: An anoxic mineralized waste reactor A, a shortcut nitrification reactor B, and an anaerobic ammonium oxidation reactor C are provided. The mineralized waste reactor A pre-treats the landfill leachate to reduce the concentration of organic matter, chroma, and harmful substances in the landfill leachate. The effluent after pre-treatment is put into the shortcut nitrification reactor B, and the reactor B converts part of the ammonia nitrogen into nitrite nitrogen, so as to provide the corresponding proportion of ammonia nitrogen and nitrite nitrogen for the anaerobic ammonium oxidation reactor C, and carry out denitrification treatment under the action of anaerobic ammonium oxidizing bacteria.

[0007] The mineralized waste reactor A mentioned above is composed of a reactor main body, a ventilation pipe, a flowmeter, an air pump, a control box, etc. Three solid sampling ports are evenly arranged on the side, and an effluent sampling port and an air diffuser pipe are arranged at the bottom. The air diffuser pipe is connected to a rotameter, the rotameter is connected to an air pump, and the air pump is connected to the control box. A ventilation pipe is arranged in the center, its top is sealed, the pipe wall is perforated and the lower part is connected to the air diffuser pipe, and the outside of the ventilation pipe is wrapped with a gauze net. The top of the mineralized waste reaction bed is covered with a cover and a funnel, a valve is arranged between the funnel and the cover, and a uniformly perforated PVC board is added to the bottom of the cover. The mineralized waste reactor is filled with a gravel layer, a mineralized waste layer, and an inclined gravel layer. The inclined gravel layer is supported by an inclined plate with uniformly distributed holes, and three temperature probes are evenly buried in the mineralized waste layer.

[0008] The shortcut nitrification reactor B mentioned above is composed of a reactor main body, a constant temperature water bath, an SBR automatic control device, a rotameter, an aeration pump, a peristaltic pump, etc. The reactor main body is a PVC column with a column height of 1.2 m, a diameter of 9 cm, and an effective volume of 7.6 L. An inlet is arranged at the upper part of the PVC column, an outlet is arranged in the middle, and a sludge discharge port is arranged at the lower part. A water bath device is arranged outside the reactor, and the upper and lower parts are connected to a constant temperature water bath tank for constant temperature water bath. A constant temperature heating rod is connected to the constant temperature water bath tank, a stirrer is connected inside, and a micro-aeration disc is arranged at the lower end. The reactor is controlled by an automatic control device for the water bath heating system and the operation system, and operates according to the mode of inlet water - aeration - sedimentation - drainage - idle.

[0009] The anaerobic ammonium oxidation reactor C is a sealed PVC column body. An inlet and outlet are arranged at the top of the column, a stirrer is connected inside, the outer body of the column is heated by a constant temperature water bath, a constant temperature heating rod is connected to the constant temperature water bath tank for temperature control, and the column body and the periphery of the water bath tank are wrapped with heat preservation and light-shielding materials.

[0010] The aeration volume and operating parameters of the reactor can be adjusted according to actual needs, and the adjustment range includes: to ensure that the mineralized waste reactor A can effectively pre-treat the landfill leachate and provide the corresponding ammonia nitrogen value for shortcut nitrification, the optimal hydraulic retention time and hydraulic load of this reactor are 10 h and 3 L respectively, the influent frequency is 1 time / d, and the particle size of the mineralized waste is 4 - 10 mm; to ensure that the reactor B can achieve shortcut nitrification, intermittent aeration is used for it to quickly achieve shortcut nitrification; to enable the anaerobic ammonium oxidation bacteria to better adapt to the landfill leachate, the hydraulic retention time of the anaerobic ammonium oxidation reactor C is appropriately extended.

