CN103011507A - Control method and device for deep denitrification treatment of garbage leachate by combination of short-range nitrification and anaerobic ammoxidation - Google Patents

Abstract

The control method and device for deep denitrification treatment of landfill leachate by short-range nitrification combined with anaerobic ammonium oxidation relate to the field of sewage biological treatment and can solve the problem of difficult deep denitrification of landfill leachate. The denitrification reaction and the removal of organic matter are carried out in the first SBR reactor, which is controlled by real-time ORP and pH monitoring. 60% of the effluent from the first SBR reactor directly enters the second SBR reactor for short-cut nitrification, which is controlled by real-time DO and pH monitoring. 40% of the effluent of the first SBR reactor is mixed with the effluent of the second SBR reactor, and then enters the ASBR reactor in the form of continuous water inflow for anaerobic ammonium oxidation reaction. During the period, real-time pH monitoring is used to control, and 70% of the effluent is refluxed after drainage To the water tank, the remaining water is discharged, and then the next cycle is carried out. The invention can accurately control the stirring time of denitrification, the removal of organic matter and the aeration time of short-range nitrification, and has the advantages of saving energy consumption, shortening reaction time, not requiring external carbon sources, and high TN removal rate.

Description

Control method and device for deep denitrification treatment of landfill leachate by short-cut nitrification combined with anaerobic ammonium oxidation

technical field

The invention relates to the field of sewage biological treatment, in particular to a control method and device for deep denitrification treatment of landfill leachate.

Background technique

With the rapid development of the economy and the gradual improvement of people's living standards, the output of urban waste continues to increase. At present, most of the garbage in our country is treated by landfill. Landfill is an effective and cheap way to deal with it. However, the landfill leachate has seriously affected the water environment in our country. Garbage leachate is the sewage leached out of the garbage in the process of stacking and landfilling through rain shower, scouring and fermentation, as well as immersion of surface water and groundwater. The landfill leachate is dark brown and has very complex components. It contains a large amount of organic matter and ammonia nitrogen, and is also rich in toxic and harmful heavy metal ions. It belongs to high-ammonia nitrogen refractory wastewater. The discharge of landfill leachate will cause serious pollution to the surrounding atmosphere, water body, soil and other environments, especially the high concentration of ammonia nitrogen will poison the water body and cause eutrophication in the water body.

Landfill leachate treatment mainly adopts physical chemical method and biological method. However, the cost of physical and chemical methods is relatively high, and they are generally used for pretreatment or advanced treatment of leachate. At present, biological methods are mainly used to treat landfill leachate. However, the traditional biological treatment for denitrification is not only difficult to meet the treatment standards, but also the additional carbon source added by denitrification also increases the treatment cost. Therefore, how to treat leachate economically and effectively is the focus and difficulty of water treatment in my country.

At present, many new processes have been reported for biological nitrogen removal, such as the anaerobic ammonium oxidation process. According to the anammox reaction, anammox bacteria are able to convert ammonia nitrogen and nitrite nitrogen into nitrogen gas. Since anammox bacteria are anaerobic autotrophs, the reaction process does not require oxygen and organic matter, so it can save 50% of oxygen supply costs and a large amount of organic carbon sources, thereby greatly reducing the treatment costs and infrastructure costs of sewage treatment. However, a large amount of organic matter contained in landfill leachate will adversely affect the anammox bacteria. At the same time, the anammox reaction will produce a certain amount of nitrate nitrogen, resulting in the nitrate nitrogen in the system effluent, which will affect the denitrification of the system. efficiency. These are the urgent problems to be solved in the application of anaerobic ammonium oxidation process.

Contents of the invention

Aiming at the deficiencies of the above-mentioned technologies, the present invention provides a device and a method, which can solve the problem of difficult deep denitrification of landfill leachate.

A control device for deep denitrification of landfill leachate combined with nitrification combined with anaerobic ammonium oxidation, characterized in that:

The water inlet tank 2 is connected to the first SBR reactor 9 through the water inlet pipe _SBR1 4, the water inlet pump _SBR1 3 and the water inlet valve _SBR1 5; the first SBR reactor 9 is connected to the first intermediate water tank 19 through the water outlet pipe _SBR1 18 and the water outlet valve _SBR1 17 The first intermediate water tank 19 is connected with the second SBR reactor 74 through the water inlet pipe _SBR2 34, the water inlet pump _SBR2 21 and the water inlet valve _SBR2 22, and the first intermediate water tank 19 is also passed through the water inlet pipe _{The second intermediate water tank} 35, the water inlet pump _{No. Two intermediate water tanks} 23 and water inlet valve _{The second intermediate water tank} 24 is connected with the second intermediate water tank 33; the second SBR reactor 74 is connected with the second intermediate water tank 33 through the water outlet pipe _SBR2 32 and the water outlet valve _SBR2 31; the second intermediate water tank 33 The ASBR reactor 42 is connected to the ASBR reactor 42 through the water inlet pipe _ASBR 36, the water inlet pump _ASBR 37 and the water inlet valve ASBR 38 _{; the ASBR reactor 42 is connected to the outlet pipe ASBR 43} and the outlet valve _ASBR 44, and the ASBR reactor 42 is also passed through the ASBR reactor return valve 45. The ASBR reactor reflux pipe 46 and the ASBR reactor reflux pump 47 are connected to the water inlet tank 2;

