Occurrence and fate of CECs transformation products

Abstract

The wastewater originating from various domestic, industrial, and agricultural sources contains chemical compounds that are not commonly monitored in the environment. These compounds are collectively termed as “Contaminants of Emerging Concern (CECs)” or “emerging contaminants” or “emerging pollutants.” These include pharmaceutically active compounds, personal care products, pesticides, and many other synthetic organic compounds. Advancements in domestic, industrial, and agricultural sectors have resulted in an increased concentration of CECs in the aquatic environment to hazardous levels. The existing treatment systems do not assure the complete removal of CECs. Moreover, from CECs, many transformation products (TPs) are formed through biological and chemical processes. Some TPs formed are found to be much more hazardous and persistent than their parent compound. They may also get converted back into their parent compound under certain conditions. With recent scientific advancement in the analysis and detection of trace compounds, CEC TPs’ presence has been identified and quantified at diverse environments like sewage effluent, surface and groundwater, drinking water, etc. While the knowledge on the occurrence and fate of CECs is increasing, the potential risk caused by their TPs is rarely investigated. Hence, a better understanding of the fate and existence of CEC TPs is required to assess their impacts on human health and the environment.