A treatment system and method for simultaneously removing organic matter and sulfate from wastewater

Abstract

The present invention relates to a treatment system and method for synchronously removing organic matter and sulfate from wastewater, comprising a cylindrical reaction tank body, wherein the reaction tank body is provided with: a water inlet system for introducing wastewater containing organic matter and sulfate to be treated into the reaction tank body; a hydrolytic acidification bacteria injection system for providing a wastewater treatment system with hydrolytic acidification bacteria for hydrolyzing organic matter in wastewater into small organic molecules; and a plurality of microbial fuel cell systems. The anode of the microbial fuel cell system in the system of the present invention adopts a three-dimensional anode electrode, and the regular structure of the electrode and the properties of the biochar itself expand the area of ​​the anode, increase the abundance of electrochemically active microorganisms, and promote the ability to generate electrons. The cathode adopts a three-dimensional iron electrode, which not only increases the abundance of sulfate-reducing bacteria, but also can realize the sulfate reduction ability of the self-strengthening system through the action of the transferred electrons and zero-valent iron.

Description

Technical Field

[0001] The invention relates to the technical field of industrial wastewater treatment, and in particular to a treatment system and method for synchronously removing organic matter and sulfate in wastewater. Background Art

[0002] At present, wastewater containing high concentrations of sulfate is often produced in the fields of mining, metal smelting, electroplating, etc., which not only threatens the ecological environment and human life and health, but also wastes resources. The efficient treatment of wastewater containing high concentrations of sulfate has become an environmental and social problem that needs to be solved urgently. How to achieve efficient removal of sulfate has become one of the current focuses of attention. Biological methods have become a promising method due to their low cost and environmental friendliness, but microorganisms are easily restricted by environmental conditions, which affects their cell structure and growth conditions, thereby affecting their performance.

[0003] In the existing research on the treatment of sulfate-containing wastewater with sulfate-reducing bacteria, adding magnetite to the wastewater treatment process can improve the structure and abundance of sulfate-reducing bacteria, thereby improving the removal of sulfate; zero-valent iron can act as an additional electron donor to reduce sulfate and enhance the reducing atmosphere of the anaerobic reactor, which may have a promoting effect on the enzyme activity of sulfate-reducing bacteria. Under anaerobic conditions, the reducing property of zero-valent iron is expected to be protected, and its electron-donating effect can enhance the anaerobic reduction process. When wastewater flows through the iron-carbon filler, due to the Fe 0 There is an electrode potential difference between the C and the ZV iron, thus forming countless galvanic cell systems, which can remove specific pollutants through the synergistic effects of redox reaction, electrochemical enrichment, physical adsorption, and iron ion coagulation. However, adding too much zero-valent iron may also poison microorganisms and have the opposite effect.

[0004] However, the treatment efficiency of sulfate-containing wastewater is relatively slow and the treatment effect is not ideal. Especially for wastewater containing a certain concentration (COD concentration <10000mg / L, SO4 2- When the concentration of organic matter and sulfate is 2000-3000 mg / L, efficient and standard treatment cannot be guaranteed. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a treatment system for simultaneously removing organic matter and sulfate in wastewater, comprising a cylindrical reaction tank body, wherein the reaction tank body is provided with the following components from bottom to top:

[0006] A water inlet system for introducing the wastewater containing organic matter and sulfate to be treated into the main body of the reaction tank;

[0007] Provide a hydrolytic acidifying bacteria injection system for the wastewater treatment system, which is used to hydrolyze organic matter in the wastewater into small organic molecules;

[0008] as well as

[0009] Several microbial fuel cell systems.

[0010] Based on the above scheme, the microbial fuel cell system includes an anode enriched with electroactive bacteria and a cathode enriched with sulfate-reducing bacteria.

[0011] On the basis of the above scheme, the anode enriched with electrically active bacteria is a biochar particle board enriched with electrically active bacteria; the biochar particle board is made of Enteromorpha.

[0012] On the basis of the above scheme, the cathode enriched with sulfate-reducing bacteria is a multi-layer stacked wire mesh enriched with sulfate-reducing bacteria.

[0013] On the basis of the above scheme, the distance between the anode and cathode of the same microbial fuel cell system is no more than 10 cm; the distance between two adjacent microbial fuel cell systems is no less than 15 cm.