The inside of the first SBR reactor 9 is provided with an agitator _SBR1 10, a pH sensor _SBR1 11, a DO sensor _SBR1 12 and an ORP sensor _SBR1 13; while the first SBR reactor 9 is also connected to the aeration head 6, the air compressor _SBR1 7 and the gas Flow meter 8; the second SBR reactor 74 is internally provided with agitator _SBR2 28, pH sensor _SBR2 29 and DO sensor _SBR2 30; while the second SBR reactor 74 is also connected to aeration head 6, air compressor _SBR2 20 and gas flow rate meter 8; ASBR reactor 42 is equipped with stirrer _ASBR 41 and pH sensor _ASBR 39; pH sensor _SBR1 11, DO sensor _SBR1 12, ORP sensor _SBR1 13, pH sensor _SBR2 29, DO sensor _SBR2 30 and pH sensor _ASBR 39 The data lines are respectively connected with the pH measuring instrument _SBR1 11, the DO measuring instrument _SBR1 12, the ORP measuring instrument _SBR1 13, the pH measuring instrument _SBR2 29, the DO measuring instrument _SBR2 30 and the pH measuring instrument _ASBR 39, and then connect with the data signal input interface 49 of the computer 48 Connection, the computer 48 is connected with the process controller 55 through the data signal output interface, the water inlet pump _SBR1 relay, the water inlet valve _SBR1 relay, the agitator _SBR1 relay, the air compressor SBR1 relay, _the water outlet valve _SBR1 relay, the water inlet pump _SBR2 of the process controller Relay, water inlet valve _SBR2 relay, agitator _SBR2 relay, air compressor _SBR2 relay, water inlet pump _{second intermediate water tank} relay, water inlet valve _{second intermediate water tank} relay, water outlet valve _SBR2 relay, water inlet pump _ASBR relay, water inlet valve _ASBR Relay, agitator _ASBR relay, outlet valve _ASBR relay, ASBR reactor reflux valve relay, ASBR reactor reflux pump relay and water inlet pump _SBR1 3, water inlet valve _SBR1 5, agitator _SBR1 10, air compressor _SBR1 7, water outlet Valve _SBR1 17, water inlet pump _SBR2 21, water inlet valve _SBR2 22, agitator _SBR2 28, air compressor _SBR2 20, water inlet pump _{second intermediate water tank} 23, water inlet valve _{second intermediate water tank} 24, water outlet valve _SBR2 31, water inlet pump _ASBR 37, water inlet valve _ASBR 38, agitator _ASBR 41, water outlet valve _ASBR 44, ASBR reactor reflux valve 45, ASBR reactor reflux pump 47 are connected.

The technical problem to be solved by the present invention is to provide a control method for deep denitrification of landfill leachate treated with short-range nitrification combined with anaerobic ammonium oxidation, including:

A1, the water intake of the first SBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically opened, and the mixed solution in the water intake tank is injected into the first SBR reaction In the reactor, when the water intake of the SBR reactor reaches 50% of the volume of the SBR reactor, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically closed, and the water intake is completed;

_A2 , after the water inflow is finished, the agitator _SBR1 is automatically turned on, and the first SBR reactor enters the anoxic denitrification process during the agitation process. When the anoxic denitrification in the first SBR reactor is completed, the first order derivative of ORP changes from greater than -25mv/min to less than -30mv/min, and the stirring time t is greater than 2h. Machine SBR1 is automatically turned on;

A3, after the air compressor _SBR1 is automatically turned on, the air diffuses into the first SBR reactor through the aeration pipe and the aeration head, and enters the stage of organic matter removal. The pH value in the water is monitored by the pH sensor _SBR1 , and the data is recorded by the pH meter _SBR1 . The data is input into the computer through the data acquisition card, and the data are used as real-time control parameters for the removal of organic matter; when the condition for the removal of organic matter in the first SBR reactor is that the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 3h, the end During the organic matter removal process, the air compressor _SBR1 and the agitator _SBR1 are automatically shut down;

A4. The settling time of the first SBR reactor is timed by the time controller in the real-time control system. When it reaches 1 hour, it starts to drain, and the drainage time is timed by the time controller in the real-time control system. The system automatically opens the valve of the outlet pipe _SBR1 , the treated water enters the first intermediate water tank through the outlet pipe _SBR1 , and when the displacement reaches 50% of the volume of the first SBR reactor, the outlet pipe valve _SBR1 is automatically closed;

A5, after the drainage is finished, the system automatically enters the next cycle of A1;

B1, 60% of the effluent from the first SBR reactor in the first intermediate water tank enters the second SBR reactor, and 40% enters the second intermediate water tank. The water intake of the second SBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _SBR2 and the water inlet pipe valve _SBR2 are automatically opened, and 60% of the first SBR reactor in the first intermediate water tank is discharged. Inject into the second SBR reactor. When 60% of the first SBR reactor effluent in the first intermediate water tank is discharged, the water inlet pump _SBR2 and the water inlet pipe valve _SBR2 are automatically closed, and the water inlet is completed. Subsequently, 40% of the effluent from the first SBR reactor in the first intermediate water tank enters the second intermediate water tank, and its time is counted by the time controller in the real-time control system. The second _{intermediate water tank} of the water inlet pump and the water inlet pipe valve are automatically Open, inject 40% of the first SBR reactor effluent in the first intermediate water tank into the second intermediate water tank. When the first SBR reactor in the first intermediate water tank is discharged, _{the second intermediate water tank} of the water inlet pump and _{the second intermediate water tank} of the water inlet pipe valve are automatically closed, and the water intake is completed;

