Device and method for co-treatment of sulfur-containing wastewater and perchlorate-contaminated wastewater

Abstract

The application provides a device and method for treating sulfur-containing wastewater and perchlorate-polluted wastewater, and belongs to the field of wastewater treatment.The device comprises an anaerobic reactor, an anoxic reactor and a sedimentation tank; the inside of the anaerobic reactor is inoculated with sulfate-reducing bacteria; a sulfur-containing wastewater inlet pipe is arranged at the lower part of the anaerobic reactor; the inside of the anoxic reactor is inoculated with sulfur autotrophic bacteria and perchlorate-reducing bacteria; a perchlorate-containing wastewater inlet pipe is arranged at the lower part of the anoxic reactor; the upper part of the anaerobic reactor is connected with the upper part of the anoxic reactor through a first water conveying pipe in a stepped manner; the top of the sedimentation tank is connected with the upper part of the side wall of the anoxic reactor through a second water conveying pipe; a sediment discharge pipe is arranged at the bottom end of the sedimentation tank; and a supernatant outlet pipe is arranged at the upper part of the side wall of the sedimentation tank. The application can solve the problem that the prior art cannot simultaneously treat sulfur-containing wastewater and perchlorate-polluted wastewater.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically, to a device and method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater. Background Technology

[0002] The common method for removing sulfate from sulfur-containing (sulfate) wastewater is chemical precipitation. This involves introducing calcium ions (using lime or calcium chloride) into the wastewater to form calcium sulfate precipitate, thus removing the sulfate ions. The disadvantages of chemical precipitation are: 1. High dosage and cost; 2. According to the principle of chemical equilibrium, an excess of calcium ions is required to facilitate the formation of calcium sulfate precipitate, while unreacted calcium ions need to be removed by adding reagents (such as sodium carbonate) to avoid adverse effects on downstream treatment. The large dosage of these reagents increases the conductivity of the wastewater, reducing the recovery rate of the membrane treatment unit; 3. Because calcium sulfate is a slightly soluble compound, a high concentration of sulfate ions is always present in the solution, resulting in a low sulfate removal rate.

[0003] Perchlorate pollution wastewater mainly originates from the production and processing of industrial products such as electronic component cleaning and etching wastewater, fireworks and firecracker production wastewater, and solid fuel oxidants. Perchlorate is chemically stable, difficult to treat, and poses a significant threat to human health and the ecological environment. Commonly used treatment methods include physical adsorption, ion exchange, membrane separation, catalytic reduction, and biodegradation. Adsorption, ion exchange, and membrane separation primarily achieve separation through pollutant enrichment or phase transfer, without transforming the pollutant's chemical form. Furthermore, these technologies suffer from bottlenecks such as low regeneration efficiency of ion exchange resins, the risk of secondary discharge of high-salt concentrates, and the need for additional treatment of regenerated wastewater. While catalytic reduction possesses degradation potential, it relies on precious metal catalysts, resulting in high costs, catalyst deactivation, and stringent reaction conditions, limiting its engineering application.

[0004] Biodegradation, which completely converts perchlorate into non-toxic chloride salts, has attracted widespread attention due to its high removal efficiency and low cost. However, because perchlorate, as an oxidant, needs to obtain electrons from the outside during reduction, a carbon source is typically added as an electron donor, resulting in relatively high operating costs.

[0005] In summary, current technologies treat sulfur-containing wastewater and perchlorate-contaminated wastewater separately, lacking an effective solution that can treat both simultaneously. Summary of the Invention

[0006] In view of the above problems, the purpose of this invention is to provide a device and method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater, so as to solve the problem that in the prior art, the treatment of sulfur-containing wastewater and perchlorate-polluted wastewater are carried out separately, and there is a lack of an effective solution that can treat sulfur-containing wastewater and perchlorate-polluted wastewater simultaneously.

[0007] The present invention provides a co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater, comprising an anaerobic reactor, an anoxic reactor, and a sedimentation tank arranged in sequence; wherein,

[0008] Sulfate-reducing bacteria are inoculated inside the anaerobic reactor; a sulfur-containing wastewater inlet pipe is installed on the lower part of the side wall of the anaerobic reactor.

[0009] The interior of the anoxic reactor is inoculated with sulfur autotrophic bacteria and perchlorate-reducing bacteria; a perchlorate-containing wastewater inlet pipe is installed at the lower part of the side wall of the anoxic reactor.