[0014] On the basis of the above scheme, the hydrolytic acidifying bacteria injection system injects sludge rich in hydrolytic acidifying bacteria;

[0015] The hydrolytic acidifying bacteria injection system comprises a mud inlet pipe for injecting domesticated sludge rich in hydrolytic acidifying bacteria into the wastewater treatment system, a supporting layer for supporting the sludge injected by the mud inlet pipe, and a stirrer for stirring the sludge on the sludge supporting layer to keep the sludge in a suspended state.

[0016] Based on the above scheme, a water outlet pipe for discharging treated water is arranged on the top of the reaction tank body, and a reflux pipe is arranged on the water outlet pipe for returning part of the discharged treated water to the lower part of the reaction tank body and driving the agitator to rotate.

[0017] On the basis of the above scheme, it also includes a three-phase separator arranged on the top of the reaction tank body for separating the treated water into solid, liquid and gas phases.

[0018] The present application also provides a method for treating wastewater containing organic matter and sulfate, which uses the above-mentioned treatment system and comprises the following steps:

[0019] (1) Before system operation

[0020] Injecting sludge containing hydrolytic acidifying bacteria onto a supporting layer provided in the reaction tank body through a hydrolytic acidifying bacteria injection system; sequentially installing a plurality of microbial fuel cell systems into the reaction tank body; and finally installing a three-phase separator on the top of the reaction tank body;

[0021] (2) System operation

[0022] The wastewater to be treated is circulated into the reaction tank body of the assembled wastewater treatment system through the water inlet system, and the valve of the reflux pipe is opened;

[0023] (3) System operation and maintenance

[0024] During the operation of the system, when the sludge concentration in the main body of the reaction tank exceeds 20gVSS / L, sludge is discharged. After discharge, the sludge concentration in the main body of the reactor is maintained at 8-15gVSS / L.

[0025] (4) Replacement of microbial fuel cell system

[0026] During the long-term operation of the system, the working status of the microbial fuel cell system is observed. If the electrode holes of the microbial fuel cell system are clogged with sludge, which hinders the upward flow of sewage, the water inlet system can be closed, the three-phase separator can be opened, and the electrode can be replaced.

[0027] The anode of the microbial fuel cell system in the system of the present invention adopts a three-dimensional anode electrode. The regular structure of the electrode and the properties of the biochar itself expand the area of ​​the anode, increase the abundance of electrochemically active microorganisms, and promote the ability to generate electrons. The cathode adopts a three-dimensional iron electrode, which not only increases the abundance of sulfate-reducing bacteria, but also can realize the sulfate reduction ability of the self-strengthening system through the action of the transferred electrons and zero-valent iron. The treatment system of the present invention drives the agitator through the downstream potential energy of the reflux water to complete the dilution and mixing of the sewage, thereby achieving the mitigation of the toxic effects of toxic substances and iron in the sewage on microorganisms. In the method of the present invention, the electroactive bacteria, sulfate-reducing bacteria and hydrolytic acidifying bacteria used can all use commercially available bacteria, or can use the method of the present invention to domesticate and screen from the sewage treatment plant by themselves, and the bacteria directly extracted from the sewage treatment plant belong to a composite flora, and the use effect is better than using a single commercially available bacteria, and the bacteria are directly domesticated and screened from the sludge, which is more economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of the wastewater treatment system of this application;

[0030] Figure 2This is a schematic diagram of the structure of the microbial fuel cell system in the wastewater treatment system of the present application;

[0031] Figure 3 This is a graph showing the output voltage during the electroactive bacteria collection process in Example 1;

[0032] Figure 4 This is a diagram showing the removal effect of sulfate and COD in Example 3. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, the present application provides a wastewater treatment system for synchronously removing organic matter and sulfate, comprising a cylindrical reaction tank body 1, wherein the reaction tank body 1 is provided with:

[0036] A water inlet system 2 for introducing the wastewater containing organic matter and sulfate to be treated into the reaction tank body 1;

[0037] A sludge inlet system 3 for providing a wastewater treatment system with acclimated sludge rich in hydrolytic acidifying bacteria for hydrolyzing organic matter in wastewater into small organic molecules;

[0038] as well as

[0039] Several microbial fuel cell systems 4.

