A method for deep treatment and reuse of high-salt organic wastewater

Abstract

The present invention provides a method for deep treatment and reuse of high-salt organic wastewater. The high-salt organic wastewater is pretreated and then mixed with an oxidant I. A primary catalytic oxidation reaction is performed to oxidize and decompose most of the organic matter in the wastewater into carbon dioxide and water. The effluent from the primary catalytic oxidation is then mixed with an oxidant II. A secondary catalytic oxidation reaction is performed to further oxidize and decompose the organic matter in the wastewater. The pH of the effluent is adjusted, and the catalyst can be recovered and recycled. The effluent from the secondary catalytic oxidation is then adsorbed and sent to a chlor-alkali plant as raw material for the production of chemical raw materials such as chlorine. The treatment method is simple and easy to implement, has low treatment cost, and is highly efficient. It can achieve resource reuse of high-salt organic wastewater without generating secondary pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical engineering and environmental engineering wastewater treatment, and more specifically, relates to a method for deep treatment and reuse of high-salt organic wastewater. Background Art

[0002] Epichlorohydrin (ECH) is primarily used in the production of epoxy resin, an important chemical raw material. Currently, there are three main synthesis processes: the high-temperature chlorination of propylene, the propylene acetate method, and the glycerol method. The high-temperature chlorination of propylene is currently the most widely used production process in the industry. The glycerol method, due to its economic and environmental advantages, is the future development direction of ECH production. ECH wastewater primarily comes from the saponification process of dichloropropanol with calcium hydroxide or sodium hydroxide. The wastewater primarily contains NaCl / CaCl2, glycerol, alcohol condensation products, and chlorohydrin reaction byproducts. Bisphenol A (BPA)-based epoxy resins are primarily produced by the reaction of BPA and epichlorohydrin under alkaline conditions. The wastewater primarily contains NaCl and glycerol, both of which are high-salt organic wastewater.

[0003] ECH and BPA epoxy resin wastewater has a NaCl content of 4.0wt% to 22.0wt% and a total organic carbon (TOC) of 1000 to 5000 mg / L. It is characterized by high salt content, large fluctuations in water quality, and a high organic content. Currently, there are three common treatment options in the industry. The first is to mix and dilute the wastewater with low-salt production wastewater and domestic sewage, then send it for biochemical treatment. Once qualified, it is directly discharged. However, this does not recover the NaCl and water resources in the wastewater, resulting in high treatment costs and significant resource waste. The second is to evaporate the salt after simple pretreatment. However, due to the large amount of organic matter in the salt, it is difficult to sell and poses a significant environmental pollution risk. The third is to deeply treat the organic matter in the wastewater through advanced oxidation processes such as catalytic wet oxidation, and then send it for chlor-alkali treatment after meeting the brine acceptance standards of the chlor-alkali plant. This process realizes the resource utilization of the brine, but it requires large equipment investment, high treatment costs, and high maintenance expenses.

[0004] Invention patent CN 105621764 B discloses a process for treating ECH production wastewater. High-salinity organic wastewater undergoes catalytic wet oxidation and UV-hydrogen peroxide oxidation before being transferred to chlor-alkali. However, catalytic wet oxidation equipment requires significant investment, high reaction temperatures and pressures, resulting in high treatment costs and unstable operation. Consequently, high-salinity organic wastewater urgently requires an efficient, low-cost treatment technology that can fully reuse the brine. Summary of the Invention

[0005] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0006] The present invention aims to provide a method for the advanced treatment and reuse of ECH and BPA epoxy resin wastewater. The method is simple and easy to implement, has high treatment efficiency, can realize the resource reuse of waste brine, and does not cause secondary pollution.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] A method for deep treatment and reuse of high-salt organic wastewater, characterized in that the method comprises the following steps:

[0009] S1: High-salt organic wastewater is mixed with oxidant I, and after adjusting the pH value, it is sent to the primary catalytic oxidation reactor. Under the action of the heterogeneous catalyst, some organic matter in the wastewater is oxidized and decomposed into carbon dioxide and water;

[0010] S2: The waste gas obtained in S1 is discharged, and the effluent from the primary catalytic oxidation reactor is mixed with oxidant II after adjusting the pH value, and then sent to the secondary catalytic oxidation reactor. Under the action of the composite catalyst, the residual organic matter in the wastewater is further oxidized and decomposed, and the pH value of the effluent is adjusted;

[0011] S3: The waste gas obtained in S2 is treated and discharged, and the effluent from S2 is sent to the chlor-alkali unit as raw material after adsorption;

[0012] Among them, the composite catalyst described in S2 is Cu, Fe, Mn and lactide tar modified with chitosan and dextran.

[0013] In the present invention, the high-salt organic wastewater described in S1 preferably meets the following conditions: TOC ≤ 5000 mg / L, preferably 10-4000 mg / L; SS ≤ 100 mg / L, preferably 20-60 mg / L; NaCl 4.0 wt% to 25.0 wt%, preferably 5.0 wt% to 20.0 wt%, based on the total amount of wastewater.

[0014] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0015] The present invention aims to provide a method for the advanced treatment and reuse of ECH and BPA epoxy resin wastewater. The method is simple and easy to implement, has high treatment efficiency, can realize the resource reuse of waste brine, and does not cause secondary pollution.

[0016] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0017] A method for deep treatment and reuse of high-salt organic wastewater, characterized in that the method comprises the following steps:

[0018] S1: High-salt organic wastewater is mixed with oxidant I, and after adjusting the pH value, it is sent to the primary catalytic oxidation reactor. Under the action of the heterogeneous catalyst, some organic matter in the wastewater is oxidized and decomposed into carbon dioxide and water;

[0019] S2: The waste gas obtained in S1 is discharged, and the effluent from the primary catalytic oxidation reactor is mixed with oxidant II after adjusting the pH value, and then sent to the secondary catalytic oxidation reactor. Under the action of the composite catalyst, the residual organic matter in the wastewater is further oxidized and decomposed, and the pH value of the effluent is adjusted;

[0020] S3: The waste gas obtained in S2 is treated and discharged, and the effluent from S2 is sent to the chlor-alkali unit as raw material after adsorption;

[0021] Among them, the composite catalyst described in S2 is Cu, Fe, Mn and lactide tar modified with chitosan and dextran.

[0022] In the present invention, the high-salt organic wastewater described in S1 preferably meets the following conditions: TOC ≤ 5000 mg / L, preferably 10-4000 mg / L; SS ≤ 100 mg / L, preferably 20-60 mg / L; NaCl 4.0 wt% to 25.0 wt%, preferably 5.0 wt% to 20.0 wt%, based on the total amount of wastewater.