[0010] The upper part of the sidewall of the anaerobic reactor is connected to the upper part of the sidewall of the anoxic reactor by a stepped first water supply pipe, and the water inlet end of the first water supply pipe connected to the anaerobic reactor is higher than the water outlet end connected to the anoxic reactor.

[0011] The top of the sedimentation tank is connected to the upper side wall of the anoxic reactor via a second water supply pipe; the inlet end of the second water supply pipe connected to the anoxic reactor is higher than the outlet end connected to the sedimentation tank; a sediment discharge pipe is provided at the bottom of the sedimentation tank; and a supernatant discharge pipe is provided on the upper side wall of the sedimentation tank.

[0012] Furthermore, in a preferred embodiment, the supernatant outlet pipe includes a supernatant main pipe and a supernatant circulation pipe connected to the body of the supernatant main pipe; a supernatant valve is provided at the supernatant outlet of the supernatant main pipe; a first circulation branch pipe and a second circulation branch pipe are respectively provided on the supernatant circulation pipe; the first circulation branch pipe is connected to the body of the sulfur-containing wastewater inlet pipe; and the second circulation branch pipe is connected to the lower side wall of the anoxic reactor.

[0013] Furthermore, a preferred embodiment is to install a first reflux pump on the first circulation branch pipe and a second reflux pump on the second circulation branch pipe.

[0014] Furthermore, a preferred embodiment is that an online water quality monitoring instrument for monitoring sulfate and perchlorate concentrations is installed in the sedimentation tank; the online water quality monitoring instrument is connected to a smart water management platform; the smart water management platform is equipped with a sulfate and perchlorate concentration acquisition module connected to the online water quality monitoring instrument, an analysis and comparison module connected to the sulfate and perchlorate concentration acquisition module, and a signal command module connected to the analysis and comparison module; the signal command module is connected to the first reflux pump, the second reflux pump, and the clear liquid valve, respectively.

[0015] In addition, a preferred embodiment is to install an anaerobic inlet pump at the inlet end of the sulfur-containing wastewater inlet pipe; and / or to install an anoxic inlet pump at the inlet end of the perchlorate-containing wastewater inlet pipe.

[0016] Furthermore, a preferred embodiment is to provide a sedimentation valve on the sediment discharge pipe.

[0017] Furthermore, a preferred embodiment is that a stirrer is installed inside the anoxic reactor.

[0018] The present invention provides a method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater, which uses the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater as described above to simultaneously treat sulfur-containing wastewater and perchlorate-polluted wastewater; the method includes the following steps:

[0019] Sulfur-containing wastewater is introduced into the anaerobic reactor through the sulfur-containing wastewater inlet pipe, where it is reduced to sulfides by sulfate-reducing bacteria, forming the first effluent containing sulfides.

[0020] The first effluent is introduced into the anoxic reactor through the first water supply pipe, and the perchlorate-containing wastewater is introduced into the anoxic reactor through the perchlorate-containing wastewater inlet pipe. The sulfur-chlorine ratio in the anoxic reactor is controlled to be ≥4:1, so that the first effluent and the perchlorate-containing wastewater react with the sulfur autotrophic bacteria and the perchlorate-reducing bacteria respectively in the anoxic reactor to form the second effluent containing elemental sulfur, sulfate and chloride ions.

[0021] The second effluent is introduced into the sedimentation tank through the second water supply pipe. In the sedimentation tank, the sludge and elemental sulfur in the second effluent settle to the bottom and are discharged from the sediment outlet pipe. The supernatant containing sulfate and chloride ions in the second effluent is discharged from the supernatant outlet pipe.

[0022] Furthermore, a preferred embodiment is that when the sulfate concentration in the supernatant of the sedimentation tank is greater than the preset sulfate standard concentration, the supernatant discharged from the supernatant outlet pipe is recycled back into the anaerobic reactor; when the perchlorate concentration in the supernatant of the sedimentation tank is greater than the preset perchlorate standard concentration, the supernatant discharged from the supernatant outlet pipe is recycled back into the anoxic reactor.

