A hazardous waste materialization disposal system

Abstract

The application provides a hazardous waste materialization disposal system, comprising: a materialization pretreatment unit for classifying and pretreating liquid hazardous waste, the materialization pretreatment unit comprising an inorganic waste liquid treatment line and an organic waste liquid treatment line; an evaporation concentration unit connected with a water outlet of the materialization pretreatment unit, for evaporating and crystallizing pretreated wastewater; and a deep treatment unit connected with a water outlet of the evaporation concentration unit, for deeply purifying evaporated and condensed water. The application systematically integrates the classified materialization pretreatment, the quality-divided evaporation concentration and the deep membrane biochemical method, forms a complete closed-loop treatment chain, and fully embodies the concept of waste treatment by waste and energy saving and emission reduction, so that the overall operation cost is low and good economic and environmental benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of hazardous waste treatment technology, and more specifically to a hazardous waste physical and chemical treatment system. Background Technology

[0002] Hazardous waste possesses one or more hazardous characteristics such as toxicity, corrosivity, flammability, reactivity, or infectivity, posing a serious threat to the ecological environment and human health. Liquid hazardous waste can be broadly classified into two categories based on its source and properties: inorganic waste liquid and organic waste liquid. Inorganic waste liquid mainly includes waste liquid containing heavy metals (such as chromium-containing waste liquid, copper-containing waste liquid, etc.), photosensitive material waste liquid, and waste acids and alkalis, while organic waste liquid mainly includes oil-containing / emulsion waste liquid and high-concentration organic waste liquid. Different categories of waste liquid differ significantly in chemical composition, pollutant forms, and disposal requirements; a single disposal process is insufficient to achieve the comprehensive treatment goals of efficiency, economy, and environmental protection. In particular, photosensitive material waste liquid has a high silver content (high resource value) and high concentrations of recalcitrant organic matter (hydroquinone, methotrexate, thiosulfate, etc.), with organic pollution concentrations reaching 50,000 to 100,000 mg / L. It is neutral to weakly acidic and unsuitable for biological or incineration treatment, making its disposal extremely difficult.

[0003] Currently, several hazardous waste physicochemical treatment systems have been disclosed in existing technologies. For example, Chinese utility model patent CN212246571U discloses an integrated hazardous waste physicochemical treatment device, which mainly includes components such as a tank, stirring shaft, dosing system, and sedimentation tank, capable of performing chemical reaction and sedimentation separation on hazardous waste. Another example is Chinese invention patent CN102344214A, which discloses a comprehensive physicochemical treatment system for hazardous waste liquid. This system includes units such as a waste liquid storage tank, paper belt filter, conditioning tank, reagent tank, reaction vessel, membrane processor, filter press, and filtrate collection tank, allowing for flexible switching and combination between the various treatment units. Furthermore, Chinese utility model patent CN204151203U discloses a wastewater treatment system for a hazardous waste disposal center, comprising a physicochemical treatment system, a biochemical treatment system, a collection tank, and a deep treatment system connected in sequence.

[0004] However, the aforementioned existing technologies still have the following shortcomings: First, existing systems lack precise pretreatment for the classification of inorganic and organic waste liquids. The treatment processes for inorganic and organic waste liquids differ significantly, and existing systems often employ a uniform or coarsely classified approach, making it difficult to achieve efficient treatment tailored to the characteristics of different waste liquids. In particular, photosensitive material waste liquids contain large amounts of valuable metals such as silver, as well as high concentrations of organic pollutants. Existing systems generally lack independent, efficient treatment units specifically for this type of waste liquid, resulting in low silver recovery rates and incomplete degradation of organic matter.

[0005] Second, the design of the evaporation and concentration unit in the existing system is relatively simple. Inorganic waste liquids and organic waste liquids face very different problems such as scaling tendency and boiling point elevation during the evaporation and concentration process. Using the same evaporation technology often leads to problems such as low operating efficiency, frequent equipment maintenance, and high energy consumption.

[0006] Third, the existing systems have limited deep processing capabilities. Small amounts of organic pollutants and salts may still remain in the condensate after pretreatment and evaporation concentration. Conventional biological treatment or simple membrane separation technology cannot guarantee that the effluent will consistently meet standards, let alone achieve water recycling.

[0007] Therefore, how to construct an integrated physicochemical treatment system that is precise in classification, efficient in treatment, fully recovers resources, and allows for the reuse of effluent that meets standards, taking into account the multi-source characteristics of liquid hazardous waste, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned technical defects of existing hazardous waste physicochemical disposal systems when treating multi-source liquid hazardous waste, and to provide a hazardous waste physicochemical disposal system.

[0009] To achieve the above technical solution, the present invention provides a hazardous waste physicochemical treatment system, comprising: a physicochemical pretreatment unit for classifying and pretreating liquid hazardous waste, the physicochemical pretreatment unit including an inorganic waste liquid treatment line and an organic waste liquid treatment line; the inorganic waste liquid treatment line including an independently designed photosensitive material waste liquid treatment unit, a reduction reaction tank, a neutralization reaction tank and a first advanced oxidation reaction tank connected in sequence, and a first filter press and a second filter press respectively connected to the outlet of the neutralization reaction tank and the first advanced oxidation reaction tank; the organic waste liquid treatment line including an oil separator tank, a demulsification reaction tank, an air flotation device, a coagulation and flocculation tank and a second advanced oxidation reaction tank connected in sequence. The system includes a reaction vessel, and a third and a fourth filter press connected to the outlets of the coagulation and flocculation vessel and the second advanced oxidation reaction vessel, respectively; an evaporation and concentration unit connected to the outlet of the physicochemical pretreatment unit for evaporating and crystallizing the pretreated wastewater, the evaporation and concentration unit comprising a first evaporation system and a second evaporation system connected in parallel, the first evaporation system being used to treat organic wastewater and the second evaporation system being used to treat inorganic wastewater; and a deep treatment unit connected to the outlet of the evaporation and concentration unit for deep purification of the evaporation condensate, the deep treatment unit comprising a biochemical treatment system, a membrane separation system, and a reverse osmosis system connected in sequence.

