Resourceful treatment method for waste brine generated in trichloroisocyanuric acid production

Abstract

The invention relates to the technical field of wastewater treatment, and particularly discloses a resourceful treatment method for waste brine generated in trichloroisocyanuric acid production. According to the invention, the waste brine from trichloroisocyanuric acid production is subjected to twice sedimentation treatment and wet catalytic oxidation treatment to obtain the sodium chloride brine meeting the feeding standard of an electrolytic bath in the chlor-alkali industry. Wherein in the wet catalytic oxidation, an Re-MnO2 / vermiculite composite material is used as a catalyst, and Re is any one of Y, La or Ce. According to the technical scheme, the problems that in the prior art, the treatment process for the waste brine produced in trichloroisocyanuric acid production is poor in effect, the treated sodium chloride has many impurities and is difficult to recycle, and treatment equipment can be damaged are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and specifically discloses a resource treatment method for waste brine produced from trichloroisocyanuric acid production. Background Art

[0002] Trichloroisocyanuric acid is an organic compound of N-chloroimide, in the form of white powder or granules, with strong oxidizing and chlorinating properties, and has a killing effect on bacteria, fungi, viruses, spores, etc. Trichloroisocyanuric acid is widely used in disinfection, sterilization and bleaching in industrial and civil fields, and has the advantages of high efficiency, broad spectrum and safety. Trichloroisocyanuric acid has broad market application prospects, and the market demand is increasing year by year. The output of trichloroisocyanuric acid in my country is also expanding. At the same time, the amount of wastewater and waste gas brought by the production of trichloroisocyanuric acid is also increasing, and the impact on the environment is also increasing.

[0003] In the production process, in order to obtain high-purity solid trichloroisocyanuric acid, the generated trichloroisocyanuric acid suspension needs to be centrifuged and dehydrated. After separation, the solid trichloroisocyanuric acid product can be obtained by drying. The centrifugal wastewater generated during the centrifugal dehydration process is trichloroisocyanuric acid wastewater. Trichloroisocyanuric acid wastewater contains a large amount of organic matter such as sodium chloride, trichloroisocyanuric acid and cyanuramide, and is a high-salt and high-organic wastewater.

[0004] At present, there are two main treatment methods for this type of high-salt and high-organic wastewater at home and abroad. One is the traditional treatment method, the main process of which is wastewater acidification, purging dechlorination and neutralization reduction. Hydrochloric acid is used to react with trichloroisocyanuric acid to generate cyanuric acid and chlorine. The chlorine is blown out by air stripping and absorbed by alkali solution to form hypochlorite. The dechlorinated wastewater enters the neutralization reduction process, and is neutralized and reduced with alkali and sodium sulfite to completely convert trichloroisocyanuric acid into cyanuric acid. Finally, the obtained cyanuric acid is converted into monosodium cyanuric acid by adjusting the pH and precipitating to obtain low-concentration cyanuric acid wastewater. However, the cyanuric acid wastewater treated by this treatment method cannot meet the national emission targets and still needs further treatment. What's more, the need to introduce sodium sulfite during the treatment process causes the effluent to contain impurity sulfate ions, which further increases the difficulty of reusing sodium chloride in the water. The second method is to first use resin adsorption and then photocatalytic oxidation treatment, and finally electrolysis treatment. Compared with the first treatment method, the second treatment method not only greatly reduces the treatment process but also avoids secondary treatment, and the efficiency is greatly improved. However, the wastewater after photocatalytic oxidation treatment still contains certain organic matter and a high TOC content, which does not meet the water inlet requirements of the chlor-alkali industrial electrolytic cell (TOC≤10ppm), and will cause damage to the ion exchange membrane in the electrolytic cell, reducing the service life of the ion exchange membrane.

