A baffling membrane bioreactor and method for partitioned resource utilization of sulfate wastewater

Abstract

The application provides a baffle type membrane bioreactor and method for partitioned resource utilization of sulfate wastewater, and relates to the field of wastewater treatment. The reactor is divided into a sulfate reduction compartment, an anaerobic-microaerobic transition compartment and a sulfur oxidation compartment which are sequentially connected in series by a baffle plate arranged in the vertical direction. The sulfate reduction compartment is provided with a first filler area. The anaerobic-microaerobic transition compartment is provided with a gas curtain device and a second filler area from bottom to top. The sulfur oxidation compartment is provided with a third filler area and a sulfur trapping device from bottom to top. The first filler area, the second filler area and the third filler area are respectively used for filling fillers loaded with sulfate reducing bacteria, H2S adsorption fillers and fillers loaded with sulfur oxidizing bacteria. The application realizes effective separation of sulfate reducing bacteria and sulfate oxidizing bacteria in space, and overcomes the problems of poor system stability, low sulfur conversion rate and low recovery rate caused by cross interference and bacterial population inhibition in the reaction zone.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, specifically to a baffled membrane bioreactor and method for the zoned resource recovery of sulfate wastewater. Background Technology

[0002] With rapid economic development, the industrial sector generates large amounts of high-salinity wastewater. The high concentrations of salts in this wastewater, such as chlorides and sulfates, lead to a series of environmental problems, including water quality deterioration and damage to soil ecosystems, ultimately impacting people's daily lives. High-sulfate wastewater mainly originates from various industrial production processes, including chemical, pharmaceutical, petroleum, and papermaking industries. Given its large discharge volume and significant hazards, efficient treatment and the recovery and utilization of sulfur resources have become key research areas in wastewater treatment.

[0003] Sulfate transformation mainly consists of two stages: dissimilar sulfate reduction and assimilar sulfate oxidation. Dissimilar sulfate reduction, represented by bacteria such as *Desulfovibrio*, reduces SO42- under strictly anaerobic conditions (ORP < -300 mV). 2- Reduced to H2S; assimilatory sulfate oxidation, represented by bacteria such as Thiobacillus, oxidizes H2S to elemental sulfur (S) in a microaerobic environment (DO = 0.1~0.5 mg / L). 0 The two groups differ significantly in metabolic pathways, redox states, and microbial community composition.

[0004] However, using a single anaerobic process cannot separate the two stages of sulfate conversion, making it difficult to achieve the synergistic utilization of dissimilatory sulfate-reducing bacteria and assimilatory sulfate-oxidizing bacteria. This results in problems such as sulfide accumulation, bacterial community interference, and mixed functions in the reaction zone, leading to poor system stability and low sulfur conversion and recovery rates.

[0005] Therefore, how to effectively separate dissimilar sulfate-reducing bacteria and assimilar sulfate-oxidizing bacteria in space, and overcome the defects of poor system stability, low sulfur conversion rate and recovery rate caused by cross-interference and bacterial community inhibition in the reaction zone, has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defects of poor system stability, low sulfur conversion rate and low recovery rate caused by the difficulty in effectively separating dissimilar sulfate-reducing bacteria and assimilar sulfate-oxidizing bacteria in space during the treatment and resource utilization of sulfate wastewater. Thus, a baffled membrane bioreactor and method for the zoned resource utilization of sulfate wastewater is provided.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a baffled membrane bioreactor for the zoned resource utilization of sulfate wastewater, wherein the reactor is divided by baffles arranged vertically into a sulfate reduction compartment, an anaerobic-microaerobic transition compartment, and a sulfur oxidation compartment connected in series, wherein:

[0009] The sulfate reduction compartment is provided with a first packing area, which is used to fill the packing material loaded with sulfate-reducing bacteria;

[0010] The anaerobic-microaerobic transition compartment is provided with a gas curtain device and a second packing area from bottom to top. The gas curtain device is arranged with the gas outlet direction facing upwards, and the second packing area is used to fill H2S adsorption packing.

[0011] The sulfur oxidation chamber is arranged from bottom to top as a third packing zone and a sulfur capture device. The third packing zone is used to fill the packing material loaded with sulfur-oxidizing bacteria.

[0012] Furthermore, each compartment is divided by a set of baffles, including sequentially arranged baffles and vertical plates. The upper end of the baffle is connected to the top of the reactor, and the lower end folds downwards to the right. The lower end of the vertical plate is connected to the bottom of the reactor, so that wastewater enters from the bottom of the compartment and flows out from the top. Preferably, the inclination angle of the folded end of the baffle is 50~55°. The distance between the lower end of the baffle and the vertical plate is 1:2~3 of the distance between the upper end of the baffle and the vertical plate.

[0013] Furthermore, the sulfate reduction chamber is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen purging device, a pressure sensor, a pH sensor, and an alkali dosing device. Preferably, the temperature sensor, temperature control device, redox potential sensor, nitrogen purging device, pressure sensor, pH sensor, and alkali dosing device are connected to a PLC module.

[0014] Furthermore, the first packing zone is provided with a perforated plate for supporting the packing and a support mesh disposed on the perforated plate, as well as a constraint mesh for covering the top of the packing. Preferably, the perforated plate has a hole diameter of 2-3 mm and an opening ratio of 35%-40%, preferably a stainless steel perforated plate; the support mesh has a mesh count of 200-300, preferably a nylon mesh; and the constraint mesh has a hole diameter of 2-3 mm, preferably a polypropylene mesh.

[0015] Furthermore, within the second packing zone, perforated plates for supporting the packing and staggered flow guide baffles for enhancing liquid turbulence and preventing back-mixing are sequentially arranged from bottom to top; the number of staggered flow guide baffles is at least two, with each staggered flow guide baffle arranged parallel and inclined, and intersecting in the vertical direction. Preferably, the aperture of the perforated plate is no greater than 2 mm; the inclination angle of the staggered flow guide baffles is 55°~65°. The perforated plate is preferably a stainless steel perforated plate; the staggered flow guide baffles are preferably stainless steel plates.

[0016] Furthermore, a flow-guiding section narrowing structure is provided below the gas curtain device. Preferably, the narrowing ratio of the flow-guiding section narrowing structure is 2~4:1.

[0017] Furthermore, a pressure sensor and a redox potential sensor are installed in the anaerobic-microaerobic transition chamber.

[0018] Furthermore, an air distribution device is provided below the third packing zone; the air distribution device is a hollow fiber membrane bundle. Preferably, the pore size of the hollow fiber membrane bundle is 1~2mm.

[0019] Furthermore, the third packing zone is provided with a stainless steel corrugated plate with backflow holes for supporting the packing, and a stainless steel grid disposed on the stainless steel corrugated plate with backflow holes; the number of the stainless steel corrugated plate with backflow holes and the stainless steel grid is at least two sets, stacked in the vertical direction; the aperture of the stainless steel corrugated plate with backflow holes is 3~5mm, and the opening ratio is 50%~55%; the volume of a single grid of the stainless steel grid is 120~130cm³. 3 A steel wire restraint mesh is installed on top of the uppermost stainless steel grating.

[0020] Furthermore, the sulfur capture device includes a lower capture net and an upper capture net arranged sequentially from bottom to top, wherein the aperture of the lower capture net is smaller than that of the upper capture net. Preferably, the aperture of the lower capture net is 0.4~0.6mm; the aperture of the upper capture net is 2.5~3mm; and both the lower and upper capture nets are preferably stainless steel mesh.

[0021] Furthermore, a first aeration device is provided in the sulfur oxidation chamber. Preferably, the first aeration device is a rubber molded aeration pipe; the wall thickness of the rubber molded aeration pipe is 1~2mm; the first aeration device is located at the top of the sulfur oxidation chamber.

[0022] Furthermore, the sulfur oxidation chamber is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen filling device, a pH sensor, an alkali addition device, and a dissolved oxygen sensor. Preferably, the temperature sensor, temperature control device, redox potential sensor, nitrogen filling device, pH sensor, alkali addition device, and dissolved oxygen sensor are connected to a PLC module.

[0023] Furthermore, the reactor is also equipped with a sulfur resource recovery compartment connected in series with the sulfur oxidation compartment. The sulfur resource recovery compartment is equipped with an external circulation microbubble flushing device, a sulfur collection net, a second aeration device and a gas collection hood from bottom to top.

[0024] Furthermore, the sulfur collecting mesh is inclined and has a reciprocating scraper on it. Preferably, the inclination angle of the sulfur collecting mesh is 40°~50°, and the aperture is 0.2~0.4mm. The sulfur collecting mesh is preferably stainless steel wire mesh.

[0025] Furthermore, the second aeration device adopts a closed vertical aeration pipe with a hydrophobic hollow fiber aeration membrane inside. Preferably, the pore size of the hydrophobic hollow fiber aeration membrane is 0.3~0.5μm.

[0026] Furthermore, the sulfur resource recovery compartment is sequentially connected to a vacuum suction device and a sulfur paste collection device, and the vacuum suction device is connected to the lower area of ​​the sulfur collection net.

[0027] Furthermore, the sulfur resource recovery compartment is sequentially connected to the desulfurization filter cartridge and the alkaline absorption tower, and the desulfurization filter cartridge is connected to the gas collection hood.

[0028] Secondly, the present invention provides a method for the zoned resource recovery of sulfate wastewater, based on the aforementioned baffled membrane bioreactor for zoned resource recovery of sulfate wastewater, the method comprising the following steps:

[0029] The reactor is filled with packing materials loaded with sulfate-reducing bacteria, H2S adsorption materials, and sulfur-oxidizing bacteria, respectively, into the first, second, and third packing zones. Sulfate wastewater is introduced into the reactor, flowing from below the sulfate reduction chamber. In the first packing zone, the sulfate in the wastewater is reduced to H2S. After flowing out of the sulfate reduction chamber, the wastewater enters the anaerobic-microaerobic transition chamber from below. A gas curtain device is controlled to blow air upwards, forming a continuous gas seal to prevent oxygen from flowing back into the sulfate reduction chamber. The wastewater then passes through the second packing zone to adsorb residual H2S. After flowing out of the anaerobic-microaerobic transition chamber, the wastewater enters the sulfur oxidation chamber from below. A first aeration device is controlled to aerate the wastewater. The wastewater then passes through the third packing zone, where H2S is oxidized to elemental sulfur. The generated elemental sulfur is collected by the sulfur capture device.

[0030] Furthermore, 0.4~0.6 mol / L Ti(III)-NTA is added as a strong reducing agent in the sulfate reduction chamber; the pressure in the sulfate reduction chamber is controlled at 0.3~0.6 kPa, the temperature at 30~36℃, the pH value at 7.0~8.0, the oxidation-reduction potential at ≤-300mV, and the hydraulic retention time at 18~30h.