B2, after the water intake is completed, the agitator _SBR2 and the air compressor _SBR2 are automatically turned on, and the air diffuses into the second SBR reactor through the aeration pipe and the aeration head, and the second SBR reactor enters aerobic short-range nitrification during aeration In the aerobic short-range nitrification process, the online pH sensor _SBR2 and DO sensor _SBR2 monitor the pH value and dissolved oxygen concentration DO in the water respectively, and the data are input into the computer through the data acquisition card through the pH measuring instrument _SBR2 and DO measuring instrument _SBR2 . As a real-time control parameter of short-cut nitrification; when the short-cut nitrification is completed in the second SBR reactor, the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 6h, and DO is greater than 2mg/L at the same time, the short-cut nitrification process is ended , the air compressor _SBR2 and the agitator _SBR2 are automatically shut down;

B3, the precipitation in the second SBR reactor is timed by the time controller in the real-time control system. When the water discharge reaches 1 hour, the time is timed by the time controller in the real-time control system. The system automatically opens the outlet pipe valve _SBR2 , and the treated The water enters the second intermediate water tank through the outlet pipe _SBR2 , and when the displacement reaches 30% of the volume of the second SBR reactor, the outlet pipe valve _SBR2 is automatically closed;

B4, after the drainage is completed, the system automatically enters the next cycle of B1;

C1, the water intake of the ASBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically opened, and the mixed solution in the second intermediate water tank is injected into the second SBR reactor. In the process, when the water intake reaches 50% of the volume of the ASBR reactor, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically closed, and the water intake ends;

C2, after the water inflow is finished, the agitator _ASBR is automatically turned on, and the _ASBR reactor enters the anammox reaction during the stirring process. The data information is transmitted to the computer, and when the anaerobic ammonium oxidation reaction in the ASBR reactor is completed, the first order derivative of the pH changes from positive to negative, and when the stirring time t is greater than 6h, the agitator _ASBR is automatically closed;

C3, ASBR reactor precipitation is timed by the time controller in the real-time control system. When it reaches 1 hour, 50% of the treated water is discharged, and 70% of the effluent is returned to the original water tank. First, the effluent backflow is timed by the time controller in the real-time control system, and the system automatically opens the outlet pipe valve _ASBR , and the treated water enters the water inlet tank through the return pipe. When the effluent return flow reaches 35% of the volume of the ASBR reactor, The outlet pipe valve _ASBR is automatically closed; the remaining outlet water is discharged through the time controller in the real-time control system for timing, and the system automatically opens the outlet pipe valve _ASBR . When the discharged water reaches 15% of the ASBR reactor, the outlet pipe valve _ASBR automatically closes;

C4, after the drainage is completed, the system automatically enters the next cycle of C1;

In summary, the present invention provides a method and device for controlling the deep denitrification of landfill leachate by short-range nitrification combined with anaerobic ammonium oxidation. Taking urban landfill leachate as the research object, the denitrification and pre-exposure of the first SBR reactor are firstly carried out. The organic matter and nitrogen are removed, and part of the effluent from the first SBR reactor is subjected to short-range nitrification treatment in the second SBR reactor. Finally, the effluent from the first SBR reactor and the second SBR reactor are mixed in a ratio of 1:1.3. Entering the ASBR reactor for anaerobic ammonium oxidation reaction to achieve deep denitrification. At the same time, the ASBR effluent is refluxed, so that the produced nitrate nitrogen can be removed by denitrification using the organic carbon source in the raw water, which improves the denitrification rate of the system. The concentration of ammonia nitrogen in the system inlet water is 2000±100 mg/L, the ammonia nitrogen and nitrite nitrogen in the effluent water are both lower than 10mg/L, and the total nitrogen is about 60mg/L. The system denitrification rate reaches 95% under the condition of no external carbon source above. The whole system achieves the purpose of deep denitrification of landfill leachate without adding any organic carbon source.

Description of drawings

Fig. 1 is the structural schematic diagram of the deep denitrification control device for landfill leachate by short-range nitrification combined with anaerobic ammonium oxidation of the present invention;

Fig. 2 is the schematic flow sheet of A1～A5 in the control method of deep denitrification of landfill leachate by short-range nitrification combined with anammox of the present invention;

Fig. 3 is the schematic flow sheet of B1～B4 in the control method of deep denitrification of landfill leachate by short-range nitrification combined with anammox of the present invention;

Fig. 4 is the schematic flow sheet of C1～C4 in the control method of deep denitrification of landfill leachate by short-range nitrification combined with anaerobic ammonium oxidation of the present invention;

Typical ORP and pH variation law schematic diagram in the first SBR reactor operation process in the specific embodiment of the present invention in Fig. 5;

Fig. 6 is a schematic diagram of a typical pH change law during the operation of the second SBR reactor in a specific embodiment of the present invention;