[0005] Based on this, studying a treatment process for trichloroisocyanuric acid production waste brine with simple process and excellent treatment effect has great practical significance in the field of wastewater treatment. Summary of the invention

[0006] In view of the problems that the treatment process of trichloroisocyanuric acid production waste brine in the prior art has poor effect, the sodium chloride impurities after treatment are too much to be reused, and the treatment equipment will be damaged, the present invention provides a resource treatment process for trichloroisocyanuric acid production waste brine. The present invention efficiently treats trichloroisocyanuric acid wastewater through a sedimentation treatment combined with a wet catalytic oxidation process, so that the obtained qualified waste liquid meets the feed requirements of the chlor-alkali industrial electrolyzer, that is, TOC≤10ppm, wherein the wet catalytic oxidation adopts a heterogeneous catalytic material Re-MnO2 / vermiculite composite material. The present invention provides a resource treatment method for trichloroisocyanuric acid production waste brine with excellent effect, and the treated waste liquid can meet the feed requirements of the chlor-alkali industrial electrolyzer, thereby realizing efficient reuse of sodium chloride.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions: The first aspect of the present invention provides a method for resource treatment of waste brine from trichloroisocyanuric acid production, comprising the following steps: Step 1: sending the waste brine from the production of trichloroisocyanuric acid into a sedimentation tank, adjusting the pH to 1-3, adding a sulfate precipitant for primary precipitation, filtering, and obtaining a first treatment liquid; adding a calcium magnesium precipitant to the first treatment liquid for secondary precipitation, solid-liquid separation, and obtaining a sedimentation treatment liquid; Step 2: adjusting the pH of the sedimentation treatment liquid to 3-4, adding an oxidant and a catalyst to perform catalytic oxidation to obtain a standard brine; The catalyst is a Re-MnO2 / vermiculite composite material, wherein Re is any one of Y, La or Ce.

[0008] The invention firstly performs a precipitation treatment on trichloroisocyanuric acid waste brine by using a sulfate precipitant to remove sulfate ions therein, and obtains a first treatment liquid after filtering; then a calcium and magnesium precipitant is used to perform a secondary precipitation on the first treatment liquid to remove calcium and magnesium hardness ions in the first treatment liquid, and obtains a sedimentation treatment liquid free of impurity metal ions after solid-liquid separation.

[0009] Then, the present invention adjusts the pH of the sedimentation treatment liquid, removes the introduced impurity anions, and obtains wastewater without other inorganic ions except sodium ions and chloride ions. The present invention uses Re-MnO2 / vermiculite composite material as a heterogeneous catalyst to carry out wet catalytic oxidation treatment on the obtained wastewater. Since the manganese dioxide in the heterogeneous catalyst contains abundant oxygen vacancies and easily reducible surface adsorbed oxygen, the utilization rate of the oxidant can be effectively improved, so that the rate of generating strong oxidizing hydroxyl radicals is increased, and the hydroxyl radicals can first decompose the macromolecular organic matter in the trichloroisocyanuric acid wastewater into small molecular organic matter, and then further mineralize into inorganic compounds, such as carbon dioxide and nitrogen. Vermiculite, as a typical layered silicate clay mineral, not only has a large specific surface area and a good two-dimensional spatial structure, but also its surface is rich in silanol reaction groups, which facilitates the loading of metal oxides and rare earth ions, while avoiding the carbon deposition of manganese dioxide and rare earth metals, thereby blocking the contact between dissolved oxygen and the active sites on the catalyst surface, resulting in a decrease in catalytic oxidation efficiency. The doping of rare earths effectively adjusts the electronic structure of manganese dioxide, increases more catalytic active sites, and further improves the efficiency of wet catalytic oxidation, thereby achieving the purpose of efficiently degrading organic matter.

[0010] In summary, the present invention designs a resource treatment method for trichloroisocyanuric acid production waste brine with simple process, low cost and no need for complex instruments. The brine that meets the feed standard of the chlor-alkali industrial electrolyzer is obtained by two sedimentation treatments combined with a process of wet catalytic oxidation using a heterogeneous catalyst, which not only does not damage the treatment equipment of the subsequent electrolyzer, but also realizes the efficient reuse of sodium chloride in the trichloroisocyanuric acid production waste brine. The technical solution of the present invention effectively solves the problems of poor treatment process effect of trichloroisocyanuric acid production waste brine in the prior art, and the sodium chloride impurities after treatment are too many to be reused and damage to the treatment equipment, which provides a new idea for the treatment of trichloroisocyanuric acid production waste brine.