[0010] In the above technical solution, by classifying liquid hazardous waste into inorganic and organic categories at the source and setting up independently designed inorganic and organic wastewater treatment lines respectively, targeted treatment of wastewater with different properties is achieved. The inorganic wastewater treatment line, targeting the characteristics of inorganic pollutants such as heavy metal ions and photosensitive material wastewater, incorporates multi-stage treatment processes including reduction, complex-breaking, neutralization, and advanced oxidation, and is coupled with a two-stage filter press to achieve efficient solid-liquid separation. The organic wastewater treatment line, targeting the characteristics of organic wastewater such as oil-containing / emulsion liquids, incorporates multi-stage treatment processes including oil separation, demulsification, flotation, coagulation and flocculation, and advanced oxidation, and is also coupled with a two-stage filter press to achieve solid-liquid separation. The two treatment lines operate in parallel without interference, significantly improving the system's capacity and efficiency in treating multi-source wastewater. The inorganic wastewater treatment line includes a separate photosensitive material wastewater treatment unit, enabling the separate treatment of this special hazardous waste. Photosensitive material wastewater contains a large amount of valuable metals such as silver, as well as high concentrations of organic pollutants. Conventional inorganic wastewater treatment methods are insufficient to simultaneously achieve efficient recovery of valuable metals and deep degradation of organic matter. A separately designed photosensitive material wastewater treatment unit allows for customized treatment processes based on its specific properties, achieving the dual goals of resource recovery and pollutant degradation. The evaporation and concentration unit employs a parallel arrangement of a first evaporation system and a second evaporation system, used to treat organic and inorganic wastewater respectively. Organic wastewater often faces problems such as coking and foaming during evaporation and concentration, while inorganic wastewater faces problems such as salt crystallization and scaling, and increased boiling point. The requirements for evaporation technology differ between the two. By setting up two independent evaporation systems, the optimal evaporation process can be selected based on the characteristics of different wastewaters, improving evaporation efficiency and reducing energy consumption and failure rates. The deep treatment unit uses a sequentially connected structure of a biochemical treatment system, a membrane separation system, and a reverse osmosis system to perform three-stage deep purification of the evaporation condensate. The biochemical treatment system degrades residual organic matter, the membrane separation system further removes suspended solids and macromolecules, and the reverse osmosis system efficiently removes salts and trace pollutants, ensuring that the effluent meets strict discharge standards and can even be reused.

[0011] Preferably, the photosensitive material waste liquid treatment unit includes a solid-liquid separation and waste liquid pretreatment unit, a targeted silver recovery unit, an organic super-oxidation mineralization unit, and a residue final disposal unit connected in sequence. The solid-liquid separation and waste liquid pretreatment unit separates the mixed-collected photosensitive material waste liquid into solid photosensitive material and liquid waste liquid, and pretreats each separately. The targeted silver recovery unit achieves efficient silver recovery through multi-stage coupled precipitation-electrolysis technology. The organic super-oxidation mineralization unit utilizes a two-stage combined technology of wet catalytic oxidation and supercritical water oxidation to degrade high-concentration organic pollutants. The residue final disposal unit performs plasma melting vitrification treatment on the trace amounts of solid residue generated during thermal oxidation to achieve ultimate harmlessness. In actual operation, the sequential connection of the four functional units forms a complete technical chain from solid-liquid separation, silver recovery, organic degradation to harmless disposal of residues, realizing "full-component, full-process" treatment of photosensitive material waste liquid.

[0012] Preferably, the specific process of the photosensitive material waste liquid treatment unit is as follows: S1. The mixed and collected photosensitive material waste liquid is fed into the shearing and crushing machine in the solid-liquid separation and waste liquid pretreatment unit via a closed conveyor belt. It is crushed into flakes and the crushed material enters the countercurrent washing drum. It is washed with warm water in a countercurrent flow to remove the residual liquid on the surface of the film / photo paper and let it enter the aqueous phase. The washing liquid is discharged into the waste liquid storage tank and combined with the subsequent waste liquid for treatment. The film base material is dewatered by a vibrating screen and then enters the next step of processing. S2. Add a 3-5% sodium hydroxide solution to the dehydrated sheet base material, while continuously introducing ozone. Heat and stir at 65-75℃ for 60-90 minutes. Combine the silver-containing solutions after the reaction into the waste liquid storage tank. S3. Pump the waste liquid in the waste liquid storage tank into the high temperature reactor, heat it to 120-150℃, keep it at that temperature for 30 minutes, and then feed it into the centrifuge to remove the colloidal sulfur produced by decomposition. The liquid phase flows into the precipitation reaction tank in the targeted silver recovery unit. S4. Add sodium sulfide solution to the precipitation reaction vessel, then use dilute... Adjust the pH of the waste liquid to 3-4, so that After complete precipitation and filtration, The precipitate is sent to the next stage of electrolytic refining, and the filtered liquid phase is transported to the high-pressure reactor in the organic super oxidation mineralization unit. S5, Filter the obtained The precipitate dissolves in dilute nitric acid, forming The solution is added to a rotating cathode electrolytic cell, and flake silver with a purity of 95-99% is obtained by direct current electrolysis. S6. Pure oxygen is introduced into the high-pressure reactor, and one or more of Pt, Pd, Rh, and Ru are added as active components, and one or more of La, Ce, Pr, and Nd are added as auxiliary agents, supported on... The catalyst on the support was reacted at a temperature of 220-280℃, a pressure of 4.0-8.0 MPa, and a time of 60-90 minutes. S7. The waste liquid after oxidation in the high-pressure reactor is transported to the supercritical water oxidation reactor, liquid oxygen or hydrogen peroxide is added as an oxidant, and the reaction temperature is controlled at 450-550℃, the reaction pressure at 20-30 MPa, and the reaction time at 2-5 minutes. S8. The liquid treated by the supercritical water oxidation reactor is transported to the rotary kiln pyrolysis furnace in the residue final disposal unit for low-temperature pyrolysis pretreatment, and then transported to the plasma gasification melting furnace for vitrification final treatment.

[0013] Preferably, the inorganic waste liquid treatment line further includes: multiple first dosing tanks for storing and adding ferrous sulfate, hydrogen peroxide, sodium carbonate, sodium hydroxide, TMT, PAC, and PAM reagents, the first dosing tanks being connected to the reduction reaction tank, neutralization reaction tank, and first advanced oxidation reaction tank respectively; the organic waste liquid treatment line further includes: multiple second dosing tanks for storing and adding sulfuric acid, PAC, PAM, ferrous sulfate, hydrogen peroxide, sodium hydroxide, and TMT reagents, the second dosing tanks being connected to the demulsification reaction tank, coagulation and flocculation tank, and second advanced oxidation reaction tank respectively. Through the above configuration, each line is independently equipped with a dosing system, allowing for adjustments to the reagent type and dosage based on incoming material testing results without interference. Different reaction stages (reduction, complex breaking, oxidation) require different optimal pH values ​​and redox potentials; independent dosing points ensure that each chemical reaction proceeds under optimal conditions.