Fig. 7 is a schematic diagram of the typical pH change law during the operation of the ASBR reactor in the specific embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Referring to FIG. 1 , the present invention provides a schematic structural diagram of a control device for deep denitrification of landfill leachate by combined short-cut nitrification combined with anaerobic ammonium oxidation. The water inlet tank 2 is connected to the first SBR reactor 9 through the water inlet pipe SBR14, the water inlet pump SBR13 and the water inlet valve SBR15; the first SBR reactor 9 is connected to the first intermediate water tank 19 through the water outlet pipe SBR118 and the water outlet valve SBR117; the first intermediate water tank 19 is connected to the second SBR reactor 74 through the water inlet pipe SBR234, the water inlet pump SBR221 and the water inlet valve SBR222, and the first intermediate water tank 19 is also connected to the second intermediate water tank 35 through the water inlet pipe, the second intermediate water tank 23 of the water inlet pump and the water inlet valve The second intermediate water tank 24 is connected with the second intermediate water tank 33; the second SBR reactor 74 is connected with the second intermediate water tank 33 through the water outlet pipe SBR232 and the water outlet valve SBR231; the second intermediate water tank 33 is connected with the water inlet pipe ASBR36, the water inlet pump ASBR37 and the water inlet The water valve ASBR38 is connected to the ASBR reactor 42; the ASBR reactor 42 is connected to the outlet pipe ASBR43 and the outlet valve ASBR44, and the ASBR reactor 42 also passes through the ASBR reactor return valve 45, the ASBR reactor return pipe 46 and the ASBR reactor return pump 47 Connect with water inlet tank 2.

The inside of the first SBR reactor 9 is provided with an agitator _SBR1 10, a pH sensor _SBR1 11, a DO sensor _SBR1 12 and an ORP sensor _SBR1 13; while the first SBR reactor 9 is also connected to the aeration head 6, the air compressor _SBR1 7 and the gas flowmeter8. The second SBR reactor 74 is provided with a stirrer _SBR2 28 , a pH sensor _SBR2 29 and a DO sensor _SBR2 30 ; meanwhile, the second SBR reactor 74 is also connected with the aeration head 6 , the air compressor _SBR2 20 and the gas flow meter 8 . The ASBR reactor 42 is provided with a stirrer _ASBR 41 and a pH sensor _ASBR 39 inside. pH sensor _SBR1 11, DO sensor _SBR1 12, ORP sensor _SBR1 13, pH sensor _SBR2 29, DO sensor _SBR2 30 and pH sensor _ASBR 39 are respectively connected with pH measuring instrument _SBR1 11, DO measuring instrument _SBR1 12, ORP measuring instrument _SBR1 via data lines 13. After the pH measuring instrument _SBR2 29, the DO measuring instrument _SBR2 30 and the pH measuring instrument _ASBR 39 are connected, they are connected with the data signal input interface 49 of the computer 48, and the computer 48 is connected with the process controller 55 through the data signal output interface. Inlet pump _SBR1 relay, water inlet valve _SBR1 relay, agitator SBR1 relay, air compressor _SBR1 relay, water outlet valve _{SBR1 relay, water inlet pump SBR2 relay} , water inlet valve _SBR2 relay, agitator _SBR2 relay, air compressor _SBR2 relay, _inlet Water pump _{second intermediate water tank} relay, water inlet valve _{second intermediate water tank} relay, water outlet valve _SBR2 relay, water inlet pump _ASBR relay, water inlet valve _ASBR relay, agitator _ASBR relay, water outlet valve _ASBR relay, ASBR reactor return valve relay, ASBR The reactor reflux pump relay is connected with water inlet pump _SBR1 3, water inlet valve _SBR1 5, agitator _SBR1 10, air compressor _SBR1 7, water outlet valve _SBR1 17, water inlet pump _SBR2 21, water inlet valve _SBR2 22, agitator _SBR2 28, Air compressor _SBR2 20, water inlet pump _{second middle water tank} 23, water inlet valve _{second middle water tank} 24, water outlet valve _SBR2 31, water inlet pump _ASBR 37, water inlet valve _ASBR 38, agitator _ASBR 41, water outlet valve _ASBR 44, ASBR The reactor reflux valve 45 and the ASBR reactor reflux pump 47 are connected.

Referring to Figure 2, it is a schematic flow diagram of A1~A5 in the control method of short-range nitrification combined with anaerobic ammonium oxidation for deep denitrification of landfill leachate, including:

A1, the water intake of the first SBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically opened, and the mixed solution in the water intake tank is injected into the first SBR reaction In the reactor, when the water intake of the SBR reactor reaches 50% of the volume of the SBR reactor, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically closed, and the water intake is completed;

_A2 , after the water inflow is finished, the agitator _SBR1 is automatically turned on, and the first SBR reactor enters the anoxic denitrification process during the agitation process. When the anoxic denitrification in the first SBR reactor is completed, the first order derivative of ORP changes from greater than -25mv/min to less than -30mv/min, and the stirring time t is greater than 2h. Machine SBR1 is automatically turned on;

A3, after the air compressor _SBR1 is automatically turned on, the air diffuses into the first SBR reactor through the aeration pipe and the aeration head, and enters the stage of organic matter removal. The pH value in the water is monitored by the pH sensor _SBR1 , and the data is recorded by the pH meter _SBR1 . The data is input into the computer through the data acquisition card, and the data are used as real-time control parameters for the removal of organic matter; when the condition for the removal of organic matter in the first SBR reactor is that the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 3h, the end During the organic matter removal process, the air compressor _SBR1 and the agitator _SBR1 are automatically shut down;

A4. The settling time of the first SBR reactor is timed by the time controller in the real-time control system. When it reaches 1 hour, it starts to drain, and the drainage time is timed by the time controller in the real-time control system. The system automatically opens the valve of the outlet pipe _SBR1 , the treated water enters the first intermediate water tank through the outlet pipe _SBR1 , and when the displacement reaches 50% of the volume of the first SBR reactor, the outlet pipe valve _SBR1 is automatically closed;

A5, after the drainage is finished, the system automatically enters the next cycle of A1;