[0040] like Figure 2 As shown, the microbial fuel cell system 4 includes an anode 4-1 enriched with electroactive bacteria and a cathode 4-2 enriched with sulfate-reducing bacteria.

[0041] In addition, it also includes wires and resistors connecting the anode 4-1 and the cathode 4-2.

[0042] The anode 4-1 enriched with electrically active bacteria is a biochar particle board enriched with electrically active bacteria; it is specifically prepared by the following method:

[0043] (1) Firing of activated carbon particle board

[0044] Wash the fresh Enteromorpha, place it in a blast drying oven, dry it at 60℃ for 2h, and grind it into powder in a mortar. Then, put the ground Enteromorpha into a crucible, seal it with fine sand and glass wool to isolate the air, and heat it in a muffle furnace at 260℃ for 2h before taking it out. After the crucible cools to room temperature, take out the sample and wash it repeatedly until there are no impurities. The washed biochar is dried, ground into powder, and stored for later use.

[0045] Enteromorpha-based biochar has a good pore structure and has a certain positive effect on electron transfer and microbial growth.

[0046] (2) The biochar obtained by the above sintering is placed in a mold and pressed into a regular hexagonal frame structure, with each hexagon being about 3-8 cm 3 , with a thickness of 3-4 cm, and then several hexagonal biochar particle boards are bonded together with an adhesive, and finally punched into a circular plate shape;

[0047] The Enteromorpha-based biochar particle board prepared by the present invention has cavities inside, which is convenient for microorganisms to attach and effectively increases the contact area of ​​sewage.

[0048] (3) Enrichment of electroactive bacteria

[0049] Electroactive bacteria can be directly enriched on biochar particle boards using commercially available strains, or they can be directly collected from sewage treatment plants for enrichment. The bacteria directly extracted from sewage treatment plants belong to composite flora, and the effect is better than using a single commercially available bacteria. In addition, the bacteria are directly domesticated and screened from sludge, which is more economical and environmentally friendly.

[0050] As a specific implementation method, the present application uses sludge from the Qingdao Nibuwan Sewage Treatment Plant to collect and enrich it on a biochar particle board. The specific method is as follows:

[0051] Construct a single-chamber microbial fuel cell with air as the cathode. Mix sludge and artificial water (artificial water can also be replaced by domestic sewage) in a volume ratio of 1:1 as the inlet water of the air cathode microbial fuel cell, and build in an electrode with a biochar particle board as the main body. During the first few cycles of inoculation, replace the fresh inlet water every 48 hours; after the voltage rises significantly, replace the fresh inlet water when the voltage is lower than 50mV. When the output voltage curve shape of two consecutive cycles is the same, it is considered that the electrochemically active microorganisms have completed enrichment and domestication (such as Figure 3As shown), no domestic sewage is added to the influent during the stable operation stage. At this time, a well-developed biofilm can be observed with the naked eye on the three-dimensional biochar particle plate, and then the biological sample is scraped and sequenced by high-throughput sequencing. The results show that a highly efficient electroactive bacterial community with the electroactive bacteria Geobacter as the dominant species is successfully enriched. The electroactive bacteria collected from the sludge of different sewage treatment plants may be different, but the method of the present invention can be used to collect the electroactive bacteria present in the sludge of the sewage treatment plant.

[0052] If water is prepared artificially, 1-5 g / L sodium acetate is used as the substrate, and 50 mmol / L phosphate buffer solution, 12.5 mL / L trace element solution, and 5 mL / L vitamin solution are added.

[0053] If domestic sewage is used to replace artificial water, it is only necessary to add the same phosphate buffer solution, trace element solution, and vitamin solution.

[0054] The cathode 4-2 enriched with sulfate-reducing bacteria is a multi-layer stacked wire mesh enriched with sulfate-reducing bacteria. The specific preparation method is as follows:

[0055] (1) Use iron wire with a diameter of 5 mm to weave a wire mesh plate. The mesh of the wire mesh plate is diamond-shaped and has an area of ​​3-8 cm 2 ; Then stack multiple layers of wire mesh plates together to form an electrode with a thickness of 3-4 cm; each electrode is composed of 3-4 layers of wire mesh;

[0056] (2) Soak the prepared electrode in 1% sodium hydroxide overnight to remove oil stains on the surface, and then rinse with dilute hydrochloric acid and deionized water;

[0057] (3) Enrichment of sulfate-reducing bacteria on the electrode surface.