[0031] Furthermore, in the first packing zone, packing material loaded with sulfate-reducing bacteria is added at a filling rate of 65% to 70%, and the gaps between the packing materials are filled with nano-zero valent iron (nZVI) particles with a diameter of 1 to 2 mm. The volume ratio of the packing material loaded with sulfate-reducing bacteria to the nano-zero valent iron particles is 8 to 12:1; the height of the first packing zone is 50 to 55 cm.

[0032] Furthermore, the oxidation-reduction potential in the anaerobic-microaerobic transition chamber is controlled to be -150 to -100 mV, and the hydraulic retention time is 0.5 to 1 h; the gas flow rate of the gas curtain device is controlled to be 0.5 to 0.6 m / s, and inert gas is injected to make the pressure in the anaerobic-microaerobic transition chamber 0.2 to 0.4 kPa; the filling rate of the second packing zone is 55% to 60%, and the height is 15 to 20 cm.

[0033] Furthermore, the temperature in the sulfur oxidation chamber is controlled at 28~32℃, the pH value at 6.8~7.2, the oxidation-reduction potential at <-50mV, the dissolved oxygen at 0.1~0.5mg / L, and the hydraulic retention time at 8~14h.

[0034] Furthermore, the gas flow rate of the first aeration device is controlled to be 0.1~0.15 L / (min·m). 3 ).

[0035] Furthermore, the filling rate of the third filling zone is 50%~55%, and the height is 25~35cm.

[0036] Furthermore, the method for zoned resource utilization of sulfate wastewater further includes the following steps:

[0037] After the wastewater flows out of the sulfur oxidation chamber, it enters the sulfur resource recovery chamber from below. The second aeration device is controlled to aerate the sulfur, and H2S is oxidized to generate elemental sulfur. The elemental sulfur is deposited on the sulfur collection net and peeled off into sulfur paste by a reciprocating scraper. The external circulation microbubble flushing device is controlled to flush the sulfur collection net to promote deposition and prevent scaling. The sulfur paste is sucked into the sulfur paste collection device by a vacuum suction device. The residual H2S is collected through the gas collection hood and converted into elemental sulfur or FeS by the desulfurization filter cartridge. The residual tail gas discharged from the desulfurization filter cartridge is neutralized by the alkaline absorption tower.

[0038] Furthermore, the dissolved oxygen in the sulfur resource recovery chamber is controlled to be 0.1~0.3 mg / L, the pH value is 6.8~7.2, the oxidation-reduction potential is 50~100 mV, and the hydraulic retention time is 2~4 h.

[0039] Furthermore, the gas flow rate of the external circulation microbubble flushing system is controlled to be 0.1~0.3m / s, and air flushing is performed once every 4~8 hours. The gas flow rate during air flushing is 0.4~0.6m / s, and each flush lasts for 2~4 minutes.

[0040] Furthermore, the frequency of the reciprocating scraper is controlled to be 2-3 times / h, the stroke speed is 4-6 cm / s, and the scraper pressure is 0.1-0.3 MPa.

[0041] Furthermore, the vacuum suction device is operated at a pressure of -12 to -8 kPa.

[0042] Furthermore, the desulfurization filter cartridge is filled with Fe(III)-NTA chelating agent, and the molar ratio of iron ions to NTA chelating agent is 1:2~3.

[0043] Further, the filler material loaded with sulfate-reducing bacteria is a gel bead loaded with sulfate-reducing bacteria. Preferably, the preparation method of the gel bead loaded with sulfate-reducing bacteria includes the following steps: adding sodium alginate, nano-SiO2, and polyvinyl alcohol to water and mixing to obtain a mixture, wherein the mass concentrations of sodium alginate, nano-SiO2, and polyvinyl alcohol in the mixture are 2%~4%, 0.5%~1%, and 0.5%~1%, respectively; freezing the mixture at -25~-15℃, then thawing it at 20~25℃, repeating this cycle 2~4 times; sterilizing and then cooling to room temperature. A sterile mixture was obtained; a sterile calcium chloride solution with a mass concentration of 2%–3% and a strontium chloride solution with a mass concentration of 0.1–0.2 mol / L were prepared separately, and the calcium chloride solution and strontium chloride solution were mixed at a volume ratio of 6–8:2–4 to obtain a solidified solution; sulfate-reducing bacteria sludge was prepared, and under sterile anaerobic conditions, the sludge was slowly and evenly added to the sterile mixture at a volume ratio of 1–2:3–4 to obtain a final bacterial concentration >10. 9 A CFU / mL gel solution is prepared; the gel solution is added dropwise to the curing solution under continuous and slow stirring to form spherical gel beads, which are then soaked and cured for 40-50 minutes. The cured gel beads are then removed, washed, and the sulfate-reducing bacteria-loaded gel beads are obtained. The preparation method of the sulfate-reducing bacteria sludge includes: enriching and culturing the target bacterial population under strictly anaerobic conditions using Postgate B liquid medium until the late logarithmic growth phase or early stationary phase; collecting the pre-cultured cells by centrifugation, and resuspending them in a small amount of sterile physiological saline to obtain the sulfate-reducing bacteria sludge. Preferably, the viability of the sulfate-reducing bacteria sludge is 3.0 × 10⁻⁶.9 ~1.0×10 10 cfu / g.

[0044] Furthermore, the sulfate-reducing bacteria include Desulfovibrio, Desulfobacter, and Desulfotomaculum.

[0045] Furthermore, the gel beads loaded with sulfate-reducing bacteria are activated before use. The activation steps include: placing the gel beads loaded with sulfate-reducing bacteria in a nutrient solution containing 2000~3000 mg / L sodium lactate, 1800~2200 mg / L sodium sulfate, 120~180 mg / L yeast extract, 250~350 mg / L ammonium chloride, and 120~180 mg / L dipotassium hydrogen phosphate; adding 0.5 mol / L Ti(III)-NTA dropwise to the nutrient solution to ensure reduction conditions; controlling the activation environment temperature at 30~36℃, redox potential <-300mV, and pH value at 7.0~8.0; and activating for 30~42 hours.

[0046] Further, the preparation method of the H2S adsorption packing includes the following steps: mixing activated carbon and clinoptilolite at a volume ratio of 1.5~2.5:1 to obtain a mixture; mixing the mixture with an 80~120g / L FeCl3·6H2O aqueous solution at a solid-liquid ratio of 1g:3~5mL, and immersing in the mixture at a constant temperature of 55~65℃ and 100~150rpm for 10~14h; draining the mixture, aging it at 100~110℃ for 10~14h, and then calcining it at 345~355℃ for 2~4h; and obtaining the H2S adsorption packing after cooling.

[0047] Further, the filler material loaded with sulfur-oxidizing bacteria is polyurethane foam loaded with sulfur-oxidizing bacteria. The preparation method of the polyurethane foam loaded with sulfur-oxidizing bacteria includes the following steps: cutting open-cell polyurethane foam into cubic foam blocks, soaking them in a 95% (v / v) ethanol solution for 5-10 min, then rinsing them with deionized water and drying them to obtain pretreated cubic foam blocks; soaking the pretreated cubic foam blocks in a 0.4%-0.6% (w / v) chitosan acetate solution for 1-3 h, sterilizing them, and then placing them into Postgate B liquid medium enriched with sulfur-oxidizing bacteria, culturing them on a shaker at 30-36°C at a speed of 120-180 rpm for 120-168 h to obtain the polyurethane foam loaded with sulfur-oxidizing bacteria. Preferably, the preparation method of Postgate B liquid medium enriched with sulfur-oxidizing bacteria includes: enriching and culturing the target bacterial population using Postgate B liquid medium under micro-aerobic conditions (DO = 0.1-0.5 mg / L) until the late logarithmic growth stage or early stationary phase.

[0048] Furthermore, the sulfur-oxidizing bacteria include Thiobacillus thioparus and T. denitrificans.

[0049] Furthermore, the polyurethane foam loaded with sulfur-oxidizing bacteria is activated before use. The activation steps include: squeezing and rinsing the polyurethane foam loaded with sulfur-oxidizing bacteria 2-3 times with 0.1-0.2 mol / L phosphate buffer, then immersing it in 1-2 mol / L EDTA solution for 30-50 min, and placing the treated filler in a nutrient solution containing 2500-3500 mg / L sodium thiosulfate, 1000-1400 mg / L sodium acetate, 250-350 mg / L ammonium chloride, 100-200 mg / L dipotassium hydrogen phosphate, and 0.4-0.6 mg / L zinc sulfate. The activation environment is controlled with dissolved oxygen at 0.1-0.5 mg / L, temperature at 28-32℃, oxidation-reduction potential <-50 mV, and pH at 6.5-7.5 for 42-54 h.

[0050] The technical solution of this invention has the following advantages:

[0051] 1. The baffled membrane bioreactor for zoned resource utilization of sulfate wastewater provided by the present invention clearly divides the deep anoxic reductive core zone (DARCZ) and the micro-oxidative sulfur conversion zone (MOSCZ), with a DARCZ-MOSCZ transition zone set between the two zones. The DARCZ consists of a sulfate reduction chamber, while the MOSCZ consists of a sulfur oxidation chamber. The sulfate reduction chamber and the sulfur oxidation chamber are separated by an anaerobic-micro-aerobic transition chamber. On the one hand, the gas curtain device is located below the second packing area and is set with the gas outlet direction facing upward. It is used to blow gas upward (usually nitrogen or other inert gas) to form a continuous gas seal (or gas curtain), which can effectively prevent trace amounts of oxygen (DO) in the downstream sulfur oxidation chamber from flowing back to the upstream sulfate reduction chamber. This physically blocks oxygen backflow, which helps maintain the anaerobic environment required by the sulfate reduction chamber and improves the activity of sulfate-reducing bacteria. On the other hand, the second packing area is conducive to effectively adsorbing residual H2S gas that has not been converted by the downstream sulfur oxidation chamber and catalyzing local oxygen reduction reaction. Thus, without changing the overall redox potential (ORP), it achieves molecular oxygen consumption and interface buffering, and mitigates the toxic impact at the inlet of the sulfur oxidation chamber. By setting up an anaerobic-microaerobic transition compartment, a dual physical and chemical isolation and transition buffer are achieved, establishing a clear and stable interface transition environment between the sulfate reduction compartment and the sulfur oxidation compartment. This effectively separates the two types of microbial communities in space and enables the directional enrichment of microbial communities, preventing metabolic conflicts and mutual inhibition between microbial communities, improving the stability and biological activity of the microbial cells, and thus ensuring the long-term stable operation of the system under high-load conditions. This overcomes the problems of poor system stability, low sulfur conversion rate and recovery rate caused by cross-interference in the reaction zone and microbial community inhibition.

