IMPLEMENTATION OF DECENTRALIZED SEWAGE TREATMENT SYSTEM FOR RURAL SET UP: A CASE STUDY

摘要

CDecentralized approach for sewage treatment which employs combination of onsite and/or cluster system is gaining more attention, particularly in developing countries owing to its suitability to build in areas with low population densities, dispersed households, small and isolated villages or settlements. This study presents an overall approach to design and implement a decentralized sewage treatment system for a residential colony situated near Nagpur. Detailed physico-chemical characterization of sewage was done to assess its strength and to design techno-economical sewage treatment facility. Data collection and field studies were carried out to measure the daily flow and existing status of sewage treatment. Based upon the physico-chemical characteristics of domestic wastewater and flow, a natural sewage treatment system having design capacity of 150 m~3/day was designed & developed to meet the requirement of decentralized STP according to site specific conditions. The natural sewage treatment system includes a combination of improved anaerobic system followed by horizontal sub-surface flow constructed wetland. After implementation and successful commissioning of natural sewage treatment system, its performance was evaluated over a period of two years. The adequacy assessment studies showed that the natural sewage treatment system met all the effluent discharge standards set by regulatory bodies and the treated water can be reused for non-potable purpose.