Comparative Performance Evaluation of Sewage Treatment Plants in Gurgaon

Abstract

The rapid growth of the population, the technological and industrial boom has brought enormous problems and degradation of the environment. Pollution caused by sewage discharged from cities and towns is the primary cause for degradation of water resources. Hence a proper and planned sewage treatment is needed.

Gurgaon city hosts two sewage treatment plants located in Dhanwanpur village. These plants are designed and constructed with an aim to manage wastewater so as to minimize and/or remove organic matter, solids, disease-causing organisms and other pollutants, before disposal. This article evaluates and compares the actual behaviour of full-scale anaerobic and aerobic wastewater treatment plants in operation in Gurgaon, providing information on the performance of the processes in terms of the quality of the generated effluent and the removal efficiency achieved. The observed results of effluent concentrations and removal efficiencies of the constituents TSS, BOD, COD, VSS and BOD/COD ratio have been compared with the typical expected performances as per the standards given by CPCB. The treatment technologies selected for study were anaerobic-UASB and aerobic-ASP plants. The results, confirmed by statistical tests, showed that, in general, the best performance was achieved by ASP, but closely followed by UASB reactor, when operating with any kind of post-treatment. It was revealed from the performance study that efficiency of the two treatment plants was adequate with respect to removal of TSS, BOD, COD and VSS. In UASB, TSS, BOD, COD and VSS removal efficiency was 90.2, 87.4, 86.96 and 86.4% respectively, while in ASP, TSS, BOD, COD and VSS removal efficiency was 88.8, 90.07, 84.15 and 90.5 % respectively. The order of removal efficiency was VSS < COD < BOD < TSS and COD < TSS < BOD < VSS respectively in UASB and ASP STPs. Additionally, the problems associated with the operation and maintenance of wastewater treatment plants is discussed.