It is difficult to treat the wastewater containing salt and phenol. Kang Jinghui optimized the process route and used evaporation crystallization device to treat the wastewater containing salt and phenol. Today, Kang Jinghui will talk with you about the treatment of salt-containing phenol wastewater by evaporative crystallization device.
　　The amount of wastewater from pesticide production and discharge is large, and it is difficult to treat. Generally, the main way to treat pesticide wastewater is to optimize emission reduction and control discharge, which is mainly based on treatment. There are many kinds of pesticide wastewater, which need targeted treatment. Kang Jinghui's Xiaobian introduces the wastewater containing salt and phenol discharged from a pesticide plant as an example.
　　I. Composition and Characteristics of Wastewater from Pesticide Project
　　The owner's wastewater of this project is mainly herbicide 2,4- sodium disodium salt (full name: sodium 2,4- dichlorophenoxyacetate) wastewater.
　　Phenoxyacetic acid was synthesized by the reaction of chloroacetic acid and phenol, and the mixed solution of phenoxyacetic acid and acetic acid was chlorinated under the catalysis of hydrochloric acid to synthesize 2,4- drip, and then the product 2,4- drip sodium salt was obtained through alkali washing, acidification, suction filtration, drying and recrystallization.
　　Therefore, the wastewater contains unreacted raw materials: phenol, chloroacetic acid and acetic acid; Trace intermediates and products: 2,4- dichlorophenol, p-chlorophenoxyacetic acid; Additives and by-products: ether, acetic acid, sodium chloride.
　　Second, the treatment process of wastewater containing salt and phenol
　　Because phenol and chlorophenol are extremely strong carcinogens, and the content of phenol is high, firstly, phenol is enriched by membrane system, RO effluent directly enters the reclaimed water recycling system, and RO concentrated water enters the rectification system to realize the separation of water and phenol, and then phenol and toluene are distilled and separated, and phenol is recycled, and toluene is recycled as an azeotropic agent.
　　The bottom liquid of azeotropic distillation column enters wet catalytic oxidation system (CWO system), and then enters MVR evaporation crystallization system for desalination. The separated salt can be sold as industrial salt, and the evaporated condensate can be reused in reclaimed water reuse system.
　　Third, Kang Jinghui optimized the evaporation crystallization device to treat the wastewater containing salt and phenol.
　　In order to optimize the process route, Kang Jinghui preferred MVR compressor technology after comparing the multi-effect crystallization process.
　　Under the condition of evaporation temperature of 75℃ to 90℃, the evaporation temperature is determined to be 90℃ by comparing the parameters such as compressor power, cooling water volume, total energy consumption and total area of evaporation crystallization device.
　　In order to improve the energy utilization rate, the heat such as condensed water, crystal slurry output and mother liquor reflux is reasonably utilized.
　　Multi-stage plate preheater and plate evaporator are used in the equipment design, and the separator and condensate vapor-liquid separation device all adopt the patented structure to improve the operation efficiency.
　　In engineering application, the equipment runs well by adjusting the crystallization circulation and the heat matching between evaporation section and crystallization section. The average particle size of wastewater crystallization salt is 0.4mm, and the COD content of condensate water is less than 50ppm. Because of the anisotropy of pesticide wastewater, different wastewater still needs to be developed and designed.
　　There are many cases of treating wastewater containing salt and phenol by Kang Jinghui evaporation crystallization device. If necessary, you can directly consult online customer service.