[0052] 2. This invention achieves precise partitioning and directional immobilization of Deep Reductive Sulfurotrophic Microbionts (DRSM) and Micro-Oxidative Sulfur Constructive Microbionts (MOSCM). Specifically: DRSM preferably uses gel beads as the carrier for sulfate-reducing bacteria, encapsulating the bacteria within a porous gel mesh. This provides high mechanical strength, preventing bacterial loss and making it suitable for loading sulfate-reducing bacteria requiring a specific anaerobic microenvironment. MOSCM preferably uses open-cell polyurethane foam as the carrier for sulfur-oxidizing bacteria, adsorbing and immobilizing the bacteria onto the foam. Its lightweight, porous structure facilitates micro-oxygen transfer, making it suitable for loading sulfur-oxidizing bacteria requiring a micro-aerobic environment. By designing differentiated immobilization carriers and employing partitioned immobilization methods, stable biofilms can be formed in different spaces, thereby improving sulfate conversion efficiency.

[0053] 3. Preferably, the present invention sets up a sulfur resource recovery compartment in series with the sulfur oxidation compartment in the reactor. Through the multi-stage structure of micro-oxygen oxidation-sulfur crystallization-tail gas purification, the directional conversion and recovery of sulfur resources are realized, which not only improves the resource recovery rate, but also significantly reduces the risk of membrane fouling and corrosion, which is conducive to the long-term stable operation of the system.

[0054] 4. The method for zoned resource utilization of sulfate wastewater provided by this invention preferably constructs controllable microenvironmental conditions and precisely regulates the oxidation-reduction potential (ORP) and dissolved oxygen (DO) gradients to achieve zoned microecological optimization and form a clear and stable "anaerobic-microaerobic" microenvironmental gradient zone. This environmental stratification greatly enhances the growth adaptability and substrate selectivity of the two types of functional bacterial communities, and improves the reactor's adaptability to complex sulfur-containing wastewater and the efficiency of biological co-conversion. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the structure of a baffled membrane bioreactor for the zoned resource utilization of sulfate wastewater provided by the present invention.

[0056] Figure label:

[0057] 1-Sulfate reduction compartment; 2-Anaerobic-microaerobic transition compartment; 3-Sulfate oxidation compartment; 4-Sulfate resource recovery compartment; 101-Redox potential sensor; 102-Nitrogen protective layer; 103-Perforated plate; 104-Support mesh; 105-Constraint mesh; 106-Gel beads loaded with sulfate-reducing bacteria; 107-Nano-zero-valent iron particles; 201-Gas curtain device; 202-Staggered flow guide baffle; 203-H2S adsorption packing; 301-Sulfate capture device; 302-First aeration device 303-Gas distribution device; 304-Stainless steel corrugated plate with backflow holes; 305-Dissolved oxygen sensor; 306-Polyurethane foam loaded with sulfur-oxidizing bacteria; 401-External circulation microbubble flushing device; 402-Sulfur collection net; 403-Second aeration device; 404-Gas collection hood; 405-Reciprocating scraper; 406-Vacuum suction device; 407-Sulfur paste collection device; 408-Desulfurization filter cartridge; 409-Alkali absorption tower; 410-Air pump; 411-Storage tank; 412-Water pump. Detailed Implementation

[0058] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] In the description of this invention, it should be noted that the terms "upper," "lower," "right," "vertical," and "inner," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0060] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] The following provides a detailed description of the optional embodiments of the technical solution provided by the present invention.

[0063] I. Baffled membrane bioreactor for zoned resource utilization of sulfate wastewater

[0064] like Figure 1 As shown, the reactor is divided into a series of interconnected sulfate reduction chamber 1, anaerobic-microaerobic transition chamber 2, and sulfur oxidation chamber 3 by baffles arranged vertically. Sulfate reduction chamber 1 contains a first packing zone, which is filled with packing material loaded with sulfate-reducing bacteria. Anaerobic-microaerobic transition chamber 2 contains a gas curtain device 201 and a second packing zone arranged from bottom to top, with the gas curtain device 201 venting upwards. The second packing zone is filled with H2S adsorption packing material 203. Sulfur oxidation chamber 3 contains a third packing zone and a sulfur capture device 301 arranged from bottom to top, with the third packing zone filled with packing material loaded with sulfur-oxidizing bacteria.

[0065] In sulfate reduction compartment 1, sulfate is reduced to H2S (SO4) by inoculating sulfate-reducing bacteria. 2- +2CH3COO - →H2S + 2HCO3 - In sulfur oxidation compartment 3, sulfur-oxidizing bacteria are inoculated to oxidize H2S into elemental sulfur (H2S + 0.5O2 → S). 0 +H2O).

[0066] The baffles are configured to allow water to enter from below and exit from above in each compartment, with the water flowing up and down between the compartments. In an optional embodiment of the invention, each compartment is divided by a set of baffles, including sequentially arranged folded plates and vertical plates. The upper end of the folded plate is connected to the top of the reactor, and the lower end folds downwards to the right. The lower end of the vertical plate is connected to the bottom of the reactor, allowing wastewater to enter from below and exit from above. Preferably, the angle of the folded end of the folded plate is 50~55° (preferably 55°). The distance between the lower end of the folded plate and the vertical plate is 1:2~3 (preferably 1:2) of the distance between the upper end of the folded plate and the vertical plate.

[0067] To ensure the filling and fixation of the packing material within the corresponding filling zones, support and fixing components are provided in the first, second, and third filling zones. Different support and fixing components can be provided depending on the specifications and properties of the packing material used in each filling zone.

[0068] As an optional embodiment of the present invention, a sulfur resource recovery compartment 4 connected in series with the sulfur oxidation compartment 3 is also provided in the reactor.

[0069] The following provides a detailed description of the optional implementation methods for the sulfate reduction chamber 1, the anaerobic-microaerobic transition chamber 2, the sulfur oxidation chamber 3, and the sulfur resource recovery chamber 4:

[0070] (a) Sulfate reduction compartment

[0071] The number of sulfate reduction compartments 1 is 2 to 3, preferably 2. The volume of each sulfate reduction compartment 1 is 40 to 50 L, preferably 45 L.

[0072] The sulfate reduction chamber 1 is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor 101, a nitrogen purging device, a pressure sensor, a pH sensor, and an alkali dosing device. Preferably, the temperature sensor, temperature control device, redox potential sensor 101, nitrogen purging device, pressure sensor, pH sensor, and alkali dosing device are connected to a PLC module. Temperature sensors and temperature control devices are connected to the PLC module to achieve precise temperature control within the sulfate reduction chamber 1. Oxidation-reduction potential (ORP) sensors 101 and a nitrogen purging device are also connected to the PLC module to achieve precise ORP control within the sulfate reduction chamber 1. Pressure sensors and a nitrogen purging device are connected to the PLC module to achieve precise pressure control within the sulfate reduction chamber 1 (within a safe pressure range of 0.3~0.6 kPa, the nitrogen purging device is finely adjusted based on the ORP signal from the ORP sensor 101, while simultaneously monitoring the pressure signal from the pressure sensor; if the pressure exceeds the safe range, the nitrogen purging device is shut off to control pressure and ensure equipment safety). A pH sensor and an alkali dosing device (e.g., adding a 0.1 mol / L NaHCO3 solution) are connected to the PLC module to achieve precise pH control within the sulfate reduction chamber 1.

[0073] The first packing zone is provided with a perforated plate 103 for supporting the packing, a support mesh 104 disposed on the perforated plate 103, and a restraining mesh 105 for covering the top of the packing. Preferably, the perforated plate 103 has a hole diameter of 2-4 mm, preferably 3 mm, and an opening ratio of 30%-40%, preferably 40%, and is preferably a stainless steel perforated plate 103; the support mesh 104 has a mesh count of 150-250, preferably 200, and is preferably a nylon mesh; the restraining mesh 105 has a hole diameter of 1-3 mm, preferably 2 mm, and is preferably a polypropylene mesh.

[0074] (ii) Anaerobic-microaerobic transition compartment

[0075] The number of anaerobic-microaerobic transition chambers 2 is 1 to 2, preferably 1. The volume of each anaerobic-microaerobic transition chamber 2 is 25 to 35 L, preferably 30 L.

[0076] The gas curtain device 201 helps to create a slight positive pressure (0.2~0.4kPa) in the anaerobic-micro-aerobic transition chamber 2, which is higher than the water pressure in the downstream sulfur oxidation chamber 3, thereby effectively blocking the diffusion and backflow of dissolved oxygen (DO) in the micro-aerobic environment of the sulfur oxidation chamber 3 to the upstream sulfate reduction chamber 1.

[0077] In the second packing zone, perforated plates for supporting the packing and staggered flow guide baffles 202 for enhancing liquid turbulence and preventing back-mixing are arranged sequentially from bottom to top. At least two staggered flow guide baffles 202 are provided, each arranged parallel and inclined, and intersecting vertically. Preferably, the perforation diameter of the perforated plate is less than 2 mm, more preferably 2 mm; the inclination angle of the staggered flow guide baffles 202 is 55°~65°, more preferably 60°. The perforated plate is preferably a stainless steel perforated plate; the staggered flow guide baffles 202 are preferably stainless steel plates. The staggered flow guide baffles 202 ensure that the liquid flow folds upwards into the subsequent compartments, enhancing fluid turbulence and preventing back-mixing.

[0078] The second packing zone is used to fill H2S adsorption packing (highly efficient catalyst), which can adjust the redox potential in the anaerobic-microaerobic transition compartment 2.

[0079] A flow-guiding section narrowing structure is provided below the gas curtain device 201. Preferably, the narrowing ratio (cross-sectional area of ​​the channel before narrowing: cross-sectional area of ​​the channel after narrowing) of the flow-guiding section narrowing structure is 2~4:1, preferably 3:1. The narrowing structure of the flow-guiding section helps to improve the local water flow shear force, ensuring the zoning effect from a fluid dynamics perspective, preventing the anaerobic sludge in the sulfate reduction compartment 1 from being carried by the water flow to the subsequent sulfur oxidation compartment 3, and preventing the runaway of redox potential caused by the mixing of substances.

[0080] Pressure sensors and redox potential sensors are installed in the anaerobic-microaerobic transition chamber 2.

[0081] (iii) Sulfur oxidation compartment

[0082] The number of sulfur oxidation chambers 3 is 2 to 4, preferably 3. The volume of each sulfur oxidation chamber 3 is 25 to 35 L, preferably 30 L.

[0083] A gas distribution device 303 is installed below the third packing zone; the gas distribution device 303 is a hollow fiber membrane bundle. Preferably, the pore size of the hollow fiber membrane bundle is 1~2mm, more preferably 1mm. H2S in the anaerobic-microaerobic transition compartment 2 enters the third packing zone through the gas distribution device 303 below the third packing zone, forming a uniform gas flow, which is beneficial to the stable progress of the reaction and avoids excessively high local gas concentrations.

