Comparison of Performance of Sewage Treatment Facilities in Shimla

Abstract

Effective sewage treatment is crucial for healthy living. The comparison of various sewage treatment facilities of sewage treatment plants in Shimla draws a difference between the operational and design parameters for pre-monsoon, monsoon and post-monsoon season. Phase 1 included the comparison of three sewage treatment plants namely Lalpani, Sanjauli and Dhalli. Phase 2 includes the rest three plants situated in Summer Hill, North Disposal and Snowdon. The objective of this project was to establish the experimental and operational parameters of the plants and relate it with other plants. Influent and effluent parameters used for this study include pH, settleable solids, suspended solids (total and volatile), temperature (influent and effluent) BOD, COD, DO and chloride content. The study of various treatment processes in waste water treatment shows that temperature and pH are the important factors affecting efficiency of flocculation and settling properties. This study was performed to determine the effects of pH and temperature on settling of the flocs in these processes. Psychrophilic anaerobic process is an attractive option for sewage treated at moderate and low temperature. Anaerobic wastewater treatment differs from conventional aerobic treatment. The absence of oxygen leads to controlled conversion of complex organic pollutions, mainly to carbon dioxide and methane. Anaerobic treatment has favourable effects like removal of higher organic loading, low sludge production, high pathogen removal, biogas gas production and low energy consumption. Psychrophilic anaerobic treatment can be an attractive option to conventional anaerobic digestion for municipal sewage and industrial wastewaters that are discharged at moderate to low temperature. The effluent quality of a sewage treatment plant using activated sludge process and finally secondary treatment depends on the flocculation efficiency and settling of the flocs. The two main reasons behind the importance of using UASB are, generation of large volumes of low-strength wastewaters, which are often disposed untreated due to high costs, and the potential of stabilizing the organic wastes by producing valuable energy as by product. The report discusses possibilities of municipal sewage treatment in UASB and Extended aeration process provided in Shimla.