[0014] Preferably, the first evaporation system is a multi-effect evaporator, and the second evaporation system is an MVC evaporator; the evaporation concentration unit also includes an enamel-lined kettle evaporator connected to the concentrate outlet of the multi-effect evaporator and the MVC evaporator. By paralleling the high efficiency and energy saving of MVC with the stability of multi-effect evaporation, and then connecting them in series with an enamel-lined kettle for final treatment, a stepped evaporation reduction system is formed. This combination of "parallel + series" is specifically designed for the stringent requirements of "zero discharge" or "minimal residue" in hazardous waste disposal. Moreover, since organic wastewater is usually high in COD, prone to foaming, and easily corroded, multi-effect evaporation can utilize steam heat energy, making it suitable for treating such complex water qualities; inorganic wastewater mainly contains salt, and the energy efficiency of MVC (mechanical vapor recompression) is extremely high, significantly reducing operating power consumption. Conventional evaporators are inefficient and prone to crystallization and pipe blockage when treating high-concentration mother liquor. Adding a corrosion-resistant and easy-to-clean enamel-lined kettle as the terminal evaporation equipment can further dry the concentrate or form crystals, achieving maximum waste reduction and even resource recovery.

[0015] Preferably, the biochemical treatment system of the advanced treatment unit includes a hydrolysis acidification tank, an anoxic tank, an aerobic tank, and an MBR membrane tank connected in sequence. A buffer tank, an activated carbon filter, and a reverse osmosis system are connected in sequence after the MBR membrane tank. The permeate outlet of the reverse osmosis system is connected to an effluent tank. In actual operation, the hydrolysis acidification tank decomposes large organic molecules into smaller organic molecules, improving the biodegradability of the wastewater; the A / O process composed of the anoxic and aerobic tanks achieves efficient degradation of organic matter and nitrogen and phosphorus removal; the MBR membrane tank separates sludge retention time and hydraulic retention time, improving the system's treatment load and effluent quality; the buffer tank and activated carbon filter further remove trace organic matter and suspended solids; and the reverse osmosis system efficiently removes salts and trace pollutants. The series connection of multiple advanced treatment units ensures that the effluent quality meets strict discharge standards and can even be reused.

[0016] Preferably, the hazardous waste disposal system is implemented according to the following process steps: a) Liquid hazardous waste is classified and pretreated in the physicochemical pretreatment unit according to inorganic and organic categories, and physicochemical reactions and solid-liquid separation are carried out respectively to obtain pretreated clear liquid and sludge; b) The pretreated clear liquid obtained in step a) is sent to the evaporation and concentration unit, and then sent to the organic wastewater treatment line or the inorganic wastewater treatment line for evaporation and concentration according to its source, to obtain condensate, crystalline salt and concentrated residue. c) The condensate obtained in step b) is sent to the advanced treatment unit for sequential biochemical treatment, membrane separation and reverse osmosis treatment, so that the effluent meets the discharge standards or is reused.

[0017] Preferably, the pretreatment of inorganic waste liquid in step a) includes: independent treatment of photosensitive material waste liquid; reduction or complex-breaking reaction of chromium-containing waste liquid or waste liquid containing other heavy metals, followed by neutralization, coagulation sedimentation, and a first advanced oxidation treatment; the pretreatment of organic waste liquid includes: demulsification and flotation treatment of oil / emulsion waste liquid, followed by coagulation sedimentation and a second advanced oxidation treatment. In actual operation, the chromium-containing waste liquid and other heavy metal waste liquid are reduced (by... Restore to The demulsification and flotation treatment of oily / emulsified wastewater significantly improves the removal efficiency of heavy metals. It also effectively removes oil pollutants, creating favorable conditions for subsequent coagulation sedimentation and advanced oxidation treatment.

[0018] Preferably, in step b), the organic wastewater is treated using a multi-effect evaporation system, and the inorganic wastewater is treated using an MVC evaporation system; the concentrated residue produced by evaporation is sent to an enamel-lined kettle for further evaporation and crystallization. In actual operation, multi-effect evaporation of organic wastewater can fully utilize multi-effect heat recovery technology to reduce energy consumption; MVC evaporation of inorganic wastewater utilizes mechanical vapor recompression technology, and its energy consumption is only 1 / 10 to 1 / 30 of that of traditional evaporation; the concentrated residue is further sent to an enamel-lined kettle for evaporation and crystallization, which can minimize the amount of residue discharged and achieve near-zero wastewater discharge.

[0019] Preferably, in step c), the biochemical treatment includes hydrolysis acidification and anoxic / aerobic activated sludge treatment, followed by solid-liquid separation via an MBR membrane; the reverse osmosis treatment includes primary reverse osmosis treatment of the MBR permeate and secondary reverse osmosis treatment of the concentrate produced from the primary reverse osmosis. In actual operation, hydrolysis acidification pretreatment improves the biodegradability of wastewater; the A / O activated sludge process effectively degrades organic matter and removes nitrogen and phosphorus; MBR membrane separation replaces the traditional secondary sedimentation tank, resulting in excellent effluent quality and a small footprint; the addition of concentrated water reverse osmosis further improves the total water recovery rate of the system, reduces concentrated water discharge, and maximizes water resource reuse.

[0020] The beneficial effects of the hazardous waste physicochemical disposal system provided by this invention are as follows: (1) This hazardous waste physical and chemical treatment system classifies liquid hazardous waste into inorganic and organic categories at the source, sets up independent treatment lines for each category, and sets up an independently designed photosensitive material waste liquid treatment unit in the inorganic waste liquid treatment line. It classifies and grades different types of hazardous waste for pretreatment, and the process is highly targeted. It can effectively remove pollutants such as heavy metals, organic matter, and oils from waste liquid, and realize the refined and targeted treatment of multi-source liquid hazardous waste, which significantly improves the treatment efficiency and effect of various types of waste liquid.

[0021] (2) In this hazardous waste physicochemical disposal system, the photosensitive material waste liquid treatment unit uses multi-stage coupled precipitation-electrolysis technology to achieve efficient recovery of valuable metals such as silver; the evaporation and concentration unit recovers crystalline salts through evaporation and crystallization; and the deep treatment unit achieves water resource reuse through reverse osmosis. The system achieves harmlessness while maximizing resource utilization.

[0022] (3) The present invention sets up two evaporation systems (multi-effect evaporation and MVC evaporation) for different water qualities in the evaporation and concentration unit, which can select the optimal evaporation process according to the characteristics of wastewater, save energy and reduce consumption, and improve evaporation efficiency. At the same time, an enamel kettle is set up to perform secondary evaporation and crystallization of the concentrate, realizing near-zero discharge of wastewater and resource utilization of salt.

[0023] (4) The present invention integrates multiple protection processes of “biochemical + MBR + activated carbon + reverse osmosis” in the deep treatment unit, which can effectively remove residual organic matter, ammonia nitrogen and salt in the evaporation condensate, ensuring that the final effluent water quality is stable and meets the standards, and can even be reused in production, realizing the recycling of water resources.

[0024] (5) The design of this hazardous waste physical and chemical disposal system is reasonable, and the units work together to fully embody the concept of "treating waste with waste" and energy conservation and emission reduction. The overall operating cost is low, and it has good economic and environmental benefits. Attached Figure Description

[0025] Figure 1 This is a system structure block diagram of the present invention.

