Salt-containing wastewater treatment system

Abstract

The invention belongs to the technical field of wastewater treatment, and particularly discloses a salt-containing wastewater treatment system which comprises a pretreatment module, a membrane separation module, a post-treatment module and a sludge treatment module, the pretreatment module is used for removing suspended solids, grease, large-particle impurities and part of soluble pollutants in water through a decontaminating method; the burden of follow-up treatment is relieved, the overall treatment efficiency is improved, and the water quality meets the requirements of a follow-up treatment process; the membrane separation module is used for intercepting substances in the wastewater by using a filtering device, purifying the wastewater and separating salt in the wastewater from effluent; the post-treatment module is used for purifying the effluent treated by the membrane separation module to improve the water quality, purification comprises disinfection and water quality detection, and it is ensured that the effluent meets the reuse or discharge standard; the sludge treatment unit is used for reducing the volume of the sludge through sludge concentration, sludge conditioning, sludge dewatering, sludge stabilization and sludge drying and separating free moisture in the sludge.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to a saline wastewater treatment system. Background Art

[0002] During the gold smelting process, a large amount of wastewater is generated, and its sources are wide-ranging, such as the filtrate after the zinc powder replacement of the gold-rich precious liquid in the cyanide gold extraction process. The wastewater contains cyanide, heavy metal ions (such as zinc, copper, lead, mercury, etc.), sulfate, chloride ions and other harmful substances.

[0003] If these wastewaters are discharged directly, they will cause serious pollution to the environment, such as destroying water ecology, polluting soil, etc., endangering human health and ecological balance. With the increasingly stringent national environmental protection requirements, especially the policy orientation for industrial wastewater treatment, zero discharge and resource utilization have become important goals for gold smelting wastewater treatment. The policy requires enterprises to not only achieve harmless treatment of wastewater, but also recycle useful resources in wastewater as much as possible to reduce the impact on the environment. Some methods may produce new pollutants or hazardous wastes during the treatment process. For example, the acidification process may produce highly toxic cuprous cyanide precipitates and other mixed metal slags, which increases the difficulty and cost of subsequent treatment and disposal. Summary of the invention

[0004] The object of the present invention is to provide a saline wastewater treatment system to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a salt-containing wastewater treatment system, comprising a pretreatment module, a membrane separation module, a post-treatment module and a sludge treatment module.

[0006] The pretreatment module is used to remove suspended matter, grease, large particle impurities and some soluble pollutants in the water through a decontamination method, which includes grid filtration, regulating tank treatment and sedimentation; so as to reduce the burden of subsequent treatment, improve the overall treatment efficiency, and ensure that the water quality meets the requirements of subsequent treatment processes.

[0007] The membrane separation module is used to intercept substances in wastewater by filtering devices, purify wastewater, and separate salt in wastewater from effluent; the filtering devices include ultrafiltration devices, nanofiltration devices, and reverse osmosis devices.

[0008] The post-processing module is used to purify the effluent after being treated by the membrane separation module to improve the water quality. The purification includes disinfection and water quality testing to ensure that the effluent meets the reuse or discharge standards.

[0009] The sludge treatment unit is used to reduce the volume of sludge through sludge concentration, sludge conditioning, sludge dehydration, sludge stabilization and sludge drying, and separate free water in the sludge to facilitate subsequent transportation and disposal.

[0010] Preferably, the grid filter is provided to intercept larger solid impurities and suspended matter in the wastewater to prevent the solid impurities and suspended matter from clogging or damaging the filter device.

[0011] Preferably, the wastewater enters the regulating tank for treatment, and the water quality and water volume are regulated to make the wastewater flow and water quality more stable and reduce the impact on the subsequent treatment process. In the regulating tank, some reducing substances in the wastewater can also be initially oxidized by aeration and other methods, and the mixing and stirring effect can be achieved.

[0012] Preferably, the conditioned wastewater enters a sedimentation tank, where some heavier particulate matter in the wastewater settles to the bottom of the tank by gravity to form sludge, and the supernatant enters the membrane separation module. Sedimentation can remove some suspended solids and sediments in the wastewater, reducing the load of subsequent membrane treatment.

[0013] Preferably, the ultrafiltration membrane used in the ultrafiltration device has a pore size of 1-100 nanometers; the pretreated supernatant enters the ultrafiltration device, and the ultrafiltration membrane can effectively intercept macromolecular substances, suspended particles, and bacterial impurities in the supernatant to further purify the wastewater, while protecting subsequent nanofiltration or reverse osmosis membranes to reduce the risk of contamination and clogging.