Referring to Figure 3, it is a schematic flow diagram of B1~B4 in the control method for deep denitrification of landfill leachate by combined short-range nitrification combined with anaerobic ammonium oxidation, specifically including:

B1, 60% of the effluent from the first SBR reactor in the first intermediate water tank enters the second SBR reactor, and 40% enters the second intermediate water tank. The water intake of the second SBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _SBR2 and the water inlet pipe valve _SBR2 are automatically opened, and 60% of the first SBR reactor in the first intermediate water tank is discharged. Inject into the second SBR reactor. When 60% of the first SBR reactor effluent in the first intermediate water tank is discharged, the water inlet pump _SBR2 and the water inlet pipe valve _SBR2 are automatically closed, and the water inlet is completed. Subsequently, 40% of the effluent from the first SBR reactor in the first intermediate water tank enters the second intermediate water tank, and its time is counted by the time controller in the real-time control system. _{The second intermediate} water tank of the water inlet pump and the water inlet pipe valve are automatically Open, inject 40% of the first SBR reactor effluent in the first intermediate water tank into the second intermediate water tank. When the first SBR reactor in the first intermediate water tank is discharged, _{the second intermediate water tank} of the water inlet pump and _{the second intermediate water tank} of the water inlet pipe valve are automatically closed, and the water intake is completed;

B2, after the water intake is completed, the agitator _SBR2 and the air compressor _SBR2 are automatically turned on, and the air diffuses into the second SBR reactor through the aeration pipe and the aeration head, and the second SBR reactor enters aerobic short-range nitrification during aeration In the aerobic short-range nitrification process, the online pH sensor _SBR2 and DO sensor _SBR2 monitor the pH value and dissolved oxygen concentration DO in the water respectively, and the data are input into the computer through the data acquisition card through the pH measuring instrument _SBR2 and DO measuring instrument _SBR2 . As a real-time control parameter of short-cut nitrification; when the short-cut nitrification is completed in the second SBR reactor, the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 6h, and DO is greater than 2mg/L at the same time, the short-cut nitrification process is ended , the air compressor _SBR2 and the agitator _SBR2 are automatically shut down;

B3, the precipitation in the second SBR reactor is timed by the time controller in the real-time control system. When the water discharge reaches 1 hour, the time is timed by the time controller in the real-time control system. The system automatically opens the outlet pipe valve _SBR2 , and the treated The water enters the second intermediate water tank through the outlet pipe _SBR2 , and when the displacement reaches 30% of the volume of the second SBR reactor, the outlet pipe valve _SBR2 is automatically closed;

B4, after the drainage is completed, the system automatically enters the next cycle of B1;

Referring to Figure 4, it is a schematic flow chart of C1~C4 in the control method of deep denitrification of landfill leachate by combined short-range nitrification combined with anaerobic ammonium oxidation, specifically including:

C1, the water intake of the ASBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically opened, and the mixed solution in the second intermediate water tank is injected into the second SBR reactor. In the process, when the water intake reaches 50% of the volume of the ASBR reactor, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically closed, and the water intake ends;

C2, after the water inflow is finished, the agitator _ASBR is automatically turned on, and the _ASBR reactor enters the anammox reaction during the stirring process. The data information is transmitted to the computer, and when the anaerobic ammonium oxidation reaction in the ASBR reactor is completed, the first order derivative of the pH changes from positive to negative, and when the stirring time t is greater than 6h, the agitator _ASBR is automatically closed;

C3, ASBR reactor precipitation is timed by the time controller in the real-time control system. When it reaches 1 hour, 50% of the treated water is discharged, and 70% of the effluent is returned to the original water tank. First, the effluent backflow is timed by the time controller in the real-time control system, and the system automatically opens the outlet pipe valve _ASBR , and the treated water enters the water inlet tank through the return pipe. When the effluent return flow reaches 35% of the volume of the ASBR reactor, The outlet pipe valve _ASBR is automatically closed; the remaining outlet water is discharged through the time controller in the real-time control system for timing, and the system automatically opens the outlet pipe valve _ASBR . When the discharged water reaches 15% of the ASBR reactor, the outlet pipe valve _ASBR automatically closes;

C4, after the drainage is completed, the system automatically enters the next cycle of C1;

The scheme described in the present invention will be further described below in conjunction with examples. Taking the leachate of a certain landfill as the research object, it has been operated continuously for 90 days and has obtained stable operation results.

Parameter setting: the first SBR reactor: the water inflow time is 3 minutes, the sedimentation time is 1 hour, and the drainage time is 5 minutes; the stirring time is monitored in real time by the online ORP sensor _SBR1 and the pH sensor _SBR1 , and the ORP and pH changes can be seen in Figure 5. , the process controller starts aeration after receiving the signal representing the completion of denitrification, and the aeration time is monitored in real time by the online pH sensor. After the process controller obtains the signal representing the completion of organic matter removal, the aeration and stirring are stopped;

The second SBR reactor: the water inlet time is 3min, the sedimentation time is 1h, the drainage time is 5min, the aeration time and stirring time are monitored in real time by the online pH sensor _SBR2 and the DO sensor _SBR2 , and the process controller obtains the end of short-range nitrification After the signal, the aeration and stirring are stopped; the typical pH and the schematic diagram of the change law are shown in Figure 6.

ASBR reactor: the water intake time is 6 hours, the precipitation time is 1 hour, and the drainage time is 5 minutes. The stirring time is monitored in real time by the online pH sensor ASBR, and the process controller stops stirring after receiving the signal indicating the end of the anaerobic ammonium oxidation reaction; typical See Figure 7 for the schematic diagram of pH variation.

