A medical and pharmaceutical chemical industry wastewater emission reduction and recovery treatment system

Abstract

This invention relates to the field of pharmaceutical and chemical wastewater treatment technology, and particularly to a pharmaceutical and chemical wastewater reduction and recycling system, comprising: an oxidation pretreatment module for degrading antibiotics and organic pollutants; a physicochemical treatment module for removing suspended solids by controlling a coagulation sedimentation tank through pH feedback; a biological treatment module for degrading biodegradable organic matter using an upflow anaerobic sludge bed and a biofilm aerobic reactor; a deep treatment module for multi-stage water purification through an ultrafiltration device, a reverse osmosis membrane module, and an ion exchange device; a zero-emission evaporation module for obtaining crystalline salt and condensate through evaporation and concentration; a resource recovery module for recovering phosphorus-containing chemical sludge, anaerobic biological sludge, organic solvents, and biogas; an intelligent monitoring module for ensuring system stability by detecting key data from each module; and a membrane fouling prevention module for maintaining membrane flux. This invention solves the problems of incomplete pollutant degradation, insufficient resource recovery, and system instability in pharmaceutical and chemical wastewater treatment.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical and chemical wastewater treatment technology, and in particular to a pharmaceutical and chemical wastewater reduction and recycling system. Background Technology

[0002] Early pharmaceutical and chemical wastewater treatment primarily relied on traditional physicochemical-biological combined processes. While these methods could remove some suspended solids and conventional organic matter, their effectiveness was very limited in treating complex pollutants such as residual antibiotics, high-concentration organic solvents, and recalcitrant compounds in the wastewater. Oxidation processes often employed conventional Fenton oxidation or ozone treatment, which had low degradation efficiency for some drug intermediates and easily generated toxic intermediate products. Phosphorus in the wastewater was largely wasted in the form of precipitation, failing to achieve targeted recovery in forms such as hydroxyapatite, resulting in resource waste. Furthermore, in advanced treatment, reverse osmosis membranes were easily clogged by colloidal substances, requiring frequent cleaning and incurring high operating costs.

[0003] With the increasing emphasis placed on environmental protection by the nation and the public, environmental regulations are becoming increasingly stringent, placing higher demands on the discharge standards for pharmaceutical and chemical wastewater. Traditional wastewater treatment technologies are facing challenges in meeting these standards, and pharmaceutical and chemical companies are facing enormous environmental pressure. This has prompted the industry to explore and develop wastewater treatment technologies to achieve advanced wastewater treatment and emission reduction goals.

[0004] Currently, pharmaceutical and chemical wastewater treatment technologies have made some progress, such as the use of single biological treatment and advanced oxidation technologies. However, these technologies still have many bottlenecks. Single biological treatment technologies are difficult to effectively degrade organic pollutants in wastewater, resulting in low and unstable treatment efficiency. While existing advanced oxidation technologies have improved wastewater treatment to some extent, they still face problems such as high treatment costs and incomplete oxidation for complex pharmaceutical and chemical wastewater. Existing systems lack standardized treatment for sludge generated from coagulation sedimentation and anaerobic reactions, which can easily lead to secondary pollution or phosphorus resource loss. Furthermore, the lack of effective monitoring and feedback adjustment mechanisms makes it difficult to guarantee long-term stable treatment results.

[0005] Chinese invention patent CN114956446B discloses a zero-discharge reuse system for pharmaceutical and chemical wastewater, which achieves zero discharge through an improved Fenton pretreatment, biochemical treatment (anaerobic and aerobic), sludge dewatering, and advanced treatment process. However, this invention lacks a design for the synergistic oxidation degradation of antibiotics using photocatalysis and electrochemical processes, a phosphorus and organic solvent targeted recovery module, and a pre-filtration and cleaning design for membrane fouling prevention.

[0006] Therefore, this invention discloses a system for reducing and recycling pharmaceutical and chemical wastewater. Summary of the Invention

[0007] The purpose of this invention is to propose a pharmaceutical and chemical wastewater reduction and recycling system to solve the problems of incomplete pollutant degradation, insufficient resource recovery, and poor system stability in the prior art.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a pharmaceutical and chemical wastewater reduction and recycling treatment system, comprising:

[0009] The oxidation pretreatment module includes a titanium dioxide-coated ultraviolet reactor and a boron-doped diamond electrode device, used to degrade antibiotics and organic pollutants in pharmaceutical and chemical wastewater.

[0010] The physicochemical treatment module includes a coagulation sedimentation tank, a multi-media filter, and an activated carbon adsorption tower, used to discharge phosphorus-containing chemical sludge and adsorb residual organic pollutants in pharmaceutical and chemical wastewater after primary degradation.

[0011] The biological treatment module includes an upflow anaerobic sludge blanket and a biofilm aerobic reactor, used to degrade biodegradable organic matter in clarified wastewater;

[0012] The advanced treatment module, including an ultrafiltration unit, a reverse osmosis membrane module, and an ion exchange unit, is used to purify the biochemical effluent in multiple stages to meet reuse standards and produce concentrated water.

[0013] The zero-emission evaporation module uses an evaporation crystallization device to evaporate and concentrate the concentrated water generated by the deep treatment module, separating it into crystalline salt and condensate.

