Method for treating acid wastewater of 2-methyl-4-chlorophenoxyacetic acid through extraction, neutralization and distillation integration

Abstract

The invention discloses a method for treating acid wastewater of 2-methyl-4-chlorophenoxyacetic acid through extraction, neutralization and distillation integration. The method is characterized by comprising the following steps of: performing liquid-liquid extraction on the acid wastewater by taking diethyl ether as an extracting agent to extract organic impurities from the acid wastewater; distilling a diethyl ether layer under reduced pressure, and recovering the diethyl ether serving as the extracting agent for recycling; adding NaOH into an aqueous phase, neutralizing, distilling, concentrating to obtain a NaCl concentrated solution, cooling, and filtering to obtain NaCl crystals; and collecting organic substances remained after the diethyl ether is recovered, accumulating, separating and recovering useful ingredients in the organic substances, returning a filtrate to the acid wastewater, and continuing to extract NaCl. By the method, 213kg of white NaCl crystals can be obtained from each ton of acid wastewater; and the product meets industrial-grade NaCl standard. The NaCl and the organic substances in the acid wastewater of the 2-methyl-4-chlorophenoxyacetic acid can be effectively separated and extracted; the process is simple, easy and low in energy consumption, and a method which can be industrially applied is used for comprehensively treating the acid wastewater of the 2-methyl-4-chlorophenoxyacetic acid; and the purity of the NaCl is high.

Description

technical field [0001] The present invention relates to a treatment method of dimethyltetrachlor acidic wastewater in dimethyltetrachloride production, in particular to a method for integrated treatment of dimethyltetrachloric acidic wastewater by extraction and neutralization distillation, separating and extracting dimethyltetrachloric acidic wastewater Organic matter and NaCl in wastewater. Background technique [0002] Dimethyltetrachloride, chemical name 2-methyl-4-chlorophenoxyacetic acid, its sodium salt Dimethyltetrachlorosodium is a phenoxyacetic acid-type herbicide with high efficiency, low toxicity and high selectivity, which can destroy Gemini The dredging tissue of leaf plants interferes with the growth and development of plants. Common formulations are 13%, 20% water, 56% wettable powder. [0003] The production process of 2M4Cl (dimethylamine salt) is divided into five processes, including the synthesis of sodium chloroacetate, the synthesis of sodium o-creso...

AI Technical Summary

Problems solved by technology

In the past, manufacturers mainly used diluted discharge for the treatment of acid wastewater in the chlorination section, which was not conducive to environmental protection, but also resulted in the loss of a large amount of useful substances

Treatment and recycling of process wastewater in the production of dimethyltetrachloride has not been reported in various journals

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