[0023] In the present invention, the catalyst described in S1 mainly includes TiO2 and Ni and Fe supported on the titanium dioxide in the form of oxides; based on the weight of the TiO2, the content of the following components in the catalyst is: Ni 2.0wt% to 10.0wt%, preferably 3.0wt% to 8.0wt%; Fe 1.0wt% to 3.0wt%, preferably 2.0wt% to 3.0wt%, Ni and Fe are the main active components, and TiO2 is the carrier. Preferably, the catalyst includes a Ce-modified TiO2 carrier and Ni and Fe supported on the Ce-modified TiO2 carrier in the form of oxides, and based on the weight of the TiO2, the Ce content in the Ce-modified TiO2 carrier is 1.0wt% to 2.0wt%, preferably 1.2wt% to 1.5wt%.

[0024] The TiO2 carrier described in S1 is a Ce-NCA-Zn modified TiO2 carrier, and the TiO2 carrier is loaded with a low eutectic solvent of n-octanoic acid-zinc chloride (NCA-Zn). A low eutectic solvent is a low melting point mixture formed by hydrogen bond acceptors such as quaternary ammonium salts and hydrogen bond donors such as amides, carboxylic acids, and alcohols through hydrogen bonding in a certain proportion. It has excellent properties such as easy preparation, degradability, and strong polarity. By changing the types and proportions of hydrogen bond acceptors and donors, the physical properties, hydrogen bond forming ability, action intensity, and characteristics of the low eutectic solvent can be changed to improve the solubility of the solute and its own catalytic effect; TiO2 has good stability under both acidic and alkaline conditions and is widely used in the processing of catalysts, but its small specific surface area limits its wider application. Mixing Ce with a low eutectic solvent such as NCA-Zn before loading can significantly improve the loading effect of Ce on the TiO2 carrier, improve the structural properties of the TiO2 carrier, increase the specific surface area and strength of the carrier, provide more active sites, and give full play to the adsorption and catalytic ability of n-octanoic acid-zinc chloride itself, thereby improving catalytic efficiency. At the same time, Ce has good storage and release oxygen performance, and the generation of active oxygen free radicals by the oxidant I on the main active component of the catalyst is the key to degrading organic matter. When the carrier of the catalyst is a Ce-NCA-Zn modified TiO2 carrier, when the catalyst catalyzes oxidation of the oxidant I (such as sodium hypochlorite), the active oxygen free radicals generated by the oxidant I on the main active component of the catalyst can be promptly migrated to the Ce of the Ce-NCA-Zn modified TiO2 carrier for storage, thereby increasing the number of sites for active oxygen free radicals and increasing the reaction sites. This can significantly improve the oxidation efficiency during the catalytic oxidation process and improve the removal effect of organic matter.

[0025] For example, when the catalyst carrier is Ce-NCA-Zn modified TiO2 and the oxidant I is NaClO, ClO - In NiO x Active oxygen free radicals are generated on NiO x -Ce-NCA-Zn-TiO2 structure can timely transfer NiO x The active oxygen free radicals generated on the surface migrate to Ce-NCA-Zn, thereby increasing the number of reaction sites, effectively degrading organic matter and improving TOC removal rate. The catalytic oxidation mechanism is as follows:

[0026] ClO - →Cl - +[O], i.e. CAT+NaClO→CAT-O+NaCl ①;

[0027] ORG+CAT-O→ORG-O+CAT ②;

[0028] ORG-O+CAT-O→CO3 2-+H2O+CAT ③.

[0029] Where [O] represents the active oxygen radical, CAT represents the catalyst, and ORG represents the organic matter. CAT-O represents the active site on the catalyst, which contains [O]. ORG-O represents the organic matter bound to [O]. Formula 1 describes the process by which sodium hypochlorite is catalyzed to produce [O] on the catalyst; Formula 2 describes the process by which the catalyst with the [O] active site contacts the organic matter and transfers [O] to the organic matter; and Formula 3 describes the process by which the organic matter bound to [O] is degraded into small molecules or carbon dioxide and water under the action of the catalyst.

[0030] Preferably, the Ni, Fe, and Ce are respectively derived from one or more of nitrates, hydrochlorides, carbonates, or acetates containing the corresponding metal elements, preferably nitrates.

[0031] Preferably, the NCA-Zn low eutectic solvent is added in an amount of 2.5 wt% to 10.0 wt%, preferably 3.0 wt% to 9.0 wt%, based on the weight of TiO2.

[0032] Furthermore, the preparation method of NCA-Zn deep eutectic solvent is as follows:

[0033] Octanoic acid and zinc chloride were dissolved in anhydrous ethanol at a molar ratio of 1:0.5 and stirred continuously for 4 h. The ethanol was then removed by distillation. The resulting liquid was the NCA-Zn low eutectic solvent and stored in a vacuum dry state.

[0034] In one embodiment, the method for preparing the catalyst comprises the following steps:

[0035] (1) adding an impregnation solution containing a Ce salt to a low eutectic solvent of NCA-Zn, mixing the mixture by ultrasound, then adding the NCA-Zn solution containing the Ce salt to TiO2, impregnating the TiO2 for 30 to 120 minutes, and then drying and calcining the obtained solid to obtain a Ce-NCA-Zn modified TiO2 carrier; preferably, the impregnation is performed by an equal volume impregnation process; preferably, the drying temperature is 100 to 130°C, the drying time is 2 to 5 hours, the calcination temperature is 450 to 550°C, and the calcination time is 3 to 6 hours; further preferably, the TiO2 is vacuum pretreated before impregnation, the vacuum pretreatment time is 10 to 30 minutes, and the vacuum degree is 96.0 to 98.0 kPa;

[0036] (2) adding the impregnation solution containing Ni salt and Fe salt to the Ce-NCA-Zn modified TiO2 carrier obtained in step (1), impregnating it for 30 to 120 minutes, and then drying and calcining the obtained solid to obtain the catalyst; preferably, the impregnation is carried out by an equal volume impregnation process; preferably, the drying temperature is 100 to 130°C, the drying time is 2 to 5 hours, the calcination temperature is 450 to 550°C, and the calcination time is 3 to 6 hours.

[0037] Preferably, in the above-mentioned method for preparing the catalyst, the impregnation solutions in steps (1) and (2) are both from one or more of water, methanol and ethanol, preferably water and / or ethanol.

[0038] In the present invention, the catalyst in the catalytic oxidation reactor described in S1 is filled in two layers. The lower layer catalyst mainly performs the catalytic oxidation reaction of sodium hypochlorite, and the upper layer catalyst mainly decomposes the incompletely reacted sodium hypochlorite to ensure that the effective chlorine content of the reactor effluent is ≤0.5 mg / L.

[0039] The waste gas obtained in S1 described in S2 can be directly sent to the chimney for external discharge treatment.

[0040] The reagents used for pH adjustment in S2 are hydrochloric acid solution and NaOH solution.

[0041] The oxidant II in the secondary catalytic oxidation reaction of S2 is one or more of hydrogen peroxide, ozone and methyl hydrogen peroxide, preferably hydrogen peroxide, with a hydrogen peroxide content of 25.0 wt% to 32.0 wt%, based on the total weight of the oxidant II.