[0014] The resource recovery module includes a sludge dewatering device, a magnetic separation pretreatment device, a hydroxyapatite purification device, a distillation extraction tower, and a biogas collection device, used to recover phosphorus-containing chemical sludge, anaerobic biological sludge, organic solvents, and biogas.

[0015] The intelligent monitoring module includes a water quality monitoring component, an extractant purity monitoring component, a membrane fouling early warning component, and a current feedback control unit, which are used to monitor the data of each module and ensure the stable operation of the system.

[0016] The membrane fouling prevention module includes a pre-filter and a citric acid cleaning device, which is used to extend the service life of ultrafiltration units and reverse osmosis membrane modules.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention utilizes a synergistic technology of nitrogen-doped titanium dioxide dual-band photocatalysis and boron-doped diamond electrode electrochemical oxidation to simultaneously generate hydroxyl radicals using ultraviolet and visible light, thereby enhancing the degradation efficiency of antibiotics and organic pollutants in pharmaceutical and chemical wastewater and solving the problem of incomplete degradation by single oxidation technology.

[0019] This invention, through a combination of magnetic separation pretreatment for phosphorus enrichment, hydroxyapatite purification, dichloromethane regeneration and recycling, and targeted biogas collection, enables the targeted recovery and high-value utilization of phosphorus, organic solvents, and biogas energy, thereby improving resource recovery rate while reducing recovery energy consumption.

[0020] This invention uses an intelligent monitoring module to set up differentiated monitoring and coordinated control of different modules, which can adapt to water quality fluctuations in real time, ensure stable system operation, and reduce human intervention.

[0021] This invention uses a polypropylene pre-filter to intercept large particulate impurities and combines it with a citric acid-chelating agent to regularly clean the ultrafiltration and reverse osmosis membrane modules. This can maintain stable flux of the deep treatment membrane modules and adapt to water quality fluctuations, thereby improving the long-term operational stability of the system.

[0022] This invention utilizes the anaerobic-aerobic synergistic metabolism of an upflow anaerobic sludge bed and a biofilm aerobic reactor to ensure microbial activity and improve the degradation efficiency of biodegradable organic matter, thus solving the problem of insufficient treatment of biodegradable organic matter by single biological treatment. Attached Figure Description

[0023] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a pharmaceutical and chemical wastewater reduction and recycling system provided in an embodiment of the present invention. Detailed Implementation

[0025] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a pharmaceutical and chemical wastewater reduction and recycling treatment system proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] The following description, in conjunction with the accompanying drawings, details a specific scheme for a pharmaceutical and chemical wastewater reduction and recycling system provided by the present invention.

[0029] Example

[0030] An embodiment of the present invention provides a pharmaceutical and chemical wastewater reduction and recycling treatment system, comprising:

[0031] The oxidation pretreatment module includes a titanium dioxide-coated ultraviolet reactor and a boron-doped diamond electrode device, used to degrade antibiotics and organic pollutants in pharmaceutical and chemical wastewater.

[0032] The physicochemical treatment module includes a coagulation sedimentation tank, a multi-media filter, and an activated carbon adsorption tower, used to discharge phosphorus-containing chemical sludge and adsorb residual organic pollutants in pharmaceutical and chemical wastewater after primary degradation.

[0033] The biological treatment module includes an upflow anaerobic sludge blanket and a biofilm aerobic reactor, used to degrade biodegradable organic matter in clarified wastewater;

[0034] The advanced treatment module, including an ultrafiltration unit, a reverse osmosis membrane module, and an ion exchange unit, is used to purify the biochemical effluent in multiple stages to meet reuse standards and produce concentrated water.

[0035] The zero-emission evaporation module uses an evaporation crystallization device to evaporate and concentrate the concentrated water generated by the deep treatment module, separating it into crystalline salt and condensate.

[0036] The resource recovery module includes a sludge dewatering device, a magnetic separation pretreatment device, a hydroxyapatite purification device, a distillation extraction tower, and a biogas collection device, used to recover phosphorus-containing chemical sludge, anaerobic biological sludge, organic solvents, and biogas.

[0037] The intelligent monitoring module includes a water quality monitoring component, an extractant purity monitoring component, a membrane fouling early warning component, and a current feedback control unit, which are used to monitor the data of each module and ensure the stable operation of the system.

[0038] The membrane fouling prevention module includes a pre-filter and a citric acid cleaning device, which is used to extend the service life of ultrafiltration units and reverse osmosis membrane modules.

[0039] Please refer to Figure 1 This is a schematic diagram of the system configuration of a pharmaceutical and chemical wastewater reduction and recycling treatment system provided in an embodiment of the present invention.

[0040] Oxidation pretreatment module:

[0041] The oxidation pretreatment module receives raw pharmaceutical and chemical wastewater and obtains primary-degraded pharmaceutical and chemical wastewater, wherein:

[0042] The titanium dioxide-coated ultraviolet reactor generates hydroxyl radicals under ultraviolet light irradiation. These hydroxyl radicals, in turn, work synergistically with those generated by the boron-doped diamond electrode device through an anodic electrochemical reaction to degrade antibiotics and organic pollutants in the raw pharmaceutical and chemical wastewater, resulting in primary degraded pharmaceutical and chemical wastewater.

