Energy from Domestic Wastewater and Recovering the Potential Energy of Sewage Sludge

Abstract

This paper gives a concept overview of energy from sludge in term of anaerobic digestion method. Wastewater is grossly undervalued as a resource of energy. The sludge production is a function of the wastewater treatment system used for liquid phase. In principal, all the biological treatment process generate sludge. Nevertheless, waste and wastewater treatment have been a neglected problem in Afghanistan, where 80 % of our energy importing from neighborhood countries. As world going toward renewable energy, sewage treatment plants can retrieve valuable resources such as water, green energy and fertilizers. Developing and implementing renewable energy systems such as biogas from anaerobic digestion (AD), based on national and regional biomass resources, will increase security of national energy supply and diminish dependency on imported electricity and gases. In Afghanistan there is a lot of opportunities to capture affordable energy and heat from biomass and biogas and it enable every individual households to generate their own energy demand, but unfortunately people don not aware about this valuable resource and it is utilization. So in this study struggled to provide basic information about the value of waste and biomass and then promulgate to local people and governments to consider on their financing institutions operating in the future. Therefore, the objective of this study focused on the concept of resource efficiency in sewerage sludge to convert into green energy. The methodology was based on anaerobic process which is widely used for treatment of municipal waste sludge and has excellent potential for treatment of many industrial waste; and the design criteria are based on a volumetric organic load (kgBOD/m³·d). In particular, calculation and simulation results from treated flow of 2000 m³/d, resulting from amount of yielding gas is 109 m³/d which is huge amount of capturing energy at small treatment plant. In consequence, the production of energy from sewage sludge through anaerobic digestion has been able to effectively offset energy demand for wastewater treatment plant and methane is a useful end product. Developing source of clean, renewable energy will boost local and regional economics strengthen our national energy security as well decrease our energy dependency.

Keywords: Domestic Wastewater, Sludge, and green energy.