Suitability of Macrophytes for Wastewater Treatment and Biogas Generation

Abstract

In this paper three sustainable approaches are made in waste management option. Firstly primary treated domestic sewage is treated by aquatic macrophytes using duckweed, water hyacinth and water lettuce. Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Phosphate, Nitrates are tested before and after. Result indicates in terms of water quality, almost all three plants shows same removal efficiencies. BOD and TSS removal efficiency is attained more than 95%. COD and TDS removal is reached upto 50% for almost all plants. Secondly the used aquatic macrophytes for wastewater treatment is again used for generation of biogas (water lettuce unit, duckweed unit, water lettuce unit). In addition to three aquatic macrophytes, sludge is collected from aquatic macrophyte unit for generation of biogas. Comparison is made with conventional cow dung biogas unit. Result indicates water lettuce and duckweed produce biogas at earlier stage itself and water hyacinth takes some time for starting of biogas production. This may be due to the structure and texture causes some time for decomposition. Sludge gives maximum biogas generation among all experimental setup. Also in this study cow dung did not give biogas more may be due to poor blend ratio of cow dung with water is one of the reason.