[0011] Advantages of the method of the present utility model:

[0012] Aiming at the problems that high-concentration organic matters, harmful substances and deep color in the landfill leachate inhibit the anaerobic ammonium oxidation process, this method pre-treats the landfill leachate by establishing an anoxic mineralized waste bioreactor, reduces the organic matter concentration, and at the same time keeps the ammonia nitrogen at a high concentration value, reducing the inhibitory effect on the subsequent anaerobic ammonium oxidation bacteria, and can realize the efficient nitrogen removal of the mineralized waste reactor combined with the shortcut nitrification-anaerobic ammonium oxidation device. Description of the drawings

[0013] Figure 1 It is a schematic structural diagram of the device used in the present utility model. Markings in the figure: 1 - water inlet; 2 - gas sampling valve; 3 - liquid distributor; 4 - upper gravel layer; 5 - solid sampling hole; 6 - lower gravel layer; 7 - water outlet; 8 - water storage tank; 9 - water pump; 10 - stirrer; 11 - water inlet; 12 - water outlet; 13 - SBR control panel; 14 - peristaltic pump; 15 - rotameter; 16 - aeration pump; 17 - water inlet; 18 - water outlet; 19 - heat preservation and light-shielding material (glass wool); 20 - constant temperature heating rod; 21 - water bath heating cylinder. Specific embodiments

[0014] Example:

[0015] (1)Construct a combined device of a mineralized waste reactor A, a shortcut nitrification reactor B and an anaerobic ammonium oxidation reactor C. The mineralized waste reactor A consists of a reactor main body, a ventilation pipe, a flowmeter, an air pump, a control box, etc. Three solid sampling ports are evenly arranged on the side, and a water outlet sampling port and an air diffuser pipe are arranged at the bottom. The air diffuser pipe is connected to a rotameter, the rotameter is connected to an air pump, and the air pump is connected to the control box; a ventilation pipe is arranged in the center, its top is sealed, the pipe wall is perforated and the lower part is connected to the air diffuser pipe, and the outside of the ventilation pipe is wrapped with a gauze net; the top of the mineralized waste reaction bed is covered with a cover and a funnel, a valve is arranged between the funnel and the cover, and a uniformly perforated PVC board is added to the bottom of the cover; the mineralized waste reactor is filled with a gravel layer, a mineralized waste layer and an inclined gravel layer, and the inclined gravel layer is supported by an inclined plate with uniformly distributed holes, and three temperature probes are evenly buried in the mineralized waste layer. To ensure that the reactor B can achieve shortcut nitrification, the reactor sludge is aerobic sludge, and intermittent aeration is used to quickly achieve shortcut nitrification; anaerobic ammonium oxidation sludge is cultivated in the reactor C. In order to make the anaerobic ammonium oxidation bacteria better adapt to the landfill leachate, the hydraulic retention time is appropriately extended.

[0016] The landfill leachate is taken from the Shankou landfill in Guilin, the mineralized waste is taken from the Chongkou landfill in Guilin, and the fresh waste is taken from the Yanshan Town waste transfer station in Guilin; the sludge in the shortcut nitrification reactor is taken from the aerobic activated sludge of the Yanshan Town sewage treatment plant in Guilin; the anaerobic ammonium oxidation reactor sludge is taken from the sludge cultivated in this laboratory.

[0017] The mineralized waste is mineralized waste with a landfill age of 10 years. After being transported back to the laboratory from the landfill, it is screened through a sieve to a particle size range of 4-10 mm, and then filled into the mineralized waste reactor, and the filling density is 740 kg / m 3 . The physical properties of the mineralized waste appearance are: similar to soil and odorless.

[0018] (2)Set the reactor operation parameters according to actual needs. Pump the landfill leachate into the mineralized waste reactor A through a water pump. After a certain hydraulic retention time, export the landfill leachate from the mineralized waste reactor A, and then immediately close the water outlet valve. The discharged landfill leachate enters the shortcut nitrification reactor B. After a certain hydraulic retention time, it is discharged into the anaerobic ammonium oxidation reactor C for nitrogen removal. During the test process, the concentration changes of various pollutants in the influent and effluent landfill leachate are measured once every two days.

