Preparation method of bromochlorohydantoin for disinfection, sterilization and algae removal of drinking water

Abstract

The invention provides a preparation method of bromochlorohydantoin for disinfection, sterilization and algae removal of drinking water, and relates to the technical field of preparation of halogenated hydantoin. The indexes of arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, trichloromethane, monochlorodibromomethane, dichlorodibromomethane, tribromomethane, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and the like in the treated drinking water meet the requirements of Drinking Water Sanitary Standard (GB 5749-2022). The powdery bromochlorohydantoin is rolled into particles with the diameter of 2.0-0.25 mm by a pelletizer, and then the granular bromochlorohydantoin is prepared into blocky bromochlorohydantoin for a drinking water treatment system, so that harmful bacteria, spores, viruses and harmful algae can be effectively killed.

Description

Technical Field

[0001] The invention relates to the technical field of halogenated hydantoin preparation, and in particular to a method for preparing bromochlorohydantoin for drinking water disinfection, sterilization and algae removal. Background Art

[0002] Bromochlorohydantoin is a new type of chlorine- and bromine-containing disinfectant with specific properties. It can react with water in aqueous solution to generate strong oxidizing active substances, effectively destroying the cell walls, active enzymes or DNA of microorganisms, causing the microorganisms to be inactivated due to oxidative decomposition, killing various pathogens, fungi, viruses, algae and some parasites. It has the inherent advantages of high efficiency, stability, safety and environmental protection, and is a widely used new broad-spectrum fungicide. It can be used as a fruit preservative to effectively kill crops and fruit trees to prevent and control powdery mildew, rot, bacterial wilt, wilt, verticillium wilt, black root rot, anthrax and spot disease. As an important chemical intermediate, it is used in chemical, pharmaceutical and pesticide intermediate synthesis oxidant industries.

[0003] Bromine chlorine hydantoin flake (block) products can be used for disinfection, sterilization and algae removal of industrial cooling circulating water, swimming pools, mineral springs and hot springs, baths, sewage, central air conditioning circulating water, tap water, agricultural irrigation water and toilet water tank water. The dried powdered products can also be used for chemical, pharmaceutical and pesticide intermediate synthesis oxidants. The dried powdered products can also be added to other materials and mixed into bromine chlorine hydantoin compound fungicides for killing various bacteria and fungi in the process of crop planting, soil sterilization and disinfection, aquaculture and animal husbandry seed disinfection and sterilization, fruit preservatives and daily life disinfection.

[0004] Bromochloromethane products can also be used as drinking water disinfectants, but after using bromochloromethane products as drinking water disinfectants, they must meet the various index requirements of the "Sanitary Standard for Drinking Water (GB 5749-2022)", including the arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, chloroform, monochlorodibromomethane, dichlorodibromomethane, bromoform, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and other indicators in the treated drinking water.

[0005] At present, the production of bromochlorohydantoin at home and abroad mainly uses 5,5-dimethylhydantoin, liquid alkali, bromine and chlorine as raw materials, which are synthesized, centrifuged and dried into powder products, and then granulated and pressed into tablets (blocks).

[0006] After searching, the Chinese invention patent with application number "CN200310105375.6" discloses a preparation method of bromochlorohydantoin disinfectant, bactericidal algaecide, which uses 5,5-dimethylhydantoin as the main raw material, dissolves it in water or in the mother liquor containing sodium bromide produced when producing dibromohydantoin, uses bromine and chlorine as halogenating agents, and simultaneously drips sodium hydroxide solution to carry out bromination and chlorination reactions, and the halogenated product is centrifuged, washed with water, and dried to obtain bromochlorohydantoin; the characteristics are: the concentration of the dripped sodium hydroxide solution is 33-37%, the molar ratio of the material addition is controlled by the online metering method, and the whole reaction process is instantaneously optimized. It has the remarkable effects of simple operation and control, high product yield of more than 96%, high product purity of more than 99%, and low wastewater discharge.

[0007] The preparation method of the above-mentioned bromine chlorine hydrazine disinfectant algaecide does not purify the trace elements inside, and the purity of the bromine chlorine hydrazine product produced by it cannot meet the drinking water treatment standard and the use requirements of the drinking water disinfectant. Therefore, the development of a bromine chlorine hydrazine production process technology for drinking water disinfection and sterilization has great and far-reaching strategic significance.

