Are waste liquids produced during Wastewater Monitoring hazardous? Should they be treated? And who bears the responsibility—third-party operation and maintenance agencies or the discharging entities themselves? In this article, we will examine the management of waste liquids from wastewater monitoring processes in collaboration with Modi.
It is widely acknowledged that chemical reagents used by personnel during wastewater monitoring generate waste liquids containing harmful substances, such as toxic materials and carcinogenic substances. These waste liquids typically include tit-ration solutions after COD ref-lux, mercury-containing color-developing solutions for ammonia nitrogen colorimetry, carbon tetra-chloride extraction solutions from laboratory tests, and solutions after heavy metal sample digestion. According to the National Hazardous Waste List, inorganic waste liquids containing fluorine, cyanide, or heavy metals, as well as organic wastes (e.g., mineral oil, organic solvents) derived from chemical reagents used in environmental monitoring (including water environment monitoring), fall under hazardous waste. Accordingly, relevant authorities require entities engaged in the generation, collection, and disposal of such waste to adopt proper measures to reduce environmental pollution and potential risks to human health—this covers the treatment of waste liquids from wastewater monitoring.
Hazardous substances of various categories may bring risks to the ecological environment and human health. Therefore, there is a clear conclusion regarding the hazardous nature of these waste liquids. Relevant staff shall ensure proper treatment of such waste, and enterprises managing these liquids are required to: identify hazardous chemicals via monitoring and analysis, collect and store waste liquids in line with chemical management regulations. High-concentration waste acids and alkali’s can be neutralized to a neutral level prior to discharge, or collected centrally for recovery. Low-concentration waste can be discharged after corresponding treatment. For storage, containers and storage conditions shall be selected according to the properties of waste liquids; mixing different types of waste liquids is not allowed, so as to prevent secondary chemical reactions. As treatment approaches differ based on types of hazardous substances, disposal plans need to be formulated according to specific pollutants produced in monitoring activities.