[0043] The titanium dioxide-coated ultraviolet photoreactor uses a nitrogen-doped titanium dioxide photocatalyst. By introducing nitrogen, the light response wavelength range is extended to the visible light region of 400-700nm. The light source of the ultraviolet photoreactor is a composite light source, including a light-emitting component that emits ultraviolet light of 254-400nm and a light-emitting component that emits visible light of 400-700nm, forming a dual-band synergistic catalytic system.

[0044] The titanium dioxide-coated ultraviolet reactor has an internal flow guiding structure to extend the retention time of raw pharmaceutical and chemical wastewater.

[0045] The boron-doped diamond electrode device uses a titanium-based boron-doped diamond anode and a stainless steel cathode, and the current density of the boron-doped diamond electrode device is adjusted by an intelligent monitoring module.

[0046] The oxidation pretreatment module transports the pharmaceutical and chemical wastewater after primary degradation to the physicochemical treatment module.

[0047] It should be noted that in the oxidation pretreatment module, pharmaceutical and chemical wastewater is the first to enter the system. Titanium dioxide, as a photocatalyst, is uniformly coated on the inner wall of the ultraviolet reactor or a specific carrier to ensure that hydroxyl radicals are fully generated under ultraviolet light irradiation.

[0048] The flow guiding structure inside the titanium dioxide-coated ultraviolet reactor adopts a baffle or spiral guide plate design. By changing the water flow path, the wastewater residence time is extended, thereby enhancing the contact time and reaction efficiency between the raw pharmaceutical and chemical wastewater and the titanium dioxide photocatalyst coated on the inner wall of the ultraviolet reactor or a specific carrier.

[0049] The boron-doped diamond electrode device uses a combination of titanium-based boron-doped diamond anode and stainless steel cathode, which has excellent electrochemical stability and high oxygen evolution potential, and can continuously generate a large number of hydroxyl radicals. The titanium-based boron-doped diamond anode and stainless steel cathode are arranged in parallel (to ensure electrolysis uniformity).

[0050] The current density of the electrode device is not fixed, but is precisely adjusted by an intelligent monitoring module based on the real-time water quality of the wastewater (such as pollutant concentration) to ensure the stability of the treatment effect and energy saving.

[0051] Photocatalysis generates hydroxyl radicals that can rapidly attack the cyclic structure of antibiotics, while electrochemically generated hydroxyl radicals can further decompose intermediate products after photocatalysis. The combination of the two enhances the degradation efficiency.

[0052] Physicochemical processing module:

[0053] The physicochemical treatment module receives the primary degradation wastewater from the oxidation pretreatment module and obtains clarified wastewater, wherein:

[0054] The coagulation sedimentation tank is equipped with a calcium hydroxide dosing device. The calcium hydroxide dosing device uses calcium hydroxide in combination with coagulant and coagulant aid to promote the flocculation reaction of suspended particles and colloidal substances in the pharmaceutical and chemical wastewater after primary degradation, and obtains supernatant and phosphorus-containing chemical sludge. A sludge discharge port is set at the bottom of the coagulation sedimentation tank for discharging phosphorus-containing chemical sludge.

[0055] The dosage of calcium hydroxide is adjusted based on feedback from the pH sensor to control the pH value of the supernatant within the range of 6.0-8.0;

[0056] The multi-media filter receives the supernatant and traps suspended particles within it. The filter layer of the multi-media filter is made of anthracite and quartz sand laid in layers.

[0057] The activated carbon adsorption tower receives the effluent from the multi-media filter and adsorbs the residual organic pollutants in the effluent through the columnar activated carbon packed inside, resulting in clarified wastewater. The activated carbon adsorption tower is equipped with a bypass pipe to adjust the adsorption ratio of the activated carbon adsorption tower according to the chemical oxygen demand when the activated carbon adsorption tower receives the effluent from the multi-media filter.

[0058] The physicochemical treatment module transports clarified wastewater to the biological treatment module, while simultaneously transporting phosphorus-containing chemical sludge to the sludge dewatering device of the resource recovery module.

[0059] It should be noted that polyaluminum chloride is used as the coagulant, and anionic polyacrylamide is used as the coagulant aid. The synergistic effect of the coagulant and the coagulant aid is used to achieve effective flocculation of suspended particles and colloidal substances in wastewater.

[0060] The calcium hydroxide dosing device in the coagulation sedimentation tank uses a metering pump for dosing. The dosing sequence is as follows: first, calcium hydroxide is added to adjust the pH; then, polyaluminum chloride (coagulant) is added to form micro-flocculations; and finally, anionic polyacrylamide (coagulant aid) is added to promote floc growth. A pH sensor is installed at the outlet of the coagulation sedimentation tank to monitor the pH value of the supernatant in real time. When the monitored value is <6.0, the metering pump automatically increases the amount of calcium hydroxide added; when the monitored value is >8.0, the amount added is reduced.

[0061] The bottom of the coagulation sedimentation tank is specially equipped with a sludge discharge port to regularly discharge phosphorus-containing chemical sludge. This sludge is then transported to the sludge dewatering device of the resource recovery module to prepare for phosphorus resource recovery. The supernatant after sedimentation in the coagulation sedimentation tank flows into a multi-media filter to reduce the turbidity of the wastewater.

