Developing a prototype for treatment of biowaste with microorganisms to produce biogas and compost

Abstract

Waste management in South Africa faces many challenges. The growing population and the expanding economy results in increased volumes of waste being produced, thereby putting a burden on waste management facilities. South Africa is collaborating in an EU sponsored project whose objectives are to convert biowaste into valuable products. The project is part of an initiative that targets to develop environmentally appropriate and socio-economically sustainable biotechnological processes for converting biodegradable fractions of identified African and Mediterranean agricultural and industrial waste as well as fractions of municipal and animal solid waste into food, feed and value-added products. Our contribution is to develop an anaerobic digester to convert solid waste into biogas, and the indigestible component collected for use in the compost facility to produce biofertilizer. This project is based at EThekwini Municipality’s Northdene Research and development centre, which is located within a residential area from which the biowaste is collected. The conversion technology to be developed will rely on simple and locally available equipment and naturally occurring microorganisms. The appropriate prototype will be assessed through selection of proper operating conditions to evaluate the performance of an anaerobic digester and to optimise the anaerobic microorganisms. Determination of the technical potential for the production of biogas from biowaste will be carried out using biochemical methane potential tests. Pilot scale trials will be performed on the selected equipment to produce biogas and compost. The biogas can be used to warm water for the fish project at Northdene during cold weather, and/or it can also be used to heat the reactor to the operating temperature and the compost can be sold as an organic based fertiliser.