Treatment process for 3,5,6-Trichloropyridin-2-ol sodium and chlorpyrifos production wastewater

Abstract

The present invention relates to a treatment process for 3,5,6-Trichloropyridin-2-ol sodium and chlorpyrifos production wastewater, and belongs to the technical field of environmental protection. The process comprises steps of evaporation, incineration, and biochemical method. The invention provides a method, which is simple for management and operation and capable of treating organic wastewater with high toxicity, high COD and high salinity. Water quality of the wastewater treated by the process provided by the invention is stable and can reach grade two in Integrated wastewater discharge standard GB89781996. In addition, aiming at the characteristics of high heat value of high-boiling residue and concentrated organic waste liquid generated in the production process of 3,5,6-Trichloropyridin-2-ol sodium, the present invention employs a waste heat boiler to fully utilize heat generated from incineration to produce a by-product steam, so as to basically achieve self-sufficiency of steam for the system, and greatly reduce cost of the wastewater treatment process provided by the invention.

Description

technical field [0001] The invention relates to a process for treating wastewater produced by sodium clopyridinate and chlorpyrifos, and belongs to the technical field of environmental protection. Background technique [0002] Sodium clopyridinate is an important chemical raw material, mainly used in the production of pesticides chlorpyrifos and class A chlorpyrifos, and is a pesticide intermediate. Generally speaking, about 6 tons of waste water are produced for every ton of triclopyridin sodium produced. The composition of sodium clopyridinate wastewater is quite complex: it contains various toxic and harmful substances such as cyanide, chloride, chlorobenzene, sodium clopyridinate and heavy metals. In addition, clopyridox sodium has poor biodegradability and is difficult to handle by common biochemical methods. [0003] The chemical name of chlorpyrifos is 0,0-diethyl-0-(3,5,6,-trichloro-2-pyridyl)phosphorothioate. It is a high-efficiency, broad-spectrum, low-residue o...

AI Technical Summary

Problems solved by technology

It is a high-efficiency, broad-spectrum, low-residue organophosphorus pesticide. It is one of the pesticide varieties with the largest output in the world. It is widely used in European and American countries. It is also an excellent variety for my country to replace the highly toxic pesticide methamidophos. The market prospect Vast, but the wastewater produced in the production process of chlorpyrifos has high pollutant concentration (CODcr concentration is high, between 30,000 and 50,000), high salt content, high chroma and high toxicity, which has a great toxicity to microorganisms and biodegradation Poor (B / C ratio between 0.15 and 0.2), it is a high-concentration, refractory organophosphorus pesticide wastewater

[0004] At present, scholars at home and abroad have carried out a lot of research on the treatment of sodium clopyridinate and chlorpyrifos production wastewater, using such as physical and chemical methods (such as extraction, adsorption, precipitation, etc.), chemical methods (such as chemical oxidation, catalytic oxidation ) and biochemical methods (such as traditional activated sludge method, SBR, MBR, A / O, UASB, A 2 / O process, etc.) or a combined process between them to treat it, but due to the presence of high concentration of salt in the wastewater, the practical application of the above process is not ideal.

At present, in order to meet the sewage standards, the production enterprises actually use the dilution-biochemical method or the vacuum distillation-incineration method to treat this type of wastewater, but the problem is that the dilution-biochemical method has a dilution factor of 20 to 40 times. It is a great waste of water resources, and the quality of the effluent water is unstable, and the vacuum distillation-incineration method will still cause pollution due to the high COD value of the distillate during the decanting process of a small amount of residual liquid after distillation.

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