[0014] Preferably, the nanofiltration device uses a nanofiltration membrane with a pore size of 0.5-2 nanometers; after the supernatant is treated by ultrafiltration, it enters the nanofiltration device, and the nanofiltration membrane separates the salt, heavy metal ions and some organic matter in the supernatant.

[0015] Preferably, the pore size of the reverse osmosis membrane used in the reverse osmosis device is not 0.1-1 nanometers; under pressure, the supernatant flows from the high-concentration solution side through the membrane to the low-concentration solution side, and the retained solutes include ions, organic matter, and microorganisms; the wastewater after nanofiltration treatment enters the reverse osmosis device, and the reverse osmosis membrane further removes the residual salt, heavy metal ions, and organic pollutants in the wastewater, so that the effluent water quality reaches a higher standard, which can be reused in certain links in the gold smelting process, such as washing, cooling, etc., or discharged after meeting the emission standards.

[0016] Preferably, the disinfection is used to disinfect the effluent after the membrane separation module is treated, to kill the remaining bacteria and viruses, and to ensure the hygienic safety of the effluent. The disinfection is carried out by ultraviolet disinfection or chlorination disinfection.

[0017] The water quality monitoring is used to monitor the water quality parameters of the effluent after disinfection in real time. The water quality parameters include pH value, conductivity, heavy metal content, and chemical oxygen demand, to ensure that the effluent quality meets the reuse or discharge standards. If the water quality does not meet the standards, it will be returned to the membrane separation module for reprocessing, or the treatment process parameters will be adjusted.

[0018] Preferably, the sludge concentration is used to reduce the volume of the sludge, and the free water in the sludge is separated by gravity sedimentation, flotation or centrifugation to increase the solid content of the sludge; the sludge conditioning is used to improve the dewatering performance of the sludge by adding chemical agents to change the colloidal structure of the sludge to make it easier to dehydrate, and the chemical agents include polyaluminum chloride and polyacrylamide; the sludge dehydration is used to further remove the moisture in the sludge by mechanical dehydration equipment to obtain mud cakes or mud blocks with low moisture content, and the mechanical dehydration equipment includes plate and frame filter press, belt filter press or centrifugal dehydrator; the sludge stabilization, stabilization treatment is used to reduce the organic matter content in the sludge, reduce its biological activity, and prevent the generation of odor and harmful gases during subsequent treatment or disposal. The stabilization method includes aerobic digestion or anaerobic digestion; the sludge drying is used to further reduce the moisture content of the sludge, and the moisture in the sludge is evaporated by drying technology thermal drying or solar drying to obtain dry sludge with extremely low moisture content.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The gold smelting saline wastewater treatment system of the present invention, based on membrane separation technology, utilizes the selective permeability of the membrane to effectively separate and remove salt, heavy metal ions and other harmful substances in the wastewater, so as to achieve purification and reuse of the wastewater. It has the advantages of high efficiency and environmental protection and is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the system of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1 The present invention provides a technical solution: a salt-containing wastewater treatment system, including a pretreatment module, a membrane separation module, a post-treatment module and a sludge treatment module.

[0024] The pretreatment module is used to remove suspended matter, grease, large particle impurities and some soluble pollutants in the water through a decontamination method, which includes grid filtration, regulating tank treatment and sedimentation; so as to reduce the burden of subsequent treatment, improve the overall treatment efficiency, and ensure that the water quality meets the requirements of subsequent treatment processes.

[0025] The grid filtration is provided to intercept larger solid impurities and suspended matter in the wastewater, thereby preventing the solid impurities and suspended matter from clogging or damaging the filtering device.

[0026] In the regulating tank, wastewater enters the regulating tank to adjust the water quality and water volume, making the wastewater flow and water quality more stable and reducing the impact on the subsequent treatment process. In the regulating tank, some reducing substances in the wastewater can also be initially oxidized through aeration and other methods, and it can also play a role in stirring and mixing.

[0027] In the above-mentioned sedimentation, the conditioned wastewater enters the sedimentation tank, and through gravity sedimentation, some heavier particulate matter in the wastewater settles to the bottom of the tank to form sludge, and the supernatant enters the membrane separation module. Sedimentation can remove some suspended solids and sediments in the wastewater and reduce the load of subsequent membrane treatment.

[0028] The membrane separation module is used to intercept substances in wastewater by filtering devices, purify wastewater, and separate salt in wastewater from effluent; the filtering devices include ultrafiltration devices, nanofiltration devices, and reverse osmosis devices.

