Anaerobic Digestion of Composite Organic Wastes: An Ecologically Balanced Approach for Improvement of Health, Hygiene, and Environment of Rural Communities

Anaerobic digestion of composite organic wastes comprising human excreta (HE), partially-digested market waste (PMW), and partially-digested water hyacinth (PWH) in community latrine-linked field digester as well as in laboratory-scale anaerobic digester using sewage treatment plant primary sludge (PS), liquefied market wastes (LMW), and liquefied water hyacinth (LWH) was studied with an aim to curtail huge costs associated with transportation and ultimate disposal of market wastes into landfill.

While the optimum proportions of waste feed components viz, PS, LMW, and LWH of 2:1.5:1 and HE: PMW: PWH of 11.8:6:1 were observed, the maximum bio-gas productions were 0.015 sm³ and 0.042 sm³ per kg of composite wastes for laboratory and field digesters, respectively. The total coliform removals were 98.6% and 99.22%, whereas the faecal coliform removals were 98.45% and 99.62% in the laboratory and field digesters, respectively. The digester effluent was beneficially used for irrigation and pisciculture through post-treatment in WSP system.