[0058] Sulfate-reducing bacteria can be directly enriched on the cathode using commercially available strains, or they can be directly collected from sewage treatment plants for domestication and enrichment.

[0059] As a specific implementation method, the present application uses sludge from the Qingdao Nibuwan Sewage Treatment Plant for collection and enrichment on the cathode 4-2, and the specific method is as follows:

[0060] (3-1) The efficient sulfate-reducing bacteria need to be domesticated in advance to obtain the efficient sulfate-reducing bacteria. The domestication step is to use a culture medium (the culture medium formula is: 0.65g L -1 KH2PO4, 0.06 g L -1 MgCl2·6H2O, 2.22 g L - 1 Na2SO4, 0.04 g L -1CaCl2·2H2O, 1 g L -1 NH4Cl, 1.0 g L -1 Yeast extract and 2.0 mL L -1 The sludge is tamed with sodium lactate, and the volume ratio of sludge to culture solution is 1-3:9-7; after taming and culturing, the supernatant contains the enriched sulfate-reducing bacteria, and the supernatant is used as a new inoculation source, and the new culture solution is used for enrichment culture again, and the volume of the inoculation source and the culture solution is 1-3:9-7. After multiple enrichments, until the sulfate removal rate reaches more than 60% and is maintained for about 10 days, it shows that the flora has a stable sulfate-reducing ability at this time, and the enrichment of the sulfate-reducing flora is considered to be complete. The enriched flora is identified by high-throughput sequencing to obtain a sulfate-reducing flora with Desulfobulbus as the dominant species. The sulfate-reducing bacteria collected from the sludge of different sewage treatment plants may be different, but the sulfate-reducing bacteria in the sludge of the sewage treatment plant can be collected using the method of the present invention.

[0061] (3-2) The cathode 4-2 prepared by the above method is immersed in a solution of sulfate-reducing bacteria (the solution of sulfate-reducing bacteria is: the fresh culture solution of step (3-1): the bacterial solution enriched with domesticated sulfate-reducing bacteria in step (3-1) = 7-9: 1-3), the sulfate concentration in the solution is 250 mg / L, and a new solution is replaced every 48-72 hours, and after multiple replacements, until the sulfate removal rate reaches more than 90% and is maintained for about 10 days. In addition, a well-developed biofilm can be observed on the iron mesh, and the biological samples are scraped and high-throughput sequencing is performed to prove that the microbial flora attached to the iron mesh is an efficient sulfate-reducing flora with Desulfobulbus as the dominant species, and the sulfate-reducing flora load of the biological cathode is completed.

[0062] The anode 4-1 enriched with electroactive bacteria biofilm and the cathode 4-2 enriched with sulfate-reducing bacteria are located on the upper part of the bottom sludge layer (rich in hydrolytic acidifying bacteria). The distance between the anode 4-1 and the cathode 4-2 should not be greater than 10 cm (optimally 5-8 cm), and there are no less than 4 sets of wires around to connect the two, and the wires are arranged at equal intervals. The main principle is: the sewage hydrolyzed by hydrolytic acidifying bacteria, small molecular organic matter is further processed by the bacterial community dominated by electroactive bacteria, and the generated electrons migrate to the cathode 4-2 through the wires for the sulfate-reducing bacteria to reduce sulfate. When the sulfate from the sewage migrates to the cathode, the sulfate-reducing bacteria achieves efficient sulfate reduction performance under the combined action of the electron donor, the electrons generated from the anode, and the electrons provided by zero-valent iron, etc., achieving the effect of removing higher sulfate performance by relying solely on the sulfate-reducing bacteria.

[0063] The above-mentioned three-dimensional anode 4-1 enriched with electroactive bacteria biofilm and the three-dimensional cathode 4-2 enriched with sulfate-reducing bacteria are often more than one set in the system ( Figure 1 According to the height of the reaction tank body 1, the concentration of organic matter in the sewage and the concentration of sulfate, multiple microbial fuel cell systems 4 can be set. The distance between two adjacent microbial fuel cell systems should not be less than 15 cm.