[0084] The third packing zone is equipped with stainless steel corrugated plates 304 with backflow holes for supporting the packing, and stainless steel gratings disposed on the stainless steel corrugated plates 304 with backflow holes. The number of stainless steel corrugated plates 304 with backflow holes and stainless steel gratings is at least two sets, preferably three sets, stacked vertically. A wire mesh with a hole diameter of 3-5 mm (preferably 4 mm) is provided on top of the uppermost stainless steel grating. Preferably, the hole diameter of the stainless steel corrugated plates with backflow holes is 3-5 mm (preferably 4 mm), and the opening ratio is 50%-55% (preferably 55%). The volume of a single stainless steel grating is 120-130 cm³. 3 (Preferred size: 125cm) 3 The 304 stainless steel corrugated plate with backflow holes has perforations at its crests and troughs. This not only supports the packing material above to prevent compaction, but also enhances water flow turbulence through its corrugated structure to prevent clogging. The stainless steel grating divides the packing material into sections, with the top section secured by a wire mesh to prevent displacement of the lightweight polyurethane foam packing material.

[0085] The sulfur capture device 301 includes a lower capture net and an upper capture net arranged sequentially from bottom to top, with the aperture of the lower capture net being smaller than that of the upper capture net. Preferably, the aperture of the lower capture net is 0.4~0.6mm, more preferably 0.5mm; the aperture of the upper capture net is 2~4mm, more preferably 3mm; both the lower and upper capture nets are preferably stainless steel mesh. The sulfur capture net is used to intercept, deposit, and concentrate generated elemental sulfur, and the arrangement of capture nets with different apertures is beneficial to enhancing the capture effect.

[0086] A first aeration device 302 is installed inside the sulfur oxidation chamber 3; the first aeration device 302 is a rubber-molded aeration pipe. Preferably, the wall thickness of the rubber-molded aeration pipe is 1~2mm, more preferably 1.5mm. The first aeration device 302 is used to aerate the sulfur oxidation chamber 3, providing the micro-aerobic environment required by the sulfur-oxidizing bacteria.

[0087] The sulfur oxidation chamber 3 is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen filling device, a pH sensor, an alkali addition device, and a dissolved oxygen sensor 305. Preferably, the temperature sensor, temperature control device, redox potential sensor, nitrogen filling device, pH sensor, alkali addition device, and dissolved oxygen sensor 305 are connected to a PLC module. By connecting the temperature sensor and temperature control device to the PLC module, precise temperature control within the sulfur oxidation chamber 3 is achieved; by connecting the redox potential sensor and nitrogen filling device to the PLC module, precise redox potential control within the sulfur oxidation chamber 3 is achieved; by connecting the pH sensor and alkali addition device (e.g., adding a 0.1 mol / L NaHCO3 solution) to the PLC module, precise pH control within the sulfur oxidation chamber 3 is achieved; and by connecting the dissolved oxygen sensor 305 and the first aeration device 302 to the PLC module, precise dissolved oxygen control within the sulfur oxidation chamber 3 is achieved.

[0088] (iv) Sulfur resource recovery compartment

[0089] The sulfur resource recovery compartment 4 is equipped with an external circulation microbubble flushing device 401, a sulfur collection net 402, a second aeration device 403, and a gas collection hood 404, arranged from bottom to top.

[0090] The sulfur resource recovery chamber achieves targeted sulfur resource recovery through three methods: The first part is the sulfur oxidation reaction section, where a second aeration device 403 controls dissolved oxygen to form a low-oxygen-limited interface, inducing H2S to be oxidized at the solution-oxygen interface to generate elemental sulfur particles; the second part is the sulfur crystallization deposition section, where a sulfur collection net 402 is used to capture the elemental sulfur particles generated in the sulfur oxidation reaction section, and an external circulation microbubble flushing device 401 is configured to promote the deposition of newly generated elemental sulfur on the net surface and prevent scaling and sealing. At the same time, the interface activity and surface flow can be maintained by periodic air flushing; the third part is the gas purification and tail gas collection section, where a gas collection hood 404 collects the escaped H2S gas.

[0091] The number of sulfur resource recovery compartments 4 is 1 to 2, preferably 1. The volume of each sulfur oxidation compartment 3 is 40 to 50 L, preferably 45 L.

[0092] The sulfur collecting mesh 402 is inclined, and a reciprocating scraper 405 is mounted on it. Preferably, the inclination angle of the sulfur collecting mesh 402 is 40°~50°, more preferably 45°, and the aperture is 0.2~0.4mm, more preferably 0.3mm. The sulfur collecting mesh 402 is preferably stainless steel wire mesh. The reciprocating scraper 405 above the sulfur collecting plate is used to peel off the hardened sulfur scale into sulfur paste.

[0093] The second aeration device 403 adopts a closed vertical aeration pipe and is equipped with a hydrophobic hollow fiber aeration membrane. Preferably, the pore size of the hydrophobic hollow fiber aeration membrane is 0.2~0.5μm, and more preferably 0.3μm.

[0094] The sulfur resource recovery compartment 4 is sequentially connected to a vacuum suction device 406 and a sulfur paste collection device 407. The vacuum suction device 406 is connected to the lower part of the sulfur collection net 402. The vacuum suction device 406 is used to draw the sulfur paste scraped off by the reciprocating scraper 405 into the sulfur paste collection device 407 through a negative pressure pipeline (-10kPa).

[0095] The sulfur resource recovery compartment 4 is sequentially connected to the desulfurization filter cartridge 408 and the alkaline absorption tower 409. The desulfurization filter cartridge 408 is connected to the gas collection hood 404. An air pump 410 is installed between the gas collection hood 404 and the desulfurization filter cartridge 408, and another air pump 410 is installed between the desulfurization filter cartridge 408 and the alkaline absorption tower 409. The alkaline absorption tower 409 is connected to a storage tank 411 (through which alkaline solution, such as a 5%~10% NaOH solution by mass percentage), and the two are circulated and supplied with liquid by a water pump 412. Preferably, the desulfurization filter cartridge 408 is filled with Fe(III)-NTA chelating agent (ferric hyponitrotriacetate), with a molar ratio of iron ions to NTA chelating agent of 1:2, further converting the unconverted H2S collected by the gas collection hood 404 into elemental sulfur or FeS. The residual tail gas discharged from the desulfurization filter cartridge 408 is neutralized and treated by the alkaline absorption tower 409.

[0096] II. Zonal Resource Utilization Method for Sulfate Wastewater

[0097] This method is based on a baffled membrane bioreactor for the zoned resource recovery of sulfate wastewater, and includes the following steps:

[0098] S1. Fill the first packing zone, the second packing zone, and the third packing zone with packing material loaded with sulfate-reducing bacteria, H2S adsorption packing material 203, and packing material loaded with sulfur-oxidizing bacteria, respectively.

[0099] S2. Sulfate wastewater is introduced into the reactor. The water flows in from below the sulfate reduction compartment 1 and passes through the first packing zone to reduce the sulfate in the wastewater to H2S.

[0100] S3. After the wastewater in the sulfate reduction compartment 1 flows out, it enters the anaerobic-micro-aerobic transition compartment 2 from below. The control gas curtain device 201 blows air upward to form a continuous gas seal to prevent oxygen from flowing back to the sulfate reduction compartment 1. The wastewater passes through the second packing area to adsorb residual H2S.

[0101] S4. After the wastewater flows out of the anaerobic-microaerobic transition compartment 2, it enters the sulfur oxidation compartment 3 from below. The first aeration device 302 is controlled to perform aeration. The wastewater passes through the third packing zone to oxidize H2S into elemental sulfur. The generated elemental sulfur is collected by the sulfur capture device 301.

[0102] Preferably, the method further includes the following steps:

[0103] S5. After the wastewater flows out of the sulfur oxidation chamber 3, it enters the sulfur resource recovery chamber 4 from below. The second aeration device 403 is controlled to aerate the sulfur, and H2S is oxidized to generate elemental sulfur. The elemental sulfur is deposited on the sulfur collection net 402 and is stripped into sulfur paste by the reciprocating scraper 405. The external circulation microbubble flushing device 401 is controlled to flush the sulfur collection net 402 to promote deposition and prevent scaling. The sulfur paste is sucked into the sulfur paste collection device 407 by the vacuum suction device 406. The residual H2S is collected through the gas collection hood 404 and converted into elemental sulfur or FeS by the desulfurization filter cartridge 408. The residual tail gas discharged from the desulfurization filter cartridge 408 is neutralized and treated by the alkaline absorption tower 409.

[0104] The optional embodiments of the zoned resource recovery method for sulfate wastewater provided by the present invention will be described in detail below, step by step:

[0105] (a) Step S1

[0106] 1. Setting up the first packing zone

[0107] 1.1 Preparation method of packing material loaded with sulfate-reducing bacteria

[0108] The packing material loaded with sulfate-reducing bacteria is a gel bead loaded with sulfate-reducing bacteria. These sulfate-reducing bacteria include *Desulfovibrio*, *Desulfobacter*, and *Desulfotomaculum*.

[0109] A method for preparing gel beads loaded with sulfate-reducing bacteria includes the following steps: Sodium alginate, nano-SiO2, and polyvinyl alcohol are added to water and mixed to obtain a mixture. The mass concentrations of sodium alginate, nano-SiO2, and polyvinyl alcohol in the mixture are 2%~4% (preferably 3%), 0.5%~1% (preferably 1%), and 0.5%~1% (preferably 0.5%), respectively. The mixture is first frozen at -25~-15℃ (preferably -20℃), then thawed at 20~25℃ (preferably 25℃), and this cycle is repeated 2~4 times (preferably 3 times). Freeze-thaw cycles enhance the shear strength of the carrier, achieving a breaking strength >50 N / bead; pore size is adjusted to 50-100 μm to facilitate substrate diffusion. After autoclaving and cooling to room temperature, a sterile mixture is obtained. A 2%-3% (preferably 2.5%) sterile calcium chloride solution and a 0.05-0.15 mol / L (preferably 0.1 mol / L) strontium chloride solution are prepared separately. These solutions are mixed at a volume ratio of 6-8:2-4 (preferably 7:3) to obtain a solidified solution. Under strictly anaerobic conditions, the target bacterial population is enriched and cultured using Postgate B liquid medium until the late logarithmic growth phase or early stationary phase. The pre-cultured cells are collected by centrifugation and resuspended in a small amount of sterile physiological saline to obtain sulfate-reducing bacteria sludge. Preferably, the viability of the sulfate-reducing bacteria sludge is 3.0 × 10⁻⁶. 9 ~1.0×10 10 CFU / g; Under aseptic anaerobic conditions, the bacterial sludge is slowly and evenly added to the aseptic mixture at a volume ratio of 1~2:3~4 (preferably 1:3) to obtain a final bacterial concentration >10. 9 The adhesive solution is prepared at CFU / mL. The adhesive solution is added dropwise to a curing solution that is continuously and slowly stirred to form spherical gel beads with a particle size of 4~5mm (preferably 4.5mm). The solution is then soaked and cured for 40~50min (preferably 45min). The cured gel beads are then removed, washed, and the gel beads loaded with sulfate-reducing bacteria are obtained.