[0008] In summary, there is an urgent need for a method for preparing bromine chloramine for drinking water disinfection, sterilization and algaecide to solve the above problems. Summary of the invention

[0009] In order to make up for the above shortcomings, the present invention provides a method for preparing bromochlorohydantoin for drinking water disinfection, sterilization and algaecide, which is used to solve the problems that the above-mentioned existing bromochlorohydantoin preparation method does not purify the internal trace elements, the purity of the bromochlorohydantoin products produced by it cannot reach the drinking water treatment standard, and cannot meet the requirements for the use of drinking water disinfectants.

[0010] The present invention is achieved in that:

[0011] A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal comprises the following steps:

[0012] Step S1, raw material purification treatment;

[0013] Specifically, for bromine purification, the bromine raw material is first treated with a cationic resin, the feed liquid after the cationic resin treatment is treated with an anionic resin, and the purified bromine is stored separately;

[0014] Step S2, dissolving and mixing 5,5-dimethylhydantoin and sodium hydroxide;

[0015] Specifically, 5,5-dimethylhydantoin, sodium hydroxide and pure water are weighed and added to an enameled reactor, and frozen brine is introduced into the jacket of the enameled reactor at the same time, and the material temperature is controlled to be constant at 52° C. to 60° C. until the material is completely dissolved to obtain a mixed solution, and the pH value of the mixed solution is 13 to 14;

[0016] Step S3, filtering the mixed solution for the first time;

[0017] The mixed solution obtained in step S2 is filtered through a bag filter to obtain a primary filtered solution;

[0018] Step S4, filtering the mixed solution twice;

[0019] The primary filtered solution is filtered through a folded filter cartridge filter for secondary filtration to obtain a secondary filtered solution;

[0020] Step S5, bromination and chlorination synthesis reaction;

[0021] Specifically, step S5.1, the filtered secondary filtered solution is pressed into the synthesis process reactor; at the same time, frozen brine is introduced into the jacket of the reactor to cool it down to 4°C to 16°C;

[0022] Step S5.2, while maintaining a constant temperature, adding the bromine in step S1 into the reactor to carry out a bromination reaction, until the bromination reaction is completed and the pH value of the solution in the reactor drops to 11.5-13.0;

[0023] Step S5.3, introducing chlorine gas into the reactor at a constant temperature for chlorination reaction, and shutting off the chlorine gas and the frozen brine until the pH value of the solution in the reactor reaches 5.0-6.6, and the reaction is completed to obtain a bromine chlorine hydrazine solution;

[0024] Step S6, centrifugation, washing, purification and drying of the bromochlorohydantoin solution;

[0025] The bromochlorohydantoin solution obtained in step S5 is placed in a scraper bottom discharge centrifuge for centrifugal drying, and the washing liquid centrifuged each time is collected; then deionized water is introduced into the scraper bottom discharge centrifuge to centrifugally wash the bromochlorohydantoin crude product, and the washing is repeated 3 to 5 times; the mother liquor obtained by centrifugal drying and washing is collected, treated to meet the standards, and then discharged.

[0026] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enameled reactor, and after being completely dissolved, filtered with an enamel filter to collect the secondary wet bromochlorohydantoin and the filtrate, and the secondary wet bromochlorohydantoin is dried with a vacuum belt dryer, and the secondary dry product obtained after drying is the powdered bromochlorohydantoin used for drinking water disinfection, sterilization and algaecide.

[0027] As a preferred embodiment, the cationic resin in step S1 is one of 001*1, LX-004, and ZG-007.

[0028] As a preferred embodiment, the anion resin in step S1 is one of LX-8000, AM-207, AM-300, and ZGA-302.

[0029] As a preferred embodiment, in step S1, the bromine raw material passes through the cationic resin at a flow rate of 1.0-3.0 BV / h, and then passes through the anionic resin at a flow rate of 1.0-3.0 BV / h.

[0030] As a preferred embodiment, in step S2, the weight ratio of 5,5-dimethylhydantoin, sodium hydroxide and pure water is 1:(0.5-0.8):(11-14).

[0031] As a preferred embodiment, the conductivity of pure water used in the method for preparing bromochlorohydantoin is less than 20um / cm.

[0032] As a preferred implementation, the pore size of the bag filter in step S3 is 0.5 um.

