This book consists of 11 chapters that address the current issues and technologies in water contaminants. The contents are divided into three relevant themes, such as recent significant issues on water contaminants, treatment technology for inorganic contaminants, and treatment technology for organic contaminants. Over time, the water environment has become contaminated with thousands of chemical compounds that are discharged from sewage and industrial effluent. New emerging pollutants, such as microplastics and antibiotics, deserve particular attention due to their recalcitrant nature. Due to that, several technologies to treat these pollutants are discussed in this book including adsorption, phytoremediation, enhanced biological phosphorus removal, anaerobic process, and biogranules technology. Understanding these issues, prospects and challenges in harnessing the available technology are crucial to ensure sustainable solutions that will not bring further damage to the environment. This book provides an insight to multidisciplinary researchers, scientists and professionals in exploring new technology and improving current technology for the treatment of various pollutants in water and wastewater.