[0064] The hydrolytic acidifying bacteria injected by the hydrolytic acidifying bacteria injection system 3 mentioned above can be commercially available hydrolytic acidifying bacteria, or can be sludge rich in hydrolytic acidifying bacteria from a sewage treatment plant. The following is an example of sludge from the Qingdao Nibuwan Sewage Treatment Plant.

[0065] The specific domestication steps of the above-mentioned sludge rich in hydrolytic acidifying bacteria are as follows:

[0066] (1) Sludge was collected from a sewage treatment plant. The treated sewage was diluted 5-10 times and then acclimated with the sludge at a solid-liquid ratio of 5:3 at 35±1°C for 1 month. During the acclimation stage, glucose, ammonium sulfate and potassium dihydrogen phosphate were used as carbon, nitrogen and phosphorus sources, and the ratio of carbon, nitrogen and phosphorus was controlled to be 200:5:1. In addition, 10 mL of trace elements were added per liter of inoculated sludge. The trace element components are shown in Table 1.

[0067] (2) After the acclimation and cultivation in step (1), the precipitated sludge is used as a new inoculum source and the new diluted sewage is used as the culture medium for enrichment, with a solid-liquid ratio of 3:2. After multiple acclimation, the sludge acclimation is completed until the COD removal rate reaches more than 40% and is maintained for 5 consecutive days, indicating that it has a stable hydrolysis and fermentation capacity.

[0068] Table 1 Trace element composition

[0069]

[0070] After the sludge is tamed, it is input into the reaction tank body 1. The sludge concentration in the reaction tank body 1 is controlled at 8 gVSS / L to 15 gVSS / L.

[0071] Based on the above technical solution, the hydrolytic acidifying bacteria injection system 3 includes a mud inlet pipe 3-1 for injecting domesticated sludge rich in hydrolytic acidifying bacteria into the wastewater treatment system, a supporting layer 3-2 for supporting the sludge injected by the mud inlet pipe 3-1, and an agitator 3-3 for stirring the sludge on the sludge supporting layer 3-2 to maintain the sludge in a suspended state. As a specific implementation scheme, the agitator 3-3 is arranged on the upper part of the sludge supporting layer 3-2, and the agitator 3-3 can be powered by connecting an external power supply. Through the setting of the agitator 3-3, the sludge on the supporting layer 3-2 can be kept in a suspended state as much as possible, and then can be fully in contact with the wastewater. At the same time, it can also prevent the sludge from falling and passing through the supporting layer 3-2, causing blockage of the water inlet system 2.

[0072] like Figure 1 As shown, the water inlet system 2 includes a water inlet pipe 2-1 and a liquid distributor 2-2, and the arrangement of the agitator 3-3 can effectively prevent the liquid distributor 2-2 from being blocked.

[0073] When in use, the domesticated sludge containing hydrolytic acidifying bacteria enters from the sludge inlet pipe 3-1 and is received by the supporting layer 3-2. Under the stirring action of the rotating blades of the agitator 3-3, the sludge is suspended on the upper part of the supporting layer 3-3 and is in full contact with the wastewater. After the agitator stops running, the sludge can be discharged from the sludge outlet 7. The sludge containing hydrolytic acidifying bacteria is injected once, and the sludge concentration is measured regularly. When the sludge concentration exceeds 20gVSS / L, the sludge is discharged. After the sludge is discharged, the sludge concentration in the reactor body 1 is maintained at 8-15gVSS / L. The main principle is: the organic matter in the influent is initially hydrolyzed and acidified by hydrolytic acidifying bacteria to obtain small molecular organic matter for subsequent use by electroactive bacteria.

[0074] like Figure 1 As shown, there are two mud discharge ports 7, one of which is arranged on the wall of the reaction tank body 1 corresponding to the supporting layer 3-2, for discharging the sludge on the supporting layer 3-2; the other is arranged at the bottom of the reaction tank body 1, for discharging the sludge falling to the lower part of the supporting layer 3-2.