[0019] The operating parameters of the reactor include that the hydraulic load of the mineralized waste reactor A is 3 L / time, and its hydraulic retention time is controlled at 8 - 10 h, with the outlet water valve and the aeration port in the closed state; the shortcut nitrification reactor B operates in an intermittent aeration mode of aerobic (aeration for 30 min) - anoxic (stopping aeration for 30 min), and this mode divides a day into two cycles (12 h / cycle) for operation, with the dissolved oxygen controlled at about 0.5 - 1.0 mg / L. The hydraulic retention time of the anaerobic ammonium oxidation reactor C is controlled at 24 - 48 h. To enable ammonia-oxidizing bacteria and anaerobic ammonium-oxidizing bacteria to better attach to the packing to form a biofilm, the shortcut nitrification reactor and the anaerobic ammonium oxidation reactor are inoculated with packing of the polyethylene PE-03 model (φ15 mm × 15 mm, specific surface area is 800 m 2 / m 3 ), and the filling rate is 30%; the combined device has been operating for 4 months. The mineralized waste reactor A is used as the pretreatment of landfill leachate. Before the influent, the outlet water valve of the device is closed, and the valve is also immediately closed after the effluent is discharged. The oxidation-reduction potential of the effluent leachate is basically about 113 mv, the pH is about 7.9, and the conductivity is 14 mS / cm.

[0020] The operation results show that under the conditions of the hydraulic load of landfill leachate being 3 L and the retention time being 10 h, the COD removal rate of the effluent of the mineralized waste reactor A can basically be guaranteed to be below 70%, and at the same time, the ammonia nitrogen removal rate remains below 60%. After the landfill leachate is treated by the mineralized waste, a high ammonia nitrogen concentration can be guaranteed. The ammonia nitrogen removal rate of the device for treating landfill leachate by the combined mineralized waste reactor and shortcut nitrification - anaerobic ammonium oxidation can reach up to 94% at most, and the total nitrogen removal rate basically remains at about 88%.

Claims

1. A device for treating landfill leachate by combining a mineralized garbage reactor with short-cut nitrification-anaerobic ammonium oxidation, characterized in that: The anoxic mineralized garbage reactor A, the short-range nitrification reactor B and the anaerobic ammonia oxidation reactor C are integrated devices. Reactor A consists of a main body, a ventilation pipe, a flow meter, an air pump and a control box. Three solid sampling ports are evenly arranged on the side, and a water sampling port and an aeration pipe are arranged at the bottom. The aeration pipe is connected to the rotor flowmeter, the rotor flowmeter is connected to the air pump, and the air pump is connected to the control box; a ventilation pipe is arranged in the center, the top of which is sealed, the wall of the pipe is perforated, and the lower part is connected to the aeration pipe. The outside of the ventilation pipe is wrapped with a gauze; the top of the mineralized garbage reaction bed is covered with a cover and a funnel, a valve is arranged between the funnel and the cover, and a PVC board with uniform holes is added to the bottom of the cover; it is used for pretreatment of garbage leachate to reduce the concentration of organic pollutants; Reactor B consists of a reactor main body, a constant temperature water bath, an SBR automatic control device, a rotor flowmeter, an aeration pump and a peristaltic pump; the reactor main body adopts a column with a height of 1.2 m, a diameter of 9 cm, and an effective volume of 7.6 The PVC column L is used to achieve nitrite nitrogen accumulation; the reactor C is a sealed PVC column, the top of the column is provided with a water inlet and outlet, an agitator is connected inside, the outer body of the column is heated by a constant temperature water bath, a constant temperature heating rod is connected to the constant temperature water bath for temperature control, and the outer periphery of the column and the water bath is wrapped with heat preservation and shading materials to achieve anaerobic oxygen ammonia oxidation denitrification; The landfill leachate is pretreated in the mineralized waste reactor A to ensure that the organic matter concentration, harmful substances and chromaticity in the landfill leachate are reduced, the inhibition on anaerobic ammonia oxidizing bacteria is reduced, and the ammonia nitrogen is kept at a high concentration value; the effluent of the mineralized waste reactor A enters the short-range nitrification reactor B, and part of the ammonia nitrogen in the landfill leachate is converted into nitrite nitrogen; the effluent of the leachate containing ammonia nitrogen and nitrite nitrogen in the short-range nitrification reactor B enters the anaerobic ammonia oxidation reactor C to achieve anaerobic ammonia oxidation denitrification; through this device, the adverse effects of high-concentration organic pollutants in the landfill leachate on anaerobic ammonia oxidizing bacteria can be reduced, and the denitrification efficiency of the anaerobic ammonia oxidation system can be improved.

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