Treatment process for acid mine wastewater and combined reactor thereof

Abstract

The invention discloses a treatment process for acid mine wastewater and a combined reactor thereof, and relates to the technical field of water treatment. The method specifically comprises the following steps: oxidizing the mine acid wastewater through an aerobic reactor; adjusting the pH value to 2.8 by using KOH in a first neutralization reactor, and further adjusting the pH value to 4.5 by using KOH in a second neutralization reactor; the wastewater enters a pretreatment reactor, H2S is introduced for treatment, and the treated wastewater continuously enters two anaerobic reactors for reaction. According to the method, an aerobic-anaerobic combined reactor containing iron oxidizing bacteria and sulfate reducing bacteria is adopted for treating the mine acid wastewater, on one hand, AMD can be effectively treated, on the other hand, heavy metal can be selectively precipitated, and Schwertmannite and metal sulfide with utilization value are obtained. The method not only realizes the economic value of effectively utilizing the wastewater, but also realizes the target of environmental treatment, and has better economic value.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a treatment process for acid mine wastewater and a combined reactor thereof. Background Art

[0002] Mineral resources are precious treasures given to mankind by nature. However, with the exploitation of various mineral resources, a large amount of acid mine drainage (AMD) will be produced, mainly including mine water, waste rock leaching water, tailings wastewater and ore dressing wastewater. AMD has a low pH (generally between 2 and 4), heavy metal ions (Pb, Zn, Cu, Cd, Mn, Al, Fe, As, etc.) and SO4 2- The concentration of AMD is relatively high. If AMD is discharged without treatment, it will not only waste mining resources, but also cause serious acid pollution and heavy metal pollution to rivers, lakes, groundwater and soil around the mines. Therefore, controlling AMD is one of the urgent tasks facing my country's current environmental governance.

[0003] At present, AMD remediation technology is a hot topic of research. Compared with existing AMD remediation methods, the method of microbial remediation of AMD can not only effectively reduce the formation of solid waste, but also effectively recycle heavy metals. Through extensive research by scholars at home and abroad, we have also gained an in-depth understanding of the formation mechanism and microbial ecology of AMD. However, the basic research on AMD microbial remediation technology is relatively weak, which is not conducive to the governance of AMD.

[0004] According to the different physiological and biochemical characteristics of microorganisms, the microbial method includes the method of using iron-oxidizing bacteria and sulfate-reducing bacteria to treat AMD. Iron-oxidizing bacteria are autotrophic microorganisms that grow in acidic mine wastewater and can mediate the formation of secondary iron-containing minerals. The types of minerals formed in the extreme environment of AMD are diverse. Among them, when the pH is 2.5-4.5 and there are fewer monovalent cations, a Schmidt mineral with a strong adsorption capacity for heavy metals can be formed in AMD; when the pH is <2.5 and there are monovalent cations (Na + , K + NH4 + In the presence of ferrous sulfate, ferrous sulfate minerals will be transformed into pyrite minerals. These secondary minerals are often present in acidic environments in the form of complexes. The ferrous sulfate minerals formed in AMD are the precipitation reservoirs of toxic heavy metal ions in acidic water bodies. Sulfate-reducing bacteria (SRB) usually refer to a type of anaerobic bacteria that can perform dissimilatory reduction of sulfate, provide organic matter as an electron donor, and produce S under anaerobic conditions through reduction. 2-It can combine with heavy metal ions to form metal sulfide precipitation, remove heavy metal ions in AMD, and consume H in the system during the reaction. + Therefore, how to process with low cost, no secondary pollution and recyclable metals is the technical problem that the present invention aims to solve. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a treatment process for acid mine wastewater and a combined reactor thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A process for treating acid mine wastewater comprises the following steps:

[0008] S1: The acid mine wastewater is oxidized through an aerobic reactor, and air is introduced using an oxygen pump to promote the oxidation process;

[0009] S2: In the first neutralization reactor, the pH of the fully oxidized acid mine drainage water is adjusted to 2.8 with KOH, and a stirrer is used to achieve uniform mixing, and the pH is further adjusted to 4.5 with KOH in the second neutralization reactor;

[0010] S3: The effluent after the above treatment enters the anaerobic pretreatment reactor and is introduced with H2S;

[0011] S4: The filtered filtrate is passed into the first anaerobic reactor for anaerobic treatment, and the effluent is passed into the second anaerobic reactor for anaerobic treatment.