[0033] As a preferred implementation, the pore size of the folded filter element in step S4 is 0.1 um.

[0034] As a preferred embodiment, the weight ratio of 5,5-dimethylhydantoin to liquid bromine in steps S1 and S5 is 1:(0.5-0.6).

[0035] As a preferred embodiment, the mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer are collected, the solvents are mixed and then distilled, and the remaining wastewater after the acetone is collected is treated to meet the standards and then discharged.

[0036] As a preferred embodiment, the powdered bromochlorohydantoin is dried and rolled into granules with a diameter of 2.0 to 0.25 mm by a granulator, and then the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in a drinking water treatment system to effectively kill harmful bacteria, spores, viruses and harmful algae.

[0037] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0038] 1. The method for preparing bromochlorohydantoin for drinking water disinfection and algaecide shown in the present invention comprises the following steps: the bromochlorohydantoin produced by the method is used for drinking water disinfection and sterilization; the arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, chloroform, monochlorodibromomethane, dichlorodibromomethane, bromoform, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and other indicators in the treated drinking water meet the requirements of the Drinking Water Hygiene Standard (GB 5749-2022); the powdered bromochlorohydantoin is rolled into particles with a diameter of 2.0 to 0.25 mm by a granulator, and the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in a drinking water treatment system to effectively kill harmful bacteria, spores, viruses and harmful algae.

[0039] 2. The method for preparing bromine chloramine for drinking water disinfection, sterilization and algaecide shown in the present invention comprises the following steps: purifying raw materials such as bromine, removing metal ions from the raw materials by passing them through cationic resins in sequence; and then removing pigment impurities in the bromine by passing them through anionic resins, thereby ensuring that the metal ions in the bromine raw material solution meet the metal ion index requirements for drinking water.

[0040] 3. The method for preparing bromochlorohydantoin for drinking water disinfection, sterilization and algaecide shown in the present invention, by setting a bag filter with a pore size of 0.5um and a folded filter element filter with a pore size of 0.1um for filtering the mixed solution of 5,5-dimethylhydantoin and sodium hydroxide in sequence, strictly ensures that the mixed solution is free of insoluble impurities, and at the same time, the conductivity of the pure water used is less than 20um / cm, avoiding 5,5-dimethylhydantoin, sodium hydroxide, and impurities in water affecting the purity of bromochlorohydantoin.

[0041] 4. The method for preparing bromochlorohydantoin for drinking water disinfection, sterilization and algaecide shown in the present invention collects the mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer, mixes the solvents and performs distillation treatment, and the collected acetone is recycled, thereby reducing production costs and protecting the environment. DETAILED DESCRIPTION

[0042] Unless otherwise specified, the reagents and instruments used in the following examples are commercially available conventional products.

[0043] Embodiment 1:

[0044] A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal, the specific steps of which are as follows:

[0045] Step S1, raw material purification treatment;

[0046] Bromine needs to be purified before it participates in the reaction as a raw material. First, the bromine raw material is treated with a cationic resin 001*1 at a flow rate of 1.0BV / h. This step is mainly to remove metal ions in the raw material. The feed liquid treated with the cationic resin is then treated with an anionic resin LX-8000 at a flow rate of 1.0BV / h. This step mainly removes pigment impurities in bromine and ensures that the metal ions in the bromine raw material liquid meet the requirements of the drinking water metal ion index. The purified bromine is stored separately;

[0047] Step S2, dissolving and mixing 5,5-dimethylhydantoin and sodium hydroxide;

[0048] Weigh 1 kg of 5,5-dimethylhydantoin, 0.5 kg of sodium hydroxide and 11 kg of pure water with a conductivity of less than 20 um / cm and add them into an enamel kettle for dissolution. At the same time, introduce frozen brine into the jacket of the enamel reactor, and control the material temperature to be constant at 52° C. until the material is completely dissolved to obtain a mixed solution, and the pH value of the mixed solution is 13-14;

[0049] Step S3, filtering the mixed solution for the first time;

[0050] The material is filtered in two stages, and the first stage is filtered using a bag filter with a pore size of 0.5um to obtain a primary filtered solution;

[0051] Step S4, filtering the mixed solution twice;

[0052] The primary filtered solution is then filtered through a 0.1 um folded filter cartridge filter to obtain a secondary filtered solution;

