甘氨酸法生产草甘膦过程中母液产排节点与治理分析

甘氨酸法生产草甘膦过程中产生大量的母液，该母液属于《国家危险废物名录》中的危险废物，成分复杂，含有较高含量的难降解有机物、盐、草甘膦、COD和总磷等污染物，对生态环境和人体的潜在危害大. 膜处理/高温催化氧化、多效蒸发/定向转化两种组合工艺对母液都可以进行较好地处理，能够去除母液中的大部分污染物，然而处理过程中会向环境排放废气和废水，也会产生磷酸氢二钠、焦磷酸钠、氯化钠等废盐. 母液处理产生的废盐的危险废物属性不明，使得对其的管理混乱，且废盐综合利用和处置的环境风险都很大；由于缺乏甘氨酸法草甘膦废盐污染控制标准，阻碍了其综合利用；母液处理产生的废水的污染物排放标准缺失，致使废水的环境风险无法得到有效管控. 针对母液产生和处理现状以及处理过程中存在的问题，建议从优化生产工艺实现母液减量化、利用组合的母液处理工艺、《国家危险废物名录》中增加母液处理产生的废盐、制定甘氨酸法草甘膦废盐污染控制标准和农药工业水污染物排放标准5个方面全面提升母液的环境风险防治水平. 

Analysis of Nodes and Treatment of Mother Liquor Production and Discharge in Glyphosate Production Process by Glycine Method

A large amount of mother liquor is produced during the production of glyphosate by glycine method. The mother liquor is a hazardous waste in the National Hazardous Waste List. The composition of the mother liquor was complex. The content of refractory organic matter, salt, glyphosate, COD and total phosphorus in the mother liquor was high, which had great potential harm to the ecological environment and human body. The mother liquor could be better treated by membrane treatment/high-temperature catalytic oxidation or multi-effect evaporation/directional conversion. Most of the pollutants in the mother liquor could be removed by these two processes. However, during the treatment process, not only waste gas and wastewater would be discharged to the environment, but also waste salts such as disodium hydrogen phosphate, sodium pyrophosphate and sodium chloride would be produced. Because the hazardous waste properties of waste salts produced by mother liquor treatment were unknown, their management was difficult. The environmental risks of comprehensive utilization and disposal of waste salts were high. The comprehensive utilization of waste salts from glycine glyphosate process was hindered by the lack of their pollution control standards. The environmental risks of wastewater could not be effectively controlled due to the lack of pollutant discharge standards for wastewater from mother liquor treatment. In view of the current situation of mother liquor production and treatment as well as the existing problems in the treatment, it is recommended to comprehensively improve the environmental risk prevention and control level of mother liquor from five aspects, namely, reduction of mother liquor, utilization of combined mother liquor treatment process, addition of waste salt from mother liquor treatment in the National Hazardous Waste List, formulation of pollution control standard for waste salts from glycine glyphosate process and water pollutant discharge standard for pesticide industry.