—In this paper, we deal with biogas production
potential from urban wastewater based on published
information. The usual practice of the wastewater handling in
urban cities of Nepal is either direct discharge into the rivers
and streams or discharge into the septic tanks. In both cases
adverse environmental impacts has perceived through directly
polluting rivers and streams as well as releasing methane,
ammonia and hydrogen sulphide to the atmosphere. In addition
to that, the lost opportunity of biogas production along with
potential carbon trading can be realized which also help to
make the project economically and environmentally sustainable.
An estimation of methane (CH4) production and carbon
emission reduction from urban wastewater are being done
allowing wastewater treatment in an anaerobic baffled reactor
(ABR) and upflow anaerobic sludge blanket (UASB). In this
regard, average value of some pilot plant experimental results
of efficiency of chemical oxygen demand (COD) removal at
ABR and UASB from various studies have been taken into
consideration. The estimated biogas production potential from
urban wastewater is about 22 million m3/ year equivalent to
14.5MWth, at the same time the carbon dioxide (CO2) emission
reduction potential is about 94,500 tons per year. An estimated
revenue collection potential through fuel substitution is about 8
million USD per annum while additional benefits from GHG
reduction and other improved condition of health, pollution and
reuse of wastewater is significantly remarkable.
—Energy recovery, wastewater, anaerobic
baffled reactor, upflow anaerobic sludge blanket, chemical
Sunil Prasad Lohani is with the Department of Mechanical Engineering,
Kathmandu University, Nepal (email: email@example.com).
Rune Bakke is with Telematk University College, Prosgrunn, Norway.
Cite:S. P. Lohani, A. Chhetri, J. Adhikari, and R. Bakke, "Sustainable Biogas Production Potential from Urban Wastewater in Nepal," International Journal of Environmental Science and Development vol. 4, no. 5, pp. 595-599, 2013.