Anaerobic biogas generation from cow dung and water hyacinth: a comparative study with reference to quality of gas and retention time

The aim of this work was to study the potential use of biological solid materials aquatic weeds as alternative sources for the production of biogas. In this study six different slurry samples were used for the production of biogas. Aquatic vegetation is an essential component of the aquatic ecosystem with both positive and negative implications on the water body. In This study the aquatic weed was analyzed for total solids, volatile solids, total dissolved solids and pH content. The pH value of the digesters was taken before and after the production of biogas in anaerobic condition. Biogas production was carried out from 6 digesters containing varying cow dung and others. This was studying was carried out for a period of 63 days at ambient temperature. It is essential to replace conventional energy source with the renewable energy source to save our natural resources and environment. The anaerobic digestion of cow dung with water weeds is feasible and could serve the dual roles of producing biogas, a clean renewable energy source and reducing the cost of weeds control. Two species of water weeds Typha latifolia and Water hyacinth were evaluated as substrates for biogas production. Water hyacinth (Eichhornia crassipes) is one of the fastest growing aquatic weed known to man. It is a free-floating perennial aquatic plant with broad, thick, glossy, ovate leaves with long, spongy and bulbous stalks. The results also show that digesters with dried water hyacinth (DWH) produced slightly more biogas in comparison to digesters with cow manure (CM). This indicated the fact that substrates for methanogenic bacteria were readily available in water hyacinth.