S. Prasad Lohani
Abstract
The composition of waste generated in urban areas of Nepal is primarily decomposable which provides scope to convert the waste into energy. In addition, organic fraction of municipal waste is a serious environmental and economic burden in Nepal. In this study, samples from food waste were taken ...
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The composition of waste generated in urban areas of Nepal is primarily decomposable which provides scope to convert the waste into energy. In addition, organic fraction of municipal waste is a serious environmental and economic burden in Nepal. In this study, samples from food waste were taken from household of Biratnagar Metropolitan city and Kathmandu University Canteen, Dhulikhel. The samples were analyzed for physical and chemical properties and biogas production. The feed containing 6% TS were analyzed for the potential of biogas production from the canteen food waste (CFW) of Kathmandu University (KU) and household food waste (HFW) from Biratnagar in ambient and control temperature (35 ℃) in a batch reactor. This was also conducted for food waste mixed with 30% cow manure in both the conditions. The average total solid and volatile solid for BFW were 17.7 and 93.2% of TS and CFW were 19.9 and 90.2% of TS, respectively. In every run of the experiment, the volume changes of gas were monitored. Both in the ambient and the controlled temperature, biogas production and yield were higher when 30% cow dung as inoculum was added in both samples. Moreover, the biogas production and yield of CFW was also higher than the BFW at different conditions. This shows that food wastes characteristics and biogas production potential varies depending on the source of the food waste, inoculum added and operating condition for the anaerobic digestion process.
M. A. Sayid Mia; M. Nur-E-Alam; S. Huque; M. M. Rahman; H. Ratnaweera
Abstract
Annually about 85,000 tons of raw hides and skins are estimated to be processed for leather production in Bangladesh. Tannery generates huge amount of solid and liquid wastes. Anaerobic digestion (AD) is a potential treatment to stabilize waste and produce biogas for renewable energy. The aim of this ...
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Annually about 85,000 tons of raw hides and skins are estimated to be processed for leather production in Bangladesh. Tannery generates huge amount of solid and liquid wastes. Anaerobic digestion (AD) is a potential treatment to stabilize waste and produce biogas for renewable energy. The aim of this study was to investigate the potential of AD of tannery solid waste (TSW) generated from the pre-tanning operation and to compare the effect of cow dung as the substrate to TSW. For the reaction with TSW by mixing with different substrates, biogas production was observed starting on 4th day with a steady increase. The cumulative gas production from each of the test reactors operating at the various organic loading of tannery solid waste, domestic sewage, and cow dung were different. This study shows an optimal AD process of TSW by mixing with different substrates for the obtained optimum C/N ratio and also for the high volatile solids (VS). The COD removal rates for the series of 5 reactors (R1, R2, R3, R4 and R5) were 48.75, 50.84, 46.07, 45.94 and 47.78% respectively. Maximum COD removal was achieved from reactor R2 where maximum gas was also produced.