[0012] Preferably: in the step S1, enriched iron oxidizing bacteria are added to the aerobic reactor, the culture medium for enriching iron oxidizing bacteria adopts a modified 9K culture medium, 1% high-grade FeS is used instead of FeSO4 as an energy matrix, and the medium is sterilized at 121°C by high pressure for 20 minutes. The acid mine wastewater sample is inoculated at a ratio of 1:100 in a clean bench, and shaken and cultured at room temperature of 25°C; 5% of the culture solution is transferred to fresh culture solution each time to transfer and culture enriched iron oxidizing bacteria; the enriched iron oxidizing bacteria are collected by centrifugation, and the cells are resuspended with 20mL of distilled water; the collected iron oxidizing bacteria are added to the aerobic reactor containing 5L of acid mine wastewater, and sufficient oxygen is provided by an oxygen pump. When the pH no longer decreases and the ferrous ions are completely oxidized, the oxidized acid mine wastewater enters the next reactor.

[0013] Furthermore: in the step S2, the pH of the completely oxidized acid mine wastewater is adjusted to about 2.8 with 5 mol / L KOH in the first neutralization reactor. After standing for 2 hours, the supernatant enters the second neutralization reactor, and the pH is adjusted to 4.5 with 5 mol / L KOH. After standing for 1 hour, the supernatant is filtered and the filtrate enters the next anaerobic pretreatment reactor.

[0014] On the basis of the above scheme: in the step S3, the H2S introduced into the anaerobic pretreatment reactor comes from the excess H2S produced in the anaerobic reactor, and the introduction of gas is stopped when no precipitation is produced.

[0015] A better solution among the above solutions is: in the step S4, the first anaerobic reactor is operated, the water is discharged once every 4 days, and an equal amount of anaerobic pre-treated acid mine wastewater is immediately introduced, and glycerol is added as a carbon source when the water is introduced, COD / SO4 2- =2, K2HPO4 0.05 g / L, yeast extract 0.2 g / L.

[0016] A combined reactor for acid mine wastewater comprises an aerobic reactor, a neutralization reactor, a stirrer, an anaerobic pretreatment reactor and an anaerobic processor.

[0017] At the same time, the neutralization reactor includes a tank body and a tank cover fixed to the top of the tank body, a water inlet pipe is arranged on one side of the bottom of the tank body, a water inlet pump is connected to the other side of the water inlet pipe, the other side of the water inlet pump is connected to the outlet of the aerobic reactor, an output pipe is arranged on one side of the top of the tank body, a detection component is arranged on the side wall of the output pipe, the top of the tank cover is connected to an opening valve through a neutralization pipe fitting, the other side of the opening valve is connected to a neutralization pump, and the other side of the neutralization pump is connected to an alkali liquid tank.

[0018] As a preferred embodiment of the present invention: the inner wall of the tank body is fixed with a spiral blade, the neutralizing pipe comprises a fixed pipe fixed to the inner wall of the tank cover and a movable pipe rotatably connected to the fixed pipe, a turbine fan is fixed to the inner wall of the top opening of the movable pipe, and a uniform liquid spray hole is opened on the side wall of the movable pipe;

[0019] The direction of rotation of the spiral blades for guiding the wastewater is opposite to the direction of rotation of the turbine fan for receiving the impact of the water flow;

[0020] The detection assembly comprises two groups of glass electrodes and a reference electrode, and the two groups of glass electrodes and the reference electrode are fixedly embedded in the inner wall of the output tube.

[0021] At the same time, the opening valve includes a valve body and a ball core rotatably connected to the inner wall of the valve body through a valve stem; an outer shell is fixed on one side of the valve body, and a slider is slidably connected to the inner wall of the outer shell. A spiral groove is provided on the outer wall of the valve stem, and a movable limit column is fixed on the inner wall of the slider that cooperates with the movable limit of the spiral groove. An electromagnet is respectively fixed on the outer wall of the slider and the inner wall of the outer shell. The two electromagnets cooperate with each other and have the same magnetic poles on the opposite side. A spring 1 is fixed on the end of the slider, and the other end of the spring 1 is fixed to the outer wall of the valve body.