[0011] Preferably, the preparation method of the Re-MnO2 / vermiculite composite material comprises the following steps: Step a, mixing vermiculite with deionized water, wet-milling the mixture, drying the mixture, and calcining the mixture at 600° C.-650° C. to obtain a vermiculite carrier; Step b, dissolving a rare earth precursor and a manganese salt precursor in deionized water to obtain a mixed solution; heating the mixed solution to 150° C.-180° C. for hydrothermal reaction, filtering, washing, and drying to obtain a metal precursor; Step c: ball-milling the metal precursor and the vermiculite carrier, and sintering them at 550° C.-650° C. to obtain a Re-MnO2 / vermiculite composite material.

[0012] Further preferably, in step a, the mass ratio of the vermiculite to deionized water is 10:2-10:3.

[0013] Further preferably, in step a, the rotation speed of the wet ball milling is 600 rpm-1000 rpm; and the time of the wet ball milling is 1 h-3 h.

[0014] Further preferably, in step a, the calcination time is 3h-5h.

[0015] Further preferably, in step b, the rare earth precursor is any one of yttrium nitrate, lanthanum chloride or cerium nitrate.

[0016] Further preferably, in step b, the manganese salt precursor is manganese nitrate or manganese chloride.

[0017] Further preferably, in step b, the concentration of the rare earth precursor in the mixed solution is 0.3 mol / L-0.6 mol / L.

[0018] Further preferably, in step b, the concentration of the manganese salt precursor in the mixed solution is 0.8 mol / L-1.4 mol / L.

[0019] Further preferably, in step b, the hydrothermal reaction time is 36h-48h.

[0020] Further preferably, in step b, the washing is performed with deionized water for 2-4 times.

[0021] Further preferably, in step b, the drying temperature is 70° C.-100° C., and the drying time is 1 h-3 h.

[0022] Further preferably, in step c, the mass ratio of the metal precursor to the vermiculite carrier is 1:2-1:4.

[0023] Further preferably, in step c, the rotation speed of the ball mill is 300 rpm-800 rpm, and the ball milling time is 2 h-5 h.

[0024] Further preferably, in step c, the sintering is performed by programmed temperature increase at a heating rate of 10° C. / min-20° C. / min.

[0025] Further preferably, in step c, the sintering time is 4h-6h.

[0026] Preferably, in step 1, the sulfate precipitant is calcium chloride.

[0027] Preferably, in step 1, the calcium and magnesium precipitating agent is any one of sodium carbonate or sodium bicarbonate.

[0028] Preferably, in step 1, the treatment time of the primary precipitation and the secondary precipitation is 3h-5h.

[0029] Preferably, in step 1, the molar ratio of the sulfate precipitant to the sulfate ion in the trichloroisocyanuric acid production waste brine is 1.5:1-2:1.

[0030] Preferably, in step 1, the molar ratio of the calcium and magnesium precipitant to the total amount of calcium and magnesium ions in the trichloroisocyanuric acid production waste brine is 1.3:1-2:1.

[0031] Preferably, in step 1, the solid-liquid separation uses a pore size of 0.2 μm-0.5 μm and a flux of 3 L / m 2 -5L / m 2 filter membrane.

[0032] Preferably, in step 2, the oxidant is a hydrogen peroxide solution with a mass concentration of 20%-30%.

[0033] Preferably, in step 2, the volume ratio of the oxidant to the sedimentation treatment liquid is 0.01:1-0.03:1.

[0034] Preferably, in step 2, the mass volume ratio of the catalyst to the sedimentation treatment liquid is 0.5g:10mL-0.5g:15mL.

[0035] Preferably, in step 2, the temperature of the catalytic oxidation is 130° C.-140° C., the vacuum degree is 0.6 MPa-0.7 MPa, and the time of the catalytic oxidation is 30 min-90 min.