[0053] Step S5, bromination and chlorination synthesis reaction, centrifugal drying and washing, purification, drying, granulation and tableting

[0054] Specifically, step S5.1, the filtered secondary filtered solution is pressed into the synthesis process reactor; at the same time, frozen brine is introduced into the jacket of the reactor to cool it down to 4°C;

[0055] Step S5.2, while maintaining a constant temperature, adding 0.5 kg of bromine into the reactor for bromination reaction, the bromination reaction is completed, and the pH value of the solution in the reactor drops to 11.5-13.0;

[0056] Step S5.3, introducing chlorine gas into the reactor at a constant temperature for chlorination reaction until the pH value of the solution in the reactor reaches 5.0, shutting off the chlorine gas and the frozen brine, and ending the reaction to obtain a bromochlorohydrin solution;

[0057] Step S6, centrifugation, washing, purification and drying of the bromochlorohydantoin solution;

[0058] The bromochlorohydantoin solution obtained in step S5 is placed in a scraper bottom discharge centrifuge for centrifugal drying, and the washing liquid centrifuged each time is collected; then deionized water is introduced into the scraper bottom discharge centrifuge to centrifugally wash the bromochlorohydantoin crude product, and the washing is repeated 3 times; the mother liquor obtained by centrifugal drying and washing is collected, treated to meet the standards, and then discharged.

[0059] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enameled reactor, and after being completely dissolved, filtered with an enamel filter to collect the secondary wet bromochlorohydantoin and the filtrate, and the secondary wet bromochlorohydantoin is dried with a vacuum belt dryer, and the secondary dry product obtained after drying is the powdered bromochlorohydantoin used for drinking water disinfection, sterilization and algaecide.

[0060] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enamel reactor, and the materials in the reactor are filtered through an enamel filter after being completely dissolved, and the secondary wet bromochlorohydantoin and the filtrate are collected. The secondary wet bromochlorohydantoin is dried by a vacuum belt dryer, and the secondary dry product obtained after drying is powdered bromochlorohydantoin for drinking water disinfection, sterilization and algaecide.

[0061] Preferably, the mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer are collected, the two parts of the solvent are mixed and then distilled, the collected acetone is recycled, the production cost is reduced, the environment is protected, and the remaining wastewater is discharged after being treated to meet the standards.

[0062] After drying, the powdered bromochlorohydantoin is rolled into granules with a diameter of 2.0-0.25 mm by a granulator, and then the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in drinking water treatment systems to effectively kill harmful bacteria, spores, viruses, and harmful algae.

[0063] The bromochlorohydantoin produced by the method is used for drinking water disinfection and sterilization. The indicators of arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, chloroform, monochlorodibromomethane, dichlorodibromomethane, bromoform, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and the like in the treated drinking water meet the requirements of the Drinking Water Hygiene Standard (GB 5749-2022). The powdered bromochlorohydantoin is rolled into particles with a diameter of 2.0 to 0.25 mm by a granulator, and the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in a drinking water treatment system to effectively kill harmful bacteria, spores, viruses and harmful algae.

[0064] Embodiment 2:

[0065] A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal, the specific steps of which are as follows:

[0066] Step S1, raw material purification treatment;

[0067] Bromine needs to be purified before it participates in the reaction as a raw material. First, the bromine raw material is treated with a cationic resin 001*1 at a flow rate of 3.0BV / h. This step is mainly to remove metal ions in the raw material. The liquid treated with the cationic resin is then treated with an anionic resin LX-8000 at a flow rate of 3.0BV / h. This step mainly removes pigment impurities in bromine and ensures that the metal ions in the bromine raw material liquid meet the requirements of the drinking water metal ion index. The purified bromine is stored separately;

[0068] Step S2, dissolving and mixing 5,5-dimethylhydantoin and sodium hydroxide;

[0069] Weigh 1 kg of 5,5-dimethylhydantoin, 0.8 kg of sodium hydroxide and 14 kg of pure water with a conductivity of less than 20 um / cm and add them into an enamel kettle for dissolution. At the same time, introduce frozen brine into the jacket of the enamel reactor, and control the material temperature to be constant at 60° C. until the material is completely dissolved to obtain a mixed solution, and the pH value of the mixed solution is 13-14;

[0070] Step S3, filtering the mixed solution for the first time;