[0026] Figure 2 This is a flowchart of the inorganic waste liquid treatment process in an embodiment of the present invention.

[0027] Figure 3 This is a flowchart of the organic waste liquid treatment process in an embodiment of the present invention.

[0028] Figure 4 This is a flowchart of the wastewater treatment process in the evaporation workshop according to an embodiment of the present invention.

[0029] Figure 5 This is a flowchart of the wastewater treatment process in the wastewater treatment workshop according to an embodiment of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0031] Example: A hazardous waste physical and chemical disposal system.

[0032] Reference Figures 1 to 5 As shown, a hazardous waste physicochemical disposal system mainly includes a physicochemical pretreatment unit, an evaporation and concentration unit, and an advanced treatment unit.

[0033] I. Physicochemical Pretreatment Unit The physicochemical pretreatment unit is used to classify and pretreat various types of liquid hazardous waste entering the system. Based on the nature of the waste, it is mainly divided into inorganic waste liquid treatment lines (such as...). Figure 2 (as shown) and organic wastewater treatment lines (such as) Figure 3 (As shown).

[0034] The principle for treating inorganic waste liquid is to prioritize "treating waste with waste and saving energy and reducing emissions," that is, to prioritize the use of waste alkali to neutralize waste acid, and then use waste alkali or alkali solution to neutralize the remaining waste acid to ensure that the pH value and heavy metals meet the standards. This invention uses waste alkali or liquid alkali as a neutralizing agent, and then utilizes the strong oxidizing properties of Fenton's reagent to oxidize the organic matter in the waste liquid.

[0035] Organic wastewater treatment principles: Due to the variety of emulsified wastewater types and the different applications and methods of use, its composition can vary significantly. Using a single demulsification method can lead to substantial demulsification errors. Therefore, chemical methods are more stable and reliable for treating various emulsions. This invention employs an acid precipitation intermittent demulsification method to ensure complete demulsification. Specifically, sulfuric acid is added to the demulsification reactor, and after stirring and demulsification, the mixture enters the oil flotation unit. The upper oil phase is collected, and the lower aqueous phase undergoes solid-liquid separation in a filter press. The filtrate is temporarily stored in a filtrate tank and then pumped to an oxidation reactor for oxidation.

[0036] The wastewater treatment system employs a sequencing batch process, facilitating timely adjustment and control of effluent quality. First, organic and inorganic wastewater are pretreated separately. Then, they are combined for neutralization, flocculation, sedimentation, and advanced oxidation treatment before being discharged separately to designated boundary areas.

[0037] (1) Inorganic waste liquid treatment line This processing line is used to treat HW16 (photosensitive material waste liquid), HW17 (surface treatment waste), HW21 (chromium-containing waste), HW23 (zinc-containing waste), HW34 (waste acid), HW35 (waste alkali), HW49 (other inorganic waste liquid), etc.

[0038] Treatment principle: Prioritize "waste-to-waste" treatment, that is, prioritize the use of waste alkali to neutralize waste acid.

[0039] Main equipment includes: a photosensitive material waste liquid treatment unit, reduction reaction tanks R01001A / B, reduction reaction tanks R01003A / B / C / D, neutralization reaction tanks R01004A / B / C, a first advanced oxidation reaction tank R01005A / B / C / D / E / F, a first filter press F01001A / B, a second filter press F01002A / B, and multiple reagent preparation, storage, and conveying systems (such as ferrous sulfate preparation tank T01001, etc.). Ash silo H01001, sodium carbonate silo H01002, hydrogen peroxide dosing tank T01003A / B, lime slurry dosing tank T01012A / B, Na2CO3 dosing tank T01013A / B, NaOH dosing tank T01008A / B / C / D, TMT dosing tank T01011A / B, PAC dosing tank T01004A / B, PAM dosing tank T01005A / B, sulfuric acid dosing tank T01010A / B, etc.

[0040] Detailed operating instructions: 1. Feeding and Pretreatment: Different types of inorganic waste liquids enter different pretreatment units according to their characteristics.

[0041] HW16 (Photosensitive Material Waste Liquid): Entering the photosensitive material waste liquid treatment unit, it sequentially passes through the solid-liquid separation and waste liquid pretreatment unit, the targeted silver recovery unit, the organic matter super oxidation mineralization unit, and the residue final disposal unit, realizing the full resource utilization and near-zero emission process of HW16 photosensitive material waste liquid.

[0042] This photosensitive material wastewater treatment unit is designed to address the two core characteristics of HW16 photosensitive material wastewater: high silver content (extremely high resource value) and high concentration of recalcitrant organic pollutants (hydroquinone, methotrexate, thiosulfate, etc.). It employs a step-by-step, resource recovery and harmless treatment strategy, starting with the easier components and progressing to the more difficult ones. HW16 photosensitive material waste mainly contains silver complexes, hydroquinone, methotrexate, sodium carbonate, sodium thiosulfate, sodium sulfite, acetic acid, etc., and contains high concentrations of organic pollutants, ranging from 50,000 to 100,000 mg / L. It is neutral to weakly acidic and unsuitable for biological or incineration treatment, making it highly difficult to handle. Direct discharge without treatment would cause significant environmental pollution. Almost all the silver from color film enters the fixing solution, while approximately 70-80% of the silver from black and white film enters the fixing solution. Achieving efficient silver recovery is a key consideration in this process.

[0043] To achieve this goal, the photosensitive material wastewater treatment unit is divided into four sequentially connected functional areas: a solid-liquid separation and wastewater pretreatment unit, a targeted silver recovery unit, an organic super-oxidation mineralization unit, and a residue final disposal unit. The solid-liquid separation and wastewater pretreatment unit separates the mixed-collected photosensitive material wastewater into solid photosensitive material and liquid wastewater, and pretreats each separately. The targeted silver recovery unit achieves efficient silver recovery through multi-stage coupled precipitation-electrolysis technology. The organic super-oxidation mineralization unit utilizes a two-stage combined technology of wet catalytic oxidation and supercritical water oxidation to degrade high-concentration organic pollutants. The residue final disposal unit uses plasma melting and vitrification to treat the trace amounts of solid residue generated during thermal oxidation, achieving ultimate harmlessness. In actual operation, the sequential connection of these four functional units forms a complete technical chain from solid-liquid separation, silver recovery, organic degradation to the harmless disposal of residues, realizing the "full-component, full-process" treatment of photosensitive material wastewater.