[0036] In summary, the present invention successfully obtains sodium chloride brine that meets the feed standard of chlor-alkali industrial electrolyzer by subjecting trichloroisocyanuric acid production waste brine to two sedimentation treatments and wet catalytic oxidation treatments. Wherein, the wet catalytic oxidation uses Re-MnO2 / vermiculite composite material as a heterogeneous catalyst, wherein Re is any one of Y, La or Ce. The technical solution of the present invention treats trichloroisocyanuric acid production waste brine to obtain a treated liquid with a TOC content of less than 10ppm, which can effectively avoid damage to the ion exchange membrane when entering the chlor-alkali industrial electrolyzer, and at the same time achieves efficient reuse of sodium chloride in trichloroisocyanuric acid production waste brine. The technical solution of the present invention effectively solves the problems of poor treatment process effect of trichloroisocyanuric acid production waste brine in the prior art, and the sodium chloride impurities after treatment are too many to be reused and damage to the processing equipment, providing a new treatment idea for the treatment of trichloroisocyanuric acid production waste brine. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1This is a flow chart for resource recovery treatment of waste brine from the production of trichloroisocyanuric acid as described in Example 1. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1 This embodiment provides a method for resource treatment of waste brine from trichloroisocyanuric acid production, which specifically includes the following contents: Step 1, take 1000mL of trichloroisocyanuric acid production waste brine, and use a total organic carbon analyzer to measure the TOC content of the trichloroisocyanuric acid waste brine to be 826ppm; the total amount of calcium and magnesium ions is 759.51mg / L; the total amount of sulfate ions is 2272.51mg / L; the trichloroisocyanuric acid production waste brine is sent to a sulfate precipitation tank, the pH is adjusted to 2.4, 5g of calcium chloride is added for primary precipitation, let stand for 4h, and filter to obtain a first treated liquid; the first treated liquid is sent to a calcium and magnesium precipitation tank, 3g of sodium carbonate is added to the first treated liquid for secondary precipitation, let stand for 3.5h, and the suspension after the precipitation reaction is sent to a filter with a pore size of 0.3μm and a flux of 4L / m 2 The solid-liquid separation is carried out through the filter membrane to obtain the sedimentation treatment liquid.

[0040] Step 3: Adjust the pH of the sedimentation treatment liquid to 3.6, send the sedimentation treatment liquid into a catalytic oxidation reactor, add 20 mL of 27.5% hydrogen peroxide solution, use 40 g of Y-MnO2 / vermiculite composite material as a catalyst, carry out catalytic oxidation at 135 ° C and a vacuum degree of 0.7 MPa for 40 minutes, separate the solid and liquid, and obtain a standard brine with a TOC of 8.15 ppm.

[0041] The preparation method of the Y-MnO2 / vermiculite composite material comprises the following steps: Step a, 100 g of vermiculite and 20 g of deionized water were mixed evenly, wet-milled at a rotation speed of 800 rpm for 2 h, dried, and calcined at 620° C. for 4 h to obtain a vermiculite carrier; Step b, dissolving 19.2 g of yttrium nitrate and 17.9 g of manganese nitrate in 100 mL of deionized water, transferring the mixture to a reactor, placing the reactor in a muffle furnace, performing a hydrothermal reaction at 170 ° C. for 38 h, filtering, washing with deionized water 3 times, and drying at 80 ° C. for 2 h to obtain 17.6 g of a metal precursor; Step c, the metal precursor is mixed evenly with 45g of the vermiculite carrier, ball-milled at a rotation speed of 500rpm for 3h, and then the ball-milled composite material is heated to 620℃ at a heating rate of 15℃ / min by a programmed temperature rise method, sintered for 5h, and cooled to obtain a Y-MnO2 / vermiculite composite material.

