Fate of Micropollutants in Engineered and Natural Environment

Recent trend in urbanization and lifestyle choice has led to a rapid increase in the occurrence of varying classes of micropollutants in the environment. Due to incomplete removal of these pollutants in sewage treatment plants (STPs), many micropollutants enter and persist in water bodies. Typically, the removal via biodegradation and other tertiary treatment techniques is insufficient, especially for hydrophilic and non-biodegradable micropollutants, compared to their hydrophobic counterparts. Although present at concentrations of parts per billion (µg/L) to parts per trillion (ng/L), micropollutants elicit severe chronic effects in aquatic organisms, including endocrine disruption and antibiotic resistance. Common micropollutants in wastewater include pharmaceuticals and personal care products (PPCPs), steroids, hormones, surfactants, heavy metals, pesticides, fertilizers, disinfectants, and other industrial chemicals and solvents. This review aims to provide an overview of the classification of micropollutants, their origin, effects on the ecosystem, and insufficiency of the current treatment techniques. Novel treatment techniques for the removal of micropollutants are also discussed.