Significance of Constructed Wetlands for Enhancing Reuse of Treated Sewages in Rural India

Abstract

Constructed wetland (CW) is an eco-centric technology. It is gaining attention due to its extensive applicability all over the world owing to the distinguishing characteristics such as eco-friendly, simple construction, easy operation and maintenance along with process stability as well as its cost-effectiveness (both, capital and O&M costs). CWs employ the natural processes including wetland vegetation, soils and their accompanying microbial populations for treatment of wastewaters of all kinds—especially sewages. The principal purposes for development of CWs includes improvement of water quality, creation of food (constructed aquaculture wetlands) and establishment of habitats to augment the natural wetlands which are contaminated by disposing urban sewages. Based on our earlier research, an assessment of energy consumption for the wastewater treatment in small cities, towns and villages (approximately population of 85–95 Crores and 35,000 MLD wastewater) has been performed for activated sludge process and contrasted with CW. The parameters selected during assessment of the above-mentioned technologies include electrical energy consumed during operation of treatment facility, corresponding coal required for generation of electricity as well as assessment of the long-term impacts on environment in terms of global warming potential, acidification potential and abiotic resource depletion potential. The CWs in the towns of rural India clearly demonstrate the reuse of treated water by the local community for animals and irrigation purposes as well as achieves reduction of health problems (improved sanitation, absence of mosquito breeding, foul smell, etc.). Thus, the CWs fulfil social, economic and environmental goals. It is hoped that engineered CWs will play important role in rural India. Our research as well as the work of other groups in India has demonstrated that the CWs could be considered as viable and promising alternative for the treatment as well as reuse of sewages and sullages in rural and peri-urban communities.