[0075] The stirrer 3-3 can be powered by an external power supply for stirring. In addition, the present application also provides another specific implementation scheme, specifically, as Figure 1 As shown, the top of the reaction tank body 1 is provided with an outlet pipe 5 for discharging the treated water, and the outlet pipe 5 is provided with a reflux pipe 6 for returning part of the discharged treated water to the lower part of the reaction tank body 1 and driving the agitator 3-3 to rotate. That is, the outlet of the reflux pipe 6 corresponds to the blades of the agitator 3-3, and the agitator 3-3 is driven by the outflowing water of the reflux pipe 6. The reflux water flowing back to the reaction tank body 1 and the sewage flowing into the water inlet pipe 2-1 are fully mixed under the action of the agitator 3-3, completing the dilution and mixing of the sewage, and achieving the mitigation of the toxic effects of toxic substances and iron in the sewage on microorganisms.

[0076] During the wastewater treatment process, wastewater containing organic matter and sulfate will flow upward from the bottom of the reaction tank body 1, carrying the sludge in the reaction tank body 1 during the flow process. At the same time, acidic gas (CO2, H2S, etc.) will be generated during the treatment process. In order to facilitate the separation of solid, liquid and gas, a three-phase separator 8 is set on the top of the reaction tank body 1 to achieve solid, liquid and gas. The separated gas can be absorbed by a weak alkaline solution, and the separated solid sludge falls back to the reaction tank body 1, and the water phase overflows the reaction tank body 1 through the outlet pipe 5. The three-phase separator 8 can use a conventional UASB three-phase separator, which will not be repeated here.

[0077] Example 2

[0078] A wastewater treatment method for simultaneously removing organic matter and sulfate, using the system in Example 1, the specific steps are as follows:

[0079] (1) Before system operation

[0080] The sludge containing hydrolytic acidifying bacteria is injected into the supporting layer 3-2 provided in the reaction tank body 1 through the hydrolytic acidifying bacteria injection system 3; a plurality of microbial fuel cell systems 4 are sequentially installed in the reaction tank body 1; and finally a three-phase separator 8 is installed on the top of the reaction tank body (1);

[0081] (2) System operation

[0082] The wastewater to be treated is circulated into the reaction tank body 1 of the assembled wastewater treatment system through the water inlet system 2, and the valve of the reflux pipe 6 is opened. When the wastewater fills the reaction tank body 1, the concentration of the sludge in the reaction tank body 1 is 8-15gVSS / L;

[0083] (3) System operation and maintenance

[0084] During the operation of the system, when the sludge concentration in the reactor body 1 exceeds 20 gVSS / L, sludge is discharged. After the discharge, the sludge concentration in the reactor body 1 is maintained at 8-15 gVSS / L.

[0085] Specifically, the sludge concentration in the reaction tank body 1 is detected by taking the mud-water mixture from the sludge outlet 7 (specifically, the sludge outlet 7 arranged on the wall of the reaction tank body 1 corresponding to the supporting layer 3-2) under the condition that the return water pushes the stirring paddle to mix, and determining the sludge concentration according to the "Urban Wastewater Treatment Plant Sludge Inspection Method CJ / T 221-2005".

[0086] (4) Replacement of microbial fuel cell system 4

[0087] During the long-term operation of the system, the state of the microbial fuel cell system 4 is observed. If the electrode holes of the microbial fuel cell system 4 are clogged with sludge (generally, they are replaced when the clogging exceeds 80%), which hinders the upward flow of sewage, the water inlet system 2 can be closed and the three-phase separator 8 on the top can be opened to replace the electrodes.

[0088] Example 3

[0089] The wastewater treatment system in Example 1 was used, wherein the bacteria used in the anode 4 - 1 , the cathode 4 - 2 and the hydrolytic acidifying bacteria were all from the bacteria of the Qingdao Nibuwan Wastewater Treatment Plant in Example 1.

[0090] When the reactor volume is 600*200mm, the number of microbial fuel cells is 1, the flow rate of the wastewater is 5mL / min, the reflux ratio is 5, the sulfate concentrations in the initial wastewater are 500, 1000, 1500, and 2000mg / L, respectively, and the COD in the initial wastewater is 1000±50mg / L.

[0091] Evaluation conditions: Determine the sulfate content and COD in the water.

[0092] The results show that: Figure 4 As shown, under different initial sulfate concentrations, the sulfate removal efficiency in the effluent is higher than 90%, and the COD removal rate can reach more than 80%.