[0042] Example 2 This embodiment provides a method for resource treatment of waste brine from trichloroisocyanuric acid production, which specifically includes the following contents: Step 1: Take 1000mL of trichloroisocyanuric acid production waste brine, and use a total organic carbon analyzer to measure the TOC content of the trichloroisocyanuric acid waste brine to be 736ppm; the total amount of calcium and magnesium ions is 675.96mg / L; the total amount of sulfate ions is 2022.54mg / L; send the trichloroisocyanuric acid production waste brine into a sulfate precipitation tank, adjust the pH to 2.8, add 4.2g of calcium chloride for primary precipitation, let stand for 4h, filter, and obtain a first treated liquid; send the first treated liquid into a calcium and magnesium precipitation tank, add 3.2g of sodium carbonate to the first treated liquid for secondary precipitation, let stand for 3.5h, and send the suspension after the precipitation reaction into a filter with a pore size of 0.2μm and a flux of 5L / m 2 The solid-liquid separation is carried out through the filter membrane to obtain the sedimentation treatment liquid.

[0043] Step 3: Adjust the pH of the sedimentation treatment liquid to 3.8, send the sedimentation treatment liquid into an oxidation reactor, add 25 mL of 25% hydrogen peroxide solution, use 35 g of La-MnO2 / vermiculite composite material as a catalyst, carry out catalytic oxidation at 140°C and a vacuum degree of 0.6 MPa for 50 minutes, separate the solid and liquid, and obtain a standard brine with a TOC of 6.27 ppm.

[0044] The preparation method of the La-MnO2 / vermiculite composite material comprises the following steps: Step a, 100 g of vermiculite and 20 g of deionized water were mixed evenly, wet-milled at a rotation speed of 600 rpm for 2.5 h, dried, and calcined at 600° C. for 5 h to obtain a vermiculite carrier; Step b, dissolving 12.2 g of lanthanum chloride and 17.9 g of manganese nitrate in 100 mL of deionized water respectively, transferring the mixture to a reactor, placing the reactor in a muffle furnace, performing a hydrothermal reaction at 160° C. for 40 h, filtering, washing with deionized water 3 times, and drying at 70° C. for 3 h to obtain 16.4 g of a metal precursor; Step c, the metal precursor is mixed evenly with 40g of the vermiculite carrier, ball-milled at a rotation speed of 500rpm for 3h, and then the ball-milled composite material is heated to 630℃ at a heating rate of 15℃ / min by programmed temperature rise, sintered for 4h, and cooled to obtain La-MnO2 / vermiculite composite material.

[0045] Example 3 This embodiment provides a method for resource treatment of waste brine from trichloroisocyanuric acid production, which specifically includes the following contents: Step 1: Take 1000mL of trichloroisocyanuric acid production waste brine, and use a total organic carbon analyzer to measure the TOC content of the trichloroisocyanuric acid waste brine to be 758ppm; the total amount of calcium and magnesium ions is 679.94mg / L; the total amount of sulfate ions is 2017.86mg / L; send the trichloroisocyanuric acid production waste brine into a sulfate precipitation tank, adjust the pH to 2.2, add 4.1g of calcium chloride for primary precipitation, let stand for 4h, filter, and obtain a first treated liquid; send the first treated liquid into a calcium and magnesium precipitation tank, add 4.5g of sodium carbonate to the first treated liquid for secondary precipitation, let stand for 3h, and send the suspension after the precipitation reaction into a filter with a pore size of 0.5μm and a flux of 3L / m 2 The solid-liquid separation is carried out through the filter membrane to obtain the sedimentation treatment liquid.

[0046] Step 3: Adjust the pH of the sedimentation treatment liquid to 3.2, send the sedimentation treatment liquid into an oxidation reactor, add 20 mL of 30% hydrogen peroxide solution, use 32 g of Ce-MnO2 / vermiculite composite material as a catalyst, carry out catalytic oxidation at 140°C and a vacuum degree of 0.7 MPa for 35 minutes, separate the solid and liquid, and obtain a standard brine with a TOC of 8.05 ppm.