[0044] The specific process of the photosensitive material waste liquid treatment unit is as follows: S1. The mixed and collected photosensitive material waste liquid is fed into a shearing and crushing machine in the solid-liquid separation and waste liquid pretreatment unit via a closed conveyor belt. It is crushed into flakes of 5-10cm × 5-10cm. The crushed material enters a counter-current washing drum and is rinsed counter-currently with warm water at 35-45℃. This removes residual chemicals from the film / photo paper surface, allowing them to enter the aqueous phase. The washing liquid is discharged into a waste liquid storage tank and combined with subsequent waste liquid treatment. The film base material is dewatered by a vibrating screen before proceeding to the next step. The washing liquid uses a closed-loop circulation system, and all cleaning wastewater is recycled to the waste liquid storage tank, achieving zero external discharge. The combination of shearing and crushing with counter-current washing drum and warm water rinsing achieves efficient desorption of residual chemicals from the solid photosensitive material. The combined treatment of the washing liquid and waste liquid avoids resource waste and secondary pollution.

[0045] S2. Add a 3-5% sodium hydroxide solution to the dehydrated sheet base material, while continuously introducing ozone. Heat and stir the mixture at 65-75℃ for 60-90 minutes. Combine the resulting silver-containing solution into a waste storage tank. Ozone plays a dual role in this system: firstly, as a strong oxidant, it disrupts the macromolecular structure of the gelatin emulsion layer; secondly, under alkaline conditions, it generates •OH free radicals, which synergistically work with NaOH to efficiently peel silver halides from the sheet base. After the reaction, the silver-free sheet base is separated, rinsed thoroughly with hot water, and can be sold as waste plastic or further processed.

[0046] S3. Pump the waste liquid from the waste liquid storage tank into a high-temperature reactor, heat it to 120-150℃, maintain the temperature for 30 minutes, and then feed it into a centrifuge to remove the colloidal sulfur produced by decomposition. The liquid phase flows into the precipitation reaction tank in the targeted silver recovery unit. Because the waste liquid contains a large amount of... Complex ions exhibit extremely high stability, but direct precipitation or electrolysis yields low efficiency. The waste liquid is pumped into a high-temperature reactor, heated to 120-150℃, and held for 30 minutes to partially decompose thiosulfate into sulfite and colloidal sulfur, while simultaneously breaking down... and The complexation equilibrium was achieved, significantly reducing the complexation degree of silver ions and creating favorable conditions for subsequent efficient precipitation and recovery. Colloidal sulfur was removed by heating in a high-temperature reactor combined with centrifugal separation, eliminating the interference of sulfur on the subsequent silver recovery process.

[0047] S4. Add sodium sulfide solution to the precipitation reaction tank (the dosage is 1.2 times the stoichiometric ratio of the silver content in the waste liquid), then dilute with water. Adjust the pH of the waste liquid to 3-4, so that After complete precipitation and filtration, The precipitate is sent to the next stage of electrolytic refining, and the filtered liquid phase is transported to the high-pressure reactor in the organic super oxidation mineralization unit. The chemical precipitation method is characterized by an extremely high silver recovery rate. This precipitation method can reduce the residual silver concentration in the waste liquid to below 5 mg / L.

[0048] S5, Filter the obtained The precipitate dissolves in dilute nitric acid, forming The solution is added to a rotating cathode electrolytic cell, with a current density of 200-300 A / m², a voltage of 2.5-3.5 V, and an electrolysis time of 8-12 hours. Flake silver with a purity of 95-99% is obtained through direct current electrolysis. The dilute nitric acid mist generated in the anode area during electrolysis is treated by an alkaline spray absorption tower. The absorbent (containing...) It is returned to the process system to adjust the pH or to serve as a supplementary nitrogen source for subsequent biochemical treatment units.

[0049] S6. Pure oxygen is introduced into the high-pressure reactor, and one or more of Pt, Pd, Rh, and Ru are added as active components, and one or more of La, Ce, Pr, and Nd are added as auxiliary agents, supported on... The catalyst on the support was reacted at a temperature controlled at 220-280℃, a pressure controlled at 4.0-8.0 MPa, and a time controlled at 60-90 minutes. Noble metals were used as the active component, and rare earth elements were used as auxiliary agents. The catalyst, supported by a carrier, is subjected to wet catalytic oxidation at 220-280℃ and 4.0-8.0 MPa. The catalyst exhibits high activity and good stability, and can efficiently degrade high concentrations of organic pollutants.

[0050] S7. The waste liquid after oxidation in the high-pressure reactor is transferred to the supercritical water oxidation reactor. Liquid oxygen or hydrogen peroxide is added as an oxidant, and the reaction temperature is controlled at 450-550℃, the reaction pressure at 20-30 MPa, and the reaction time at 2-5 minutes. Because the concentration of organic matter such as hydroquinone and methotrexate in the photosensitive material waste liquid is extremely high, with organic pollution concentrations reaching 50,000 to 100,000 mg / L, and it is unsuitable for biological or incineration treatment, traditional biochemical treatment methods are ineffective. This unit adopts a two-stage oxidation route of "catalytic wet oxidation (CWAO) for pretreatment and load reduction + supercritical water oxidation (SCWO) for final mineralization." CWAO reduces COD from over 100,000 mg / L to 20,000-30,000 mg / L, and then SCWO achieves a mineralization rate of over 99%, significantly reducing the energy consumption and operating costs of SCWO. Moreover, the use of supercritical water oxidation technology (450-550℃, 20-30 MPa, 2-5 minutes) can completely mineralize residual organic matter in a very short time. and It has a fast reaction rate, complete degradation, and no secondary pollution.

[0051] S8. The liquid treated by the supercritical water oxidation reactor is transported to the rotary kiln pyrolysis furnace in the residue final disposal unit for low-temperature pyrolysis pretreatment, and then to the plasma gasification melting furnace for final vitrification treatment. Although the CWAO+SCWO process has an extremely high removal rate of organic matter, it still produces a very small amount of inorganic salt residue. In addition, trace amounts of silver-containing residue generated after the solid photosensitive material is peeled off from the substrate also need to be treated. This unit performs "final disposal" on these residues to ensure that no contaminants escape.

[0052] By employing a three-stage process of "high-temperature complex-breaking pretreatment → sulfide precipitation enrichment → electrolytic refining and purification" in the photosensitive material waste liquid treatment unit, a silver recovery rate of ≥99.5% can be achieved, with the final product being metallic silver with a purity of over 99.9%. Using CWAO for pre-degradation of high-concentration organic waste liquid (COD removal rate >95%) before final mineralization in the SCWO unit significantly reduces the investment and operating costs of SCWO, while simultaneously overcoming the efficiency and cost bottlenecks of single oxidation technology. For extremely difficult-to-dispose-of residual solids, plasma melting at temperatures above 1500℃ is used to form a highly chemically stable glassy slag, achieving ultimate harmlessness and completely eliminating the long-term environmental risks associated with landfilling.

[0053] HW17 (surface treatment waste), HW21 (chromium-containing waste), and other hexavalent chromium-containing waste liquids are introduced into reduction reaction tanks R01001A / B or R01003A / B / C / D, and FeSO4 or sodium bisulfite solution and sulfuric acid are added. Under acidic conditions, hexavalent chromium is reduced to trivalent chromium.