[0029] The ultrafiltration membrane used in the ultrafiltration device has a pore size of 1-100 nanometers; the pretreated supernatant enters the ultrafiltration device, and the ultrafiltration membrane can effectively intercept macromolecular substances, suspended particles, and bacterial impurities in the supernatant to further purify the wastewater, while protecting subsequent nanofiltration or reverse osmosis membranes and reducing their risks of contamination and clogging.

[0030] The nanofiltration device uses a nanofiltration membrane with a pore size of 0.5-2 nanometers; after the supernatant is treated by ultrafiltration, it enters the nanofiltration device, and the nanofiltration membrane separates the salt, heavy metal ions and some organic matter in the supernatant.

[0031] The pore size of the reverse osmosis membrane used in the reverse osmosis device is not 0.1-1 nanometers; under pressure, the supernatant flows from the high-concentration solution side through the membrane to the low-concentration solution side, and the retained solutes include ions, organic matter, and microorganisms; the wastewater after nanofiltration treatment enters the reverse osmosis device, and the reverse osmosis membrane further removes the residual salt, heavy metal ions, and organic pollutants in the wastewater, so that the effluent water quality reaches a higher standard and can be reused in certain links in the gold smelting process, such as washing, cooling, etc., or discharged after meeting the emission standards.

[0032] The post-processing module is used to purify the effluent after being treated by the membrane separation module to improve the water quality. The purification includes disinfection and water quality testing to ensure that the effluent meets the reuse or discharge standards.

[0033] The disinfection is used to disinfect the effluent after the membrane separation module is treated, kill the remaining bacteria and viruses, and ensure the hygienic safety of the effluent. The disinfection is carried out by ultraviolet disinfection or chlorination disinfection.

[0034] The water quality monitoring is used to monitor the water quality parameters of the effluent after disinfection in real time. The water quality parameters include pH value, conductivity, heavy metal content, and chemical oxygen demand, to ensure that the effluent quality meets the reuse or discharge standards. If the water quality does not meet the standards, it will be returned to the membrane separation module for reprocessing, or the treatment process parameters will be adjusted.

[0035] The sludge treatment unit is used to reduce the volume of sludge through sludge concentration, sludge conditioning, sludge dehydration, sludge stabilization and sludge drying, and separate free water in the sludge to facilitate subsequent transportation and disposal.

[0036] The sludge concentration is used to reduce the volume of the sludge, separate the free water in the sludge by gravity sedimentation, air flotation or centrifugation, and increase the solid content of the sludge.

[0037] The sludge conditioning is used to improve the dewatering performance of the sludge by adding chemical agents to change the colloidal structure of the sludge so that it is easier to dewater. The chemical agents include polyaluminium chloride and polyacrylamide.

[0038] The sludge dehydration is used to further remove moisture from the sludge through mechanical dehydration equipment to obtain mud cakes or mud blocks with low moisture content. The mechanical dehydration equipment includes a plate and frame filter press, a belt filter press or a centrifugal dehydrator.

[0039] The sludge stabilization treatment is used to reduce the organic matter content in the sludge, reduce its biological activity, and prevent the generation of odor and harmful gases during subsequent treatment or disposal. The stabilization method includes aerobic digestion or anaerobic digestion.

[0040] The sludge drying is used to further reduce the moisture content of the sludge. The water in the sludge is evaporated by using drying technology such as thermal drying or solar drying to obtain dry sludge with extremely low moisture content.

[0041] By utilizing the selective permeability of the membrane, the salt, heavy metal ions and other harmful substances in the wastewater are effectively separated and removed to achieve the purification and reuse of the wastewater. The system has the advantages of high efficiency, environmental protection and high degree of automation, and has broad application prospects in the gold smelting industry.

[0042] The gold smelting saline wastewater treatment system based on membrane separation technology has broad application prospects in the gold smelting industry. With the continuous advancement of membrane separation technology and the reduction of costs, the system will be promoted and applied in more fields, contributing to the sustainable development of the gold smelting industry.

