Solid waste management (SWM) has attracted global attention with the average generation rate in 23 developing countries reaching 77 kg/person/day and continuing to expand [1]. With current world population growth, it is approximated that the load of municipal solid waste (MSW) generated by the year 2020 is about nine million tons/year. Furthermore, estimation on the national recycling rate is about 3-5%, and the waste generation rate for Malaysia is 4.3% per annum for 10 years [2]. MSW is mainly introduced by households, and commercial and industrial sectors from the accumulation of community exertion in metropolitan areas. Peninsular Malaysia generated MSW of almost 17,000 tons/day (6.2 million tons/year) in 2002, an amount that is increasing annually Pol. J. Environ. Stud. Vol. 24, No. 4 (2015) AbstractThe accumulation of organic fraction in municipal solid waste (OFMSW) is now becoming scarce globally due to population and economic boosts, especially in Malaysia. Municipal solid waste (MSW) landfills remain the predominant end-state for waste disposal in most developing countries. Unsustainable MSW management accelerates environmental degradation through landfill gaseous (LFG) emissions of mainly methane (CH 4 ) and carbon dioxide (CO 2 ), which promote global warming that finally is affecting human health. Recently, harnessing CH 4 from anaerobic digestion of solid waste has attracted more interest and promised betterment in MSW management. With its current amount of more than 50%, organic material in landfills is estimated to emit 310,225 CH 4 /year with carbon credit of US$ 85.93, which can potentially generate 2.20×10 9 kWh of electricity valued at US$ 220 million. This present work is a review manuscript that discusses the state-of-the-art anaerobic digestion of OFMSW as treatment in term of waste diversion from a landfill. The study also estimates the renewable energy potentials from OFMSW waste diversion. Finally, this paper discusses the benefits of harnessing biogas from the perspectives of environmental benefits, energy recovery, and economics.

Monthly stream flow forecasting can provide crucial information on hydrological applications including water resource management and flood mitigation systems. In this statistical study, time series and artificial intelligence methods were evaluated according to implementation of each time-series technique to find an effective tool for stream flow prediction in flood forecasting. This paper explores the application of water level, rainfall data and input time series into three different models; linear regression (LR), auto-regressive integrated moving average (ARIMA) and artificial neural networks (ANN). The performances of the models were compared based on the maximum coefficient of determination (R 2 ) and minimum root means square error (RMSE). Based on the results the ANN model presents the most accurate measurement, with the R 2 value of 0.868 and 18% RMSE. The present study suggests that ANN is the best model due to its ability to recognise times series patterns and to understand non-linear relationships.

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IntroductionToday, anaerobic digestion is widely applied to treat a diverse range of organic waste that promotes betterment in landfill management and produces a potential renewable energy source. Organic waste (mainly food waste) is very attractive and a potential feedstock for anaerobic digestion due to it high fraction in waste generation, especially in Malaysia. Moreover, the high composition of fat and lipids in organic waste contributes to higher conversion of organic matter in the waste fraction for biogas production. However, degradation of lipids and fats produces longPol. J. Environ. Stud. Vol. 25, No. 4 (2016), 1549-1554 AbstractThis paper describes a batch study on four different mixture ratios of household organic waste and cow manure. The biomethane potential test is used to evaluate the suitability of high solid anaerobic co-digestion of household organic waste and cow manure and its biodegradability. The maximum methane yield was observed for both co-digestions in R 3 (247 mL/g VS) and R 4 (244 mL/g VS). The percentages of mass recovery were 65-80% (based on VS removal). The biodegradability of each reactor was recorded as 97.7%, 10.7%,71.6% and 76.8% for R 1 , R 2 , R 3 , and R 4 , respectively. High solid co-digestion of household organic waste and cow manure in different mixture ratios increase the specific methane yields compared to mono-digestion. Hence, this clearly demonstrates a synergistic effect on the stability of anaerobic digestion. Upon correcting the results of the theoretical method with experimental data, an agreement ranged 70-90% was achieved.