The performance of the first SBR reactor: The drainage ratio of the first SBR reactor is 0.5, the operating temperature is 25°C, the MLSS: 6000±500mg/L, the sludge age SRT is infinitely long, the influent COD is 2000±200mg/L, and the effluent The COD is maintained at 1100±100mg/L, the removal rate is 45±5%, the influent nitrate nitrogen concentration is 18±1 mg/L, and the effluent nitrate nitrogen concentration is maintained at 2±0.5 mg/L. The removal of nitrate nitrogen by nitrification reaches more than 85%.

The performance of the second SBR reactor: the drainage ratio of the second SBR reactor is 0.3, the operating temperature is 25°C, the MLSS: 5000±500mg/L, the sludge age SRT is infinitely long, the influent ammonia nitrogen is 800±50mg/L, and the effluent The concentration of nitrite nitrogen is 800±50mg/L, and the short-range nitrification rate is over 95%.

ASBR performance: ASBR operating cycle is not fixed for less than 24 hours, drainage ratio is 0.5, operating temperature is 30°C, MLSS: 7000±500mg/L, influent ammonia nitrogen and nitrite nitrogen concentrations are 400±50mg/L and 500± 50mg/L, the effluent ammonia nitrogen and nitrite nitrogen are both less than 10mg/L, the removal rate is above 95%, the effluent nitrate nitrogen concentration is 60±5mg/L, and the total nitrogen removal rate is above 90%.

System performance: the COD of the system influent is 2000±200mg/L, the COD of the effluent is 1500±100mg/L, and the removal rate is 25%; the TN of the influent is 2000±100 mg/L, and the TN of the effluent is 60±5mg/L. The removal rate is above 95%, and the deep removal of total nitrogen is realized without adding an external carbon source.

Further, the technical principles of the present invention are specifically:

The influent of the first SBR reactor is a mixture of raw water and ASBR effluent reflux liquid. After entering the water, anoxic stirring is performed first, and the organic carbon source in the raw water can be used to denitrify and remove the nitrate nitrogen in the ASBR effluent reflux liquid. At the same time, the organic carbon source in the raw water is more fully utilized, and the waste of the carbon source is avoided. In the process of denitrification, denitrifying bacteria use NO ₂ ^- -N as electron acceptor and organic matter as electron donor to reduce NO ₂ ^- -N to N ₂ , so that the oxidized substances in the reactor are continuously reduced, and the ORP value will decrease. After denitrification, the reactor is in anaerobic state, ORP drops rapidly, and characteristic point A appears at this time. After the end of denitrification, aeration is started only for the removal of organic matter. Late leachate contains a small amount of organic matter and a large amount of ammonia nitrogen, and organic matter will have an adverse effect on the subsequent anammox reaction. Since only the removal of organic matter is carried out in the first SBR reactor, during the process of the organic matter removal reaction, the generated _CO2 is blown off, causing the pH to rise, and the nitrification reaction after the removal of the organic matter will consume the alkalinity and cause the pH to drop. Feature point B appears. According to the above characteristics, the reaction process of denitrification and organic matter removal can be accurately judged. When the denitrification and organic matter removal are completed, stop stirring and aeration to avoid oxidation of ammonia nitrogen.

The influent water of the second SBR reactor comes from the effluent water of the first SBR reactor, and its main function is to short-range nitrify the effluent water of the first SBR reactor, and provide nitrite nitrogen substrate for the subsequent anammox reaction. After the second SBR reactor was fed with water, it started aeration and stirring. Under the combined inhibition of high free ammonia FA and high free nitrite FNA, the second SBR reactor realized short-range nitrification, so that the oxidized nitrogen in the effluent was mainly in the form of Nitrite nitrogen exists in the form of nitrite nitrogen, and the content of nitrite nitrogen is extremely low, which provides the substrate of nitrite nitrogen for the subsequent ASBR reactor. Because the nitrification reaction will consume the alkalinity to lower the pH, and the stripping of CO ₂ after the nitrification will make the pH rise, so the characteristic point C appears.

The influent water of the ASBR reactor is a mixed solution of the effluent water of the first SBR reactor and the effluent water of the second SBR reactor, which is formed by mixing 40% of the effluent water of the first SBR reactor and the effluent water of the second SBR reactor. Since the removal of organic matter is carried out in the first SBR reactor, the organic matter has little influence on the anammox at this time, and the ASBR reactor can maintain a good anammox reaction. Since the ASBR reactor adopts continuous water inflow, the alkalinity produced by the anaerobic ammonium oxidation reaction is neutralized, and the pH in the reactor remains basically unchanged. After the reaction, the pH will slowly decrease, and the characteristic point D appears at this time. After the anaerobic ammonium oxidation reaction, most of the nitrogen in the raw water will be removed from the reactor in the form of nitrogen gas, realizing complete denitrification in the true sense.

The advantage of the present invention is that the whole reaction system is composed of the first SBR reactor, the second SBR reactor and the ASBR reactor, using the original ammonia nitrogen in the leachate and the nitrite nitrogen produced by short-cut nitrification, and using the method of autotrophic denitrification Anaerobic ammonium oxidation technology performs deep denitrification treatment on landfill leachate, and at the same time, 70% of the effluent from the ASBR reactor is refluxed for further denitrification, which not only saves energy, but also removes most of the total nitrogen without adding carbon sources, greatly reducing sewage Processing charges and infrastructure charges for processing. The concentration of ammonia nitrogen in the system inlet water is 2000±100 mg/L, the ammonia nitrogen and nitrite nitrogen in the effluent water are both lower than 10mg/L, and the total nitrogen is about 60mg/L. The system denitrification rate reaches 95% under the condition of no external carbon source above.