[0023] Furthermore, in a preferred embodiment, the residence time of the sulfur-containing wastewater in the anaerobic reactor is 12–48 h, the temperature in the anaerobic reactor is 25–35 °C, the pH of the wastewater in the anaerobic reactor is 6.5–8, the oxidation-reduction potential in the anaerobic reactor is ≤-100 mV, and the sulfate concentration in the first effluent is less than 25 mg / L; the residence time of the first effluent and the perchlorate-containing wastewater in the anoxic reactor is 4–10 h, the temperature in the anoxic reactor is 20–35 °C, the pH of the wastewater in the anoxic reactor is 7–8, and the dissolved oxygen in the anoxic reactor is ≤0.5 mg / L; the perchlorate concentration in the effluent from the supernatant outlet is less than 0.05 mg / L, and the sulfate concentration is less than 80 mg / L.

[0024] As can be seen from the above technical solution, the co-treatment device and method for sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention, through the structural design of an anaerobic reactor, an anoxic reactor, and a sedimentation tank, first introduces sulfur-containing wastewater into the anaerobic reactor. Under anaerobic conditions, sulfate-reducing bacteria reduce the sulfate in the sulfur-containing wastewater to sulfides. Then, the effluent containing sulfides from the anaerobic reactor is introduced into the anoxic reactor, and simultaneously, perchlorate-polluted wastewater (containing perchlorate) is also introduced into the anoxic reactor. In the anoxic reactor, under anoxic conditions, sulfides... The electron donor loses electrons and is oxidized to elemental sulfur by sulfur autotrophic bacteria. Perchlorate (electron acceptor) gains electrons and is reduced to chloride ions by perchlorate-reducing bacteria. The sulfur autotrophic bacteria use inorganic carbon (such as carbon dioxide, carbonate, etc.) as a carbon source. The second effluent containing elemental sulfur, sulfate, and chloride ions from the anoxic reactor is then introduced into a sedimentation tank. After solid-liquid separation in the sedimentation tank, elemental sulfur settles to the bottom. Chloride ions and the byproduct sulfate are present in the supernatant. If the concentrations of perchlorate and sulfate in the supernatant of the sedimentation tank meet the requirements, they can be discharged through the supernatant outlet pipe. Sulfur-containing wastewater and perchlorate-containing wastewater form a synergistic reaction system. Utilizing sulfate-reducing bacteria, sulfur-autotrophic bacteria, and perchlorate-reducing bacteria inoculated within the reactor, the reaction proceeds simultaneously with the desulfurization of the sulfur-containing wastewater and the synergistic reduction and removal of perchlorate. This effectively removes sulfate and perchlorate from both types of wastewater, significantly reducing the need for external carbon sources (perchlorate removal in the anoxic reactor does not require carbon source addition, while in the anaerobic reactor, carbon source addition may be omitted or partially added depending on the C / S ratio in the water). The economic benefits are significant. Furthermore, compared to treating the two types of wastewater separately, the synergistic treatment process is simpler to operate, requires less floor space, and has lower investment costs.

[0025] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0026] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more complete understanding of the invention.

[0027] Figure 1 This is a schematic diagram of the structure of the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of an anoxic reactor according to an embodiment of the present invention;

[0029] Figure 3This is a schematic diagram of the sedimentation tank according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the upflow anaerobic sludge bed reactor used in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the inclined plate sedimentation tank used in an embodiment of the present invention;

[0032] Figure 6 This is a flowchart of a method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater according to an embodiment of the present invention.

[0033] In the attached diagram, 1-anaerobic reactor, 11-sulfur-containing wastewater inlet pipe, 12-anaerobic inlet pump, 2-anoxic reactor, 21-perchlorate-containing wastewater inlet pipe, 22-anoxic inlet pump, 3-sedimentation tank, 31-sediment outlet pipe, 311-sedimentation valve, 32-supernatant outlet pipe, 321-supernatant main pipe, 322-supernatant circulation pipe, 323-supernatant valve, 4-first water supply pipe, 5-second water supply pipe, 6-first circulation branch pipe, 61-first reflux pump, 7-second circulation branch pipe, 71-second reflux pump, 8-online water quality monitoring instrument, 9-stirrer.

[0034] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0035] In response to the aforementioned problem that in the prior art, sulfur-containing wastewater treatment and perchlorate-polluted wastewater treatment are carried out separately, and there is a lack of an effective solution that can treat sulfur-containing wastewater and perchlorate-polluted wastewater simultaneously, a device and method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater are proposed.

[0036] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] To illustrate the apparatus and method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention Figure 1 The structure of the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to an embodiment of the present invention is shown; Figure 2 The structure of an anoxic reactor according to an embodiment of the present invention is shown; Figure 3 The structure of a sedimentation tank according to an embodiment of the present invention is shown; Figure 4 The structure of the upflow anaerobic sludge bed reactor used in an embodiment of the present invention is shown; Figure 5 The structure of the inclined plate sedimentation tank used in an embodiment of the present invention is shown; Figure 6 The flowchart of a method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater according to an embodiment of the present invention is shown.

