Performance Appraisal of Two-stage On-site Domestic Wastewater Treatment System under Ambient Environment

Abstract

Abstract The rapid growth in population has rendered the centralized sewerage systems a non-realistic option in sparsely populated areas. Consequently, an on-site wastewater treatment system (OWTS) is a viable alternative and cost-effective solution of sewerage system. Septic tanks with soil absorption systems are a simple mean of onsite treatment of the domestic wastewater. However septic tanks have low treatment efficiency along with several technical and constructional drawbacks. In order to improve the performance efficiency of conventional septic tank, a two-stage anaerobic reactor was developed. The main purpose of the study was to develop a two-stage onsite treatment system, which could become attractive from technical, economical, social and environmental viewpoints, to the technologies that are currently employed. The treatment unit consists of a cylindrical tank, where half of the volume is used as a modified septic tank and the other half as an upflow anaerobic filter. The system was operated at a hydraulic retention time of 24 h. The system was operated at ambient temperatures in laboratory-scale. During one year of continuous operation and performance evaluation, it was observed that a steady state condition was achieved after 120 days of operation without inoculation. The system was found to deliver highly satisfactory removal rates of 88.7±3% chemical oxygen demand (COD), 86.3±4% biochemical oxygen demand (BOD), and 91.4±10% total suspended solids (TSS), observed at steady state condition. It also showed a very good endurance against imposed hydraulic shock load. On account of the highly satisfactory experimental results, low cost, and no requirement of electricity, this system can be a potential alternative to the conventional septic tank in the developing countries like India. Keywords: Anaerobic system, domestic wastewater, on-site treatment, two-stage Cite this Article Meena Kumari Sharma, Kazmi AA. Performance Appraisal of Two-stage On-Site Domestic Wastewater Treatment System under Ambient Environment. Recent Trends in Civil Engineering & Technology. 2018; 8(1): 20–28p.