[0093] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A treatment system for simultaneously removing organic matter and sulfate from wastewater, characterized in that: The invention comprises a cylindrical reaction pool body (1), characterized in that the reaction pool body (1) is provided with the following components in order from bottom to top: A water inlet system (2) for inputting wastewater containing organic matter and sulfate to be treated into the reaction tank body (1); Providing a hydrolytic acidifying bacteria injection system (3) for the treatment system to hydrolyze organic matter in the wastewater into small organic molecules; as well as Several microbial fuel cell systems (4); The microbial fuel cell system (4) comprises an anode (4-1) enriched with electroactive bacteria and a cathode (4-2) enriched with sulfate-reducing bacteria; the cathode (4-2) enriched with sulfate-reducing bacteria is a multi-layer stacked wire mesh enriched with sulfate-reducing bacteria; The hydrolytic acidifying bacteria injection system (3) injects sludge rich in hydrolytic acidifying bacteria; The hydrolytic acidifying bacteria injection system (3) comprises a mud inlet pipe (3-1) for injecting domesticated sludge rich in hydrolytic acidifying bacteria into the wastewater treatment system, a supporting layer (3-2) for supporting the sludge injected by the mud inlet pipe (3-1), and a stirrer (3-3) for stirring the sludge on the sludge supporting layer (3-2) to keep the sludge in a suspended state; The top of the reaction tank body (1) is provided with a water outlet pipe (5) for discharging the treated water, and the water outlet pipe (5) is provided with a reflux pipe (6) for returning part of the discharged treated water to the lower part of the reaction tank body (1) and driving the agitator (3-3) to rotate; When the sludge concentration exceeds 20 gVSS / L, sludge is discharged. After the sludge is discharged, the sludge concentration in the reactor body (1) is maintained at 8 to 15 gVSS / L.

2. The treatment system for simultaneously removing organic matter and sulfate from wastewater according to claim 1, characterized in that: The anode (4-1) enriched with electrically active bacteria is a biochar particle board enriched with electrically active bacteria; the biochar particle board is made of Enteromorpha.

3. The treatment system for simultaneously removing organic matter and sulfate from wastewater according to claim 1, characterized in that: The distance between the anode (4-1) and the cathode (4-2) of the same microbial fuel cell system (4) is no greater than 10 cm; and the distance between two adjacent microbial fuel cell systems (4) is no less than 15 cm.

4. The treatment system for simultaneously removing organic matter and sulfate from wastewater according to claim 1, characterized in that: It also includes a three-phase separator (8) arranged on the top of the reaction tank body (1) and used for separating the solid, liquid and gas three phases of the treated water.

5. The treatment system for simultaneously removing organic matter and sulfate from wastewater according to claim 1, characterized in that: The hydrolytic acidifying bacteria, electroactive bacteria and sulfate-reducing bacteria are all collected from the sludge of the sewage treatment plant where the wastewater to be treated is located.

6. A method for treating wastewater containing organic matter and sulfate, characterized in that: Using the processing system according to any one of claims 1 to 5 comprises the following steps: (1) Before system operation Injecting sludge containing hydrolytic acidifying bacteria onto a supporting layer (3-2) provided in a reaction tank body (1) through a hydrolytic acidifying bacteria injection system (3); sequentially installing a plurality of microbial fuel cell systems (4) into the reaction tank body (1); and finally installing a three-phase separator (8) on the top of the reaction tank body (1); (2) System operation The wastewater to be treated is circulated into the reaction tank body (1) of the assembled wastewater treatment system through the water inlet system (2), and the valve of the return pipe (6) is opened; when the reaction tank body (1) is filled with sewage, the concentration of sludge in the reaction tank body (1) is: 8-15gVSS / L; (3) System operation and maintenance During the operation of the system, when the sludge concentration in the reactor body (1) exceeds 20 gVSS / L, sludge is discharged. After the discharge, the sludge concentration in the reactor body (1) is maintained at 8 to 15 gVSS / L. (4) Replacement of microbial fuel cell system (4) During the long-term operation of the system, the working state of the microbial fuel cell system (4) is observed. If the electrode holes of the microbial fuel cell system (4) are clogged with sludge, which hinders the upward flow of sewage, the water inlet system (2) can be closed and the three-phase separator (8) on the top can be opened to replace the electrodes.

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