Micropollutants represent a broad category of chemicals, which were previously unrecognized but are being of concern due to their potential risks to environmental and human health. Because the majority of micropollutants are released into wastewater treatment plants (WWTPs), which is a final barrier preventing the spread of micropollutants into the environment, the removal of micropollutants is highly desired in WWTPs (e.g., activated sludge system) to reduce the potential toxicity in the environment. In this talk, I will present whether or not micropollutants are sufficiently removed in activated sludge processes and, if so, what mechanisms underlie the removal of micropollutants. Further, this talk will discuss what activated sludge microorganisms are responsible for the biodegradation/biotransformation of micropollutants, which has implications for predicting the fate of micropollutants in WWTPs and developing an appropriate remediation strategy for treating micropollutants-bearing waste streams.