Rivers are vital resources affecting every aspect of life". Change in the physicochemical properties of river would affect human health. Conventional treatment technologies are expensive and not suitable for developing countries. "Eco-friendly technologies are need of the time". This book provides eco-friendly technologies for the removal of pollutants from municipal sewage and industrial effluents. Emergent plants have been used as an alternative to activated sludge process. Bio-filtration coupled with aeration have been used to enhance pollutant removal.