[0062] The filter layer of the multi-media filter is made of anthracite and quartz sand in layers. The particle size, density and porosity of the two filter media are different. The anthracite is used as the upper filter media to intercept larger particulate impurities, while the quartz sand is used as the lower filter media to capture finer particles, ensuring the depth and stability of the filtration effect.

[0063] The columnar activated carbon packed inside the activated carbon adsorption tower has a highly developed pore structure and a huge specific surface area, which can adsorb residual organic pollutants in the effluent of multi-media filters.

[0064] The activated carbon adsorption tower is also equipped with a bypass pipeline, which can adjust the adsorption ratio of the activated carbon adsorption tower in real time according to the chemical oxygen demand of the influent, so as to ensure the adsorption effect while optimizing operating costs and treatment efficiency.

[0065] III. Biological Treatment Module:

[0066] The biological treatment module receives the clarified wastewater output from the physicochemical treatment module and obtains biochemical effluent, wherein:

[0067] Upflow anaerobic sludge bed receives clarified wastewater and uses anaerobic microorganisms on it to degrade biodegradable organic matter in the clarified wastewater into small molecules and produce biogas and anaerobic biological sludge. The bottom of the upflow anaerobic sludge bed is equipped with a sludge discharge port for discharging anaerobic biological sludge.

[0068] The biofilm aerobic reactor receives the effluent from the upflow anaerobic sludge bed and then performs secondary degradation of small molecules in the effluent through the metabolism of aerobic microorganisms on it, resulting in biochemical effluent.

[0069] The biofilm aerobic reactor is equipped with polyethylene packing material, which provides an attachment carrier for aerobic microorganisms.

[0070] The biological treatment module outputs biochemical effluent to the advanced treatment module, biogas to the resource recovery module, and anaerobic biological sludge to the sludge dewatering device.

[0071] It should be noted that when the upflow anaerobic sludge blanket is running, the hydraulic retention time is preferably controlled at 8-24 hours, and the anaerobic biological sludge concentration is maintained at 15-30 g / L.

[0072] The polyethylene packing material used in biofilm aerobic reactors has good chemical stability and a long service life, providing an ideal attachment surface for microorganisms.

[0073] IV. Depth Processing Module:

[0074] The advanced treatment module receives the biochemically treated effluent from the biological treatment module and produces qualified reclaimed water and concentrated water, wherein:

[0075] The ultrafiltration device receives the biochemical effluent and uses a polyvinylidene fluoride ultrafiltration membrane to remove large molecular organic matter in the biochemical effluent;

[0076] The reverse osmosis membrane module receives the effluent from the ultrafiltration unit and uses an anti-fouling composite membrane to remove dissolved salts and small molecule pollutants from the effluent, producing concentrated water and fresh water.

[0077] The ion exchange unit receives fresh water produced by the reverse osmosis membrane module and uses a series of cation and anion exchange resins to remove residual ions from the fresh water, ultimately obtaining compliant recycled water.

[0078] The advanced treatment module uses multi-stage purification to ensure that the effluent meets reuse standards, outputs compliant reclaimed water, and outputs the concentrate generated by the reverse osmosis membrane module to the zero-emission evaporation module.

[0079] It should be noted that the polyvinylidene fluoride ultrafiltration membrane used in the ultrafiltration device has good chemical stability and mechanical strength, and can effectively retain large molecular organic matter in the biochemical effluent, preventing pollution and clogging of the subsequent reverse osmosis membrane module.

[0080] The antifouling composite membrane used in the reverse osmosis membrane module has an extremely high rejection rate for pollutants such as dissolved salts, small molecule organic matter and bacteria, and can effectively separate fresh water and concentrated water.

[0081] In an ion exchange device, cation exchange resin first adsorbs cations such as calcium and magnesium ions from the fresh water, and then anion exchange resin adsorbs anions such as chloride and nitrate ions. Therefore, by using cation and anion exchange resins in series, residual trace ions in the fresh water can be removed. The fresh water treated by ion exchange can meet or even exceed reuse standards, satisfying the needs of industrial production or municipal water use.

[0082] V. Zero Evaporation Module:

[0083] The zero-emission evaporation module receives the concentrate produced by the reverse osmosis membrane module in the deep treatment module, wherein:

[0084] The evaporation crystallization unit receives the concentrated water produced by the reverse osmosis membrane unit and evaporates and concentrates the concentrated water by heating, finally separating the crystallized salt and condensate.

[0085] The condensate is returned to the ultrafiltration unit of the deep treatment module for reprocessing;

[0086] Ion chromatography was used to test the purity of crystalline salts. Some of the crystalline salts that met the purity standards were used for industrial by-product salt resource utilization, while the remaining crystalline salts that did not meet the purity standards were stabilized and then disposed of in a harmless manner.

[0087] It should be noted that the evaporation crystallization device uses mechanical vapor recompression technology, which is suitable for the evaporation and concentration of concentrated water. The condensate produced is returned to the ultrafiltration device to form a water cycle.