[0071] The material is filtered in two stages, and the first stage is filtered using a bag filter with a pore size of 0.5um to obtain a primary filtered solution;

[0072] Step S4, filtering the mixed solution twice;

[0073] The primary filtered solution is then filtered through a 0.1 um folded filter cartridge filter to obtain a secondary filtered solution;

[0074] Step S5, bromination and chlorination synthesis reaction, centrifugal drying and washing, purification, drying, granulation and tableting

[0075] Specifically, step S5.1, the filtered secondary filtered solution is pressed into the synthesis process reactor; at the same time, frozen brine is introduced into the jacket of the reactor to cool it down to 16°C;

[0076] Step S5.2, while maintaining a constant temperature, adding 0.6 kg of bromine into the reactor to carry out a bromination reaction, and the bromination reaction is completed, and the pH value of the solution in the reactor drops to 11.5-13.0;

[0077] Step S5.3, introducing chlorine gas into the reactor at a constant temperature for chlorination reaction until the pH value of the solution in the reactor reaches 6.6, shutting off the chlorine gas and the frozen brine, and ending the reaction to obtain a bromochlorohydrin solution;

[0078] Step S6, centrifugation, washing, purification and drying of the bromochlorohydantoin solution;

[0079] The bromochlorohydantoin solution obtained in step S5 is placed in a scraper bottom discharge centrifuge for centrifugal drying, and the washing liquid centrifuged each time is collected; then deionized water is introduced into the scraper bottom discharge centrifuge, the bromochlorohydantoin crude product is centrifugally washed, and the washing is repeated 5 times; the mother liquor obtained by centrifugal drying and washing is collected, treated to meet the standards, and then discharged.

[0080] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enameled reactor, and after being completely dissolved, filtered with an enamel filter to collect the secondary wet bromochlorohydantoin and the filtrate, and the secondary wet bromochlorohydantoin is dried with a vacuum belt dryer, and the secondary dry product obtained after drying is the powdered bromochlorohydantoin used for drinking water disinfection, sterilization and algaecide.

[0081] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enamel reactor, and the materials in the reactor are filtered through an enamel filter after being completely dissolved, and the secondary wet bromochlorohydantoin and the filtrate are collected. The secondary wet bromochlorohydantoin is dried by a vacuum belt dryer, and the secondary dry product obtained after drying is powdered bromochlorohydantoin for drinking water disinfection, sterilization and algaecide.

[0082] Preferably, the mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer are collected, the two parts of the solvent are mixed and then distilled, the collected acetone is recycled, the production cost is reduced, the environment is protected, and the remaining wastewater is discharged after being treated to meet the standards.

[0083] After drying, the powdered bromochlorohydantoin is rolled into granules with a diameter of 2.0-0.25 mm by a granulator, and then the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in drinking water treatment systems to effectively kill harmful bacteria, spores, viruses, and harmful algae.

[0084] The bromochlorohydantoin produced by the method is used for drinking water disinfection and sterilization. The indicators of arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, chloroform, monochlorodibromomethane, dichlorodibromomethane, bromoform, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and the like in the treated drinking water meet the requirements of the Drinking Water Hygiene Standard (GB 5749-2022). The powdered bromochlorohydantoin is rolled into particles with a diameter of 2.0 to 0.25 mm by a granulator, and the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in a drinking water treatment system to effectively kill harmful bacteria, spores, viruses and harmful algae.

[0085] Embodiment three:

[0086] A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal, the specific steps of which are as follows:

[0087] Step S1, raw material purification treatment;

[0088] Bromine needs to be purified before it participates in the reaction as a raw material. First, the bromine raw material is treated with a cationic resin ZG-007 at a flow rate of 2.0BV / h. This step is mainly to remove metal ions in the raw material. The feed liquid treated with the cationic resin is then treated with an anionic resin ZGA-302 at a flow rate of 2.0BV / h. This step mainly removes pigment impurities in bromine and ensures that the metal ions in the bromine raw material liquid meet the requirements of the drinking water metal ion index. The purified bromine is stored separately;

[0089] Step S2, dissolving and mixing 5,5-dimethylhydantoin and sodium hydroxide;

[0090] Weigh 1 kg of 5,5-dimethylhydantoin, 0.7 kg of sodium hydroxide and 13 kg of pure water with a conductivity of less than 20 um / cm and add them into an enamel kettle for dissolution. At the same time, introduce frozen brine into the jacket of the enamel reactor, and control the material temperature to be constant at 56° C. until the material is completely dissolved to obtain a mixed solution, and the pH value of the mixed solution is 13-14;

