Contaminants of Emerging Concern: a Review of Risk Assessment and Treatment Strategies

Abstract

Contaminants of emerging concern (CECs) such as pharmaceutically active compounds (PhACs), personal care products (PCPs), pesticides, artificial sweeteners (ASWs) in aquatic ecosystems entail a potential risk for the environment, due to their persistent behavior and adverse effect on living organisms during a long-term exposition, even at residual concentrations. Conventional Wastewater Treatment Plants (WWTPs) are not designed to eliminate CECs properly because the treatment technologies are not enough to remove these contaminants, which generates environmental and technological challenges. In this review, the sources of CEC contaminants to aquatic environments have been discussed in detail. Understanding the occurrences and pathways of CECs, their adverse effects on the environment, and removal techniques is a valuable key for the proper maintenance of global ecological health. This scenario was more explored through the harmful impacts of CECs on the environment, including their toxic effects and permissible limits. This review gathers information about CECs occurrences from a global perspective compiling information about their ecotoxicological effects, conventional and advanced treatment methods towards their mitigation. Advanced hybrid treatment techniques such as membrane bioreactor with ozonation, reverse osmosis, and ultrafiltration have shown to be a promising alternative for CECs removal. New advanced oxidation processes with assisted and non-assisted UVC/H2O2 systems with TiO2 photocatalysis were also demonstrated as a good approach to be implemented in the CECs mitigation strategies.