The whole system is controlled in real time by online DO, pH and ORP value sensors to accurately judge the reaction end point of each stage, saving reaction time and energy. The whole process is completed by a process real-time control system, which is convenient for management and operation, with low operating costs, and the system is resistant to impact loads and is not easy to generate sludge bulking.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (2)

1. The control device for deep denitrification treatment of landfill leachate by combined nitrification combined with anaerobic ammonium oxidation, characterized in that: The water inlet tank (2) is connected to the first SBR reactor (9) through the water inlet pipe _SBR1 (4), the water inlet pump _SBR1 (3) and the water inlet valve _SBR1 (5); the first SBR reactor (9) is connected to the first SBR reactor (9) through the water outlet pipe _SBR1 (18) and the outlet valve _SBR1 (17) are connected to the first intermediate water tank (19); the first intermediate water tank (19) is connected to the first intermediate water tank (19) through the water inlet pipe _SBR2 (34), the water inlet pump _SBR2 (21) and the water inlet valve _SBR2 (22) The two SBR reactors (74) are connected, and the first intermediate water tank (19) is also connected to _{the second intermediate water tank} (35) by the water inlet pipe (35), _{the second intermediate water tank} (23) by the water inlet pump and _{the second intermediate water tank} (24) by the water inlet valve. The second intermediate water tank (33) is connected; the second SBR reactor (74) is connected with the second intermediate water tank (33) through the outlet pipe _SBR2 (32) and the outlet valve _SBR2 (31); the second intermediate water tank (33) is connected through the inlet The water pipe _ASBR (36), the water inlet pump _ASBR (37) and the water inlet valve _ASBR (38) are connected with the ASBR reactor (42); the ASBR reactor (42) is connected with the water outlet pipe _ASBR (43) and the water outlet valve _ASBR (44), At the same time, the ASBR reactor (42) is also connected to the water inlet tank (2) through the ASBR reactor reflux valve (45), the ASBR reactor reflux pipe (46) and the ASBR reactor reflux pump (47); The first SBR reactor (9) is equipped with a stirrer _SBR1 (10), a pH sensor _SBR1 (11), a DO sensor _SBR1 (12) and an ORP sensor _SBR1 (13); at the same time, the first SBR reactor (9) is also connected Aeration head (6), air compressor _SBR1 (7) and gas flow meter (8); the second SBR reactor (74) is equipped with agitator _SBR2 (28), pH sensor _SBR2 (29) and DO sensor _SBR2 (30); while the second SBR reactor (74) is also connected to the aeration head (6), the air compressor _SBR2 (20) and the gas flow meter (8); the ASBR reactor (42) is internally provided with an agitator _ASBR ( 41) and pH sensor _ASBR (39); pH sensor _SBR1 (11), DO sensor _SBR1 (12), ORP sensor _SBR1 (13), pH sensor _SBR2 (29), DO sensor _SBR2 (30) and pH sensor _ASBR (39 ) are respectively connected with pH meter _SBR1 (11), DO meter _SBR1 (12), ORP meter _SBR1 (13), pH meter _SBR2 (29), DO meter _SBR2 (30) and pH meter _ASBR through the data line (39) is connected to the data signal input interface (49) of the computer (48), the computer (48) is connected to the process controller (55) through the data signal output interface, the water inlet pump _SBR1 relay of the process controller, and the water inlet valve _SBR1 relay, agitator _SBR1 relay, air compressor SBR1 relay, water outlet valve _SBR1 relay _, water inlet pump _SBR2 relay, water inlet valve _SBR2 relay, agitator _SBR2 relay, air compressor _SBR2 relay, water inlet pump _{second intermediate water tank} relay, inlet Water valve _{second intermediate water tank} relay, water outlet valve _SBR2 relay, water inlet pump _ASBR relay, water inlet valve _ASBR relay, agitator _ASBR relay, water outlet valve _ASBR relay, ASBR reactor reflux valve relay, ASBR reactor reflux pump relay respectively Water pump _SBR1 (3), water inlet valve _SBR1 (5) _, agitator _SBR1 (10), air compressor SBR1 (7), water outlet valve _SBR1 (17), water inlet pump _SBR2 (21), water inlet valve _SBR2 (22) , agitator _SBR2 (28), air compressor _SBR2 (20), water inlet pump _{second intermediate water tank} (23), water inlet valve _{second intermediate water tank} (24), water outlet valve _SBR2 (31), water inlet pump _ASBR (37) , water inlet valve _ASBR (38), agitator _ASBR (41), water outlet valve _ASBR (44), ASBR reactor reflux valve (45), ASBR reactor reflux pump (47). 2. Applying the device described in claim 1 to carry out process nitrification combined with anaerobic ammonium oxidation to the control method of landfill leachate deep denitrification treatment, it is characterized in that the steps are as follows; A1, the water intake of the first SBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically opened, and the mixed solution in the water intake tank is injected into the first SBR reaction In the reactor, when the water intake of the SBR reactor reaches 50% of the volume of the SBR reactor, the water intake pump _SBR1 and the water intake pipe valve _SBR1 are automatically closed, and the water intake is completed; _A2 , after the water inflow is finished, the agitator _SBR1 is automatically turned on, and the first SBR reactor enters the anoxic denitrification process during the agitation process. When the anoxic denitrification in the first SBR reactor is completed, the first order derivative of ORP changes from greater than -25mv/min to less than -30mv/min, and the stirring time t is greater than 2h. Machine SBR1 is automatically turned on; A3, after the air compressor SBR1 is automatically turned on, the air diffuses into the first SBR reactor through the aeration pipe and the aeration head, and enters the stage of organic matter removal. The pH value in the water is monitored by the pH sensor _SBR1 , and the data is recorded by the pH meter _SBR1 . The data is input into the computer through the data acquisition card, and the data are used as real-time control parameters for the removal of