[0091] Step S3, filtering the mixed solution for the first time;

[0092] The material is filtered in two stages, and the first stage is filtered using a bag filter with a pore size of 0.5um to obtain a primary filtered solution;

[0093] Step S4, filtering the mixed solution twice;

[0094] The primary filtered solution is then filtered through a 0.1 um folded filter cartridge filter to obtain a secondary filtered solution;

[0095] Step S5, bromination and chlorination synthesis reaction, centrifugal drying and washing, purification, drying, granulation and tableting

[0096] Specifically, step S5.1, the filtered secondary filtered solution is pressed into the synthesis process reactor; at the same time, frozen brine is introduced into the jacket of the reactor to cool it down to 12° C.;

[0097] Step S5.2, while maintaining a constant temperature, adding 0.55 kg of bromine into the reactor for bromination reaction, the bromination reaction is completed, and the pH value of the solution in the reactor drops to 11.5-13.0;

[0098] Step S5.3, introducing chlorine gas into the reactor at a constant temperature for chlorination reaction, until the pH value of the solution in the reactor reaches 6, shutting off the chlorine gas and the frozen brine, and ending the reaction to obtain a bromochlorohydrin solution;

[0099] Step S6, centrifugation, washing, purification and drying of the bromochlorohydantoin solution;

[0100] The bromochlorohydantoin solution obtained in step S5 is placed in a scraper bottom discharge centrifuge for centrifugal drying, and the washing liquid centrifuged each time is collected; then deionized water is introduced into the scraper bottom discharge centrifuge, the bromochlorohydantoin crude product is centrifugally washed, and the washing is repeated 4 times; the mother liquor obtained by centrifugal drying and washing is collected, treated to meet the standards, and then discharged.

[0101] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enameled reactor, and after being completely dissolved, filtered with an enamel filter to collect the secondary wet bromochlorohydantoin and the filtrate, and the secondary wet bromochlorohydantoin is dried with a vacuum belt dryer, and the secondary dry product obtained after drying is the powdered bromochlorohydantoin used for drinking water disinfection, sterilization and algaecide.

[0102] The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enamel reactor, and the materials in the reactor are filtered through an enamel filter after being completely dissolved, and the secondary wet bromochlorohydantoin and the filtrate are collected. The secondary wet bromochlorohydantoin is dried by a vacuum belt dryer, and the secondary dry product obtained after drying is powdered bromochlorohydantoin for drinking water disinfection, sterilization and algaecide.

[0103] Preferably, the mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer are collected, the two parts of the solvent are mixed and then distilled, the collected acetone is recycled, the production cost is reduced, the environment is protected, and the remaining wastewater is discharged after being treated to meet the standards.

[0104] After drying, the powdered bromochlorohydantoin is rolled into granules with a diameter of 2.0-0.25 mm by a granulator, and then the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in drinking water treatment systems to effectively kill harmful bacteria, spores, viruses, and harmful algae.

[0105] The bromochlorohydantoin produced by the method is used for drinking water disinfection and sterilization. The indicators of arsenic, cadmium, chromium (hexavalent), lead, mercury, cyanide, fluoride, nitrate, chloroform, monochlorodibromomethane, dichlorodibromomethane, bromoform, dichloroacetic acid, trichloroacetic acid, bromate, chlorite, chlorate, aluminum, iron, manganese, copper, zinc, chloride, sulfate, ammonia (in terms of N) and the like in the treated drinking water meet the requirements of the Drinking Water Hygiene Standard (GB 5749-2022). The powdered bromochlorohydantoin is rolled into particles with a diameter of 2.0 to 0.25 mm by a granulator, and the granular bromochlorohydantoin is made into flake-shaped bromochlorohydantoin, which is used in a drinking water treatment system to effectively kill harmful bacteria, spores, viruses and harmful algae.