[0042] The pH value of the primary catalytic oxidation effluent in S2 is adjusted to 1.0 to 5.0 by a hydrochloric acid solution, preferably to 2.0 to 4.0, and the mixing with the oxidant II can be completed by a static mixer, a mixing reactor and the like, preferably a static mixer. At the same time, the amount of oxidant II added should ensure that the molar ratio of hydrogen peroxide to TOC is 2:1≤n(hydrogen peroxide):n(TOC)≤5:1, preferably n(hydrogen peroxide):n(TOC)=3:1, and more preferably, the wastewater treatment effect can be improved by adding the oxidant II in batches. The wastewater is transported to a secondary catalytic oxidation reactor, where hydrogen peroxide, under the action of a catalyst, produces highly oxidizing hydroxyl radicals, further degrading organic matter. The reaction conditions are: a reaction temperature of 40-90°C, a residence time of 0.2-4.0 hours, and a catalyst dosage of 20-500 mg / L (based on the amount of wastewater), preferably 50-300 mg / L (based on the amount of wastewater); preferably, a reaction temperature of 50-80°C and a residence time of 1.0-3.0 hours. Through the secondary catalytic oxidation reaction, small molecules such as formic acid, acetic acid, and butyric acid remaining in the effluent of the primary catalytic oxidation reaction are mineralized into carbon dioxide and water.

[0043] The catalyst described in S2 is mainly a composite catalyst, and the content of the components in the catalyst is: Cu 10wt%~30wt%, preferably 15wt%~25wt%; Fe 1.0wt%~5.0wt%, preferably 2.0wt%~4.0wt%; Mn 1.0wt%~5.0wt%, preferably 2.0wt%~4.0wt%; modified lactide tar 1.0wt%~5.0wt%, preferably 2.0wt%~4.0wt%, and the remaining component is water; the added Cu, Fe and Mn mainly exist in the form of their metal oxides or metal chlorides, preferably metal chlorides; after being configured into a certain solution, they are added to the high-salt organic wastewater system.

[0044] The modified lactide tar described in S2 is a catalytic and adsorption material modified by chitosan and dextran. The lactide tar comes from the by-product of the production process of the polylactic acid device. The lactic acid raw material is separated by prepolymerization and depolymerization to obtain lactide, and finally ring-opening polymerization is used to produce polylactic acid. Lactide tar is produced in the depolymerization and separation unit, which mainly contains lactic acid polymers with different degrees of polymerization, lactide, carbon deposits and stannous oxide, etc., and is made through a series of processes such as dehydration, drying, roasting and screening. Specifically, the preparation method of the chitosan and glucan modified lactide tar described in S2 is: drying the lactide tar, mixing the chitosan, glucan and lactide tar evenly, roasting under a nitrogen atmosphere until the organic matter is partially carbonized, and crushing and screening to obtain the product; preferably, the lactide tar is a by-product in the production process of the polylactic acid device; preferably, the chitosan, glucan and lactide tar are evenly mixed in a mass ratio of (0.01~0.1):(0.01~0.1):1, preferably (0.02~0.08):(0.02~0.08):1; preferably, the lactide tar is dried at a temperature of 90~130°C and a drying time of 1~5h, preferably at a drying temperature of 100~120°C and a drying time of 2~4h; roasted at 450~700°C for 3~5h, preferably roasted at 500~650°C for 3.5~4.5h.

[0045] Chitosan and glucan molecules contain alkyl, amino, hydroxyl, pyranyl rings, and various hydrophilic and hydrophobic functional groups, resulting in excellent adsorption properties. They can also bind to a variety of inorganic materials and metal ions through chelation, complexation, and ion exchange, creating multifunctional nanocomposite derivatives. When lactide tar is modified with chitosan and glucan, the metal ions in the tar bind to the functional groups in the chitosan and glucan. Furthermore, the lactic acid polymers, lactide, and carbon deposits in the tar are rich in functional groups such as hydroxyl and carboxyl groups. After pretreatment, the modified lactide tar exhibits a high specific surface area, resulting in a tin-rich porous oxide material that significantly enhances its catalytic and adsorption properties. This material firmly adsorbs recalcitrant organic matter within its pores, allowing for its deep removal via hydrogen peroxide catalytic oxidation. Furthermore, the modified lactide tar exhibits significantly improved settling properties, increasing the precipitation rate of flocculants such as copper hydroxide and improving effluent quality.

[0046] Under the action of a composite catalyst of Cu, Fe, Mn and modified lactide tar, hydrogen peroxide can be quickly decomposed into highly oxidizing hydroxyl radicals, deeply oxidizing small molecular acids and other organic matter remaining in the water of the primary catalytic oxidation reaction. Through its huge specific surface area, it relies on van der Waals forces and hydrogen bonds between it and the adsorbed molecules (adsorbates) to play a separation and purification role. After pretreatment and modification, the selected lactide tar has good mechanical strength, stable chemical properties and excellent catalytic performance. It can adsorb organic matter that is difficult to oxidize and remove in the pores, and then rely on long-term oxidation with hydrogen peroxide to achieve deep treatment of brine.

[0047] The catalyst recovery method described in S2 is one or more of flocculation precipitation method, resin exchange method and adsorption method, preferably flocculation precipitation method.

[0048] The catalyst recovery conditions described in S2 are: pH 8.0-10.0, temperature 40-90°C, flocculant addition amount 1-5 mg / L (based on the amount of wastewater), flocculation time 10-60 min. Preferably, the pH is 8.5-9.5, the reaction temperature is 50-80°C, and the flocculant addition amount is 1-2 mg / L (based on the amount of wastewater). The amount of flocculant added is determined based on the size of the metal floc precipitate produced and the SS content of the supernatant after standing.

[0049] The catalyst recovery described in S2 can be carried out in any reactor known in the art. The pH adjustment can be performed using equipment such as a static mixer, regulating tank, regulating tank, or regulating tank, preferably a static mixer. The flocculation and sedimentation process can be performed in equipment such as a flocculation tank and an inclined plate sedimentation tank, with necessary sludge return equipment to mix the sludge with the incoming water to achieve catalyst recycling. A small amount of catalyst is added during the initial operation, and no additional catalyst is required during normal operation.

[0050] In the catalyst recovery process described in S2, the effluent needs to be filtered. The wastewater filtration equipment can be one or more of a sand filter, a multi-media filter, an activated carbon filter, a filter bag, a wire mesh filter, a microfiltration filter, and an ultrafiltration filter, preferably a multi-media filter.

[0051] In the present invention, the waste gas obtained in S2 described in S3 is directly discharged after water washing and gas-liquid separation, which can be carried out in any equipment known in the art. Preferably, a water washing tower and a gas-liquid separation tank are used. The water washing wastewater is sent to the biochemical system for treatment, and the condensate is returned to the secondary catalytic oxidation reactor.