[0047] The preparation method of the Ce-MnO2 / vermiculite composite material comprises the following steps: Step a, 100 g of vermiculite and 20 g of deionized water were mixed evenly, wet-milled at a rotation speed of 800 rpm for 2 h, dried, and calcined at 620° C. for 4 h to obtain a vermiculite carrier; Step b, dissolving 21.7 g of cerium nitrate and 17.9 g of manganese nitrate in 100 mL of deionized water respectively and transferring them to a reactor, placing the reactor in a muffle furnace, performing a hydrothermal reaction at 150° C.-180° C. for 38 h, filtering, washing with deionized water 3 times, and drying at 80° C. for 2 h to obtain 14.8 g of a metal precursor; Step c, the metal precursor is mixed evenly with 35g of the vermiculite carrier, ball-milled at a rotation speed of 800rpm for 2h, and then the ball-milled composite material is heated to 600℃ at a heating rate of 15℃ / min by programmed temperature rise, sintered for 6h, and cooled to obtain a Ce-MnO2 / vermiculite composite material.

[0048] Comparative Example 1 This comparative example provides a method for recycling waste brine from the production of trichloroisocyanuric acid. The difference from Example 1 is that the catalyst is a MnO2 / vermiculite composite material, which specifically includes the following contents: Step 1, take 1000mL of trichloroisocyanuric acid production waste brine, and use a total organic carbon analyzer to measure the TOC content of the trichloroisocyanuric acid waste brine to be 826ppm; the total amount of calcium and magnesium ions is 759.51mg / L; the total amount of sulfate ions is 2272.51mg / L; the trichloroisocyanuric acid production waste brine is sent to a sulfate precipitation tank, the pH is adjusted to 2.4, 5g of calcium chloride is added for primary precipitation, let stand for 4h, and filter to obtain a first treated liquid; the first treated liquid is sent to a calcium and magnesium precipitation tank, 3g of sodium carbonate is added to the first treated liquid for secondary precipitation, let stand for 3.5h, and the suspension after the precipitation reaction is sent to a filter with a pore size of 0.3μm and a flux of 4L / m 2 The solid-liquid separation is carried out through the filter membrane to obtain the sedimentation treatment liquid.

[0049] Step 3: Adjust the pH of the sedimentation treatment liquid to 3.6, send the sedimentation treatment liquid into an oxidation reactor, add 20 mL of 27.5% hydrogen peroxide solution, use 40 g of MnO2 / vermiculite composite material as a catalyst, carry out catalytic oxidation at 135 ° C and a vacuum degree of 0.7 MPa for 40 minutes, separate the solid and liquid, and obtain waste brine with a TOC of 37.46 ppm.

[0050] The preparation method of the MnO2 / vermiculite composite material comprises the following steps: Step a, 100 g of vermiculite and 20 g of deionized water were mixed evenly, wet-milled at a rotation speed of 800 rpm for 2 h, dried, and calcined at 620° C. for 4 h to obtain a vermiculite carrier; Step b, 17g of manganese dioxide and 45g of the vermiculite carrier are mixed evenly, ball-milled at a rotation speed of 500rpm for 3h, and then the ball-milled composite material is heated to 620°C at a heating rate of 15°C / min by a programmed temperature rise method, sintered for 5h, and cooled to obtain a MnO2 / vermiculite composite material.

[0051] According to the industry standard T / ZGZS0302-2023 "Regeneration of Industrial Salt Sodium Chloride", the TOC content, sulfate ion content and calcium and magnesium ion content of the trichloroisocyanuric acid production waste brine of Examples 1-3 and Comparative Example 1 are tested, and the specific results are shown in Table 1.

[0052] Table 1 Test indicators of waste brine from trichloroisocyanuric acid production before and after treatment

[0053] It can be seen from Table 1 that the calcium and magnesium ion content, sulfate ion content and TOC content of the trichloroisocyanuric acid production waste brine treated in Examples 1-3 of the present invention all meet the standards of the chlor-alkali industrial electrolytic cell, and the obtained standard brine can enter the electrolytic cell for sodium chloride reuse.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recycling waste brine from trichloroisocyanuric acid production, characterized in that: The steps include: Step 1: sending the waste brine from the production of trichloroisocyanuric acid into a sedimentation tank, adjusting the pH to 1-3, adding a sulfate precipitant for primary precipitation, filtering, and obtaining a first treatment liquid; adding a calcium magnesium precipitant to the first treatment liquid for secondary precipitation, solid-liquid separation, and obtaining a sedimentation treatment liquid; Step 2: adjusting the pH of the sedimentation treatment liquid to 3-4, adding an oxidant and a catalyst to perform catalytic oxidation to obtain a standard brine; The catalyst is a Re-MnO2 / vermiculite composite material, wherein Re is any one of Y, La or Ce.

2. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 1, characterized in that: The preparation method of the Re-MnO2 / vermiculite composite material comprises the following steps: Step a, mixing vermiculite with deionized water, wet-milling the mixture, drying the mixture, and calcining the mixture at 600° C.-650° C. to obtain a vermiculite carrier; Step b, dissolving a rare earth precursor and a manganese salt precursor in deionized water to obtain a mixed solution; The mixed solution is heated to 150° C.-180° C. for hydrothermal reaction, filtered, washed, and dried to obtain a metal precursor; Step c: ball-milling the metal precursor and the vermiculite carrier, and sintering them at 550° C.-650° C. to obtain a Re-MnO2 / vermiculite composite material.

3. The method for recycling waste brine from trichloroisocyanuric acid production as claimed in claim 2, characterized in that: In step a, the mass ratio of the vermiculite to deionized water is 10:2-10:3; and / or In step a, the rotation speed of the wet ball milling is 600 rpm-1000 rpm; the time of the wet ball milling is 1 h-3 h; and / or In step a, the calcination time is 3h-5h.

4. The resource treatment method for waste brine produced by trichloroisocyanuric acid production according to claim 2, characterized in that: In step b, the rare earth precursor is any one of yttrium nitrate, lanthanum chloride or cerium nitrate; and / or In step b, the manganese salt precursor is manganese nitrate or manganese chloride.

5. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 2, characterized in that: In step b, the concentration of the rare earth precursor in the mixed solution is 0.3 mol / L-0.6 mol / L; and / or In step b, the concentration of the manganese salt precursor in the mixed solution is 0.8 mol / L-1.4 mol / L; and / or In step b, the hydrothermal reaction time is 36h-48h.

6. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 2, characterized in that: In step c, the mass ratio of the metal precursor to the vermiculite carrier is 1:2-1:4; and / or In step c, the ball milling speed is 300 rpm-800 rpm, and the ball milling time is 2 h-5 h; and / or In step c, the sintering is carried out by programmed temperature increase at a heating rate of 10°C / min-20°C / min; and / or In step c, the sintering time is 4h-6h.

7. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 1, characterized in that: In step 1, the sulfate precipitant is calcium chloride; and / or In step 1, the calcium and magnesium precipitant is any one of sodium carbonate or sodium bicarbonate; and / or In step 1, the treatment time of the first precipitation and the second precipitation is 3h-5h; and / or In step 1, the molar ratio of the sulfate precipitant to the sulfate ion in the trichloroisocyanuric acid production waste brine is 1.5:1-2:1; and / or In step 1, the molar ratio of the calcium and magnesium precipitant to the total amount of calcium and magnesium ions in the trichloroisocyanuric acid production waste brine is 1.3:1-2:

1.

8. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 1, characterized in that: In step 1, the solid-liquid separation uses a pore size of 0.2 μm-0.5 μm and a flux of 3 L / m 2 -5L / m 2 filter membrane.

9. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 1, characterized in that: In step 2, the oxidant is a hydrogen peroxide solution with a mass concentration of 20%-30%; and / or In step 2, the volume ratio of the oxidant to the sedimentation treatment liquid is 0.01:1-0.03:

1.

10. The method for recycling waste brine from trichloroisocyanuric acid production according to claim 1, characterized in that: In step 2, the mass volume ratio of the catalyst to the sedimentation treatment liquid is 0.5g:10mL-0.5g:15mL; and / or In step 2, the temperature of the catalytic oxidation is 130° C.-140° C., the vacuum degree is 0.6 MPa-0.7 MPa, and the time of the catalytic oxidation is 30 min-90 min.

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