[0054] HW23 (zinc-containing waste), HW34 (waste acid), HW35 (waste alkali) and HW49 (other inorganic waste liquids): can be directly fed into neutralization reaction tanks R01004A / B / C.

[0055] 2. Neutralization and Coagulation Sedimentation: The pretreated waste liquid (or the waste liquid that enters directly) enters the neutralization reaction tank R01004A / B / C. In the neutralization reaction tank, the normal process involves adding... The pH is adjusted using NaOH solution to cause heavy metal ions to precipitate as hydroxides or carbonates. After modification, the recycled alkaline waste liquid is used instead. Additives such as NaOH are neutralized through acid-base neutralization reactions and alkaline waste liquid. Plasma simultaneously achieves the functions of pH adjustment and heavy metal removal in wastewater, realizing the effect of treating waste with waste and reducing costs. The use of auxiliary materials such as NaOH and heavy metal chelating agents reduces disposal costs. PAC (polyaluminum chloride) and PAM (polyacrylamide) are then added for coagulation and flocculation. The resulting mixture undergoes solid-liquid separation using a first filter press F01001A / B. The filtrate flows by gravity into a filter press pond, while the sludge (heavy metal sludge) is transported off-site for disposal.

[0056] 3. Advanced Oxidation: Wastewater from the filter press is pumped to the first advanced oxidation reactor R01005A / B / C / D / E / F. Sulfuric acid is first added to adjust the pH to approximately 4.0, then... and The solution undergoes Fenton oxidation for 1-2 hours to degrade organic matter in the wastewater. After the reaction, NaOH is added to adjust the pH to 7-8, producing iron-containing sludge precipitate again. PAC, PAM, and TMT are then added for coagulation. The mixture is then separated into solid and liquid phases using a second filter press F01002A / B. The wastewater enters the effluent tank and is discharged to the evaporation and concentration unit; the sludge (inorganic sludge) is transported off-site for disposal.

[0057] (2) Organic waste liquid treatment line This processing line is used to treat HW06 (waste organic solvents), HW08 (waste mineral oil), HW09 (waste emulsions), HW12 (dye and paint waste), HW49 (other organic waste liquids), etc.

[0058] Main equipment includes: floating oil tank T01025A / B / C / D, demulsification reaction tanks R01006A / B and R01007A / B / C / D, acid reaction tank R01009A / B, air flotation equipment S01005A / B / C and S01006A / B / C, coagulation and flocculation tank R01010A / B / C, second advanced oxidation reaction tank R01011A / B / C / D / E / F, third filter press F01003A / B, fourth filter press F01004A / B / C, and corresponding second dosing tanks (such as demulsifier dosing tank T01006A / B, etc.).

[0059] Detailed operating instructions: 1. Feeding and Pretreatment: High-oil / emulsion waste liquids such as HW08 (waste mineral oil) and HW09 (waste emulsion): First, perform oil separation in the storage tank area (floating oil ton tank), and allow it to stand and separate into layers to remove floating oil. The lower liquid layer enters the demulsification reaction tank (such as R01007A / B / C / D).

[0060] HW06 (waste organic solvents), HW12 (dye and paint waste) and HW49 (other organic waste liquids): can be directly fed into demulsification reaction tanks or acid reaction tanks.

[0061] 2. Demulsification and Flotation: In the demulsification reaction tanks (R01006, R01007, R01008) or acid reaction tank (R01009), sulfuric acid is added to adjust the pH to 2-3, and PAC and PAM solutions are added. Heating is performed if necessary, and the mixture is thoroughly stirred to carry out the demulsification reaction. The resulting mixture is discharged into the flotation equipment (S01005, S01006). The flotation equipment generates a large number of microbubbles through dissolved air water, carrying flocs and emulsified oil particles to the water surface to form scum, which is scraped into the oil scum tank by a scum scraper. The flotation effluent enters the buffer tank or directly enters the coagulation and flocculation tank.

[0062] 3. Coagulation and Sedimentation: The effluent from the air flotation enters the coagulation and flocculation tanks R01010A / B / C. Acidic waste liquid is added to perform secondary acidification and demulsification of the organic waste liquid. After demulsification, alkaline waste liquid is added to adjust the pH, and PAC and PAM are added again for coagulation. Then, solid-liquid separation is achieved through the third filter press F01003A / B. The filtrate enters the filter press pond, and the sludge (organic sludge) is transported off-site for disposal. This treatment further reduces the concentration of organic waste liquid, ensuring effluent quality and reducing the load on subsequent processes, while avoiding additional auxiliary material costs. By treating waste with waste, cost reduction and efficiency improvement are achieved.

[0063] 4. Advanced Oxidation: Wastewater from the filter press is pumped to the second advanced oxidation reactor R01011A / B / C / D / E / F. Its operation is the same as the first advanced oxidation reactor, using the Fenton oxidation method to further degrade organic matter. The oxidized mixture undergoes final solid-liquid separation via the fourth filter press F01004A / B / C. The wastewater enters the effluent tank and is then discharged to the evaporation and concentration unit. II. Evaporation and Concentration Unit The evaporation and concentration unit is used to receive and treat wastewater from the physicochemical pretreatment unit. For example... Figure 4 As shown, the evaporation and concentration unit employs a combination of chemical precipitation, coagulation, and gravity separation to treat wastewater of different properties separately. This unit is divided into two lines based on wastewater quality: organic wastewater and inorganic wastewater. The organic wastewater is the organic wastewater treated by the organic line in the physicochemical workshop; the inorganic wastewater is the inorganic wastewater treated by the inorganic line in the physicochemical workshop.

[0064] Main equipment includes an integrated inorganic coagulation and sedimentation system (30 m³ / h), an integrated organic coagulation and sedimentation system (15 m³ / h), a high-pressure diaphragm filter press, two DTRO membrane separation systems (total processing capacity 720 m³ / d), one MVC evaporation and crystallization system (300 t / d), one multi-effect evaporation and crystallization system (300 t / d), and supporting storage tanks, pumps, and automatic control systems.

[0065] Detailed operating instructions: 1. Pretreatment section: Organic wastewater and inorganic wastewater first enter their respective integrated coagulation and sedimentation equipment, where residual heavy metals, suspended solids and some organic matter are further removed through chemical precipitation and coagulation, reducing the load on subsequent evaporation and membrane treatment.

[0066] 2. DTRO membrane treatment section: The pretreated wastewater enters the DTRO membrane separation equipment for further concentration and purification. The separated product water enters the subsequent section, and the concentrated water enters the evaporation system.

[0067] 3. Evaporation and Crystallization Section: Organic wastewater (from the organic treatment line) enters a multi-effect evaporation system for evaporation and concentration.

[0068] Inorganic wastewater (from the inorganic treatment line) enters the MVC evaporation system for evaporation and concentration.

