Significance of Constructed Wetlands for enhancing reuse of treated effluent

Abstract

Natural treatment systems are quite effective in the treatment of biodegradable organic pollutants. Constructed wetlands (CWs) are a class of natural treatment systems which have a potential in contributing towards sustainability since they return nutrients to the environment and do not consume energy as well. They can also be incorporated in peri-urban and rural landscapes quite easily. The important criteria for categorizing constructed wetlands include hydrology (open water surface and subsurface flow), flow path (vertical and horizontal) and type of macrophytic growth of plants. One practical example is a constructed wetland installed in the Katchpua slum in Agra city where the treated effluent was used for the irrigation of grass fields. The removal of conventional pollutants has already been widely studied. However, the removal of emerging pollutants is also important for reuse of treated effluent from urban sewage streams. The emerging pollutants include pharmaceuticals, pesticides and other micropollutants. This review paper describes the application of constructed wetlands which were involved in the effective removal of both conventional and emerging pollutants along with some suitable modifications required to improve its effectiveness...