Feasibility of using Diluted and Chemically Treated Wastewater for Fish Culture

Abstract

Wastewater treatment using waste stabilization ponds is very efficient and inexpensive but requirement of large areas of land is a major constraint. An alternative is direct dilution of wastewater and treatment using floating aquatic plants. This study was undertaken to assess the effect of diluted waste water on histology of gills. The results showed severe pathological alterations in gills of Labeo rohita up to 1: 6 dilution and changes were less at dilution 1:8 and above. In urban areas, where both land and water availability are constraints, another option is chemical treatment. Phosphorus and chemical oxygen demand (COD) from wastewater was removed by chemical precipitation using zeolite, alum (Aluminium sulfate) and their combinations. It was observed that alum and zeolite absorb phosphorus; 85% and 78% respectively and remove COD; 67% and 57% respectively. But zeolite-alum mixture removes phosphorus (85%) and COD (68%) at much lower dose and also helps in balancing the pH.