[0052] The adsorption material described in S3 is one or more of macroporous adsorption resin, activated carbon or molecular sieve, preferably macroporous adsorption resin.

[0053] S3 adsorption conditions are: pH 1.0-8.0, adsorption temperature 20-60°C, liquid phase space velocity 1-10h -1 Preferably, its pH value is 2.0-5.0, adsorption temperature is 30-50°C, and liquid phase space velocity is 1-5h -1 After adsorption saturation, the adsorption tower can be regenerated using a 4wt% NaOH solution at 80°C. After regeneration, the adsorption tower is rinsed with pure water until the pH reaches ≤12. The adsorption of the secondary catalytic oxidation effluent can then be continued, and the regenerated liquid is returned to the primary catalytic oxidation reactor. The macroporous adsorption resin adsorption inlet must be controlled to contain ≤1mg / L of hydrogen peroxide to ensure the resin's service life.

[0054] The resin in S3 absorbs the water and sends it to chlor-alkali as raw material. The acceptance index of chlor-alkali for this brine is: TOC≤10mg / L, SS≤5mg / L.

[0055] Another object of the present invention is to provide a method for deep treatment and reuse of high-salt organic wastewater.

[0056] A method for deep treatment and reuse of high-salt organic wastewater is disclosed. The method is preferably used for deep treatment and reuse of high-salt organic wastewater generated during the preparation of epichlorohydrin or bisphenol A epoxy resin.

[0057] The positive effects of the present invention are:

[0058] The described method for advanced treatment and reuse of high-salt organic wastewater is simple and easy to implement, featuring mild reaction conditions, high automation and treatment efficiency, and can achieve resource-based reuse of waste brine without generating secondary pollution. This method avoids the complex post-dilution biochemical treatment process and difficult biochemical sludge disposal, while also enabling NaCl resource reuse. Furthermore, by using sodium hypochlorite wastewater as an oxidant and modified lactide tar as a catalyst, the process achieves waste treatment with one waste, reduces treatment costs, and successfully achieves the recycling of chlorine resources, thus creating an environmentally friendly wastewater treatment process. DETAILED DESCRIPTION

[0059] The following specific examples further illustrate the technical solutions of the present invention and its effects. The following examples are only used to illustrate the content of the present invention and are not intended to limit the scope of protection of the present invention. Simple changes made to the present invention by applying the concept of the present invention are all within the scope of protection claimed in the present invention.

[0060] The devices used in the embodiments and comparative examples of the present invention are as follows: a delivery pump, a static mixer, a flocculation tank, an inclined plate sedimentation tank, a multi-media filter, a catalytic oxidation reactor, a water washing tower, a gas-liquid separation tank, and an adsorption tower, all of which were purchased from Yantai Keli Chemical Equipment Co., Ltd.

[0061] The muffle furnace, model VULCAN 3-1750, was purchased from Neytech, USA.

[0062] In the embodiments and comparative examples of the present invention, the pharmaceutical raw materials used are as follows:

[0063] ECH and BPA type epoxy resin wastewater, chlor-alkali industrial wastewater, NaOH solution, hydrochloric acid solution and lactide tar, Wanhua Chemical Group Co., Ltd.

[0064] 30% hydrogen peroxide, analytical grade, Tianjin Kemeiou Chemical Reagent Co., Ltd.;

[0065] Polyacrylamide flocculant, model AN923SH, was purchased from Aisen Company, France;

[0066] Nickel nitrate, ferric nitrate, and cerium nitrate, analytical grade, were purchased from Xilong Chemical Co., Ltd.;

[0067] Ethanol, n-octanoic acid, titanium dioxide, copper chloride, manganese chloride, ferric chloride, zinc chloride, and NaCl were all of analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd.

[0068] Chitosan and dextran, concentration ≥75%, high molecular weight, purchased from Sigma-Aldrich, USA;

[0069] TOC and TN analyzers, Jena, Germany;

[0070] Suspended solids analysis was performed using a spectrophotometer from Hach Company, USA;

[0071] Metal ion analysis was performed using inductively coupled plasma atomic emission spectrometry-mass spectrometry (ICP-MS);

[0072] NaCl content was analyzed using ion chromatography (IC) from Metrohm, Switzerland.

[0073] Comparative Example 1: Preparation of 1# Primary Catalytic Oxidation Catalyst

[0074] A 20g TiO2 sample was placed in an impregnation bottle and vacuum pretreated for 30 minutes at a vacuum degree of 96.0kPa. Simultaneously, 30mL of an aqueous cerium nitrate solution containing 0.01g / mL of Ce was added to form an impregnation solution with a total volume of 30mL. The impregnation solution was added to a vacuum impregnation bottle containing a TiO2 carrier, mixed evenly, and then impregnated. After impregnation for 80 minutes, the carrier was removed and dried in an oven at 110°C for 3 hours, followed by calcination in a muffle furnace at 470°C for 4 hours to obtain a Ce-modified TiO2 carrier. The Ce content of the obtained Ce-modified TiO2 carrier was 1.5wt% based on the weight of the TiO2.

[0075] At the same time, 10.0 mL of an aqueous nickel nitrate solution containing 0.10 g / mL of Ni and 2.7 mL of an aqueous ferric nitrate solution containing 0.15 g / mL of Fe were added to an aqueous ethanol solution having an ethanol concentration of 20 wt% to prepare an impregnation solution with a total volume of 12.7 mL. The impregnation solution was added to a vacuum impregnation bottle containing the Ce-modified TiO2 support and mixed uniformly. The Ce-modified TiO2 support was impregnated for 90 minutes, then removed and dried in an oven at 120°C for 4 hours, followed by calcination in a muffle furnace at 500°C for 5 hours to obtain catalyst #1.

[0076] The obtained No. 1 primary catalytic oxidation catalyst has the following contents, based on the weight of TiO2: Ni 5.0 wt%, Fe 2.0 wt%.

[0077] Example 1: Preparation of 2# Primary Catalytic Oxidation Catalyst

[0078] A 20g TiO2 sample was placed in an impregnation bottle and vacuum pretreated for 30 minutes at a vacuum level of 96.0kPa. Simultaneously, 30mL of an aqueous cerium nitrate solution containing 0.01g / mL of Ce was added to a 1g NCA-Zn low eutectic solvent and ultrasonically mixed to complete the impregnation solution. The impregnation solution was added to a vacuum impregnation bottle containing a TiO2 support, mixed evenly, and then impregnated. After 80 minutes of impregnation, the TiO2 support was removed and dried in an oven at 110°C for 3 hours, followed by calcination in a muffle furnace at 470°C for 4 hours to produce a Ce-NCA-Zn modified TiO2 support. The Ce-NCA-Zn modified TiO2 support thus obtained had a Ce content of 1.5wt% and an NCA-Zn content of 5.0wt%, based on the weight of the TiO2.