[0110] 1.2 Activation method of gel beads loaded with sulfate-reducing bacteria

[0111] Before use, the gel beads loaded with sulfate-reducing bacteria are activated. The activation steps include: placing the gel beads loaded with sulfate-reducing bacteria in a solution containing 2000-3000 mg / L sodium lactate (preferably 2500 mg / L), 1800-2200 mg / L sodium sulfate (preferably 2000 mg / L), 120-180 mg / L yeast extract (preferably 150 mg / L), 250-350 mg / L ammonium chloride (preferably 300 mg / L), and hydrogen phosphate. In a nutrient solution containing 120-180 mg / L potassium (preferably 150 mg / L), 0.5 mol / L Ti(III)-NTA is added dropwise to ensure reduction conditions. The activation environment temperature is controlled at 30-36℃ (preferably 35±0.5℃), the redox potential is <-300mV (preferably -350~-300mV), and the pH value is 7.0-8.0 (preferably 7.5±0.2). Activation is carried out for 30-42 hours (preferably 36 hours).

[0112] 1.3 Filling in the first filling zone

[0113] In the first filling zone, gel beads 106 loaded with sulfate-reducing bacteria are added at a filling rate of 65% to 70% (preferably 68%). The gaps between the gel beads 106 loaded with sulfate-reducing bacteria are filled with 1 to 2 mm (preferably 1 mm) nano-zero-valent iron particles 107 (used to control the redox potential). The filling volume ratio of the gel beads 106 loaded with sulfate-reducing bacteria to the nano-zero-valent iron particles 107 is 8 to 12:1 (preferably 10:1). The height of the first filling zone is 50 to 55 cm (preferably 52 cm).

[0114] 2. Setting of the second packing zone

[0115] 2.1 Preparation method of H2S adsorption packing

[0116] Activated carbon and clinoptilolite are mixed at a volume ratio of 1.5~2.5:1 (preferably 2:1) to obtain a mixture. The mixture is then mixed with a FeCl3·6H2O solution with a concentration of 80~120g / L (preferably 100g / L) at a solid-liquid ratio of 1g:3~5mL (preferably 1g:5mL). The mixture is then immersed in the solution at a constant temperature of 55~65℃ (preferably 60℃) and 100~150rpm (preferably 120rpm) for 10~14h (preferably 12h). After being removed and drained, the mixture is aged at 100~110℃ (preferably 105℃) for 10~14h (preferably 12h) and then calcined at 345~355℃ (preferably 350℃) for 2~4h (preferably 3h). After cooling, the H2S adsorption filler is obtained.

[0117] 2.2 Filling in the second filling zone

[0118] The filling rate of the second filling zone is 55%~60% (preferably 60%), and the height is 15~20cm (preferably 20cm).

[0119] 3. Setting up the third packing zone

[0120] 3.1 Preparation method of packing material loaded with sulfur-oxidizing bacteria

[0121] The packing material for sulfur-oxidizing bacteria is polyurethane foam loaded with sulfur-oxidizing bacteria. These sulfur-oxidizing bacteria include *Thiobacillus thioparus* and *T. denitrificans*.

[0122] A method for preparing sulfur-oxidizing polyurethane foam includes the following steps: Under microaerobic conditions (DO = 0.1~0.5 mg / L), the target bacterial population is enriched and cultured using Postgate B liquid medium until the late logarithmic growth phase or early stationary phase to obtain Postgate B liquid medium enriched with sulfur-oxidizing bacteria; the open-cell polyurethane foam is cut into cubic foam blocks with a side length of 10~15 mm (preferably 12 mm), soaked in 95% ethanol solution for 5~10 min (preferably 10 min), then rinsed with deionized water 2~3 times (preferably 3 times), and dried to obtain pretreated cubic foam blocks; the pretreated cubic foam blocks are soaked in a 0.4%~0.6% (preferably 0.5%) chitosan acetate solution for 1~3 h (preferably 2 h) and sterilized; the sterilized cubic foam blocks are added to Postgate B liquid medium enriched with sulfur-oxidizing bacteria, with 200~300 cm³ of the bacteria added per liter of liquid medium. 3 (Preferred size: 250cm) 3 ) Cube foam blocks are cultured on a shaker at 30~36℃ (preferably 35±0.5℃) at a rotation speed of 120~180rpm (preferably 150rpm) for 120~168h (preferably 144h) to obtain polyurethane foam loaded with sulfur-oxidizing bacteria.

[0123] 3.2 Activation method of polyurethane foam loaded with sulfur-oxidizing bacteria

[0124] Before use, the polyurethane foam loaded with sulfur-oxidizing bacteria is activated. The activation steps include: rinsing the polyurethane foam loaded with sulfur-oxidizing bacteria with 0.1-0.2 mol / L (preferably 0.1 mol / L) phosphate buffer 2-3 times (preferably 3 times); then immersing it in 1-2 mol / L (preferably 1 mol / L) EDTA solution for 30-50 minutes (preferably 40 minutes); and finally placing the treated filler in a solution containing 2500-3500 mg / L (preferably 3000 mg / L) sodium thiosulfate, 1000-1400 mg / L (preferably 1200 mg / L) sodium acetate, and chlorine... In a nutrient solution containing 250-350 mg / L ammonium chloride (preferably 300 mg / L), 100-200 mg / L dipotassium hydrogen phosphate (preferably 150 mg / L), and 0.4-0.6 mg / L zinc sulfate (preferably 0.5 mg / L), the activation environment is controlled with dissolved oxygen at 0.1-0.5 mg / L (preferably 0.3 ± 0.05 mg / L), temperature at 28-32℃ (preferably 30 ± 0.5℃), redox potential <-50 mV (preferably -100 to -50 mV), and pH at 6.5-7.5 (preferably 7 ± 0.2), and activation is carried out for 42-54 h (preferably 48 h).

[0125] 3.3 Filling in the third filling zone

[0126] The filling rate of the third filling zone is 50%~55% (preferably 52%), and the height is 25~35cm (preferably 30cm).

[0127] (ii) Step S2

[0128] Add 0.4~0.6 mol / L (preferably 0.5 mol / L) of Ti(III)-NTA as a strong reducing agent to the sulfate reduction chamber 1; control the pressure of the sulfate reduction chamber 1 to 0.4~0.6 kPa (preferably 0.5 kPa), purge the chamber with nitrogen through a nitrogen purging device to form a nitrogen protective layer 102 on the top of the chamber, the temperature to 30~36℃ (preferably 35±0.5℃), the pH value to 7.0~8.0 (preferably 7.5±0.2), the oxidation-reduction potential to ≤-300mV (preferably -350~-300mV), and the hydraulic retention time to 18~30h (preferably 24h).

[0129] (III) Step S3

[0130] The oxidation-reduction potential in the anaerobic-microaerobic transition chamber 2 is controlled at -150 to -100 mV, and the hydraulic retention time is 0.4 to 0.6 h (preferably 0.5 h). The gas flow rate of the gas curtain device 201 is controlled at 0.5 to 0.6 m / s (preferably 0.5 m / s), and an inert gas (such as nitrogen) is injected to maintain the pressure in the anaerobic-microaerobic transition chamber 2 at 0.2 to 0.4 kPa (preferably 0.3 kPa).

[0131] (iv) Step S4

[0132] The temperature within the sulfur oxidation chamber 3 is controlled at 28~32℃ (preferably 30±0.5℃), the pH value at 6.8~7.2, the oxidation-reduction potential ≤-300mV (preferably -350~-300mV), the dissolved oxygen at 0.1~0.5mg / L (preferably 0.3±0.05mg / L), and the hydraulic retention time at 8~14h (preferably 12h). The gas flow rate of the first aeration device 302 is controlled at 0.1~0.2 / (min·m). 3 (Preferred value: 0.1 L / (min·m)) 3 )).

[0133] (V) Step S5

[0134] The dissolved oxygen in the sulfur resource recovery compartment 4 is controlled at 0.1~0.3 mg / L (preferably 0.2±0.05 mg / L), the pH value is 6.8~7.2, the oxidation-reduction potential is 50~100 mV, and the hydraulic residence time is 2~4 h (preferably 3 h). The liquid seal height (the static pressure height of a section of liquid column intentionally maintained to prevent gas crossflow or backflow) on the surface of the reaction liquid is set at 25~35 cm (preferably 30 cm). The lower liquid seal height significantly reduces the resistance of the liquid to the gas, allowing residual H2S bubbles to escape from the liquid surface more easily. The gas flow rate of the external circulation microbubble flushing system is controlled at 0.1~0.3 m / s (preferably 0.2 m / s), and a gas flush is performed every 4~8 h (preferably 6 h). The gas flow rate during the gas flush is 0.4~0.6 m / s (preferably 0.5 m / s), and each flush lasts for 2~4 min (preferably 3 min). The reciprocating scraper 405 is controlled at a frequency of 1-3 times / h (preferably 2 times / h), a stroke speed of 4-6 cm / s (preferably 5 cm / s), and a scraper pressure of 0.1-0.3 MPa (preferably 0.2 MPa). The vacuum suction device 406 is controlled at a pressure of -15 to -5 kPa (preferably -10 kPa) during operation. The desulfurization filter cartridge 408 is filled with Fe(III)-NTA chelating agent, and the molar ratio of iron ions to NTA chelating agent is 1:2-3 (preferably 1:2).

[0135] Example 1

[0136] This embodiment provides a baffled membrane bioreactor for the zoned resource utilization of sulfate wastewater:

[0137] like Figure 1 As shown, the reactor is divided into 7 compartments connected in series by baffles arranged vertically: the first and second compartments are sulfate reduction compartments 1, each with a volume of 45L and a length × width × liquid level height of 30cm × 20cm × 75cm; the third compartment is the anaerobic-microaerobic transition zone compartment 2, each with a volume of 30L and a length × width × liquid level height of 25cm × 20cm × 60cm; the fourth, fifth, and sixth compartments are sulfur oxidation compartments 3, each with a volume of 30L and a length × width × liquid level height of 25cm × 20cm × 60cm; and the seventh compartment is the sulfur resource recovery compartment 4, each with a volume of 45L and a length × width × liquid level height of 30cm × 20cm × 75cm.

