Performance evaluation of an Integrated On-site Greywater Treatment System in a tropical region

Integrated On-site Greywater Treatment System (IOGTS) with primary (settling/filtration), secondary (constructed wetland) and tertiary (adsorption) treatment was used to treat greywater from hostel. A field scale IOGTS was constructed for hostel located in Sakharale, District Sangli (M.S.) India. The performance evaluation of IOGTS was carried out for a study period of one year. The quality parameters used to assess feasibility of disposal for land application were COD, TKN, suspended solids, and pathogens. The effect of hydraulic loading rate (HLR), Hydraulic Retention Time (HRT) and Organic Loading Rate (OLR) on performance of the system was also studied. A consistent performance (30% COD removal and 70% turbidity removal) was observed in upflow-downflow filter throughout the study. Secondary treatment in IOGTS was evaluated for HLR (10-100 mm/d) and OLR (10-350 kg COD/ha.d). HLR (40 mm/d) and OLR (170 kg COD/ha.d) showed a better removal efficiency of COD. Overall performance of IOGTS for COD, TKN and pathogen removal was observed to be 70%, 70% and 85% respectively. Therefore, IOGTS can be considered to be an appropriate treatment option to treat greywater to satisfy effluent standards for its reuse in land application.