[0079] At the same time, 10.0 mL of nickel nitrate aqueous solution containing 0.10 g / mL Ni and 2.7 mL of ferric nitrate aqueous solution containing 0.15 g / mL Fe were prepared to prepare an impregnation solution with a total volume of 12.7 mL. This impregnation solution was added to a vacuum impregnation flask containing the Ce-NCA-Zn modified TiO2 support and mixed evenly. The Ce-NCA-Zn modified TiO2 support was impregnated for 90 minutes, then removed and dried in an oven at 120°C for 4 hours. It was then calcined in a muffle furnace at 500°C for 5 hours to obtain catalyst #2.

[0080] The obtained No. 2 primary catalytic oxidation catalyst has the following contents, based on the weight of TiO2: Ni 5.0 wt%, Fe 2.0 wt%.

[0081] Example 2: Preparation of 3# Primary Catalytic Oxidation Catalyst

[0082] A 20g TiO2 sample was placed in an impregnation bottle and vacuum pretreated for 10 minutes at a vacuum level of 98.0kPa. Simultaneously, 20mL of an aqueous cerium nitrate solution containing 0.01g / mL of Ce was added to 0.5g of a NCA-Zn eutectic solvent and ultrasonically mixed to complete the impregnation solution. The impregnation solution was then added to a vacuum impregnation bottle containing a TiO2 support, mixed thoroughly, and then impregnated. After 120 minutes of impregnation, the TiO2 support was removed and dried in an oven at 130°C for 5 hours. The sample was then calcined in a muffle furnace at 550°C for 6 hours to produce a Ce-NCA-Zn modified TiO2 support. The Ce-NCA-Zn modified TiO2 support contained 1.0wt% Ce and 2.5wt% NCA-Zn, based on the weight of the TiO2.

[0083] At the same time, 4.0 mL of an aqueous nickel nitrate solution containing 0.10 g / mL of Ni and 1.3 mL of an aqueous ferric nitrate solution containing 0.15 g / mL of Fe were added to an aqueous ethanol solution having an ethanol concentration of 10 wt% to prepare an impregnation solution with a total volume of 5.3 mL. The impregnation solution was added to a vacuum impregnation bottle containing the Ce-NCA-Zn modified TiO2 support and mixed uniformly. The Ce-NCA-Zn modified TiO2 support was impregnated for 30 minutes, then removed and dried in an oven at 100°C for 2 hours, and then calcined in a muffle furnace at 450°C for 3 hours to obtain catalyst #3.

[0084] The obtained 3# primary catalytic oxidation catalyst has the following contents, based on the weight of TiO2: Ni 2.0 wt%, Fe 1.0 wt%.

[0085] Example 3: Preparation of 4# Primary Catalytic Oxidation Catalyst

[0086] A 20g TiO2 sample was placed in an impregnation bottle and vacuum pretreated for 30 minutes at a vacuum level of 97.0kPa. Simultaneously, 40mL of an aqueous cerium nitrate solution containing 0.01g / mL of Ce was added to 2g of a NCA-Zn deep eutectic solvent and ultrasonically mixed to complete the impregnation solution. This impregnation solution was then added to a vacuum impregnation bottle containing a TiO2 support. After mixing thoroughly, the TiO2 support was impregnated. After 30 minutes of impregnation, the sample was removed and dried in an oven at 100°C for 2 hours. The sample was then calcined in a muffle furnace at 450°C for 3 hours to produce a Ce-NCA-Zn modified TiO2 support. The Ce content of the resulting Ce-NCA-Zn modified TiO2 support was 2.0wt% and 10.0wt% of NCA-Zn, based on the weight of the TiO2.

[0087] At the same time, 20.0 mL of an aqueous nickel nitrate solution containing 0.10 g / mL of Ni and 4.0 mL of an aqueous ferric nitrate solution containing 0.15 g / mL of Fe were added to an aqueous ethanol solution having an ethanol concentration of 40 wt% to prepare an impregnation solution with a total volume of 24.0 mL. The impregnation solution was added to a vacuum impregnation bottle containing the Ce-NCA-Zn modified TiO2 support and mixed uniformly. The Ce-NCA-Zn modified TiO2 support was impregnated for 120 minutes, then removed and dried in an oven at 130°C for 5 hours, and then calcined in a muffle furnace at 550°C for 6 hours to obtain catalyst #4.

[0088] The obtained 4# primary catalytic oxidation catalyst has the following contents based on the weight of TiO2: Ni 10.0 wt%, Fe 3.0 wt%.

[0089] Comparative Example 2: Preparation of 1# Secondary Catalytic Oxidation Catalyst

[0090] The lactide tar raw material was dried at 110° C. for 3 hours, and then calcined at 500° C. in a nitrogen atmosphere for 4 hours to carbonize most of the organic matter. Finally, the raw material was crushed and sieved to obtain pretreated lactide tar.

[0091] Prepare 100g of secondary catalytic oxidation catalyst, weigh 42.4g CuCl2, 8.7g FeCl3, 9.2g MnCl2 and 3g lactide tar, mix them evenly and add a certain amount of pure water to make the total mass 100g, thus obtaining 1# secondary catalytic oxidation catalyst; for easy addition and use, dilute it into a 30% aqueous solution.

[0092] The obtained No. 1 secondary catalytic oxidation catalyst contained the following components in an amount based on the total weight: 20.0 wt% of Cu, 3.0 wt% of Fe, 4.0 wt% of Mn, and 3.0 wt% of lactide tar.

[0093] Example 4: Preparation of 2# Secondary Catalytic Oxidation Catalyst

[0094] 30 g of lactide tar raw material was dried at 110°C for 3 hours, and then chitosan, dextran and lactide tar were evenly mixed in a mass ratio of 0.05:0.05:1. The mixture was then calcined at 500°C under a nitrogen atmosphere for 4 hours to carbonize most of the organic matter and obtain modified lactide tar.

[0095] Prepare 100g of secondary catalytic oxidation catalyst, weigh 42.4g CuCl2, 8.7g FeCl3, 9.2g MnCl2 and 3g modified lactide tar, mix them evenly and add a certain amount of pure water to make the total mass 100g, thus obtaining 2# secondary catalytic oxidation catalyst; for easy addition and use, dilute it into a 30% aqueous solution.

[0096] The obtained 2# secondary catalytic oxidation catalyst has the following contents based on the total weight: Cu 20.0 wt%, Fe 3.0 wt%, Mn 4.0 wt%, and modified lactide tar 3.0 wt%.

[0097] Example 5: Preparation of 3# Secondary Catalytic Oxidation Catalyst

[0098] 30 g of lactide tar raw material was dried at 90°C for 1 hour, and then chitosan, dextran and lactide tar were evenly mixed in a mass ratio of 0.01:0.01:1. The mixture was then calcined at 450°C in a nitrogen atmosphere for 3 hours to carbonize most of the organic matter and obtain modified lactide tar.