[0138] Each compartment consists of a set of sequentially arranged folded plates and vertical plates. The upper end of the folded plate is connected to the top of the reactor, and the lower end is folded downwards and to the right (the folding angle is 50°). The height of the folded plate accounts for 75% of the reactor height. The lower end of the vertical plate is connected to the bottom of the reactor, and the length of the vertical plate accounts for 75% of the reactor height. The distance between the lower end of the folded plate and the vertical plate is 1:2 of the distance between the upper end of the folded plate and the vertical plate.

[0139] The sulfate reduction compartment 1 is equipped with a first packing zone for filling packing material loaded with sulfate-reducing bacteria. Within this zone, a perforated plate 103 (made of 304 stainless steel, 3mm aperture, 40% porosity) supports the packing material. A support mesh 104 (200-mesh nylon mesh) is placed on top of the plate, and a restraining mesh 105 (2mm aperture polypropylene mesh) covers the top of the packing material. A temperature sensor, a temperature control device, a redox potential sensor 101, a nitrogen filling device, a pH sensor, and an alkali dosing device are installed and connected to a PLC module.

[0140] Below the gas curtain device 201, a flow guide section narrowing structure with a narrowing ratio of 3:1 is provided. The gas curtain device 201 and the second packing zone are arranged sequentially from bottom to top within the anaerobic-microaerobic transition chamber 2. The gas curtain device 201 has its outlet direction facing upwards. The second packing zone is used to fill H2S adsorption packing 203. Within the second packing zone, from bottom to top, perforated plates (304 stainless steel, 2mm aperture) are arranged to support the packing, and staggered flow guide baffles 202 (304 stainless steel, 60° inclination) are arranged to enhance liquid turbulence and prevent back-mixing. There are three staggered flow guide baffles 202, each arranged parallel and inclined, and intersecting vertically (the distance between adjacent staggered flow guide baffles 202 is 10cm).

[0141] The sulfur oxidation chamber 3 is arranged from bottom to top as follows: an air distribution device 303, a third packing zone, a sulfur collection device 301, and a first aeration device 302. The air distribution device 303 is a hollow fiber membrane bundle with a pore size of 1 mm. The third packing zone is used to fill the packing material loaded with sulfur-oxidizing bacteria. The third packing zone is equipped with a stainless steel corrugated plate 304 with backflow holes (pore size 3 mm, open area ratio 55%) to support the packing material, and stainless steel grids (single grid volume 125 cm³) are set on the stainless steel corrugated plate 304 with backflow holes. 3 The system consists of three sets of stainless steel corrugated plates 304 with backflow holes and stainless steel gratings, stacked vertically. A wire mesh (4mm aperture) is placed on top of the uppermost stainless steel grating. The sulfur capture device 301 comprises a lower and upper capture net; the lower capture net has an aperture of 0.5mm, and the upper capture net has an aperture of 3mm. The first aeration device 302 uses a rubber-molded aeration pipe with a wall thickness of 1.5mm. The sulfur oxidation chamber 3 is equipped with a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen filling device, a pH sensor, an alkali addition device, and a dissolved oxygen sensor 305, all connected to a PLC module.

[0142] Inside the sulfur resource recovery compartment 4, from bottom to top, are arranged an external circulation microbubble flushing device 401, a sulfur collection net 402, a second aeration device 403, and a gas collection hood 404. The sulfur collection net 402 is inclined (stainless steel wire mesh, inclination angle 45°, pore size 0.3mm), and a reciprocating scraper 405 is installed on it. The second aeration device 403 adopts a closed vertical aeration pipe with a hydrophobic hollow fiber aeration membrane (pore size 0.3μm) inside. The lower part of the sulfur collection net 402 is connected to a vacuum suction device 406 and a sulfur paste collection device 407. The gas collecting hood 404 is connected in sequence to the desulfurization filter cartridge 408 and the alkaline absorption tower 409. An air pump 410 is installed between the gas collecting hood 404 and the desulfurization filter cartridge 408, and an air pump 410 is also installed between the desulfurization filter cartridge 408 and the alkaline absorption tower 409. The alkaline absorption tower 409 is connected to the storage tank 411, and the two are circulated and supplied with liquid through a water pump 412.

[0143] Example 2

[0144] This embodiment provides a method for preparing and activating gel beads loaded with sulfate-reducing bacteria:

[0145] The preparation method of gel beads loaded with sulfate-reducing bacteria is as follows: Sodium alginate, nano-SiO2, and polyvinyl alcohol are added to water and mixed to obtain a mixture, wherein the mass concentrations of sodium alginate, nano-SiO2, and polyvinyl alcohol are 3%, 1%, and 0.5%, respectively. The mixture is first frozen at -20℃, then thawed at 25℃, and this cycle is repeated three times. After autoclaving (121℃ for 20 min), the mixture is cooled to room temperature to obtain a sterile mixture. A 2.5% calcium chloride solution and a 0.1 mol / L strontium chloride solution are prepared by adding water and sterilized (121℃ for 20 min). The calcium chloride solution and strontium chloride solution are mixed at a volume ratio of 7:3 to obtain a solidified solution. Under strictly anaerobic conditions (nitrogen purging), the target bacterial group (Desulfovibrio) is enriched using Postgate B liquid medium. sp. A2) was cultured in a shaker at 35±0.5℃ and 150rpm until the late logarithmic growth stage; the pre-cultured cells were collected by centrifugation and resuspended in a small amount of sterile physiological saline to obtain sulfate-reducing bacteria sludge (bacterial activity 5×10⁻⁶). 9 (cfu / g); Under aseptic anaerobic conditions (nitrogen purging), the bacterial sludge is slowly and evenly added to the aseptic mixture at a volume ratio of 1:3. The mixture is gently stirred to ensure even mixing, avoiding the formation of air bubbles, to obtain a final bacterial concentration >10. 9 The adhesive solution was prepared at CFU / mL. Using a sterile syringe, the adhesive solution was dripped into the curing solution with continuous and slow stirring. An ionic cross-linking reaction occurred on the surface, forming spherical gel beads with a particle size of 4.5 mm. The beads were then soaked and cured for another 45 minutes to ensure full internal cross-linking and the formation of a stable gel network. The cured gel beads were then removed and gently washed several times with sterile physiological saline to remove residual curing solution and free bacteria from the surface, resulting in gel beads loaded with sulfate-reducing bacteria.

[0146] Before use, the gel beads loaded with sulfate-reducing bacteria were activated. The activation steps were as follows: The gel beads loaded with sulfate-reducing bacteria were placed in a nutrient solution containing: 2500 mg / L sodium lactate, 2000 mg / L sodium sulfate, 150 mg / L yeast extract, 300 mg / L ammonium chloride, and 150 mg / L dipotassium hydrogen phosphate. 0.5 mol / L Ti(III)-NTA was added dropwise to the nutrient solution to ensure reduction conditions. The activation environment was controlled at a temperature of 35 ± 0.5 °C, a redox potential of -325 ± 25 mV, and a pH of 7.5 ± 0.2 for 36 h.

[0147] Example 3

[0148] This embodiment provides a method for preparing H2S adsorption packing material, the specific steps of which are as follows: Activated carbon and clinoptilolite are mixed at a volume ratio of 2:1 to obtain a mixture; the mixture is mixed with a 100g / L FeCl3·6H2O solution at a solid-liquid ratio of 1g:5mL, and impregnated at a constant temperature of 60℃ and 120rpm for 12h; after being removed and drained, it is aged at 105℃ for 12h, and then calcined at 350℃ for 3h; after cooling, H2S adsorption packing material (particle size 2~4mm, iron loading mass fraction of about 10%) is obtained.

[0149] Example 4

[0150] This embodiment provides a method for preparing polyurethane foam for loading sulfur-oxidizing bacteria. The specific steps are as follows: Under microaerobic conditions (DO=0.1~0.5mg / L), the target bacterial group (A. flavithermus DB-1) is enriched and cultured in Postgate B liquid medium. The culture is then carried out in a shaker at 30±0.5℃ and 150rpm until the late logarithmic growth stage, yielding Postgate B liquid medium enriched with sulfur-oxidizing bacteria (bacterial activity 1.0×10⁻⁶). -9 (cfu / g); Open-cell polyurethane foam was cut into cubic foam blocks with a side length of 12 mm. The blocks were soaked in 95% ethanol solution for 10 min, then rinsed three times with deionized water and dried to obtain pretreated cubic foam blocks. The pretreated cubic foam blocks were then soaked in 0.5% chitosan acetate solution for 2 h and sterilized (at 121℃ for 20 min in an autoclave). The sterilized cubic foam blocks were then placed into Postgate B liquid medium enriched with sulfur-oxidizing bacteria, with 250 cm³ of the solution added per liter of liquid medium. 3 Cube-shaped foam blocks were cultured on a shaker at 35±0.5℃ and a rotation speed of 150 rpm for 144 h to obtain polyurethane foam loaded with sulfur-oxidizing bacteria.

[0151] Before use, the polyurethane foam loaded with sulfur-oxidizing bacteria was activated. The activation steps were as follows: the polyurethane foam loaded with sulfur-oxidizing bacteria was squeezed and rinsed three times with 0.1 mol / L phosphate buffer, and then soaked in 1 mol / L EDTA solution for 40 min. The treated filler was then placed in a nutrient solution containing: sodium thiosulfate 3000 mg / L, sodium acetate 1200 mg / L, ammonium chloride 300 mg / L, dipotassium hydrogen phosphate 150 mg / L and zinc sulfate 0.5 mg / L. The dissolved oxygen was controlled at 0.3 ± 0.05 mg / L, the temperature at 30 ± 0.5℃, the oxidation-reduction potential at -75 ± 25 mV, and the pH at 7 ± 0.2. Activation was carried out for 48 h.

[0152] Example 5

[0153] This embodiment provides a method for the zoned resource utilization of sulfate wastewater, based on the reactor provided in Example 1. The preparation methods of each packing material are as described in Examples 2-4. The method specifically includes the following steps:

[0154] S1. Add sulfate-reducing bacteria-loaded gel beads 106 to the first packing zone at a filling rate of 68%, with 1mm nano-zero-valent iron particles 107 filling the gaps between the gel beads. The filling ratio of sulfate-reducing bacteria-loaded gel beads 106 to nano-zero-valent iron particles 107 is 1:10, and the filling height is 52cm. Add H2S adsorption packing 203 to the second packing zone at a filling rate of 60%, with a filling height of 20cm. Add sulfur-oxidizing bacteria-loaded polyurethane foam 306 to the third packing zone at a filling rate of 52%, with a filling height of 30cm.