[0106] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algaecide, characterized in that: Specifically include the following steps: Step S1, raw material purification treatment; Specifically, for bromine purification, the bromine raw material is first treated with a cationic resin, the feed liquid after the cationic resin treatment is treated with an anionic resin, and the purified bromine is stored separately; Step S2, dissolving and mixing 5,5-dimethylhydantoin and sodium hydroxide; Specifically, 5,5-dimethylhydantoin, sodium hydroxide and pure water are weighed and added to an enameled reactor, and frozen brine is introduced into the jacket of the enameled reactor at the same time, and the material temperature is controlled to be constant at 52° C. to 60° C. until the material is completely dissolved to obtain a mixed solution, and the pH value of the mixed solution is 13 to 14; Step S3, filtering the mixed solution for the first time; The mixed solution obtained in step S2 is filtered through a bag filter to obtain a primary filtered solution; Step S4, filtering the mixed solution twice; The primary filtered solution is filtered through a folded filter cartridge filter for secondary filtration to obtain a secondary filtered solution; Step S5, bromination and chlorination synthesis reaction; Specifically, step S5.1, the filtered secondary filtered solution is pressed into the synthesis process reactor; at the same time, frozen brine is introduced into the jacket of the reactor to cool it down to 4°C to 16°C; Step S5.2, while maintaining a constant temperature, adding the bromine in step S1 into the reactor to carry out a bromination reaction, until the bromination reaction is completed and the pH value of the solution in the reactor drops to 11.5-13.0; Step S5.3, introducing chlorine gas into the reactor at a constant temperature for chlorination reaction, and shutting off the chlorine gas and the frozen brine until the pH value of the solution in the reactor reaches 5.0-6.6, and the reaction is completed to obtain a bromine chlorine hydrazine solution; Step S6, centrifugation, washing, purification and drying of the bromochlorohydantoin solution; The bromochlorohydantoin solution obtained in step S5 is placed in a scraper bottom discharge centrifuge for centrifugal drying, and the washing liquid centrifuged each time is collected; then deionized water is introduced into the scraper bottom discharge centrifuge to centrifugally wash the bromochlorohydantoin crude product, and the washing is repeated 3 to 5 times; the mother liquor obtained by centrifugal drying and washing is collected, treated to meet the standards, and then discharged. The wet bromochlorohydantoin and acetone after centrifugal drying and washing are added into an enameled reactor, and after being completely dissolved, filtered with an enamel filter to collect the secondary wet bromochlorohydantoin and the filtrate, and the secondary wet bromochlorohydantoin is dried with a vacuum belt dryer, and the secondary dry product obtained after drying is the powdered bromochlorohydantoin used for drinking water disinfection, sterilization and algaecide.

2. A method for preparing bromine, chlorine and hydrazine for drinking water disinfection, sterilization and algaecide according to claim 1, characterized in that: The cationic resin in step S1 is one of 001*1, LX-004 and ZG-007.

3. A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algaecide according to claim 1, characterized in that: The anion resin in step S1 is one of LX-8000, AM-207, AM-300 and ZGA-302.

4. The method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal according to claim 1, characterized in that: In step S1, the bromine raw material passes through the cationic resin at a flow rate of 1.0-3.0 BV / h, and then passes through the anionic resin at a flow rate of 1.0-3.0 BV / h.

5. A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algaecide according to claim 1, characterized in that: In the step S2, the weight ratio of 5,5-dimethylhydantoin, sodium hydroxide and pure water is 1:(0.5-0.8):(11-14).

6. A method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algaecide according to claim 1, characterized in that: The conductivity of the pure water used in the method for preparing bromochlorohydantoin is less than 20um / cm.

7. The method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal according to claim 1, characterized in that: The pore size of the bag filter in step S3 is 0.5 um.

8. The method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal according to claim 1, characterized in that: The pore size of the folded filter element in step S4 is 0.1 um.

9. The method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal according to claim 5, characterized in that: In steps S1 and S5, the weight ratio of 5,5-dimethylhydantoin to liquid bromine is 1:(0.5-0.6).

10. The method for preparing bromine chlorine hydrazine for drinking water disinfection, sterilization and algae removal according to claim 9, characterized in that: The mother liquor after centrifugation and the solvent recovered by the vacuum belt dryer are collected, the solvents are mixed and then distilled, the remaining waste water after the acetone is collected is treated and discharged after reaching the standard, and the collected acetone is recycled; the powdered bromochlorohydantoin after drying is rolled into particles with a diameter of 2.0 to 0.25 mm by a granulator, and the granular bromochlorohydantoin is then used to make flake bromochlorohydantoin.