[0038] like Figures 1 to 5 As shown in the figure, the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention includes an anaerobic reactor 1, an anoxic reactor 2, and a sedimentation tank 3 arranged in sequence; wherein,

[0039] Sulfate-reducing bacteria are inoculated inside the anaerobic reactor 1; a sulfur-containing wastewater inlet pipe 11 is installed on the lower part of the side wall of the anaerobic reactor 1.

[0040] Sulfotrophic bacteria and perchlorate-reducing bacteria are inoculated inside the anoxic reactor 2; a perchlorate-containing wastewater inlet pipe 21 is installed on the lower part of the side wall of the anoxic reactor 2.

[0041] The upper part of the side wall of the anaerobic reactor 1 is connected to the upper part of the side wall of the anoxic reactor 2 by a stepped first water supply pipe 4. The inlet end of the first water supply pipe 4 connected to the anaerobic reactor 1 is higher than the outlet end connected to the anoxic reactor 2.

[0042] The top of the sedimentation tank 3 is connected to the upper side wall of the anoxic reactor 2 via a second water supply pipe 5; the inlet end of the second water supply pipe 5 connected to the anoxic reactor 2 is higher than the outlet end connected to the sedimentation tank 3; a sediment discharge pipe 31 is provided at the bottom of the sedimentation tank 3; and a supernatant discharge pipe 32 is provided on the upper side wall of the sedimentation tank 3.

[0043] In this invention, the anaerobic reactor 1 can be an upflow anaerobic sludge blanket reactor (UASB) as described in the prior art (e.g., Figure 4 As shown), internal circulation anaerobic reactors (IC), anaerobic granular sludge expanded bed reactors (EGSB), anaerobic fluidized bed reactors (AFB), etc., this invention does not particularly limit the type of anaerobic reactor.

[0044] The sedimentation tank in this invention can be an inclined plate sedimentation tank (e.g., ...) from the prior art. Figure 5 As shown), the types of sedimentation tanks include horizontal flow sedimentation tanks, vertical flow sedimentation tanks, radial flow sedimentation tanks, etc. This invention does not impose any particular limitation on the type of sedimentation tank.

[0045] Through the structural design of anaerobic reactor 1, anoxic reactor 2, and sedimentation tank 3, sulfur-containing wastewater first flows into anaerobic reactor 1. Under anaerobic conditions, sulfate-reducing bacteria reduce the sulfate in the sulfur-containing wastewater to sulfides. Then, the effluent containing sulfides from anaerobic reactor 1 flows into anoxic reactor 2, and perchlorate-contaminated wastewater (containing perchlorate) is also introduced into anoxic reactor 2. In anoxic reactor 2, under anoxic conditions, sulfides (electron donors) lose electrons and are oxidized by sulfur autotrophic bacteria to form sulfur compounds. Elemental sulfur, with perchlorate (electron acceptor) gaining electrons, is reduced to chloride ions by perchlorate-reducing bacteria. Sulfotrophic bacteria use inorganic carbon (such as carbon dioxide, carbonate, etc.) as a carbon source. The second effluent containing elemental sulfur, sulfate, and chloride ions from the anoxic reactor 2 flows into sedimentation tank 3. After solid-liquid separation in sedimentation tank 3, elemental sulfur settles to the bottom. Chloride ions and the byproduct sulfate are present in the supernatant. If the concentrations of perchlorate and sulfate in the supernatant of sedimentation tank 3 meet the requirements, they can be discharged through the supernatant outlet pipe 32. Sulfur-containing wastewater and perchlorate-containing wastewater form a synergistic reaction system. Utilizing sulfate-reducing bacteria, sulfur-autotrophic bacteria, and perchlorate-reducing bacteria inoculated within the reactor, the reaction proceeds simultaneously with the desulfurization of the sulfur-containing wastewater and the synergistic reduction and removal of perchlorate. This effectively removes sulfate and perchlorate from both types of wastewater, significantly reducing the need for external carbon sources (perchlorate removal in the anoxic reactor does not require carbon source addition, while in the anaerobic reactor, carbon source addition may be omitted or partially added depending on the C / S ratio in the water). The economic benefits are significant. Furthermore, compared to treating the two types of wastewater separately, the synergistic treatment process is simpler to operate, requires less floor space, and has lower investment costs.

