Emerging contaminants refer to the naturally occurring or synthetic chemicals or substances that have been identified recently and are toxic to human health and environment. These are known as contaminants of emerging concern (CECs). Some major sources of CECs are pharmaceuticals and personal care products, detergents, steroid hormones, industrial chemicals, and pesticides. The complete removal of the CECs requires the use of advanced chemical, physical and biological treatment techniques. Advanced oxidation processes (AOPs) is an emerging chemical technology used for treating wastewater. Ozone, catalyst and UV irradiation are oxidants that combine in AOPs for delivering more efficient wastewater treatment. The CECs have demonstrated low acute toxicity but studies have shown that they may cause significant reproductive effects at low levels of exposure. This book outlines the latest methods for detecting and treating emerging contaminants in water and wastewater in detail. It will help the new readers in foregrounding their knowledge in this area of study.