[0022] As a more preferred solution of the present invention: the power control component includes an insulating shell and a magnetically conductive core fixed to the inner wall of the insulating shell, the two ends of the magnetically conductive core are respectively wound with a primary coil and a secondary coil, the outer wall of the insulating shell is fixed with an electromagnetic telescopic rod, the telescopic end of the electromagnetic telescopic rod is fixed with an electrode head, and the electrode head contacts and is electrically conductively matched with the side wall of the secondary coil;

[0023] The primary coil is connected to the outer wall AC power supply, the electrode head and the secondary coil are respectively connected to the two wiring terminals of the water inlet pump, the electromagnetic telescopic rod is electrically connected to one set of glass electrodes and a reference electrode, and the electromagnet is electrically connected to the other set of glass electrodes and a reference electrode.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention uses an "aerobic-anaerobic" combined reactor containing iron oxidizing bacteria and sulfate reducing bacteria to treat acid mine wastewater, which can effectively treat AMD on the one hand, and selectively precipitate heavy metals on the other hand to obtain valuable Schroeder minerals and metal sulfides. This method not only realizes the economic value of effectively utilizing wastewater, but also achieves the goal of environmental governance.

[0026] 2. The present invention has good stabilizing effect in treating AMD and high heavy metal removal rate, which can not only effectively reduce the formation of solid waste, but also effectively recover heavy metals to generate economic value, and has the characteristics of low treatment cost, no secondary pollution and metal recovery.

[0027] 3. The small-scale system for treating acidic wastewater of the present invention is composed of multiple reactors, and AMD is treated through a series of biological and chemical reactions, which can effectively combine environmental protection, energy recovery and ecological benign cycle, has good environmental and economic benefits, and is suitable for large-scale promotion and use.

[0028] 4. The present invention, by providing fixed pipes, turbofans, movable pipes, spiral blades and other components, can make the wastewater and the alkali solution present a reverse rotating relative motion when mixed, so that the wastewater and the alkali solution can be in contact more fully, thereby increasing the mixing efficiency and the neutralization effect.

[0029] 5. The present invention, based on the detection of glass electrode and reference electrode, uses the electromotive force generated by the detection of glass electrode and reference electrode as a drive to control the opening of the power opening valve of the water inlet pump respectively, thereby realizing negative feedback "self-sensing, self-driving" adaptive adjustment, so that the alkali solution feed amount and the wastewater delivery speed are matched with each other to ensure the neutralization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a treatment process for acid mine wastewater proposed by the present invention;

[0031] Figure 2 This is a schematic diagram of the overall main structure of a combined reactor for acid mine wastewater proposed by the present invention;

[0032] Figure 3 This is a schematic diagram of the overall cross-sectional structure of a combined reactor for acid mine wastewater proposed by the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of a detection component of a combined reactor for acid mine wastewater proposed by the present invention;

[0034] Figure 5 This is a schematic diagram of the structure of an opening valve of a combined reactor for acid mine wastewater proposed by the present invention;

[0035] Figure 6 A combined reactor for acid mine wastewater proposed by the present invention Figure 5 The enlarged structural diagram of part A in the middle;

[0036] Figure 7 This is a schematic diagram of the structure of a power control component of a combined reactor for acid mine wastewater proposed by the present invention;

[0037] Figure 8 This is a schematic diagram of the circuit structure of a combined reactor for acid mine wastewater proposed by the present invention.

[0038] In the figure: 1. tank body; 2. tank cover; 3. opening valve; 4. neutralization pump; 5. output pipe; 6. detection component; 7. water inlet pipe; 8. water inlet pump; 9. power control component; 10. neutralization pipe fitting; 11. fixed pipe; 12. turbofan; 13. movable pipe; 14. spray hole; 15. spiral blade; 16. glass electrode; 17. reference electrode; 18. valve body; 19. valve stem; 20. ball core; 21. electromagnet; 22. shell; 23. movable limit column; 24. slider; 25. spring 1; 26. spiral groove; 27. insulating shell; 28. magnetic core; 29. ​​primary coil; 30. secondary coil; 31. electrode head; 32. electromagnetic telescopic rod. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] Embodiment 1:

[0042] A process for treating acid mine wastewater, comprising the following steps:

[0043] S1: The acid mine wastewater is oxidized through an aerobic reactor, and air is introduced using an oxygen pump to promote the oxidation process;

[0044] S2: In the first neutralization reactor, the pH of the fully oxidized acid mine drainage water is adjusted to 2.8 with KOH, and a stirrer is used to achieve uniform mixing, and the pH is further adjusted to 4.5 with KOH in the second neutralization reactor;

[0045] S3: The effluent after the above treatment enters the anaerobic pretreatment reactor and is introduced with H2S;

[0046] S4: The filtered filtrate is passed into the first anaerobic reactor for anaerobic treatment, and the effluent is passed into the second anaerobic reactor for anaerobic treatment.