[0155] S2. Sulfate wastewater is introduced into the reactor. The water flows in from below the sulfate reduction chamber 1 and passes through the first packing zone to reduce the sulfate in the wastewater to H2S. Nitrogen gas is introduced into the sulfate reduction chamber 1 through a nitrogen filling device to form a nitrogen protective layer 102 at the top of the chamber. 0.5 mol / L Ti(III)-NTA is added to the chamber as a strong reducing agent. The PLC module controls the pressure of the sulfate reduction chamber 1 to 0.5 kPa, the temperature to 35±0.5℃, the pH value to 7.5±0.2, the oxidation-reduction potential to -325±25 mV, the upward flow rate to 0.8 m / h, and the hydraulic retention time to 24 h.

[0156] S3. After the wastewater flows out of the sulfate reduction chamber 1, it enters the anaerobic-microaerobic transition chamber 2 from below. The gas curtain device 201 is controlled to blow air upward to form a continuous gas seal, preventing oxygen from flowing back into the sulfate reduction chamber 1. The wastewater passes through the second packing zone to adsorb residual H2S. Specifically: the gas flow rate of the gas curtain device 201 is controlled at 0.5 m / s, and nitrogen is injected to make the pressure in the anaerobic-microaerobic transition chamber 2 0.3 kPa; the PLC module controls the oxidation-reduction potential in the anaerobic-microaerobic transition chamber 2 to be -125±25 mV, and the hydraulic retention time to be 0.5 h.

[0157] S4. After the wastewater flows out of the anaerobic-microaerobic transition chamber 2, it enters the sulfur oxidation chamber 3 from below. The first aeration device 302 is controlled to perform aeration. The wastewater passes through the third packing zone, where H2S is oxidized to elemental sulfur. The generated elemental sulfur is collected by the sulfur capture device 301. The PLC module controls the gas flow rate of the first aeration device 302 to be 0.1 L / (min·m). 3 The temperature in sulfur oxidation chamber 3 was controlled at 30±0.5℃, the pH value at 7.0±0.2, the oxidation-reduction potential at -325±25mV, the dissolved oxygen at 0.3±0.05mg / L, the upflow velocity at 1.2m / h, and the hydraulic retention time at 12h.

[0158] S5. After the wastewater flows out of the sulfur oxidation chamber 3, it enters the sulfur resource recovery chamber 4 from below. The second aeration device 403 is controlled to aerate the water, and H2S is oxidized to generate elemental sulfur. The elemental sulfur is deposited on the sulfur collection net 402 and is stripped off as sulfur paste by the reciprocating scraper 405. The external circulation microbubble flushing device 401 is controlled to flush the sulfur collection net 402 to promote deposition and prevent scaling. The sulfur paste is sucked into the sulfur paste collection device 407 by the vacuum suction device 406. The residual H2S is collected through the gas collection hood 404 and converted into elemental sulfur or FeS by the desulfurization filter cartridge 408 (filled with Fe(III)-NTA chelating agent, with a molar ratio of iron ions to NTA chelating agent of 1:2). The residual tail gas discharged from 408 is neutralized and treated by alkaline absorption tower 409. Specifically: the PLC module controls the dissolved oxygen in the sulfur resource recovery compartment 4 to be 0.2±0.05 mg / L, the pH value to be 7±0.2, the oxidation-reduction potential to be 75±25 mV, the hydraulic residence time to be 3 h, and the liquid seal height on the surface of the reaction liquid to be 30 cm; the flow rate of the external circulation microbubble flushing system is controlled to be 0.2 m / s, with air flushing performed every 6 h at a gas flow rate of 0.5 m / s for 3 min each time; the frequency of the reciprocating scraper 405 is controlled to be 2 times / h, the stroke speed to be 5 cm / s, and the scraper pressure to be 0.2 MPa; the pressure of the vacuum suction device 406 is controlled to be -10 kPa during operation.

[0159] Experimental Example

[0160] This experimental example aims to study the treatment effect of the reactor provided in Example 1 on sulfate wastewater. The specific operation follows the method provided in Example 5.

[0161] I. Reactor Acclimation Stage

[0162] 1. Biofilm maturation period

[0163] Simulated sulfate wastewater, with the following composition: SO4, is introduced into the reactor. 2- =2000±100mg / L, sodium lactate=4000mg / L (COD / SO4) 2- =2.0), trace element solution (composition: manganese chloride 200mg / L, zinc chloride 100mg / L, cobalt chloride 200mg / L, copper chloride 30mg / L, sodium molybdate 300mg / L and boric acid 300mg / L) 5mL / L, the reactor was acclimatized under the conditions provided in Example 5, sulfate-reducing bacteria and sulfur-oxidizing bacteria proliferated and formed dense biofilm communities on the surface of gel beads and polyurethane foam, respectively.

[0164] 2. Biomembrane activity detection

[0165] The biomembrane activity was assessed using a three-tiered evaluation system: membrane structure characteristics, metabolic function, and process stability.

[0166] (1) Membrane structure characteristics: Observed using a confocal laser scanning microscope (CLSM).

[0167] The maturity standard for biofilm in the first packing zone is: average thickness > 50 μm and coverage > 85%; the maturity standard for biofilm in the second packing zone is: average thickness > 40 μm and coverage > 75%.

[0168] (2) Metabolic function: The substrate conversion rate is used as an indicator.

[0169] Sulfate reduction rate (SRR) in the first packing zone: 10g of acclimated packing was placed in 90mL of simulated wastewater (SO4). 2- The simulated wastewater was statically incubated for 2 hours in a solution with a concentration of 2000 mg / L and a COD of 4000 mg / L. SO42 in the simulated wastewater was then measured every 30 minutes using the barium chromate spectrophotometric method (HJ / T 342-2007 "Determination of Sulfate in Water - Barium Chromate Spectrophotometric Method (Trial)"). 2- Concentration, calculate SRR, and when SRR ≥ 45 mg / (g·h), it indicates that the biofilm in the first packing zone is mature.

[0170] Sulfide oxidation rate (SOR) in the second packing zone: Take 10g of acclimated packing and place it in 90mL of sulfur-containing wastewater (S... 2- In a solution of 500 mg / L (DO = 0.2 mg / L), the mixture was shaken for 1 hour. Residual sulfur was then determined using the methylene blue method (GB / T 16489-1996, "Determination of Sulfides in Water - Methylene Blue Spectrophotometric Method"). 2- Calculate SOR and S 0 Yield, when SOR ≥ 35 mg / (g·h) and S 0 A yield greater than 85% indicates that the biofilm in the second packing zone is mature.

[0171] (3) Process stability: Shear strength is used as the test index.

[0172] A certain amount of packing material was placed in an Erlenmeyer flask containing 0.1 mol / L sterile phosphate buffer. The mixture was shaken at 150 rpm for 120 min on a constant temperature shaker (amplitude 10 mm). The supernatant was collected and its suspended solids concentration (MLSS) was determined by standard gravimetric method (dried at 105℃ to constant weight). The cell shedding rate was calculated as (MLSS of the supernatant after shaking / MLSS of the initial attached biomass on the packing material) × 100%. The initial attached biomass could be obtained by placing the packing material in the same volume of sterile phosphate buffer and then subjecting it to strong ultrasonic disruption (power 300 W, working time 5 min, -4℃) and measuring the MLSS. A cell shedding rate of <5% indicates that the biofilm is mature.

[0173] Results after 14 days of acclimatization: In the first packing zone, the average thickness of the mature biofilm was 83 μm, with a coverage rate of 92%; in the second packing zone, the average thickness of the biofilm was 65 μm, with a coverage rate of 86%. SRR = 48.5 mg / (g·h); SOR = 38.1 mg / (g·h); S 0 Yield = 88.5%. Cell shedding rate in the first packing zone = 3.2%; cell shedding rate in the second packing zone = 4.1%.

[0174] Conclusion: After 14 days of reactor acclimatization, the biofilms in the first and third packing zones were mature and ready for formal use.

[0175] II. Reactor Formal Operation Phase

[0176] After the biofilm matured, it was put into formal operation according to the method provided in Example 5. The acclimatized reactor was used to simulate the treatment of high-concentration sulfate industrial wastewater (the composition of which is shown in Tables 1 and 2). The influent water quality and treatment effect were tested and calculated (10 parallel samples were taken from each chamber, and the results are expressed as "mean ± standard deviation"). The methods and results are as follows.

[0177] Table 1 Composition of high-concentration sulfate industrial wastewater

[0178]

[0179] Table 2 Composition of Trace Element Solution

[0180]

[0181] 1. Influent water quality data

[0182] The water quality indicators of the reactor influent were tested. The test indicators, results and test methods are shown in Table 3.

[0183] Table 3. Methods and Results of Influent Water Quality Testing

[0184]

[0185] 2. Processing effect data

[0186] The effluent from the sulfate reduction chamber, the anaerobic-microaerobic transition chamber, the sulfur oxidation chamber, and the sulfur resource recovery chamber were sampled and tested respectively (when there were multiple chambers, the effluent from the last chamber was used as the sample). The test indicators and results are shown in Table 4.

[0187] Table 4 Reactor treatment effect

[0188]

[0189] 3. Indicator Calculation Process

[0190] (1) Inflow rate

[0191] Table 5. Calculation process of influent flow rate

[0192]

[0193] (2) Sulfur conversion rate

[0194] Table 6. Calculation process of sulfur conversion rate

[0195]

[0196] (3) Sulfur recovery rate

[0197] Table 7 Calculation process of sulfur recovery rate

[0198]

[0199] (4) Oxygen utilization rate

[0200] Table 8 Oxygen utilization rate calculation process

[0201]

[0202] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A baffled membrane bioreactor for zoned resource recovery of sulfate wastewater, characterized in that, The reactor is divided into a sulfate reduction chamber, an anaerobic-microaerobic transition chamber, and a sulfur oxidation chamber connected in series by baffles arranged vertically. The sulfate reduction compartment is provided with a first packing area, which is used to fill the packing material loaded with sulfate-reducing bacteria; The anaerobic-microaerobic transition compartment is provided with a gas curtain device and a second packing area from bottom to top. The gas curtain device is arranged with the gas outlet direction facing upward. The second packing area is used to fill H2S adsorption packing. The second packing area is provided with a perforated plate for supporting the packing and a staggered flow guide baffle for enhancing liquid turbulence and preventing back mixing from bottom to top. The number of staggered flow guide baffles is at least two. Each staggered flow guide baffle is arranged in parallel and inclined and is arranged crosswise in the vertical direction. The sulfur oxidation chamber is arranged from bottom to top as follows: a third packing zone and a sulfur collection device. The third packing zone is filled with packing material loaded with sulfur-oxidizing bacteria. An air distribution device, which is a hollow fiber membrane bundle, is located below the third packing zone. The third packing zone contains a stainless steel corrugated plate with backflow holes for supporting the packing material, and a stainless steel grid mounted on the corrugated plate. At least two sets of the corrugated plate and grid are stacked vertically. A wire mesh is placed on top of the uppermost stainless steel grid. The sulfur collection device includes a lower collection net and an upper collection net arranged from bottom to top, with the lower collection net having a smaller aperture than the upper collection net. A first aeration device, using a rubber-molded aeration pipe, is located within the sulfur oxidation chamber.