[0069] The condensate produced by evaporation enters the advanced treatment unit. The concentrated liquid (high-concentration salt slurry) produced by evaporation is sent to an enamel-lined autoclave for further evaporation and crystallization. The crystallized salt is transported off-site for hazardous waste disposal or utilized as a resource, achieving near-zero wastewater discharge.

[0070] III. Deep Processing Unit The advanced treatment unit receives and treats condensate from the evaporation and concentration unit, as well as floor flushing water and domestic sewage within the plant area, ensuring that the final effluent meets discharge standards or is reused. For example... Figure 5 As shown.

[0071] Main equipment includes equalization tank, hydrolysis acidification tank, anoxic tank, aerobic tank, MBR membrane tank, buffer tank, activated carbon filter, RO system (including raw water reverse osmosis and concentrate reverse osmosis), sludge dewatering system, and supporting dosing system and automatic control system.

[0072] Detailed operating instructions: 1. Biological Treatment: After homogenization and equalization of various types of incoming water in the equalization tank, it is pumped into the hydrolysis acidification tank, where large, recalcitrant organic molecules are broken down into smaller molecules, improving the biodegradability of the wastewater. The wastewater then enters the anoxic and aerobic tanks, where most of the organic matter and ammonia nitrogen are removed using activated sludge. The mixed liquor from the aerobic tank is returned to the anoxic tank for denitrification. The MBR membrane tank performs solid-liquid separation on the mixed liquor from the aerobic tank, replacing the traditional secondary sedimentation tank to obtain high-quality effluent. The MBR permeate then enters the buffer tank.

[0073] 2. Advanced Treatment: Water in the buffer tank is pumped into an activated carbon filter, where the activated carbon further removes organic matter and color through adsorption. When the effluent from the activated carbon filter fails to meet discharge requirements, the effluent enters the RO system. The RO system desalinates the MBR permeate, which is then discharged into an effluent tank to meet discharge standards or reused. RO concentrate can be returned to the pre-treatment tank or subjected to specialized treatment.

[0074] 3. Sludge Treatment: The excess sludge generated in the MBR membrane tank is discharged into the sludge conditioning and thickening tank. After PAM conditioning, it undergoes deep dewatering through a high-pressure diaphragm filter press, reducing the moisture content of the sludge cake to below 60%. The filtrate is returned to the equalization tank for reprocessing.

[0075] This hazardous waste physicochemical disposal system organically combines classified physicochemical pretreatment, targeted evaporation and concentration, and multi-stage deep treatment to form a complete, efficient, and reliable overall solution for the treatment of liquid hazardous waste. It can effectively cope with complex and ever-changing waste characteristics, ensure environmental safety throughout the treatment process, and maximize waste reduction and resource recovery.

[0076] The influent water quality of this hazardous waste physical and chemical treatment system is shown in Table 1: Table 1. Influent water quality after physicochemical treatment

[0077] The effluent quality after treatment by this hazardous waste physicochemical disposal system is shown in Table 2: Table 2. Water quality of effluent from physicochemical treatment

[0078] Analysis of the data in Tables 1 and 2 above shows that this hazardous waste physicochemical treatment system has a strong acid-base neutralization capacity. The system can adjust the extreme pH to the standard discharge range (6-9) through the synergistic neutralization of acid and base waste liquids without the need to add a large amount of neutralizing agent, which significantly reduces acid and base corrosiveness and ecotoxicity.

[0079] Analysis of the data in Tables 1 and 2 shows that this hazardous waste physicochemical treatment system has extremely high ammonia nitrogen removal efficiency, >99.99% (estimated after mixing, the actual removal rate is close to 100%), which is far lower than the national emission standards (such as the first-level standard of 15 mg / L in GB 8978-1996), effectively preventing eutrophication of water bodies.

[0080] Analysis of the data in Tables 1 and 2 above shows that this hazardous waste physicochemical treatment system has excellent chemical oxygen demand (COD) reduction capacity, with a COD removal rate of >99.9%, and the effluent COD is significantly lower than the general discharge standard, significantly reducing the organic pollution load.

[0081] Analysis of the data in Tables 1 and 2 shows that this hazardous waste physicochemical treatment system has a high efficiency in removing heavy metals (copper and zinc), with a removal rate of >99.8% for copper and >99.99% for zinc, which is far below the emission standards (e.g., total copper ≤0.5 mg / L, total zinc ≤2.0 mg / L), thus avoiding long-term pollution of soil and water bodies by heavy metals.

[0082] As can be seen from the above data, this hazardous waste physicochemical treatment system can simultaneously treat five typical hazardous wastes, including waste acid, waste alkali, waste emulsion, surface treatment waste liquid, and laboratory waste liquid, achieving "waste treatment with waste": waste acid and waste alkali neutralize each other, reducing reagent consumption; high-concentration organic waste liquid and heavy metal waste liquid improve the overall treatment efficiency through co-precipitation and adsorption.

[0083] The treated effluent meets or even exceeds the national standards for water pollutant discharge limits, and can be discharged in compliance with standards or reused in production.