[0047] In the step S1, enriched iron oxidizing bacteria are added to the aerobic reactor, the culture medium for enriching iron oxidizing bacteria adopts a modified 9K culture medium, 1% high-grade FeS is used instead of FeSO4 as an energy matrix, and the medium is sterilized at 121°C by high pressure for 20 minutes. The acid mine wastewater sample is inoculated at a ratio of 1:100 in a clean bench, and shaken and cultured at room temperature of 25°C; 5% of the culture solution is transferred to fresh culture solution each time to transfer and culture enriched iron oxidizing bacteria; the enriched iron oxidizing bacteria are collected by centrifugation, and the cells are resuspended with 20mL of distilled water; the collected iron oxidizing bacteria are added to the aerobic reactor containing 5L of acid mine wastewater, and sufficient oxygen is provided by an oxygen pump. When the pH no longer decreases and the ferrous ions are completely oxidized, the oxidized acid mine wastewater enters the next reactor.

[0048] In the step S2, the pH of the completely oxidized acid mine wastewater is adjusted to about 2.8 with 5 mol / L KOH in the first neutralization reactor. After standing for 2 hours, the supernatant enters the second neutralization reactor, and the pH is adjusted to 4.5 with 5 mol / L KOH. After standing for 1 hour, the supernatant is filtered and the filtrate enters the next anaerobic pretreatment reactor.

[0049] In the step S3, the H2S introduced into the anaerobic pretreatment reactor comes from the excess H2S produced in the anaerobic reactor. When no precipitation is produced, the introduction of gas is stopped.

[0050] In the step S4, the first anaerobic reactor was operated, effluent 600 mL every 4 days, and immediately influent 600 mL of anaerobic pretreated acid mine wastewater, and glycerol was added as a carbon source during influent, COD / SO4 2- =2, K2HPO4 0.05 g / L, yeast extract 0.2 g / L;

[0051] The second anaerobic reactor was operated for 4 days and 600 mL of effluent was immediately fed into the reactor. Glycerol was added as a carbon source during the inlet. COD / SO4 2- =2, K2HPO4 0.05 g / L, yeast extract 0.2 g / L.

[0052] Embodiment 2:

[0053] A combined reactor for acid mine wastewater, which is used to implement the treatment process for acid mine wastewater in Example 1, comprises: an aerobic reactor, a neutralization reactor, a stirrer, an anaerobic pretreatment reactor and an anaerobic processor.

[0054] The neutralization reactor comprises a tank body 1 and a tank cover 2 fixed to the top of the tank body 1, a water inlet pipe 7 is arranged on one side of the bottom of the tank body 1, a water inlet pump 8 is connected to the other side of the water inlet pipe 7, and the other side of the water inlet pump 8 is connected to the outlet of the aerobic reactor, an output pipe 5 is arranged on one side of the top of the tank body 1, a detection component 6 is arranged on the side wall of the output pipe 5, the top of the tank cover 2 is connected to an opening valve 3 through a neutralization pipe fitting 10, a neutralization pump 4 is connected to the other side of the opening valve 3, and an alkali liquid tank is connected to the other side of the neutralization pump 4.

[0055] The water inlet pump 8 can pump the acidic wastewater into the interior of the tank body 1, and then the neutralization pump 4 transports the alkali solution in the alkali solution box to the interior of the tank body 1, the acidic wastewater and the alkali solution are mixed, and then flow out through the output pipe 5, the detection component 6 can detect the pH value of the wastewater flowing out of the output pipe 5, and then control the opening of the opening valve 3 and the power of the water inlet pump 8 to achieve the pH value of the neutralization standard.

[0056] A spiral blade 15 is fixed to the inner wall of the tank body 1, and the neutralization pipe 10 includes a fixed pipe 11 fixed to the inner wall of the tank cover 2 and a movable pipe 13 rotatably connected to the fixed pipe 11, a turbofan 12 is fixed to the inner wall of the top opening of the movable pipe 13, and a uniform liquid spray hole 14 is opened on the side wall of the movable pipe 13.