[0043] It is worth noting that the entire device is controlled by a main control button. Since the device matched with the control button is a common device and belongs to the existing mature technology, its electrical connection relationship and specific circuit structure will not be described in detail here.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A saline wastewater treatment system, characterized in that: It includes a pretreatment module, a membrane separation module, a post-treatment module and a sludge treatment module; The pretreatment module is used to remove suspended matter, grease, large particle impurities and some soluble pollutants in water by a decontamination method, and the decontamination method includes grid filtration, regulating tank treatment and sedimentation; The membrane separation module is used to intercept substances in the wastewater by using a filtering device, purify the wastewater, and separate the salt in the wastewater from the effluent; the filtering device includes an ultrafiltration device, a nanofiltration device, and a reverse osmosis device; The post-processing module is used to purify the effluent after the membrane separation module is treated to improve the water quality, and the purification includes disinfection and water quality testing; The sludge treatment unit is used to reduce the volume of sludge and separate free water in the sludge through sludge concentration, sludge conditioning, sludge dehydration, sludge stabilization and sludge drying.

2. A saline wastewater treatment system according to claim 1, characterized in that: The grid filtration is provided to intercept larger solid impurities and suspended matter in the wastewater, thereby preventing the solid impurities and suspended matter from clogging or damaging the filtering device.

3. A saline wastewater treatment system according to claim 1, characterized in that: In the regulating tank treatment, wastewater enters the regulating tank to adjust the water quality and water volume, so that the flow rate and water quality of the wastewater are more stable, reducing the impact on subsequent treatment processes.

4. A saline wastewater treatment system according to claim 1, characterized in that: In the sedimentation, the conditioned wastewater enters the sedimentation tank, and through gravity sedimentation, some heavier particulate matter in the wastewater settles to the bottom of the tank to form sludge, and the supernatant enters the membrane separation module. Sedimentation can remove some suspended solids and sediments in wastewater and reduce the load of subsequent membrane treatment.

5. A saline wastewater treatment system according to claim 1, characterized in that: The ultrafiltration membrane used in the ultrafiltration device has a pore size of 1-100 nanometers; the pretreated supernatant enters the ultrafiltration device, and the ultrafiltration membrane can effectively intercept macromolecular substances, suspended particles, and bacterial impurities in the supernatant to further purify the supernatant.

6. A saline wastewater treatment system according to claim 1, characterized in that: The nanofiltration device uses a nanofiltration membrane with a pore size of 0.5-2 nanometers; after the supernatant is treated by ultrafiltration, it enters the nanofiltration device, and the nanofiltration membrane separates the salt, heavy metal ions and some organic matter in the supernatant.

7. A saline wastewater treatment system according to claim 1, characterized in that: The pore size of the reverse osmosis membrane used in the reverse osmosis device is not 0.1-1 nanometers; under pressure, the supernatant flows from the high-concentration solution side through the membrane to the low-concentration solution side, and the retained solutes include ions, organic matter, and microorganisms; the wastewater after nanofiltration treatment enters the reverse osmosis device, and the reverse osmosis membrane further removes the residual salt, heavy metal ions, and organic pollutants in the wastewater.

8. A saline wastewater treatment system according to claim 1, characterized in that: The disinfection is used to disinfect the effluent after the membrane separation module is treated, kill the remaining bacteria and viruses, and ensure the hygienic safety of the effluent. The disinfection is carried out by ultraviolet disinfection or chlorination disinfection; The water quality monitoring is used to monitor the water quality parameters of the effluent after disinfection in real time. The water quality parameters include pH value, conductivity, heavy metal content, and chemical oxygen demand to ensure that the effluent quality meets the reuse or discharge standards. If the water quality does not meet the standards, it will be returned to the membrane separation module for reprocessing.

9. A saline wastewater treatment system according to claim 1, characterized in that: The sludge concentration is used to reduce the volume of the sludge, and the free water in the sludge is separated by gravity sedimentation, flotation or centrifugation to increase the solid content of the sludge; the sludge conditioning is used to improve the dewatering performance of the sludge by adding chemical agents to change the colloidal structure of the sludge to make it easier to dehydrate. The chemical agents include polyaluminium chloride and polyacrylamide; the sludge dewatering is used to further remove the water in the sludge by mechanical dewatering equipment to obtain mud cakes or mud blocks with low water content. The mechanical dewatering equipment includes plate and frame filter press, belt filter press or centrifugal dewatering machine; the sludge stabilization, stabilization treatment is used to reduce the organic matter content in the sludge, reduce its biological activity, and prevent the generation of odour and harmful gases in the subsequent treatment or disposal process. The stabilization method includes aerobic digestion or anaerobic digestion; the sludge drying is used to further reduce the water content of the sludge. The water in the sludge is evaporated by drying technology such as thermal drying or solar drying to obtain dry sludge with extremely low water content.

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