[0046] As a preferred embodiment of the present invention, the supernatant outlet pipe 32 includes a supernatant main pipe 321 and a supernatant circulation pipe 322 connected to the pipe body of the supernatant main pipe 321; a supernatant valve 323 is provided at the supernatant outlet of the supernatant main pipe 321; a first circulation branch pipe 6 and a second circulation branch pipe 7 are respectively provided on the supernatant circulation pipe 322; the first circulation branch pipe 6 is connected to the pipe body of the sulfur-containing wastewater inlet pipe 11; and the second circulation branch pipe 7 is connected to the lower side wall of the anoxic reactor 2.

[0047] Specifically, the supernatant discharged from the supernatant outlet pipe 32 can be circulated and treated according to the sulfate and perchlorate concentrations in the supernatant in the sedimentation tank 3 through the supernatant circulation pipe 322, so as to improve the sulfate and perchlorate removal rate.

[0048] As a preferred embodiment of the present invention, a first reflux pump 61 is provided on the first circulation branch pipe 6; and a second reflux pump 71 is provided on the second circulation branch pipe 7.

[0049] Specifically, the reflux pump facilitates the control of the flow of circulating supernatant into anaerobic reactor 1 and anoxic reactor 2.

[0050] As a preferred embodiment of the present invention, an online water quality monitoring instrument 8 for monitoring sulfate and perchlorate concentrations is installed in the sedimentation tank 3; the online water quality monitoring instrument 8 is connected to a smart water management platform; the smart water management platform is equipped with a sulfate and perchlorate concentration acquisition module connected to the online water quality monitoring instrument 8, an analysis and comparison module connected to the sulfate and perchlorate concentration acquisition module, and a signal command module connected to the analysis and comparison module; the signal command module is connected to the first reflux pump 61, the second reflux pump 71, and the clear liquid valve 323, respectively.

[0051] Specifically, by pre-storing preset sulfate and perchlorate standard concentrations in the analysis and comparison module, the sulfate and perchlorate concentrations in the detected supernatant are analyzed, thereby enabling automatic control of the discharge or recycling of the supernatant in sedimentation tank 3.

[0052] As a preferred embodiment of the present invention, an anaerobic inlet pump 12 is provided at the inlet end of the sulfur-containing wastewater inlet pipe 11; and / or, an anoxic inlet pump 22 is provided at the inlet end of the perchlorate-containing wastewater inlet pipe 21.

[0053] Specifically, the inflow of sulfur-containing wastewater and perchlorate-containing wastewater is controlled by anaerobic inlet pump 12 and anoxic inlet pump 22.

[0054] As a preferred embodiment of the present invention, a sedimentation valve 311 is provided on the sediment discharge pipe 31 to control the discharge of sediment.

[0055] In a preferred embodiment of the present invention, a stirrer 9 is provided inside the anoxic reactor 2. The stirring action of the stirrer 9 promotes the reaction within the anoxic reactor 2.

[0056] like Figure 6 As shown, the present invention provides a method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater, which uses the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater as described above to simultaneously treat sulfur-containing wastewater and perchlorate-polluted wastewater; it includes the following steps:

[0057] Step S1: Sulfur-containing wastewater is introduced into anaerobic reactor 1 through sulfur-containing wastewater inlet pipe 11, so that the sulfur-containing wastewater is reduced to sulfides by sulfate-reducing bacteria in anaerobic reactor 1, forming the first effluent containing sulfides.

[0058] Step S2: First effluent is introduced into anoxic reactor 2 through first water supply pipe 4, and perchlorate-containing wastewater is introduced into anoxic reactor 2 through perchlorate-containing wastewater inlet pipe 21. The sulfur-chlorine ratio in anoxic reactor 2 is controlled to be ≥4:1, so that the first effluent and perchlorate-containing wastewater react with sulfur autotrophic bacteria and perchlorate-reducing bacteria respectively in anoxic reactor 2 to form second effluent containing elemental sulfur, sulfate and chloride ions.

[0059] Step S3: The second effluent is introduced into the sedimentation tank 3 through the second water supply pipe 5. In the sedimentation tank 3, the sludge and elemental sulfur in the second effluent settle to the bottom and are discharged from the sediment outlet pipe 31. The supernatant containing sulfate and chloride ions in the second effluent is discharged from the supernatant outlet pipe 32.

