Investigation of the potential of pyrolysis for feacal sludge management and slaughter-house waste water treatment: A case study of Lubigi Treatment Plant

Abstract

Uncontrolled disposal of feacal sludge and slaughter house waste water has detrimental impacts on public health and environment. Pyrolysis would offer a sustainable solution for improved feacal sludge management through production of biochar. This study was conducted to determine the characteristics of biochar from pyrolysed feacal sludge and its potential applications including slaughterhouse wastewater treatment. Dried feacal sludge samples from Lubigi Treatment Plant were pyrolysed at temperatures of 300, 400, 5000C, and thereafter used to treat SWW from Nsooba channel at Kalerwe abattoir. Ash content, pH, EC, and NPK of biochar increased with increase in production temperature whereas calorific value decreased with temperature. Low calorific values (8-10MJ/kg) and high ash contents (70-86%) suggested that biochar was unsuitable for use as a fuel. Higher concentrations of total nutrients in biochar and alkaline pH, suggested it was suitable for use as soil enhancer. For treatment of slaughter house waste water, the biochar had relatively low removal efficiencies of COD and BOD but was able to adsorb colour from SWW and neutralize its pH as well. However, the biochar increased turbidity as well as total nitrogen and total phosphorus of the SWW.