Currently, generation of solid waste per capita in Malaysia is about 1.1 kg/day. Over 26,500 t of solid waste is disposed almost solely through 166 operating landfills in the country every day. Despite the availability of other disposal methods, landfill is the most widely accepted and prevalent method for municipal solid waste (MSW) disposal in developing countries, including Malaysia. This is mainly ascribed to its inherent forte in terms cost saving and simpler operational mechanism. However, there is a downside. Environmental pollution caused by the landfill leachate has been one of the typical dilemmas of landfilling method. Leachate is the liquid produced when water percolates through solid waste and contains dissolved or suspended materials from various disposed materials and biodecomposition processes. It is often a high-strength wastewater with extreme pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), inorganic salts and toxicity. Its composition differs over the time and space within a particular landfill, influenced by a broad spectrum of factors, namely waste composition, landfilling practice (solid waste contouring and compacting), local climatic conditions, landfill's physico-chemical conditions, biogeochemistry and landfill age. This paper summarises an overview of landfill operation and leachate treatment availability reported in literature: a broad spectrum of landfill management opportunity, leachate parameter discussions and the way forward of landfill leachate treatment applicability.

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Abstract. Construction is one of an important industry which contributes to the economic growth in Malaysia. However, it has been revealed that 79.5 percent and 66.7 percent of the public and private projects were not completed within the time specified in the contracts out of 359 projects in Malaysia. Therefore, the purpose of this study is to investigate the delay factor caused project delay at rural area. A 5-points Likert scale questionnaire survey were answered by 111 respondents which having experience with rural construction project. The questionnaire data were analysed by using Relative Importance Index (RII). Five top factors were determined from this study based on their RII values which are improper construction method implemented by contractor, weather condition, difficulties in providing delivery to site, breakdown of site equipment, and poor qualification of contractor's technical staffs.

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The effectiveness of bentonite using chitosan as a coagulant for raw water treatment was assessed in this study. The possible link between Alzheimer's disease with conventional aluminium based coagulants, has become an issue in water treatment. A method for treating water, using a natural approach as an alternate to achieve enhanced coagulation, might help to reduce risk to health, and be more environmentally friendly. One method for removing turbidity from raw water is by the adding of a primary coagulant (e.g., a natural polymer of chitosan) and a coagulant aid (e.g., natural clay of bentonite) to the raw water. A series of batch coagulation tests were conducted by jar test to obtain the optimum dosage, pH, ratio of coagulant aid and primary coagulant, and the efficiency time for the jar test, by evaluating the standard parameters, such as turbidity, pH, colour, aluminium, and chlorine. In terms of these parameters, chitosan:bentonite showed the best result, with a ratio of 30:70 in an optimal concentration of 1,000 mg/l with 0.15 g chitosan plus 0.35 g bentonite. The coagulants performed with an optimal pH of 5, with 30 min of mixing time during flocculation. However, the optimal pH condition during the jar test showed an improvement in the water alkalinity results, from pH 5 to 6.8. Coagulation with bentonite-chitosan successfully removed the turbidity with a highest efficiency of 98%. After water treatment in the optimal condition, results showed a great water quality standard, with 1.38 NTU, 10 TCU, 0.01 mg/l amount of chlorine and aluminium, and a pH of 6.8. However, data only showed slight differences of efficiency, between natural and conventional coagulants. In terms of the sludge volume index (SVI), the ratio of alum to bentonite-chitosan was found to be 3:1 which indicated that less sludge was produced by the natural coagulant. In a cost comparison between these coagulants, based on a rough estimation, bentonite-chitosan is nearly 10 times more expensive than the alum coagulant. However, with mass production and commercial availability, in the long run the price of chitosan could be reduced tremendously.