[0060] As a preferred embodiment of the present invention, it further includes: when the sulfate concentration in the supernatant in the sedimentation tank 3 is greater than the preset sulfate standard concentration, the supernatant discharged from the supernatant outlet pipe 32 is recycled back into the anaerobic reactor 1.

[0061] When the concentration of perchlorate in the supernatant in the sedimentation tank 3 is greater than the preset perchlorate standard concentration, the supernatant discharged from the supernatant outlet pipe 32 is recycled back into the anoxic reactor 2.

[0062] Specifically, the preset sulfate standard concentration is preferably, but not limited to, 80 mg / L; the preset perchlorate standard concentration is preferably, but not limited to, 0.05 mg / L. The preset sulfate and perchlorate standard concentrations can be set according to actual conditions, and the present invention does not impose any particular limitations on them.

[0063] As a preferred embodiment of the present invention, the residence time of sulfur-containing wastewater in anaerobic reactor 1 is 12-48h, the temperature in anaerobic reactor 1 is 25-35℃, the pH of the wastewater in anaerobic reactor 1 is 6.5-8, the oxidation-reduction potential in anaerobic reactor 1 is ≤-100mv, and the sulfate concentration in the first effluent is less than 25mg / L.

[0064] The residence time of the first effluent and perchlorate-containing wastewater in the anoxic reactor 2 is 4–10 h. The temperature in the anoxic reactor 2 is 20–35 °C, the pH value of the wastewater in the anoxic reactor 2 is 7–8, and the dissolved oxygen in the anoxic reactor 2 is ≤0.5 mg / L. The perchlorate concentration in the effluent from the supernatant outlet pipe 32 is less than 0.05 mg / L, and the sulfate concentration is less than 80 mg / L.

[0065] To better illustrate the practical application of the co-treatment device and method for sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention, the following specific embodiments are provided.

[0066] Example 1

[0067] Wastewater with a sulfate concentration of 2130 mg / L enters anaerobic reactor 1 via anaerobic influent pump 12. Anaerobic reactor 1 is inoculated with sulfate-reducing bacteria sludge. The temperature in anaerobic reactor 1 is controlled at 25–35℃, the pH of the wastewater in anaerobic reactor 1 is 6.5–8, the oxidation-reduction potential (ORP) is ≤-100 mV, and the residence time is 12–48 h. In this anaerobic reactor 1, sulfate is reduced to sulfide, and the sulfate concentration in the effluent is less than 25 mg / L.

[0068] The effluent from anaerobic reactor 1 flows into anoxic reactor 2. Wastewater containing 150 mg / L of perchlorate enters anoxic reactor 2 via anoxic influent pump 22. Anoxic reactor 2 is inoculated with sulfur autotrophic bacteria and perchlorate-reducing bacteria. The temperature in anoxic reactor 2 is controlled at 20–35℃, the pH of the wastewater in anoxic reactor 2 is 7–8, the dissolved oxygen in the wastewater in anoxic reactor 2 is ≤0.5 mg / L, the residence time is 4–10 h, the sulfur-chlorine ratio (S / Cl) is ≥4:1, the effluent perchlorate concentration is less than 0.05 mg / L, the sulfate concentration is less than 80 mg / L, the perchlorate removal rate is 99.9%, and the sulfate removal rate is 96.2%.

[0069] The effluent from the anoxic reactor 2 flows into the sedimentation tank 3. Sludge and elemental sulfur settle to the bottom and are discharged. The effluent from the sedimentation tank 3 is discharged through the supernatant outlet pipe 32 at the top of the sedimentation tank. A supernatant valve 323 is installed at the outlet end of the supernatant outlet pipe 32. An online water quality monitoring instrument 8 is installed near the outlet of the sedimentation tank 3. A first circulation branch pipe 6 and a second circulation branch pipe 7 are installed on the supernatant circulation pipe 322 of the sedimentation tank 3. A first return pump 61 and a second return pump 71 are respectively installed on the first circulation branch pipe 6 and the second circulation branch pipe 7.