[0099] Prepare 100g of secondary catalytic oxidation catalyst, weigh 21.2g CuCl2, 2.9g FeCl3, 2.3g MnCl2 and 1g modified lactide tar, mix them evenly and add a certain amount of pure water to make the total mass 100g, thus obtaining 3# secondary catalytic oxidation catalyst; for easy addition and use, dilute it into a 30% aqueous solution.

[0100] The obtained 3# secondary catalytic oxidation catalyst has the following contents based on the total weight: Cu 10.0 wt%, Fe 1.0 wt%, Mn 1.0 wt%, and modified lactide tar 1.0 wt%.

[0101] Example 6: Preparation of 4# Secondary Catalytic Oxidation Catalyst

[0102] 30 g of lactide tar raw material was dried at 130°C for 5 hours, and then chitosan, dextran and lactide tar were evenly mixed in a mass ratio of 0.1:0.1:1. The mixture was then calcined at 700°C in a nitrogen atmosphere for 5 hours to carbonize most of the organic matter and obtain modified lactide tar.

[0103] Prepare 100g of secondary catalytic oxidation catalyst, weigh 63.6g CuCl2, 14.5g FeCl3, 11.5g MnCl2 and 5g modified lactide tar, mix them evenly and add a certain amount of pure water to make the total mass 100g, thus obtaining 4# secondary catalytic oxidation catalyst; for easy addition and use, dilute it into a 30% aqueous solution.

[0104] The obtained 4# secondary catalytic oxidation catalyst has the following contents based on the total weight: Cu 30.0 wt%, Fe 5.0 wt%, Mn 5.0 wt%, and modified lactide tar 5.0 wt%.

[0105] In the following examples, the sampling and analysis results of ECH and BPA type epoxy resin mixed wastewater are shown in Table 1.

[0106] Table 1 Water quality composition of high-salt organic wastewater

[0107]

[0108] Example 7: Treatment of High-Salt Organic Wastewater (2# Primary Catalytic Oxidation Catalyst and 2# Secondary Catalytic Oxidation Catalyst)

[0109] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 12 mg / L to 8 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 5 wt%. The pH is adjusted to 11.5 with a 32 wt% NaOH solution. The wastewater is then fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 2# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 50°C, liquid phase space velocity 3h -1 The catalytic output water TOC is 150mg / L and the available chlorine is 0.3mg / L.

[0110] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 2.0 by hydrochloric acid solution, and then 27wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=2:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 2# catalytic oxidation catalyst, hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter, especially small molecular acids such as formic acid, acetic acid, and butyric acid. The reaction conditions are: reaction temperature of 60°C, residence time of 3.0h, and catalyst addition amount of 100mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 60°C, pH 8.5, flocculant 2mg / L, flocculation time 30min, sedimentation tank effluent TOC 17mg / L, SS 1mg / L, hydrogen peroxide 0.2mg / L.

[0111] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlorine-alkali for further treatment. The resin adsorption conditions are: pH 1.0, adsorption temperature 40℃, liquid phase space velocity 5h -1 The TOC and SS of the effluent from the resin adsorption tower are 5mg / L and 1mg / L respectively.

[0112] Example 8: Treatment of High-Salt Organic Wastewater (3# Primary Catalytic Oxidation Catalyst and 2# Secondary Catalytic Oxidation Catalyst)

[0113] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 48 mg / L to 10 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 3:1. The effective chlorine content of the chlor-alkali industrial wastewater is 13 wt%. The pH is adjusted to 10.5 with a 32 wt% NaOH solution. The wastewater is then fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 3# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 30°C, liquid phase space velocity 1h -1 The catalytic output water TOC is 210mg / L and the available chlorine is 0.8mg / L.

[0114] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 5.0 by hydrochloric acid solution, and then 25wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=5:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 2# catalytic oxidation catalyst, hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter, especially small molecular acids such as formic acid, acetic acid, and butyric acid. The reaction conditions are: reaction temperature of 40°C, residence time of 0.2h, and catalyst addition amount of 20mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 40°C, pH 10.0, flocculant 5mg / L, flocculation time 60min, TOC of the sedimentation tank effluent 22mg / L, SS 2mg / L, hydrogen peroxide 0.5mg / L.

[0115] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlorine-alkali for further treatment. The resin adsorption conditions are: pH 1.0, adsorption temperature 20℃, liquid phase space velocity 1h -1 The TOC and SS contents of the effluent from the resin adsorption tower are 7mg / L and 1mg / L respectively.

[0116] Example 9: Treatment of High-Salt Organic Wastewater (4# Primary Catalytic Oxidation Catalyst and 2# Secondary Catalytic Oxidation Catalyst)

[0117] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 97 mg / L to 15 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 10 wt%. After the pH is adjusted to 13.5 with a 32 wt% NaOH solution, it is fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 4# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 60°C, liquid phase space velocity 5h -1 The catalytic output water TOC is 320mg / L and the available chlorine is 1.5mg / L.

[0118] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 1.0 by hydrochloric acid solution, and then 32wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=3:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 2# catalytic oxidation catalyst, hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter, especially small molecular acids such as formic acid, acetic acid, and butyric acid. The reaction conditions are: reaction temperature of 90°C, residence time of 4h, and catalyst addition amount of 500mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 90°C, pH 8.0, flocculant 1mg / L, flocculation time 10min, sedimentation tank effluent TOC 31mg / L, SS 3mg / L, hydrogen peroxide 0.7mg / L.

[0119] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlor-alkali for further treatment. The resin adsorption conditions are: pH 8.0, adsorption temperature 60℃, liquid phase space velocity 10h -1 The TOC and SS of the effluent from the resin adsorption tower are 8mg / L and 1mg / L respectively.

[0120] Example 10: Treatment of High-Salt Organic Wastewater (4# Primary Catalytic Oxidation Catalyst and 3# Secondary Catalytic Oxidation Catalyst)

[0121] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 97 mg / L to 15 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 10 wt%. After the pH is adjusted to 13.5 with a 32 wt% NaOH solution, it is fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 4# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 60°C, liquid phase space velocity 5h -1 The catalytic output water TOC is 320mg / L and the available chlorine is 1.5mg / L.

[0122] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 1.0 by hydrochloric acid solution, and then 32wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=3:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 3# catalytic oxidation catalyst, hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter, especially small molecular acids such as formic acid, acetic acid, and butyric acid. The reaction conditions are: reaction temperature of 90°C, residence time of 4h, and catalyst addition amount of 500mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 90°C, pH 8.0, flocculant 1mg / L, flocculation time 10min, sedimentation tank effluent TOC 35mg / L, SS 3mg / L, hydrogen peroxide 0.7mg / L.

[0123] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlor-alkali for further treatment. The resin adsorption conditions are: pH 8.0, adsorption temperature 60℃, liquid phase space velocity 10h -1 The TOC and SS of the effluent from the resin adsorption tower are 8mg / L and 1mg / L respectively.