[0088] VI. Resource Recycling Module:

[0089] The resource recycling module recovers phosphorus-containing chemical sludge from the coagulation and sedimentation tank of the physicochemical treatment module, organic solvents from the raw water of traditional Chinese medicine and chemical wastewater in the oxidation pretreatment module, and biogas from the upflow anaerobic sludge bed of the biological treatment module. Among these:

[0090] The sludge dewatering device is connected to the sludge discharge port of the coagulation sedimentation tank in the physicochemical treatment module and the sludge discharge port of the upflow anaerobic sludge bed in the biological treatment module. It receives phosphorus-containing chemical sludge and anaerobic biological sludge. The sludge dewatering device performs preliminary dewatering on the received phosphorus-containing chemical sludge and anaerobic biological sludge through gravity thickening, and then reduces the sludge moisture content a second time through mechanical dewatering.

[0091] The sludge dewatering unit transports the dewatered phosphorus-containing chemical sludge to the hydroxyapatite purification unit, while the dewatered anaerobic biological sludge is stabilized and then used for solid waste resource utilization.

[0092] The magnetic separation pretreatment device is installed on the pipeline from the sludge dewatering device to the hydroxyapatite purification device, and is used to pre-enrich phosphorus in the dewatered phosphorus-containing chemical sludge.

[0093] The hydroxyapatite purification unit separates and purifies phosphorus-containing chemical sludge that has been pre-enriched with phosphorus through acid leaching, filtration, neutralization and calcination processes. After XRD detection and matching with the JCPDS 09-0432 standard card, phosphorus resources are recovered.

[0094] The distillation-extraction tower is connected to the inlet pipe of the oxidation pretreatment module. It uses dichloromethane as the extractant and recovers organic solvents from the raw pharmaceutical and chemical wastewater through a combination of distillation and extraction processes.

[0095] The distillation extraction tower is equipped with a waste heat exchange device to receive the waste heat from the effluent of the upflow anaerobic sludge bed; the heat exchange output end of the waste heat exchange device is connected to the distillation heating section of the distillation extraction tower, and the dichloromethane after distillation is regenerated by heating it with waste heat.

[0096] The biogas collection device is installed on top of the upflow anaerobic sludge bed to recover the biogas produced by the upflow anaerobic sludge bed.

[0097] It should be noted that after dewatering, anaerobic biological sludge undergoes stabilization treatment (aerobic or anaerobic digestion) to remove harmful substances and pathogens, reducing its environmental risks. The treated sludge can then be utilized as solid waste, for example, as a raw material for soil conditioners or building materials, achieving both harmless and resource-based treatment of the sludge.

[0098] The process of pre-enriching phosphorus in dewatered phosphorus-containing chemical sludge using a magnetic separation pretreatment device includes: adding magnetic nano Fe3O4 particles to the phosphorus-containing chemical sludge; after the magnetic nano Fe3O4 particles adsorb phosphorus in the phosphorus-containing chemical sludge, rapid solid-liquid separation is achieved through a magnetic separation device.

[0099] Dichloromethane has good solubility and a low boiling point. By precisely controlling the distillation temperature and the amount of extractant, efficient separation of organic solvent and aqueous phase can be achieved. The recovered organic solvent can be reused in the production process, significantly reducing resource waste.

[0100] Biogas, primarily composed of methane and carbon dioxide, is a clean and renewable energy source. The biogas collected by the biogas collection device is safely transported to the resource recovery module via a water seal and gas collection pipeline. After purification, it can be used for power generation or heating, achieving energy self-sufficiency and reducing energy consumption in wastewater treatment.

[0101] VII. Intelligent Monitoring Module:

[0102] The intelligent monitoring module includes a water quality monitoring component, an extractant purity monitoring component, a membrane fouling early warning component, and a current feedback control unit, wherein:

[0103] The water quality monitoring components include a COD sensor and UV254 detector installed at the inlet of the oxidation pretreatment module, a dissolved oxygen probe and temperature sensor installed in the biofilm aerobic reactor, and a conductivity meter installed at the freshwater outlet of the reverse osmosis membrane module. These components are used to detect the COD and UV absorbance of the raw pharmaceutical and chemical wastewater, monitor the dissolved oxygen concentration and water temperature in the biofilm aerobic reactor, and monitor the conductivity of the freshwater, respectively.

[0104] The extractant purity monitoring component monitors whether the purity of the regenerated dichloromethane meets the standard through a refractive index sensor. If it does, the dichloromethane is returned to the extraction section of the distillation extraction tower through a circulation pipeline for repeated extraction of organic solvents in the raw water of pharmaceutical and chemical wastewater from the oxidation pretreatment module. If it does not meet the standard, the dichloromethane is discharged to the recovery tank through a recovery pipeline.

[0105] The membrane fouling early warning component includes differential pressure sensors installed at the inlet of the ultrafiltration unit and the reverse osmosis membrane module. The differential pressure sensors are used to monitor the transmembrane pressure difference of the ultrafiltration unit and the reverse osmosis membrane module, and to issue a fouling early warning based on the monitoring results.

[0106] The current feedback control unit is based on an adaptive regulation algorithm to adjust the current density of the boron-doped diamond electrode according to the COD and UV absorbance of the raw pharmaceutical and chemical wastewater.

[0107] It should be noted that the monitoring data from the COD sensor and UV254 detector are transmitted via wired connection to the central controller of the intelligent monitoring module, which then synchronously sends the data to the current feedback control unit.