[0070] When special operating conditions are encountered during operation, such as the concentration of sulfate ions, a byproduct, in the anoxic reactor 2 being greater than 80 mg / L or higher than the design standard, the effluent from the anoxic reactor 2 flows into the sedimentation tank 3. The online water quality monitoring instrument 8 at the outlet of the sedimentation tank 3 detects the water quality abnormality and automatically feeds the water quality results back to the smart water management platform. The smart water management platform issues an instruction to automatically close the clear liquid valve 323 and simultaneously automatically start the first return pump 61. The effluent is then mixed with the effluent from the anaerobic influent pump 11 via the first return pump 61 and enters the anaerobic reactor 1 for further reduction and sulfate removal. Compared to the sulfate concentration in the raw water, the sulfate concentration in the effluent from the sedimentation tank 3 is low. After being returned to the front end, it can dilute the sulfate concentration in the influent and reduce the load on the anaerobic reactor 1.

[0071] Similarly, if the water quality online monitoring instrument 8 detects that the perchlorate concentration is greater than 0.05 mg / L or higher than the design standard, the system will automatically close the clear liquid valve 323 and automatically start the second return pump 71 to send the effluent into the anoxic reactor 2 to continue reducing the perchlorate.

[0072] It should be noted that this embodiment is merely a detailed description of the co-treatment device and method for sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention in practical applications, and does not limit the technical solution provided by the present invention.

[0073] As can be seen from the above specific embodiments, the co-treatment device and method for sulfur-containing wastewater and perchlorate-polluted wastewater provided by the present invention, through the structural design of an anaerobic reactor, an anoxic reactor, and a sedimentation tank, firstly introduces sulfur-containing wastewater into the anaerobic reactor. Under anaerobic conditions, sulfate-reducing bacteria reduce the sulfate in the sulfur-containing wastewater to sulfides. Then, the effluent containing sulfides from the anaerobic reactor flows into the anoxic reactor, and simultaneously, perchlorate-polluted wastewater (containing perchlorate) is also introduced into the anoxic reactor. In the anoxic reactor, under anoxic conditions, sulfides... The substance (electron donor) loses electrons and is oxidized to elemental sulfur by sulfur autotrophic bacteria. Perchlorate (electron acceptor) gains electrons and is reduced to chloride ions by perchlorate-reducing bacteria. The sulfur autotrophic bacteria use inorganic carbon (such as carbon dioxide, carbonate, etc.) as a carbon source. The second effluent containing elemental sulfur, sulfate, and chloride ions from the anoxic reactor then flows into a sedimentation tank. After solid-liquid separation in the sedimentation tank, elemental sulfur settles to the bottom. Chloride ions and the byproduct sulfate are present in the supernatant. If the concentrations of perchlorate and sulfate in the supernatant of the sedimentation tank meet the requirements, they can be discharged through the supernatant outlet pipe. Sulfur-containing wastewater and perchlorate-containing wastewater form a synergistic reaction system. Utilizing sulfate-reducing bacteria, sulfur-autotrophic bacteria, and perchlorate-reducing bacteria inoculated within the reactor, the reaction proceeds simultaneously with the desulfurization of the sulfur-containing wastewater and the synergistic reduction and removal of perchlorate. This effectively removes sulfate and perchlorate from both types of wastewater, significantly reducing the need for external carbon sources (perchlorate removal in the anoxic reactor does not require carbon source addition, while in the anaerobic reactor, carbon source addition may be omitted or partially added depending on the C / S ratio in the water). The economic benefits are significant. Furthermore, compared to treating the two types of wastewater separately, the synergistic treatment process is simpler to operate, requires less floor space, and has lower investment costs.

[0074] The apparatus and method for co-treating sulfur-containing wastewater and perchlorate-polluted wastewater according to the present invention have been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the apparatus and method for co-treating sulfur-containing wastewater and perchlorate-polluted wastewater according to the present invention without departing from the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A device for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater, characterized in that, It includes an anaerobic reactor, an anoxic reactor, and a sedimentation tank arranged in sequence; among them, Sulfate-reducing bacteria are inoculated inside the anaerobic reactor; a sulfur-containing wastewater inlet pipe is installed on the lower part of the side wall of the anaerobic reactor. The interior of the anoxic reactor is inoculated with sulfur autotrophic bacteria and perchlorate-reducing bacteria; a perchlorate-containing wastewater inlet pipe is installed at the lower part of the side wall of the anoxic reactor. The upper part of the sidewall of the anaerobic reactor is connected to the upper part of the sidewall of the anoxic reactor by a stepped first water supply pipe, and the water inlet end of the first water supply pipe connected to the anaerobic reactor is higher than the water outlet end connected to the anoxic reactor. The top of the sedimentation tank is connected to the upper side wall of the anoxic reactor via a second water supply pipe; the inlet end of the second water supply pipe connected to the anoxic reactor is higher than the outlet end connected to the sedimentation tank; a sediment discharge pipe is provided at the bottom of the sedimentation tank; and a supernatant discharge pipe is provided on the upper side wall of the sedimentation tank. The supernatant outlet pipe includes a supernatant main pipe and a supernatant circulation pipe connected to the supernatant main pipe; a supernatant valve is provided at the supernatant outlet of the supernatant main pipe; A first circulation branch pipe and a second circulation branch pipe are respectively provided on the clear liquid circulation pipe; The first circulating branch pipe is connected to the body of the sulfur-containing wastewater inlet pipe; The second circulation branch pipe is connected to the lower side wall of the anoxic reactor; A first reflux pump is installed on the first circulation branch pipe; A second reflux pump is installed on the second circulation branch pipe.