[0084] The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in the embodiments and drawings. Therefore, any equivalent or modified embodiments made without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A physicochemical treatment process for hazardous waste, characterized in that, include: A physicochemical pretreatment unit is used for the classification and pretreatment of liquid hazardous waste. The physicochemical pretreatment unit includes an inorganic waste liquid treatment line and an organic waste liquid treatment line. The inorganic waste liquid treatment line includes an independently designed photosensitive material waste liquid treatment unit, a reduction reaction tank, a neutralization reaction tank, and a first advanced oxidation reaction tank connected in sequence, as well as a first filter press and a second filter press connected to the discharge ports of the neutralization reaction tank and the first advanced oxidation reaction tank, respectively. The organic waste liquid treatment line includes an oil separator tank, a demulsification reaction tank, an air flotation device, a coagulation and flocculation tank, and a second advanced oxidation reaction tank connected in sequence, as well as a third filter press and a fourth filter press connected to the discharge ports of the coagulation and flocculation tank and the second advanced oxidation reaction tank, respectively. An evaporation and concentration unit, connected to the outlet of the physicochemical pretreatment unit, is used to evaporate and crystallize the pretreated wastewater. The evaporation and concentration unit includes a first evaporation system and a second evaporation system connected in parallel. The first evaporation system is used to treat organic wastewater, and the second evaporation system is used to treat inorganic wastewater. A deep treatment unit, which is connected to the outlet of the evaporation and concentration unit, is used to deeply purify the evaporated condensate. The deep treatment unit includes a biochemical treatment system, a membrane separation system, and a reverse osmosis system connected in sequence. The photosensitive material waste liquid treatment unit includes a solid-liquid separation and waste liquid pretreatment unit, a targeted silver recovery unit, an organic super-oxidation mineralization unit, and a residue final disposal unit connected in sequence. The solid-liquid separation and waste liquid pretreatment unit separates the mixed-collected photosensitive material waste liquid into solid photosensitive material and liquid waste liquid, and pretreats each separately. The targeted silver recovery unit achieves efficient silver recovery through multi-stage coupled precipitation-electrolysis technology. The organic super-oxidation mineralization unit utilizes a two-stage combined technology of wet catalytic oxidation and supercritical water oxidation to degrade high-concentration organic pollutants. The residue final disposal unit is used to perform plasma melting vitrification treatment on the extremely small amount of solid residue generated during the thermal oxidation process, achieving ultimate harmlessness. The specific process of the photosensitive material waste liquid treatment unit is as follows: S1. The mixed and collected photosensitive material waste liquid is fed into the shearing and crushing machine in the solid-liquid separation and waste liquid pretreatment unit via a closed conveyor belt. It is crushed into flakes and the crushed material enters the countercurrent washing drum. It is washed with warm water in a countercurrent flow to remove the residual liquid on the surface of the film / photo paper and let it enter the aqueous phase. The washing liquid is discharged into the waste liquid storage tank and combined with the subsequent waste liquid for treatment. The film base material is dewatered by a vibrating screen and then enters the next step of processing. S2. Add a 3-5% sodium hydroxide solution to the dehydrated sheet base material, while continuously introducing ozone. Heat and stir at 65-75℃ for 60-90 minutes. Combine the silver-containing solutions after the reaction into the waste liquid storage tank. S3. Pump the waste liquid in the waste liquid storage tank into the high temperature reactor, heat it to 120-150℃, keep it at that temperature for 30 minutes, and then feed it into the centrifuge to remove the colloidal sulfur produced by decomposition. The liquid phase flows into the precipitation reaction tank in the targeted silver recovery unit. S4. Add sodium sulfide solution to the precipitation reaction tank, and then use dilute H2SO4 to adjust the pH of the waste liquid to 3-4 so that Ag2S can precipitate completely. After filtration, the Ag2S precipitate is sent to the next stage of electrolytic refining. The filtered liquid phase is sent to the high-pressure reactor in the organic super oxidation mineralization unit. S5. Dissolve the filtered Ag2S precipitate in dilute nitric acid to generate AgNO3 solution, and add it to a rotating cathode electrolytic cell to obtain flake silver with a purity of 95-99% by DC electrolysis. S6. Introduce pure oxygen into the high-pressure reactor and add a catalyst supported on a TiO2-ZrO2 support, with one or more of Pt, Pd, Rh, and Ru as active components and one or more of La, Ce, Pr, and Nd as promoters. Control the reaction temperature at 220-280℃, the reaction pressure at 4.0-8.0 MPa, and the reaction time at 60-90 minutes. S7. The waste liquid after oxidation in the high-pressure reactor is transported to the supercritical water oxidation reactor, and liquid oxygen or hydrogen peroxide is added as an oxidant. The reaction temperature is controlled at 450-550℃, the reaction pressure at 20-30 MPa, and the reaction time at 2-5 minutes. S8. The liquid treated by the supercritical water oxidation reactor is transported to the rotary kiln pyrolysis furnace in the residue final disposal unit for low-temperature pyrolysis pretreatment, and then transported to the plasma gasification melting furnace for vitrification final treatment.

2. The hazardous waste physicochemical treatment process according to claim 1, characterized in that, The inorganic waste liquid treatment line further includes: multiple first dosing tanks for storing and adding ferrous sulfate, hydrogen peroxide, sodium carbonate, sodium hydroxide, TMT, PAC, and PAM reagents, the first dosing tanks being connected to the reduction reaction tank, neutralization reaction tank, and first advanced oxidation reaction tank respectively; the organic waste liquid treatment line further includes: multiple second dosing tanks for storing and adding sulfuric acid, PAC, PAM, ferrous sulfate, hydrogen peroxide, sodium hydroxide, and TMT reagents, the second dosing tanks being connected to the demulsification reaction tank, coagulation and flocculation tank, and second advanced oxidation reaction tank respectively.

3. The hazardous waste physicochemical treatment process according to claim 1, characterized in that, The first evaporation system is a multi-effect evaporator, and the second evaporation system is an MVC evaporator; the evaporation concentration unit also includes an enamel-lined kettle evaporator connected to the concentrate outlet of the multi-effect evaporator and the MVC evaporator.

4. The hazardous waste physicochemical treatment process according to claim 1, characterized in that, The biochemical treatment system of the advanced treatment unit includes a hydrolysis acidification tank, an anoxic tank, an aerobic tank and an MBR membrane tank connected in sequence. After the MBR membrane tank, a buffer tank, an activated carbon filter and a reverse osmosis system are connected in sequence. The product water outlet of the reverse osmosis system is connected to the effluent tank.

5. The hazardous waste physicochemical treatment process according to claim 1, characterized in that, The hazardous waste physicochemical disposal process is implemented according to the following steps: a) Liquid hazardous waste is classified and pretreated in the physicochemical pretreatment unit according to inorganic and organic waste liquids, and physicochemical reactions and solid-liquid separation are carried out respectively to obtain pretreated clear liquid and sludge; b) The pretreated clear liquid obtained in step a) is sent to the evaporation and concentration unit, and then sent to the organic wastewater treatment line or the inorganic wastewater treatment line for evaporation and concentration according to its source, to obtain condensate, crystallized salt and concentrated residue. c) The condensate obtained in step b) is sent to the advanced treatment unit for sequential biochemical treatment, membrane separation and reverse osmosis treatment, so that the effluent meets the discharge standards or is reused.

6. The hazardous waste physicochemical treatment process according to claim 5, characterized in that, The pretreatment of inorganic waste liquid in step a) includes: independent treatment of photosensitive material waste liquid; reduction or complex breaking reaction of chromium-containing waste liquid or waste liquid containing other heavy metals, followed by neutralization, coagulation and sedimentation and first advanced oxidation treatment; the pretreatment of organic waste liquid includes: demulsification and flotation treatment of oil / emulsion waste liquid, followed by coagulation and sedimentation and second advanced oxidation treatment.

7. The hazardous waste physicochemical treatment process according to claim 5, characterized in that, In step b), the organic wastewater is treated using a multi-effect evaporation system, and the inorganic wastewater is treated using an MVC evaporation system; the concentrated residue produced by evaporation is sent to an enamel kettle for further evaporation and crystallization.

8. The hazardous waste physicochemical treatment process according to claim 5, characterized in that, In step c), the biochemical treatment includes hydrolysis acidification and anoxic / aerobic activated sludge treatment, and solid-liquid separation is performed through an MBR membrane; the reverse osmosis treatment includes primary reverse osmosis treatment of the MBR permeate and concentrated water reverse osmosis treatment of the concentrated water produced by the primary reverse osmosis.

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