Potential environmental benefits of anaerobic digestion of sewage for energy production in secondary schools of Kakamega county, Kenya

Abstract

Sewage disposal poses serious environmental challenges yet it is largely full of organic compoundsthat store usable energy in their chemical bonds.A study was carried out on potentialenvironmental impact ofchemical and microbial characteristics of sewage generated in KakamegaCounty, Kenya. Samples of sewage from 75 schools were collected in July 2013 using bottles. Thesamples were taken to Water Resource and Management Authority (WRMA) and Bora laboratoriesfor the analysis of microbes, organic nutrients and heavy metals. The research design wasexperimental. The results showed that the microbial characteristics of the sewage generated insecondary schools have apotential negative impact onthe environment by causing pollution of thesoils and water. However, the chemical characteristics of the sewage, notably the P2O5,TKN andpH have a potential positive impact on the environment by being beneficial to the soils. From theresults, it is recommended that an alternative waste management technique of anaerobic digestionbe used sustainably to generate bioenergy from sewage for contribution to future global energydemands and minimize its adverse environmental impact.