2. The co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 1, characterized in that, The sedimentation tank is equipped with an online water quality monitoring instrument for monitoring sulfate and perchlorate concentrations; the online water quality monitoring instrument is connected to a smart water management platform. The smart water management platform is equipped with a sulfate and perchlorate concentration acquisition module connected to the online water quality monitoring instrument, an analysis and comparison module connected to the sulfate and perchlorate concentration acquisition module, and a signal command module connected to the analysis and comparison module. The signal command module is connected to the first reflux pump, the second reflux pump, and the clear liquid valve, respectively.

3. The co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 1, characterized in that, An anaerobic inlet pump is installed at the inlet end of the sulfur-containing wastewater inlet pipe; and / or, An oxygen-deficient inlet pump is installed at the inlet end of the perchlorate-containing wastewater inlet pipe.

4. The co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 1, characterized in that, A sedimentation valve is installed on the sediment discharge pipe.

5. The co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 1, characterized in that, A stirrer is installed inside the anoxic reactor.

6. A method for the co-treatment of sulfur-containing wastewater and perchlorate-polluted wastewater, characterized in that, The simultaneous treatment of sulfur-containing wastewater and perchlorate-polluted wastewater using the co-treatment device for sulfur-containing wastewater and perchlorate-polluted wastewater as described in any one of claims 1-5 includes the following steps: Sulfur-containing wastewater is introduced into the anaerobic reactor through the sulfur-containing wastewater inlet pipe, where it is reduced to sulfides by sulfate-reducing bacteria, forming the first effluent containing sulfides. The first effluent is introduced into the anoxic reactor through the first water supply pipe, and the perchlorate-containing wastewater is introduced into the anoxic reactor through the perchlorate-containing wastewater inlet pipe. The sulfur-chlorine ratio in the anoxic reactor is controlled to be ≥4:1, so that the first effluent and the perchlorate-containing wastewater react with the sulfur autotrophic bacteria and the perchlorate-reducing bacteria respectively in the anoxic reactor to form the second effluent containing elemental sulfur, sulfate and chloride ions. The second effluent is introduced into the sedimentation tank through the second water supply pipe. In the sedimentation tank, the sludge and elemental sulfur in the second effluent settle to the bottom and are discharged from the sediment outlet pipe. The supernatant containing sulfate and chloride ions in the second effluent is discharged from the supernatant outlet pipe.

7. The method for co-treating sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 6, characterized in that, Also includes: When the sulfate concentration in the supernatant in the sedimentation tank is greater than the preset sulfate standard concentration, the supernatant discharged from the supernatant outlet pipe is recycled back into the anaerobic reactor. When the perchlorate concentration in the supernatant in the sedimentation tank is greater than the preset perchlorate standard concentration, the supernatant discharged from the supernatant outlet pipe is recycled back into the anoxic reactor.

8. The method for co-treating sulfur-containing wastewater and perchlorate-polluted wastewater according to claim 6, characterized in that, The sulfur-containing wastewater has a residence time of 12-48 hours in the anaerobic reactor, a temperature of 25-35°C, a pH of 6.5-8, an oxidation-reduction potential of ≤-100mV, and a sulfate concentration of less than 25mg / L in the first effluent. The first effluent and the perchlorate-containing wastewater have a residence time of 4-10 hours in the anoxic reactor. The temperature in the anoxic reactor is 20-35°C, the pH value of the wastewater in the anoxic reactor is 7-8, and the dissolved oxygen in the anoxic reactor is ≤0.5 mg / L. The perchlorate concentration in the effluent from the supernatant outlet pipe is less than 0.05 mg / L, and the sulfate concentration is less than 80 mg / L.

Images