Review of Decentralized Wastewater Treatment Technologies and Systems

Nowadays, large volume of wastewater is being generated from the cities and travels very long distance from their point of generation to the Conventional Centralized Wastewater Treatment Plants (WWTPs), which in turn results in various operational troubles. Also, the WWTPs are sometimes unable to handle the large volumes of wastewater generated from the cities, as a result waste is discharged either with partial treatment or even with no treatment, which causes pollution of land or water bodies. So now a days it is being proposed that residential/commercial/industrial areas have to treat their waste prior to discharge. So in view of this, on-spot, safe and complete treatment of wastewater is needed for the places of sewage generation, the typical examples includes slums, labor camps, the army in transit, fairs and exhibitions, holiday homes, industries, resorts, etc. Specific treatment units must be designed for specific needs as well as the option of recycling or using the treated water. A Decentralized Wastewater Treatment Plant (DWTP) may be the need of the hour which can be deployed anywhere in need particularly where a conventional WWTP is not there or is not working or does not function properly or where freshwater is scarcely available so that the effluent can be reused for various non-potable uses. The present paper reviews the various DWTP systems along with typical technologies being adopted in these systems.