[0057] The rotation direction of the spiral blade 15 for guiding the wastewater is opposite to the rotation direction of the turbofan 12 for receiving the impact of the water flow.

[0058] When wastewater enters from the water inlet pipe 7 at the bottom, it moves upward and the spiral blades 15 guide the wastewater to rise in a spiral path. At the same time, when the alkali solution is transported to the movable pipe 13, the turbine fan 12 is driven by the flow force of the alkali solution to drive the movable pipe 13 to rotate, so that the alkali solution is sprayed out in a rotating manner.

[0059] The device, by arranging components such as a fixed pipe 11, a turbofan 12, a movable pipe 13, and a spiral blade 15, can make the wastewater and the alkali solution present a reverse rotating relative motion when mixed, so that the wastewater and the alkali solution can be in contact more fully, the mixing efficiency is increased, and the neutralization effect is increased.

[0060] The detection assembly 6 includes two groups of glass electrodes 16 and a reference electrode 17 . The two groups of glass electrodes 16 and the reference electrode 17 are fixedly embedded in the inner wall of the output tube 5 .

[0061] When the glass electrode 16 contacts hydrogen ions, a potential change occurs, thereby causing a potential difference between the glass electrode 16 and the reference electrode 17 to change. By sensing the potential difference, the hydrogen ion concentration can be detected to achieve pH detection.

[0062] In order to solve the problem of neutralization effect, such as Figure 5-7 As shown, the opening valve 3 includes a valve body 18 and a ball core 20 rotatably connected to the inner wall of the valve body 18 through a valve stem 19; when the ball core 20 rotates, the overlap between the ball core 20 and the flow channel of the valve body 18 will change, thereby changing the cross-sectional area of ​​the flow channel, thereby changing the flow rate of the alkali solution.

[0063] A shell 22 is fixed to one side of the valve body 18, and a slider 24 is slidably connected to the inner wall of the shell 22. A spiral groove 26 is opened on the outer wall of the valve stem 19, and a movable limit column 23 that cooperates with the spiral groove 26 is fixed to the inner wall of the slider 24. An electromagnet 21 is fixed to the outer wall of the slider 24 and the inner wall of the shell 22 respectively. The two electromagnets 21 cooperate with each other and have the same magnetic poles on opposite sides. A spring 25 is fixed to the end of the slider 24, and the other end of the spring 25 is fixed to the outer wall of the valve body 18.

[0064] When current flows into the electromagnet 21 , the electromagnet 21 can generate a magnetic field, thereby generating a magnetic repulsion force. The slider 24 moves due to the magnetic repulsion force, causing the movable limit column 23 and the spiral groove 26 to move axially relative to each other, thereby causing the valve stem 19 to rotate.

[0065] The power control component 9 includes an insulating shell 27 and a magnetic core 28 fixed to the inner wall of the insulating shell 27, the two ends of the magnetic core 28 are respectively wound with a primary coil 29 and a secondary coil 30, an outer wall of the insulating shell 27 is fixed with an electromagnetic telescopic rod 32, the telescopic end of the electromagnetic telescopic rod 32 is fixed with an electrode head 31, and the electrode head 31 contacts and electrically conducts with the side wall of the secondary coil 30.

[0066] The primary coil 29 is connected to the outer wall AC power supply, the electrode head 31 and the secondary coil 30 are respectively connected to the two wiring terminals of the water inlet pump 8, the electromagnetic telescopic rod 32 is electrically connected to one set of glass electrodes 16 and the reference electrode 17, and the electromagnet 21 is electrically connected to the other set of glass electrodes 16 and the reference electrode 17.

[0067] When the amount of alkali solution introduced is small and the neutralization is incomplete, the wastewater in the output pipe 5 is still acidic and the concentration of hydrogen ions therein is high, thereby increasing the potential difference between the glass electrode 16 and the reference electrode 17. On the one hand, the current of the electromagnet 21 increases, the magnetic field increases, the slider 24 moves downward, and the neutralization pipe 10 drives the ball core 20 to rotate, increasing the overlap between the ball core 20 and the flow channel of the valve body 18, thereby increasing the intake of alkali solution. In addition, the electromagnetic telescopic rod 32 will also be extended by the large current, causing the electrode head 31 to move, thereby changing the matching position of the electrode head 31 and the secondary coil 30, reducing the number of turns of the secondary coil 30 connected to the circuit, and according to the law of electromagnetic induction, the input power of the water inlet pump 8 is reduced, reducing the acid water delivery speed.