[0124] Example 11: Treatment of High-Salt Organic Wastewater (4# Primary Catalytic Oxidation Catalyst and 4# Secondary Catalytic Oxidation Catalyst)

[0125] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 97 mg / L to 15 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 10 wt%. After the pH is adjusted to 13.5 with a 32 wt% NaOH solution, it is fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 4# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 60°C, liquid phase space velocity 5h -1 The catalytic output water TOC is 320mg / L and the available chlorine is 1.5mg / L.

[0126] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 1.0 by hydrochloric acid solution, and then 32wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=3:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 4# catalytic oxidation catalyst, hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter, especially small molecular acids such as formic acid, acetic acid, and butyric acid. The reaction conditions are: reaction temperature of 90°C, residence time of 4h, and catalyst addition amount of 500mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 90°C, pH 8.0, flocculant 1mg / L, flocculation time 10min, sedimentation tank effluent TOC 29mg / L, SS 3mg / L, hydrogen peroxide 0.7mg / L.

[0127] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlor-alkali for further treatment. The resin adsorption conditions are: pH 8.0, adsorption temperature 60℃, liquid phase space velocity 10h -1 The TOC and SS contents of the effluent from the resin adsorption tower are 7mg / L and 1mg / L respectively.

[0128] Comparative Example 3: Treatment of High-Salt Organic Wastewater (1# Primary Catalytic Oxidation Catalyst and 4# Secondary Catalytic Oxidation Catalyst)

[0129] Compared with Example 11, the 1# primary catalytic oxidation catalyst carrier was not modified with the low eutectic solvent NCA-Zn, and the treatment effects before and after the modification were compared.

[0130] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 97 mg / L to 15 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 10 wt%. After the pH is adjusted to 13.5 with a 32 wt% NaOH solution, it is fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the first-stage catalytic oxidation catalyst 1, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 60°C, liquid phase space velocity 5h -1 The catalytic effluent TOC is 590mg / L and the available chlorine is 19.5mg / L.

[0131] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 1.0 by hydrochloric acid solution, and then a 32wt% hydrogen peroxide solution is added, n(hydrogen peroxide):n(TOC)=3:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 4# catalytic oxidation catalyst, the hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter. The reaction conditions are: reaction temperature 90°C, residence time 4h, and catalyst addition amount 500mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding a flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 90°C, pH 8.0, flocculant 1mg / L, flocculation time 10min, and the TOC of the sedimentation tank effluent is 49mg / L, SS 3mg / L, and hydrogen peroxide 0.7mg / L.

[0132] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlor-alkali for further treatment. The resin adsorption conditions are: pH 8.0, adsorption temperature 60℃, liquid phase space velocity 10h -1 The TOC of the effluent from the resin adsorption tower is 11mg / L and the SS is 1mg / L. The TOC of the effluent cannot meet the chlor-alkali index requirements.

[0133] Comparative Example 4: Treatment of High-Salt Organic Wastewater (4# Primary Catalytic Oxidation Catalyst and 1# Secondary Catalytic Oxidation Catalyst)

[0134] Compared with Examples 9 to 11, no modified lactide tar was added to the 1# secondary catalytic oxidation catalyst system, and the treatment effects before and after modification were compared.

[0135] S1: After high-salt organic wastewater is filtered through a wire mesh filter, SS can be reduced from 97 mg / L to 15 mg / L. It is then mixed with chlor-alkali industrial wastewater at a ratio of n(NaClO):n(TOC) = 2:1. The effective chlorine content of the chlor-alkali industrial wastewater is 10 wt%. After the pH is adjusted to 13.5 with a 32 wt% NaOH solution, it is fed into a catalytic oxidation reactor from the bottom of the reactor. Under the action of the 4# primary catalytic oxidation catalyst, the organic matter is oxidized and decomposed into carbon dioxide and water, and the residual sodium hypochlorite is decomposed at the same time. The reaction conditions are: 60°C, liquid phase space velocity 5h -1 The catalytic output water TOC is 320mg / L and the available chlorine is 1.5mg / L.

[0136] S2: The waste gas obtained in S1 can be directly sent to the chimney for external discharge treatment. The pH of the first-stage catalytic oxidation effluent is adjusted to 1.0 by hydrochloric acid solution, and then a 32wt% hydrogen peroxide solution is added, with n(hydrogen peroxide):n(TOC)=3:1, and a second-stage catalytic oxidation reaction is carried out in the reactor. Under the action of the 1# catalytic oxidation catalyst, the hydrogen peroxide produces strongly oxidizing hydroxyl radicals, which further degrade organic matter. The reaction conditions are: reaction temperature 90°C, residence time 4h, and catalyst addition amount 500mg / L (based on the amount of wastewater); by adjusting the pH of the second-stage catalytic oxidation effluent and adding a flocculant, the catalyst is separated from the precipitate and water in the sedimentation tank. The precipitate is transported to the second-stage catalytic oxidation inlet by a reflux pump to realize catalyst recycling. The reaction conditions are: 90°C, pH 8.0, flocculant 1mg / L, flocculation time 10min, and the effluent TOC of the sedimentation tank is 48mg / L, SS 3mg / L, and hydrogen peroxide 0.7mg / L.

[0137] S3: The waste gas obtained in S2 is directly discharged after gas-liquid separation and water washing. The effluent from catalytic oxidation is adsorbed and protected by macroporous adsorption resin and then sent to chlor-alkali for further treatment. The resin adsorption conditions are: pH 8.0, adsorption temperature 60℃, liquid phase space velocity 10h -1 The TOC of the effluent from the resin adsorption tower is 11mg / L and the SS is 1mg / L. The TOC of the effluent cannot meet the chlor-alkali index requirements.

[0138] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and such modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A method for deep treatment and reuse of high-salt organic wastewater, characterized in that: The method comprises the following steps: S1: High-salt organic wastewater is mixed with oxidant I, and after adjusting the pH value, it is sent to the primary catalytic oxidation reactor. Under the action of the heterogeneous catalyst, some organic matter in the wastewater is oxidized and decomposed into carbon dioxide and water; S2: The waste gas obtained in S1 is discharged, and the effluent from the primary catalytic oxidation reactor is mixed with oxidant II after adjusting the pH value, and then sent to the secondary catalytic oxidation reactor. Under the action of the composite catalyst, the residual organic matter in the wastewater is further oxidized and decomposed, and the pH value of the effluent is adjusted; S3: The waste gas obtained in S2 is treated and discharged, and the effluent from S2 is sent to the chlor-alkali unit as raw material after adsorption; Wherein, the heterogeneous catalyst described in S1 includes a TiO2 carrier and Ni and Fe supported in the form of oxides, the Ni content is 2.0wt%~10.0wt%, and the Fe content is 1.0wt%~3.0wt%, based on the weight of TiO2; the TiO2 carrier is a Ce-NCA-Zn modified TiO2 carrier, and the TiO2 carrier is loaded with an octanoic acid-zinc chloride NCA-Zn low eutectic solvent, and the Ce content in the TiO2 carrier is 1.0wt%~2.0wt%, and the NCA-Zn content is 2.5wt%~10.0wt%, based on the weight of TiO2; the preparation method of the NCA-Zn low eutectic solvent is: dissolving octanoic acid and zinc chloride in anhydrous ethanol in a molar ratio of 1:0.5, stirring continuously for 4h, and then removing ethanol by distillation. The resulting liquid is the NCA-Zn low eutectic solvent, which is vacuum dried and stored; Among them, the composite catalyst described in S2 is Cu, Fe, Mn and chitosan and glucan modified lactide tar; the Cu content in the composite catalyst described in S2 is 10wt%~30wt%, the Fe content is 1.0wt%~5.0wt%, the Mn content is 1.0wt%~5.0wt%, the chitosan and glucan modified lactide tar content is 1.0wt%~5.0wt%, and the remaining component is water.