organic matter; when the condition for the removal of organic matter in the first SBR reactor is that the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 3h, the end During the organic matter removal process, the air compressor _SBR1 and the agitator _SBR1 are automatically shut down; A4. The settling time of the first SBR reactor is timed by the time controller in the real-time control system. When it reaches 1 hour, it starts to drain, and the drainage time is timed by the time controller in the real-time control system. The system automatically opens the valve of the outlet pipe _SBR1 , the treated water enters the first intermediate water tank through the outlet pipe _SBR1 , and when the displacement reaches 50% of the volume of the first SBR reactor, the outlet pipe valve _SBR1 is automatically closed; A5, after the drainage is finished, the system automatically enters the next cycle of A1; B1, 60% of the first SBR reactor effluent in the first intermediate water tank enters the second SBR reactor, and 40% enters the second intermediate water tank; the water inflow of the second SBR reactor is timed by the time controller in the real-time control system After the system is started, the water inlet pump _SBR2 and the water inlet pipe valve _SBR2 are automatically opened, and 60% of the first SBR reactor effluent in the first intermediate water tank is injected into the second SBR reactor; when 60% of the first SBR reactor in the first intermediate water tank After the water out of the SBR reactor is discharged, the water inlet pump _SBR2 and the water inlet pipe valve _SBR2 are automatically closed, and the water inlet is completed; then, 40% of the water outflow from the first SBR reactor in the first intermediate water tank enters the second intermediate water tank, and the time is controlled by the real-time control system. The time controller for timing, _{the second intermediate water tank} of the water inlet pump and _{the second intermediate water tank} of the water inlet pipe valve are automatically opened, and 40% of the first SBR reactor effluent in the first intermediate water tank is injected into the second intermediate water tank; when the first intermediate water tank After the water from the first SBR reactor in the water tank is discharged, _{the second intermediate water tank} of the water inlet pump and _{the second intermediate water tank} of the water inlet pipe valve are automatically closed, and the water intake is completed; B2, after the water intake is completed, the agitator _SBR2 and the air compressor _SBR2 are automatically turned on, and the air diffuses into the second SBR reactor through the aeration pipe and the aeration head, and the second SBR reactor enters aerobic short-range nitrification during aeration In the aerobic short-range nitrification process, the online pH sensor _SBR2 and DO sensor _SBR2 monitor the pH value and dissolved oxygen concentration DO in the water respectively, and the data are input into the computer through the data acquisition card through the pH measuring instrument _SBR2 and DO measuring instrument _SBR2 . As a real-time control parameter of short-cut nitrification; when the short-cut nitrification is completed in the second SBR reactor, the first order derivative of pH changes from positive to negative, and the aeration time t is greater than 6h, and DO is greater than 2mg/L at the same time, the short-cut nitrification process is ended , the air compressor _SBR2 and the agitator _SBR2 are automatically shut down; B3, the precipitation in the second SBR reactor is timed by the time controller in the real-time control system. When the water discharge reaches 1 hour, the time is timed by the time controller in the real-time control system. The system automatically opens the outlet pipe valve _SBR2 , and the treated The water enters the second intermediate water tank through the outlet pipe _SBR2 , and when the displacement reaches 30% of the volume of the second SBR reactor, the outlet pipe valve _SBR2 is automatically closed; B4, after the drainage is completed, the system automatically enters the next cycle of B1; C1, the water intake of the ASBR reactor is timed by the time controller in the real-time control system. After the system is started, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically opened, and the mixed solution in the second intermediate water tank is injected into the second SBR reactor. In the process, when the water intake reaches 50% of the volume of the ASBR reactor, the water intake pump _ASBR and the water intake pipe valve _ASBR are automatically closed, and the water intake ends; C2, after the water inflow is finished, the agitator _ASBR is automatically turned on, and the _ASBR reactor enters the anammox reaction during the stirring process. The data information is transmitted to the computer, and when the anaerobic ammonium oxidation reaction in the ASBR reactor is completed, the first order derivative of the pH changes from positive to negative, and when the stirring time t is greater than 6h, the agitator _ASBR is automatically closed; C3, ASBR reactor precipitation is timed by the time controller in the real-time control system. When it reaches 1 hour, 50% of the treated water is discharged, and 70% of the effluent is returned to the original water tank; first, the effluent is returned to the real-time control system. The time controller for timing, the system automatically opens the outlet pipe valve _ASBR , and the treated water enters the water inlet tank through the return pipe. When the outlet water return flow reaches 35% of the volume of the ASBR reactor, the outlet pipe valve _ASBR automatically closes; the remaining outlet water The discharge is timed by the time controller in the real-time control system, and the system automatically opens the outlet valve _ASBR . When the discharged water reaches 15% of the ASBR reactor, the outlet valve _ASBR automatically closes; C4, after the drainage is finished, the system automatically enters the next cycle of C1.

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