Classification of water contaminants

Water is a basic necessity for living beings and vital for the existence of life on Earth. However, the growing development and consumption of chemicals in industries, agriculture, and domestic households is responsible for the increasing water contamination which is leaving a negative impact in the ecosystem. Use of contaminated water is giving birth to various waterborne diseases and deteriorating the natural environment for aquatic and marine life. Providing clean and freshwater for all has now become a challenging task. Several organic (organic dyes, pesticides, pharmaceutical ingredients, etc.) and inorganic (heavy metal ions, radioactive substances, etc.) contaminants are introduced into the freshwater resources from wastewater effluents. Treatment of effluents before discharging into freshwater bodies is one of the best approaches to reduce water pollution. To clean the wastewater, using several technologies, the basic understanding of functional groups and the nature of water contaminants is most important. Therefore this chapter provides a broad overview of classification, sources, structure, functional groups, and adverse effects on living beings of various water contaminants.