[0068] This device, based on the detection of the glass electrode 16 and the reference electrode 17, uses the electromotive force generated by the detection of the glass electrode 16 and the reference electrode 17 as a drive to control the opening of the power opening valve 3 of the water inlet pump 8 respectively, thereby realizing negative feedback "self-sensing, self-driving" adaptive adjustment, so that the alkali solution feed amount and the wastewater delivery speed are matched with each other to ensure the neutralization effect.

[0069] When the present embodiment is in use, the water inlet pump 8 can pump acidic wastewater into the interior of the tank body 1, and then the neutralization pump 4 transports the alkali solution in the alkali solution box to the interior of the tank body 1, the acidic wastewater and the alkali solution are mixed, and then flow out through the output pipe 5, the detection component 6 can detect the pH value of the wastewater flowing out of the output pipe 5, and then control the opening of the opening valve 3 and the power of the water inlet pump 8 to make it reach the pH value of the neutralization standard. When the amount of alkali solution introduced is small and the neutralization is incomplete, the wastewater in the output pipe 5 is still acidic, and the concentration of hydrogen ions therein is high, so that the glass electrode 16 and the reference electrode are in a state of being ... The potential difference between the poles 17 increases, which on the one hand increases the current of the electromagnet 21, increases the magnetic field, and moves the slider 24 downward. The neutralizing pipe 10 drives the ball core 20 to rotate, increasing the overlap between the ball core 20 and the flow channel of the valve body 18, thereby increasing the intake of alkali solution. In addition, the electromagnetic telescopic rod 32 will also be extended by the large current, causing the electrode head 31 to move, thereby changing the matching position of the electrode head 31 and the secondary coil 30, reducing the number of turns of the secondary coil 30 connected to the circuit. According to the law of electromagnetic induction, the input power of the water inlet pump 8 is reduced, reducing the acid water delivery speed.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for treating acid mine wastewater, characterized in that: The following steps are involved: S1: The acid mine wastewater is oxidized through an aerobic reactor, and air is introduced using an oxygen pump to promote the oxidation process; S2: In the first neutralization reactor, the pH of the fully oxidized acid mine drainage water is adjusted to 2.8 with KOH, and a stirrer is used to achieve uniform mixing, and the pH is further adjusted to 4.5 with KOH in the second neutralization reactor; S3: The effluent after the above treatment enters the anaerobic pretreatment reactor and is introduced with H2S; S4: The filtered filtrate is passed into the first anaerobic reactor for anaerobic treatment, and the effluent is passed into the second anaerobic reactor for anaerobic treatment.

2. A process for treating acid mine wastewater according to claim 1, characterized in that: In the step S1, enriched iron oxidizing bacteria are added to the aerobic reactor, the culture medium for enriching iron oxidizing bacteria adopts a modified 9K culture medium, 1% high-grade FeS is used instead of FeSO4 as an energy matrix, and the medium is sterilized at 121°C by high pressure for 20 minutes. The acid mine wastewater sample is inoculated at a ratio of 1:100 in a clean bench, and shaken and cultured at room temperature of 25°C; 5% of the culture solution is transferred to fresh culture solution each time to enrich the iron oxidizing bacteria; the enriched iron oxidizing bacteria are collected by centrifugation, and the cells are resuspended with 20mL of distilled water; the collected iron oxidizing bacteria are added to the aerobic reactor containing 5L of acid mine wastewater, and sufficient oxygen is provided by an oxygen pump. When the pH no longer decreases and the ferrous ions are completely oxidized, the oxidized acid mine wastewater enters the next reactor.

3. A process for treating acid mine wastewater according to claim 1, characterized in that: In the step S2, the pH of the completely oxidized acid mine wastewater is adjusted to about 2.8 with 5 mol / L KOH in the first neutralization reactor. After standing for 2 hours, the supernatant enters the second neutralization reactor, and the pH is adjusted to 4.5 with 5 mol / L KOH. After standing for 1 hour, the supernatant is filtered and the filtrate enters the next anaerobic pretreatment reactor.