2. The method according to claim 1, characterized in that The high-salt organic wastewater in S1 has a TOC content of ≤5000 mg / L; a SS content of ≤100 mg / L; and a NaCl content of 4.0 wt% to 25.0 wt%. Measured in terms of total wastewater volume; And / or, the oxidant I described in S1 is sodium hypochlorite wastewater; And / or, the pH value is adjusted to 10.5-13.5 in S1; and / or, the Ni content in S1 is 3.0 wt% to 8.0 wt%, and the Fe content is 2.0 wt% to 3.0 wt%, calculated based on the weight of TiO2; and / or, the Ce content in the TiO2 carrier in S1 is 1.2 wt% to 1.5 wt%, and the NCA-Zn content is 3.0 wt% to 9.0 wt%, calculated on the weight of TiO2; And / or, S1 reaction temperature 30~60℃, liquid phase space velocity 1~5h -1 .

3. The method according to claim 2, characterized in that The high-salt organic wastewater in S1 has a TOC content of 10-4000 mg / L, a SS content of 20-60 mg / L, and a NaCl content of 5.0 wt%-20.0 wt%; Measured in terms of total wastewater volume; And / or, the oxidant I in S1 is sodium hypochlorite wastewater produced by the production of ClO2 or Cl2 or the chlor-alkali industry; The amount of the oxidant I added in S1 is 2:1≤n(available chlorine):n(TOC)≤3:1; And / or, S1 reaction temperature 40~50℃, liquid phase space velocity 1~3h -1 .

4. The method according to claim 3, characterized in that The available chlorine content of the oxidant I sodium hypochlorite wastewater in S1 is 5wt% to 13wt%; The amount of oxidant I added in S1 is n(available chlorine):n(TOC)=2:

1.

5. The method according to claim 1, characterized in that S2: adjusting the pH value to 1.0-5.0; and / or, the oxidant II in S2 is one or more of hydrogen peroxide, ozone and methyl hydroperoxide; And / or, the Cu content in the composite catalyst of S2 is 15wt% to 25wt%; the Fe content is 2.0wt% to 4.0wt%; the Mn content is 2.0wt% to 4.0wt%; the chitosan and dextran modified lactide tar content is 2.0wt% to 4.0wt%; the remaining component is water; and the composite catalyst is configured as a solution; and / or, the reaction temperature in S2 is 40-90° C. and the residence time is 0.2-4.0 h; And / or, the catalyst described in S2 can be recycled, and the recycling conditions are: pH 8.0-10.0, temperature 40-90° C., flocculant addition amount 1-5 mg / L based on wastewater volume, and flocculation time 10-60 min.

6. The method according to claim 5, characterized in that S2: adjusting the pH value to 2.0-4.0; And / or, the oxidant II in S2 is hydrogen peroxide; The concentration of hydrogen peroxide in S2 is 25.0 wt% to 32.0 wt%, based on the total amount of oxidant II; The amount of oxidant II added in S2 is calculated based on the molar ratio of hydrogen peroxide to TOC to ensure that 2:1≤n(hydrogen peroxide):n(TOC)≤5:1; And / or, Cu, Fe and Mn in the composite catalyst described in S2 exist in the form of their metal oxides or metal chlorides; The amount of the composite catalyst added in S2 is 20 to 500 mg / L, based on the volume of the wastewater; and / or, S2 reaction temperature is 50-80° C., residence time is 1.0-3.0 h; And / or, the catalyst recovery conditions described in S2 are: pH 8.5-9.5, reaction temperature 50-80° C., and flocculant addition amount 1-2 mg / L based on wastewater volume.

7. The method according to claim 6, characterized in that The amount of oxidant II added in S2 is calculated based on the molar ratio of hydrogen peroxide to TOC: n(hydrogen peroxide):n(TOC)=3:1; And / or, Cu, Fe and Mn in the composite catalyst described in S2 exist in the form of metal chlorides; The amount of the composite catalyst added in S2 is 50 to 300 mg / L, based on the volume of the wastewater.

8. The method according to claim 1, characterized in that The preparation method of chitosan and glucan modified lactide tar described in S2 is: drying lactide tar, uniformly mixing chitosan, glucan and lactide tar, roasting under nitrogen atmosphere until the organic matter is partially carbonized, and crushing and screening to obtain the product.

9. The method according to claim 8, characterized in that The lactide tar described in S2 is a by-product of the production process of the polylactic acid device; The chitosan, glucan and lactide tar described in S2 are uniformly mixed in a mass ratio of (0.01-0.1):(0.01-0.1):1; The lactide tar in step S2 is dried at a temperature of 90-130° C. for 1-5 hours and calcined at a temperature of 450-700° C. for 3-5 hours.

10. The method according to claim 9, characterized in that S2 The chitosan, glucan and lactide tar are uniformly mixed in a mass ratio of (0.02-0.08):(0.02-0.08):1; The lactide tar is dried at a temperature of 100 to 120° C. for 2 to 4 hours and calcined at a temperature of 500 to 650° C. for 3.5 to 4.5 hours.

11. The method according to claim 1, wherein The adsorption in S3 is performed using a macroporous resin.

12. The method according to claim 11, characterized in that S3 adsorption conditions are: pH 1.0-8.0, adsorption temperature 20-60°C, liquid phase space velocity 1-10h -1 .

13. The method according to claim 12, characterized in that S3 adsorption conditions are: pH 2.0-5.0, adsorption temperature 30-50°C, liquid phase space velocity 1-5h -1 .

14. Use of a method for deep treatment and reuse of high-salt organic wastewater, the method being the method for deep treatment and reuse of high-salt organic wastewater according to any one of claims 1 to 13, and the method being used for deep treatment and reuse of high-salt organic wastewater generated during the preparation of epichlorohydrin or bisphenol A epoxy resin.

Images