Management of cane-sugar industry effluents by biogas generation: a case study of the Sugar Industry in Muhoroni

Abstract

This thesis describes the anaerobic digestion of cane-sugar industrial effluents as an alternative treatment mode which not only reduces pollutants but affords end-products of economic value. The results show that 75-85%reduction in COD is achieved within a retention period of 5 days. The volume of biogas generated using a floating-dome digester was found to be 0.81m 3 per cubic meter of effluent,within a retention period of 25-33 days. The COD reduction achieved,indicates an operational efficiency of 49.52% on extrapolation, and is equivalent to an estimated saving in woodfuel per annum of 21.76%. The digester effluent had a salinity of 3160 ʯs/cm, and is therefore too saline for agricultural use. Anaerobic digestion of cane-sugar effluents is effective in oxygen-demand reduction but further treatment is required to reduce the pollutants to admissible levels of discharge into the river.