[0108] The steps for monitoring dissolved oxygen concentration and water temperature in a biofilm aerobic reactor using dissolved oxygen probes and temperature sensors are as follows:

[0109] The dissolved oxygen concentration threshold is preset to 2-4 mg / L and the water temperature threshold is preset to 20-30℃ through the central controller;

[0110] If the dissolved oxygen concentration is <2mg / L, the aeration intensity in the biofilm aerobic reactor will be automatically increased by the aeration intensity adjustment device installed on the biofilm aerobic reactor; if the dissolved oxygen concentration is >4mg / L, the aeration intensity in the biofilm aerobic reactor will be automatically reduced.

[0111] If the water temperature is <20℃ or >30℃, the water temperature is adjusted to a suitable range by using the water temperature control device installed on the biofilm aerobic reactor;

[0112] If the dissolved oxygen concentration or water temperature in the biofilm aerobic reactor exceeds the threshold range for 30 consecutive minutes (and adjustment is ineffective), an audible and visual alarm will be triggered.

[0113] The steps for monitoring the conductivity of fresh water with a conductivity meter are as follows:

[0114] The conductivity threshold is preset via the central controller;

[0115] If the conductivity is ≤50μS / cm, the freshwater is deemed to meet the standard and will be transported to an ion exchange device for further treatment.

[0116] If the conductivity is >50μS / cm, the freshwater is deemed not to meet the standard and will be transported to the ultrafiltration device for re-purification through the return pipe.

[0117] If the conductivity shows an upward trend for two consecutive hours, staff should be alerted to check the fouling status of the reverse osmosis membrane module.

[0118] The steps for using a differential pressure sensor to monitor the transmembrane pressure difference in an ultrafiltration unit and a reverse osmosis membrane module are as follows:

[0119] Initial and warning thresholds are preset through a central controller;

[0120] If the transmembrane pressure difference is less than or equal to the initial threshold, the membrane fouling of the ultrafiltration unit and the reverse osmosis membrane module is considered to be normal.

[0121] If the initial threshold < transmembrane pressure difference ≤ warning threshold, it is determined to be slightly contaminated, and the next cleaning cycle is automatically shortened;

[0122] If the transmembrane pressure difference is greater than the warning threshold, the membrane fouling is determined to be moderate, and the cleaning procedure of the membrane fouling prevention module is immediately triggered.

[0123] If the transmembrane pressure difference after cleaning exceeds the warning threshold (twice consecutively), a shutdown warning will be triggered.

[0124] The steps for adjusting the current density of the boron-doped diamond electrode using the current feedback control unit are as follows:

[0125] The central controller presets an adaptive control algorithm;

[0126] If COD ≤ 500 mg / L and UV absorbance ≤ 0.3, adjust the boron-doped diamond electrode current density to 5-10 mA / cm². 2 (Low energy consumption mode);

[0127] If 500 mg / L < COD ≤ 1000 mg / L and 0.3 < UV absorbance ≤ 0.6, adjust the boron-doped diamond electrode current density to 10⁻²⁰ mA / cm². 2 (Standard mode);

[0128] If COD > 1000 mg / L and UV absorbance > 0.6, adjust the boron-doped diamond electrode current density to 20-30 mA / cm². 2 (Enhanced degradation mode).

[0129] VIII. Membrane Fouling Prevention Module:

[0130] The filter element of the pre-filter is made of polypropylene, which reduces the fouling load on the surface of the ultrafiltration device and reverse osmosis membrane module by intercepting large particulate impurities in the biochemical effluent.

[0131] Citric acid cleaning equipment, in conjunction with chelating agents, is used to regularly clean the ultrafiltration unit and reverse osmosis membrane modules to maintain stable membrane flux.

[0132] It should be noted that filter cartridges made of polypropylene typically have a filtration precision in the range of 5-10 μm, possessing good chemical stability and mechanical strength, and can effectively intercept large particulate impurities in the biochemical effluent. By reducing the fouling load of these impurities on the surface of the ultrafiltration unit and reverse osmosis membrane module, the service life of the ultrafiltration unit and reverse osmosis membrane module is significantly extended.

[0133] Citric acid, as an effective cleaning agent, can undergo a complexation reaction with metal ions and mineral scale on the membrane surface, thereby removing contaminants. The use of chelating agents in conjunction with citric acid can enhance its cleaning effect and prevent secondary pollution during the cleaning process. The cleaning cycle is determined based on the wastewater quality and the degree of membrane fouling, generally once a week or every two weeks.

[0134] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A system for reducing and recycling pharmaceutical and chemical wastewater, characterized in that, include: The oxidation pretreatment module includes a titanium dioxide-coated ultraviolet reactor and a boron-doped diamond electrode device, used to degrade antibiotics and organic pollutants in pharmaceutical and chemical wastewater. The physicochemical treatment module includes a coagulation sedimentation tank, a multi-media filter, and an activated carbon adsorption tower, used to discharge phosphorus-containing chemical sludge and adsorb residual organic pollutants in pharmaceutical and chemical wastewater after primary degradation. The biological treatment module includes an upflow anaerobic sludge blanket and a biofilm aerobic reactor, used to degrade biodegradable organic matter in clarified wastewater; The advanced treatment module, including an ultrafiltration unit, a reverse osmosis membrane module, and an ion exchange unit, is used to purify the biochemical effluent in multiple stages to meet reuse standards and produce concentrated water. The zero-emission evaporation module uses an evaporation crystallization device to evaporate and concentrate the concentrated water generated by the deep treatment module, separating it into crystalline salt and condensate. The resource recovery module includes a sludge dewatering device, a magnetic separation pretreatment device, a hydroxyapatite purification device, a distillation extraction tower, and a biogas collection device, used to recover phosphorus-containing chemical sludge, anaerobic biological sludge, organic solvents, and biogas. The intelligent monitoring module includes a water quality monitoring component, an extractant purity monitoring component, a membrane fouling early warning component, and a current feedback control unit, which are used to monitor the data of each module and ensure the stable operation of the system. The membrane fouling prevention module includes a pre-filter and a citric acid cleaning device, which is used to extend the service life of ultrafiltration units and reverse osmosis membrane modules.

2. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The oxidation pretreatment module receives raw pharmaceutical and chemical wastewater and obtains primary-degraded pharmaceutical and chemical wastewater, wherein: The titanium dioxide-coated ultraviolet reactor generates hydroxyl radicals under ultraviolet light irradiation, which work synergistically with the hydroxyl radicals generated by the boron-doped diamond electrode device through anodic electrochemical reaction to degrade antibiotics and organic pollutants in the raw pharmaceutical and chemical wastewater, resulting in primary degraded pharmaceutical and chemical wastewater. The titanium dioxide-coated ultraviolet photoreactor uses a nitrogen-doped titanium dioxide photocatalyst. By introducing nitrogen, the light response wavelength range is extended to the visible light region of 400-700nm. The light source of the ultraviolet photoreactor is a composite light source, including a light-emitting component that emits ultraviolet light of 254-400nm and a light-emitting component that emits visible light of 400-700nm, forming a dual-band synergistic catalytic system. The titanium dioxide-coated ultraviolet reactor is equipped with a flow guiding structure to extend the retention time of raw pharmaceutical and chemical wastewater. The boron-doped diamond electrode device uses a titanium-based boron-doped diamond anode and a stainless steel cathode, and the current density of the boron-doped diamond electrode device is adjusted by an intelligent monitoring module. The oxidation pretreatment module transports the pharmaceutical and chemical wastewater after primary degradation to the physicochemical treatment module.

3. The pharmaceutical and chemical wastewater reduction and recycling system according to claim 1, characterized in that, The physicochemical treatment module receives the primary degradation pharmaceutical and chemical wastewater output from the oxidation pretreatment module and obtains clarified wastewater, wherein: The coagulation sedimentation tank is equipped with a calcium hydroxide dosing device. The calcium hydroxide dosing device uses calcium hydroxide in combination with coagulant and coagulant aid to promote the flocculation reaction of suspended particles and colloidal substances in the pharmaceutical and chemical wastewater after primary degradation, and obtains supernatant and phosphorus-containing chemical sludge. A sludge discharge port is set at the bottom of the coagulation sedimentation tank for discharging phosphorus-containing chemical sludge. The amount of calcium hydroxide added is adjusted based on feedback from the pH sensor to control the pH value of the supernatant in the coagulation sedimentation tank to be in the range of 6.0-8.

0. The multi-media filter receives the supernatant and traps suspended particles within it. The filter layer of the multi-media filter is laid in layers of anthracite and quartz sand. The activated carbon adsorption tower receives the effluent from the multi-media filter and adsorbs residual organic pollutants in the effluent through the columnar activated carbon packed inside, resulting in clarified wastewater. The activated carbon adsorption tower is equipped with a bypass pipe to adjust the adsorption ratio of the activated carbon adsorption tower according to the chemical oxygen demand when the activated carbon adsorption tower receives the effluent from the multi-media filter. The physicochemical treatment module transports clarified wastewater to the biological treatment module, while simultaneously transporting phosphorus-containing chemical sludge to the sludge dewatering device of the resource recovery module.

4. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The biological treatment module receives the clarified wastewater output from the physicochemical treatment module and obtains biochemical effluent, wherein: The upflow anaerobic sludge bed receives clarified wastewater and uses anaerobic microorganisms on it to degrade biodegradable organic matter in the clarified wastewater into small molecules and produce biogas and anaerobic biological sludge. The bottom of the upflow anaerobic sludge bed is equipped with a sludge discharge port for discharging anaerobic biological sludge. The biofilm aerobic reactor receives the effluent from the upflow anaerobic sludge bed and then performs secondary degradation of small molecules in the effluent through the metabolism of aerobic microorganisms on it, resulting in biochemical effluent. The biofilm aerobic reactor is equipped with polyethylene packing material, which provides an attachment carrier for aerobic microorganisms. The biological treatment module outputs biochemical effluent to the advanced treatment module, biogas to the resource recovery module, and anaerobic biological sludge to the sludge dewatering device of the resource recovery module.

5. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The advanced treatment module receives the biochemically treated effluent from the biological treatment module and obtains qualified reclaimed water and concentrated water, wherein: The ultrafiltration device receives the biochemical effluent and uses a polyvinylidene fluoride ultrafiltration membrane to remove large molecular organic matter in the biochemical effluent. The reverse osmosis membrane module receives the effluent from the ultrafiltration device and uses an anti-fouling composite membrane to remove dissolved salts and small molecule pollutants from the effluent, producing concentrated water and fresh water. The ion exchange device receives fresh water produced by the reverse osmosis membrane module and uses a series of cation and anion exchange resins to remove residual ions from the fresh water, ultimately obtaining compliant recycled water. The advanced treatment module purifies the effluent to meet reuse standards through multi-stage purification, outputs compliant reused water, and outputs the concentrate generated by the reverse osmosis membrane module to the zero-emission evaporation module.

6. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The zero-emission evaporation module receives concentrated water produced by the reverse osmosis membrane module in the deep treatment module, wherein: The evaporation crystallization device receives the concentrated water produced by the reverse osmosis membrane module, and evaporates and concentrates the concentrated water produced by the reverse osmosis membrane module by heating, and finally separates the crystalline salt and condensate. The condensate is returned to the ultrafiltration device of the deep treatment module for reprocessing; The purity of the crystalline salt was determined by ion chromatography. Some of the crystalline salt that met the purity standard was used for industrial by-product salt resource utilization, while the remaining crystalline salt that did not meet the purity standard was stabilized and then disposed of in a harmless manner.

7. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The resource recovery module recovers phosphorus-containing chemical sludge from the coagulation sedimentation tank of the physicochemical treatment module, organic solvents from the raw water of pharmaceutical and chemical wastewater in the oxidation pretreatment module, and biogas from the upflow anaerobic sludge bed of the biological treatment module, wherein: The sludge dewatering device is connected to the sludge discharge port of the coagulation sedimentation tank in the physicochemical treatment module and the sludge discharge port of the upflow anaerobic sludge bed in the biological treatment module. It receives phosphorus-containing chemical sludge and anaerobic biological sludge and dewaters the phosphorus-containing chemical sludge and anaerobic biological sludge. The magnetic separation pretreatment device is installed on the pipeline from the sludge dewatering device to the hydroxyapatite purification device, and is used to pre-enrich phosphorus in the dewatered phosphorus-containing chemical sludge. The hydroxyapatite purification device separates and purifies phosphorus-containing chemical sludge that has been pre-enriched with phosphorus through acid leaching, filtration, neutralization and calcination processes. After XRD detection and matching with the JCPDS 09-0432 standard card, phosphorus resources are recovered. The distillation extraction tower is connected to the inlet pipe of the oxidation pretreatment module. It uses dichloromethane as the extractant and recovers organic solvents from the raw pharmaceutical and chemical wastewater through a combination of distillation and extraction processes. The distillation extraction tower is equipped with a waste heat exchange device to receive the waste heat from the effluent of the upflow anaerobic sludge bed; the heat exchange output end of the waste heat exchange device is connected to the distillation heating section of the distillation extraction tower, and the dichloromethane after distillation is regenerated by heating it with waste heat. The biogas collection device is installed at the top of the upflow anaerobic sludge bed and is used to recover the biogas produced by the upflow anaerobic sludge bed.

8. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 7, characterized in that, The process of dewatering phosphorus-containing chemical sludge and anaerobic biological sludge using a sludge dewatering device is as follows: The sludge dewatering device performs preliminary dewatering of the received phosphorus-containing chemical sludge and anaerobic biological sludge through gravity concentration, and then further reduces the sludge moisture content through mechanical dewatering. The sludge dewatering device transports the dewatered phosphorus-containing chemical sludge to the hydroxyapatite purification device, and at the same time, the dewatered anaerobic biological sludge is stabilized and then used for solid waste resource utilization.

9. The pharmaceutical and chemical wastewater reduction and recycling treatment system according to claim 1, characterized in that, The intelligent monitoring module, wherein: The water quality monitoring components include a COD sensor and a UV254 detector installed at the inlet of the oxidation pretreatment module, a dissolved oxygen probe and a temperature sensor installed in the biofilm aerobic reactor, and a conductivity meter installed at the freshwater outlet of the reverse osmosis membrane module. These components are used to detect the COD and UV absorbance of the raw pharmaceutical and chemical wastewater, to monitor the dissolved oxygen concentration and water temperature in the biofilm aerobic reactor, and to monitor the conductivity of the freshwater. The extractant purity monitoring component monitors whether the purity of the regenerated dichloromethane meets the standard through a refractive index sensor. If it does, the dichloromethane is returned to the extraction section of the distillation extraction tower through a circulation pipeline. If it does not meet the standard, the dichloromethane is discharged to the recovery tank through a recovery pipeline. The membrane fouling early warning component includes differential pressure sensors installed at the inlet of the ultrafiltration unit and the reverse osmosis membrane module. The differential pressure sensors are used to monitor the transmembrane pressure difference between the ultrafiltration unit and the reverse osmosis membrane module, and to execute fouling early warning based on the monitoring results. The current feedback control unit is based on an adaptive regulation algorithm and is used to adjust the current density of the boron-doped diamond electrode according to the COD and ultraviolet absorbance of the raw pharmaceutical and chemical wastewater.

10. The pharmaceutical and chemical wastewater reduction and recycling system according to claim 1, characterized in that, The membrane fouling prevention module, wherein: The filter element of the pre-filter is made of polypropylene, which reduces the pollution load on the surface of the ultrafiltration device and reverse osmosis membrane module by intercepting large particulate impurities in the biochemical effluent. The citric acid cleaning device, in conjunction with a chelating agent, periodically cleans the ultrafiltration unit and reverse osmosis membrane module to maintain stable membrane flux.

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