Biogas generation from sewage in four public universities in Ghana: A solution to potential health risk

Apart from waste treatment, anaerobic digestion is a reliable method for biogas generation. The digested sludge from anaerobic digesters can also be used to enhance the fertility of the soil. This paper assesses the biogas potential from the sewage generated in four public universities in Ghana for the 2008/2009 academic year. In the estimation of the amount of sewage generated in each university, the population was used and was categorized into residential and non-residential staff and students. The population of the universities varies throughout the year due to the vacation periods hence the sewage generated varies accordingly. The estimated population for the four universities was 100,313 when in session and 20,903 on vacation and the estimated daily sewage generated is 1379.9 m3 and 327.8 m3, when the universities were in session and on vacation respectively. This study revealed that an annual biogas potential of about 815,109 m3 could be obtained which is equivalent to about 4,891 MWh of energy or can replace about 4532 tonnes of firewood or 326.4 tonnes of LPG which can reduce the pressure on the forest and the use of LPG.

► The estimated biogas potential can replace about 4532 tonnes of firewood.
► About 326.4 tonnes of LPG can be offset from the estimated biogas.
► The daily sewage generated by the universities is 1378.5 m3 when in session.
► Implementing the project can reduce the pressure on the forest and use of LPG.
► Estimated Biogas of 815,109 m3/yr is equivalent to 4891 MWh of thermal energy/yr.