4. A process for treating acid mine wastewater according to claim 1, characterized in that: In the step S3, the H2S introduced into the anaerobic pretreatment reactor comes from the excess H2S produced in the anaerobic reactor. When no precipitation is produced, the introduction of gas is stopped.

5. A process for treating acid mine wastewater according to claim 1, characterized in that: In the step S4, the first anaerobic reactor is operated, and the water is discharged once every 4 days, and an equal amount of acid mine wastewater that has been anaerobic pretreated is immediately introduced, and glycerol is added as a carbon source when the water is introduced. The COD / SO4 2- =2, K2HPO4 0.05 g / L, yeast extract 0.2 g / L.

6. A combined reactor for acid mine wastewater, which is applied to a treatment process for acid mine wastewater according to any one of claims 1 to 5, characterized in that: The invention comprises an aerobic reactor, a neutralization reactor, a stirrer, an anaerobic pretreatment reactor and an anaerobic processor in steps S1-S4 of a process for treating acid mine wastewater as described in any one of claims 1-5.

7. A combined reactor for acid mine wastewater according to claim 6, characterized in that: The neutralization reactor comprises a tank body (1) and a tank cover (2) fixed to the top of the tank body (1); a water inlet pipe (7) is arranged on one side of the bottom of the tank body (1); a water inlet pump (8) is connected to the other side of the water inlet pipe (7); the other side of the water inlet pump (8) is connected to the outlet of the aerobic reactor; an output pipe (5) is arranged on one side of the top of the tank body (1); a detection component (6) is arranged on the side wall of the output pipe (5); the top of the tank cover (2) is connected to an opening valve (3) through a neutralization pipe fitting (10); the other side of the opening valve (3) is connected to a neutralization pump (4); the other side of the neutralization pump (4) is connected to an alkali liquid tank.

8. A combined reactor for acid mine wastewater according to claim 7, characterized in that: The inner wall of the tank body (1) is fixed with a spiral blade (15), the neutralizing pipe (10) comprises a fixed pipe (11) fixed to the inner wall of the tank cover (2) and a movable pipe (13) rotatably connected to the fixed pipe (11), a turbine fan (12) is fixed to the inner wall of the top opening of the movable pipe (13), and the side wall of the movable pipe (13) is provided with uniform liquid spray holes (14); The spiral blade (15) guides the wastewater in a direction opposite to the direction in which the turbine fan (12) receives the impact of the water flow; The detection assembly (6) comprises two groups of glass electrodes (16) and a reference electrode (17), and the two groups of glass electrodes (16) and the reference electrode (17) are fixedly embedded in the inner wall of the output tube (5).

9. A combined reactor for acid mine wastewater according to claim 8, characterized in that: The opening valve (3) comprises a valve body (18) and a ball core (20) rotatably connected to the inner wall of the valve body (18) through a valve stem (19); a shell (22) is fixed on one side of the valve body (18); a slider (24) is slidably connected to the inner wall of the shell (22); a spiral groove (26) is provided on the outer wall of the valve stem (19); a movable limit column (23) that is movable and limited with the spiral groove (26) is fixed on the inner wall of the slider (24); an electromagnet (21) is fixed on the outer wall of the slider (24) and the inner wall of the shell (22), respectively; the two electromagnets (21) cooperate with each other and have the same magnetic poles on opposite sides; a spring (25) is fixed on the end of the slider (24); the other end of the spring (25) is fixed to the outer wall of the valve body (18).

10. A combined reactor for acid mine wastewater according to claim 9, characterized in that: The power control component (9) comprises an insulating shell (27) and a magnetically conductive core (28) fixed to the inner wall of the insulating shell (27); the two ends of the magnetically conductive core (28) are respectively wound with a primary coil (29) and a secondary coil (30); an electromagnetic telescopic rod (32) is fixed to the outer wall of the insulating shell (27); an electrode head (31) is fixed to the telescopic end of the electromagnetic telescopic rod (32); the electrode head (31) contacts and is electrically conductively matched with the side wall of the secondary coil (30); The primary coil (29) is connected to an outer wall AC power supply, the electrode head (31) and the secondary coil (30) are respectively connected to two wiring terminals of a water inlet pump (8), the electromagnetic telescopic rod (32) is electrically connected to one set of glass electrodes (16) and a reference electrode (17), and the electromagnet (21) is electrically connected to another set of glass electrodes (16) and a reference electrode (17).

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