2. The baffled membrane bioreactor for zoned resource utilization of sulfate wastewater according to claim 1, characterized in that, The sulfate reduction chamber is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen filling device, a pressure sensor, a pH sensor, and an alkali dosing device. The first packing area is provided with a perforated plate for supporting the packing and a support mesh disposed on the perforated plate, as well as a constraint mesh for covering the top of the packing.

3. The baffled membrane bioreactor for zoned resource utilization of sulfate wastewater according to claim 1, characterized in that, A flow guide section narrowing structure is provided below the gas curtain device; Pressure sensors and redox potential sensors are installed in the anaerobic-microaerobic transition chamber.

4. The baffled membrane bioreactor for zoned resource utilization of sulfate wastewater according to claim 1, characterized in that, The sulfur oxidation chamber is equipped with at least one of the following: a temperature sensor, a temperature control device, a redox potential sensor, a nitrogen filling device, a pH sensor, an alkali addition device, and a dissolved oxygen sensor.

5. The baffled membrane bioreactor for zoned resource utilization of sulfate wastewater according to claim 1, characterized in that, The reactor is also equipped with a sulfur resource recovery compartment connected in series with the sulfur oxidation compartment. The sulfur resource recovery compartment is equipped with an external circulation microbubble flushing device, a sulfur collection net, a second aeration device and a gas collection hood from bottom to top. The sulfur collection mesh is inclined and a reciprocating scraper is installed on it; The second aeration device adopts a closed vertical aeration pipe with a hydrophobic hollow fiber aeration membrane inside; The sulfur resource recovery compartment is connected in sequence to a vacuum suction device and a sulfur paste collection device, and the vacuum suction device is connected to the lower part of the sulfur collection net. The sulfur resource recovery compartment is connected in sequence to the desulfurization filter cartridge and the alkali absorption tower, and the desulfurization filter cartridge is connected to the gas collection hood.

6. A method for zoned resource utilization of sulfate wastewater, characterized in that, Based on the baffled membrane bioreactor for zoned resource recovery of sulfate wastewater as described in any one of claims 1 to 5, the method includes the following steps: The first packing zone, the second packing zone, and the third packing zone are respectively filled with packing material loaded with sulfate-reducing bacteria, H2S adsorption packing material, and sulfur-oxidizing bacteria packing material. Sulfate wastewater is fed into the reactor. The water flows in from below the sulfate reduction chamber and passes through the first packing zone to reduce the sulfate in the wastewater to H2S. After the wastewater flows out of the sulfate reduction chamber, it enters the anaerobic-microaerobic transition chamber from below. The gas curtain device is controlled to blow air upward to form a continuous gas seal. The wastewater passes through the second packing area to adsorb residual H2S. After the wastewater flows out of the anaerobic-microaerobic transition chamber, it enters the sulfur oxidation chamber from below. The first aeration device is controlled to perform aeration. The wastewater passes through the third packing zone to oxidize H2S into elemental sulfur. The generated elemental sulfur is collected by the sulfur capture device.

7. The method for zoned resource utilization of sulfate wastewater according to claim 6, characterized in that, It also includes the following steps: After the wastewater flows out of the sulfur oxidation chamber, it enters the sulfur resource recovery chamber from below. The second aeration device is controlled to aerate the sulfur, and H2S is oxidized to generate elemental sulfur. The elemental sulfur is deposited on the sulfur collection net and peeled off into sulfur paste by a reciprocating scraper. The external circulation microbubble flushing device is controlled to flush the sulfur collection net to promote deposition and prevent scaling. The sulfur paste is sucked into the sulfur paste collection device by a vacuum suction device. The residual H2S is collected through the gas collection hood and converted into elemental sulfur or FeS by the desulfurization filter cartridge. The residual tail gas discharged from the desulfurization filter cartridge is neutralized by the alkaline absorption tower. The dissolved oxygen in the sulfur resource recovery chamber is controlled at 0.1~0.3 mg / L, pH at 6.8~7.2, oxidation-reduction potential at 50~100 mV, and hydraulic retention time at 2~4 h; the gas flow rate of the external circulation microbubble flushing system is controlled at 0.1~0.3 m / s, and air flushing is performed once every 4~8 h, with a gas flow rate of 0.4~0.6 m / s during air flushing, and each flush lasting 2~4 min; the frequency of the reciprocating scraper is controlled at 2~3 times / h, the stroke speed at 4~6 cm / s, and the scraper pressure at 0.1~0.3 MPa; the pressure of the vacuum suction device is controlled at -12~-8 kPa during operation; the desulfurization filter cartridge is filled with Fe(III)-NTA chelating agent, and the molar ratio of iron ions to NTA chelating agent is 1:2~3.

8. The method for zoned resource utilization of sulfate wastewater according to claim 6, characterized in that, The filler material loaded with sulfate-reducing bacteria is a gel bead loaded with sulfate-reducing bacteria; the preparation method of the gel bead loaded with sulfate-reducing bacteria includes the following steps: Sodium alginate, nano-SiO2, and polyvinyl alcohol were added to water and mixed to obtain a mixture. The mass concentrations of sodium alginate, nano-SiO2, and polyvinyl alcohol in the mixture were 2%~4%, 0.5%~1%, and 0.5%~1%, respectively. The mixture was first frozen at -25~-15℃, then thawed at 20~25℃, and the cycle was repeated 2~4 times. After sterilization, it was cooled to room temperature to obtain a sterile mixture. A 2%~3% mass concentration calcium chloride solution and a 0.1~0.2 mol / L strontium chloride solution were prepared separately and sterilized. The calcium chloride solution and strontium chloride solution were mixed at a volume ratio of 6~8:2~4 to obtain a solidified solution. Sulfate-reducing bacteria sludge was prepared. Under sterile anaerobic conditions, the sludge was slowly and evenly added to the sterile mixture at a volume ratio of 1~2:3~4 to obtain a final bacterial concentration >10. 9 The adhesive solution is prepared at CFU / mL. The adhesive solution is added dropwise to the curing solution under continuous and slow stirring to form spherical gel beads. The beads are then soaked and cured for 40-50 minutes. The cured gel beads are then removed, washed, and the gel beads loaded with sulfate-reducing bacteria are obtained. The preparation method of the H2S adsorption packing includes the following steps: Activated carbon and clinoptilolite were mixed at a volume ratio of 1.5-2.5:1 to obtain a mixture. The mixture was then mixed with an 80-120 g / L FeCl3·6H2O aqueous solution at a solid-liquid ratio of 1 g:3-5 mL. The mixture was then immersed in the solution at a constant temperature of 55-65°C and 100-150 rpm for 10-14 h. After being removed and drained, the mixture was aged at 100-110°C for 10-14 h and then calcined at 345-355°C for 2-4 h. After cooling, the H2S adsorption filler was obtained. The filler material loaded with sulfur-oxidizing bacteria is polyurethane foam loaded with sulfur-oxidizing bacteria; the preparation method of the polyurethane foam loaded with sulfur-oxidizing bacteria includes the following steps: Open-cell polyurethane foam was cut into cubic foam blocks, soaked in 95% ethanol solution for 5-10 minutes, then rinsed with deionized water and dried to obtain pretreated cubic foam blocks. The pretreated cubic foam blocks were soaked in 0.4%-0.6% chitosan acetate solution for 1-3 hours, sterilized, and then placed in Postgate B liquid medium enriched with sulfur-oxidizing bacteria. The medium was cultured on a shaker at 30-36°C at 120-180 rpm for 120-168 hours to obtain the polyurethane foam loaded with sulfur-oxidizing bacteria.

9. The method for zoned resource utilization of sulfate wastewater according to claim 8, characterized in that, The gel beads loaded with sulfate-reducing bacteria are activated before use. The activation steps include: The gel beads loaded with sulfate-reducing bacteria were placed in a nutrient solution containing 2000-3000 mg / L sodium lactate, 1800-2200 mg / L sodium sulfate, 120-180 mg / L yeast extract, 250-350 mg / L ammonium chloride, and 120-180 mg / L dipotassium hydrogen phosphate. 0.5 mol / L Ti(III)-NTA was added dropwise to the nutrient solution to ensure reduction conditions. The activation environment temperature was controlled at 30-36℃, the redox potential was <-300 mV, and the pH value was 7.0-8.

0. Activation was carried out for 30-42 h. The polyurethane foam loaded with sulfur-oxidizing bacteria is activated before use. The activation steps include: The polyurethane foam loaded with sulfur-oxidizing bacteria was squeezed and rinsed with 0.1-0.2 mol / L phosphate buffer, and then soaked in 1-2 mol / L EDTA solution for 30-50 min. The treated packing was then placed in a nutrient solution containing 2500-3500 mg / L sodium thiosulfate, 1000-1400 mg / L sodium acetate, 250-350 mg / L ammonium chloride, 100-200 mg / L dipotassium hydrogen phosphate, and 0.4-0.6 mg / L zinc sulfate. The activated environment was controlled with dissolved oxygen at 0.1-0.5 mg / L, temperature at 28-32℃, redox potential <-50 mV, and pH at 6.5-7.5 for 42-54 h.

10. The method for zoned resource utilization of sulfate wastewater according to claim 6, characterized in that, 0.4-0.6 mol / L Ti(III)-NTA is added as a strong reducing agent in the sulfate reduction chamber; the pressure in the sulfate reduction chamber is controlled at 0.3-0.6 kPa, the temperature at 30-36℃, the pH at 7.0-8.0, the oxidation-reduction potential at ≤-300 mV, and the hydraulic retention time at 18-30 h; sulfate-reducing bacteria-loaded packing material is added to the first packing zone at a filling rate of 65%-70%, and the gaps between the packing materials are filled with nano-zero-valent iron particles with a diameter of 1-2 mm. The volume ratio of sulfate-reducing bacteria-loaded packing material to nano-zero-valent iron particles is 8-12:

1. The oxidation-reduction potential in the anaerobic-microaerobic transition chamber is controlled at -150 to -100 mV, and the hydraulic retention time is 0.5 to 1 h; the gas flow rate of the gas curtain device is controlled at 0.5 to 0.6 m / s, and inert gas is injected to make the pressure in the anaerobic-microaerobic transition chamber 0.2 to 0.4 kPa; the filling rate of the second packing zone is 55% to 60%. The temperature in the sulfur oxidation chamber is controlled at 28~32℃, the pH value at 6.8~7.2, the oxidation-reduction potential at <-50mV, the dissolved oxygen at 0.1~0.5mg / L, and the hydraulic retention time at 8~14h; the gas flow rate of the first aeration device is controlled at 0.1~0.15L / (min·m). 3 The filling rate of the third filling zone is 50%~55%.

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