Municipal solid waste management in Malaysia: Practices and challenges

Rapid economic development and population growth, inadequate infrastructure and expertise, and land scarcity make the management of municipal solid waste become one of Malaysia’s most critical environmental issues. The study is aimed at evaluating the generation, characteristics, and management of solid waste in Malaysia based on published information. In general, the per capita generation rate is about 0.5–0.8 kg/person/day in which domestic waste is the primary source. Currently, solid waste is managed by the Ministry of Housing and Local Government, with the participation of the private sector. A new institutional and legislation framework has been structured with the objectives to establish a holistic, integrated, and cost-effective solid waste management system, with an emphasis on environmental protection and public health. Therefore, the hierarchy of solid waste management has given the highest priority to source reduction through 3R, intermediate treatment and final disposal.     

Faecal sterols as sewage markers in the Langat River, Malaysia: Integration of biomarker and multivariate statistical approaches

The Langat River in Malaysia has been experiencing anthropogenic input from urban, rural and industrial activities for many years. Sewage contamination, possibly originating from the greater than three million inhabitants of the Langat River Basin, were examined. Sediment samples from 22 stations (SL01-SL22) along the Langat River were collected, extracted and analysed by GC-MS. Six different sterols were identified and quantified. The highest sterol concentration was found at station SL02 (618.29 ng/g dry weight), which situated in the Balak River whereas the other sediment samples ranged between 11.60 and 446.52 ng/g dry weight. Sterol ratios were used to identify sources, occurrence and partitioning of faecal matter in sediments and majority of the ratios clearly demonstrated that sewage contamination was occurring at most stations in the Langat River. A multivariate statistical analysis was used in conjunction with a combination of biomarkers to better understand the data that clearly separated the compounds. Most sediments of the Langat River were found to contain low to mid-range sewage contamination with some containing `significant' levels of contamination. This is the first report on sewage pollution in the Langat River based on a combination of biomarker and multivariate statistical approaches that will establish a new standard for sewage detection using faecal sterols.     

What affects perceptions of local residents toward protected areas? A case study from Kure Mountains National Park,Turkey

Local residents’ active participation is essential in protected areas to ensure achievement of conservation goals. One of the important steps for ensuring the active participation of local residents is to determine the perceptions and the factors that influence the perceptions of the local residents toward the protected area. In this context, the researchers of this study try to come up with the perception formed among the local residents toward the protected areas and especially toward Kure Mountains National Park (KMNP), the factors that would influence their perceptions and the ways how their perceptions are influenced. Multivariate linear regression was used to examine the putative influence of variables on perceptions toward protected areas. According to study results, the survey respondents have displayed a positive perception toward the protected areas in the world and in KMNP. It was determined that the respondents formed a positive perception from their economic, environmental and recreational interaction with KMNP. Also, the outcomes of this study showed that the perception developed by local residents toward the protected areas in the world and KMNP are influenced by gender, the level of satisfaction derived from the national park, duration of their residence in the national park, and that the perception that KMNP conservation are beneficial for the source values of the area, the current protection works in the world, as well as its impacts on their living conditions.     

Solid-state bioconversion of organic wastes into compost as bio-organic fertilizer by screened fungal isolates and its performance in agronomic usage

Journal of Material Cycles and Waste Management - Rejuvenation of composting of organic wastes (OW) by application of useful potential microbes is an emerging science of solid waste management....     

Extrication of biodiesel feedstock from early stage of food waste liquefaction

Biodiesel is commonly produced from vegetable oils, mostly edible and more expensive than petroleum diesel. By considering the cost of the conversion processes, cheap feedstock such as triglycerides and fatty acids (FA) extracted from early stage of food waste liquefaction has become a better choice than vegetable oils, as it could provide high yield of biodiesel without any compromise to food supply and other resources. In this study, FA from early stage of food waste liquefaction was extracted and tested for use as feedstock for biodiesel synthesis. The raw material was not pretreated but extraction was done by dry and wet methods. It was found that wet method could minimized the lost of short and medium-chained FA as well as reducing the number of steps required, thus, yielding higher amount of FA as feedstock. The effects of mixing, methanol ratio, reaction time and catalyst content were investigated for the acid-catalyzed esterification. The maximum biodiesel conversion obtained was 97.4 %.     

Facile Green Preparation of Lignocellulosic Biosorbent from Lemongrass Leaf for Cationic Dye Adsorption

Journal of Polymers and the Environment - Lignocellulosic biosorbents for wastewater treatment are generally powders. However, powdered biosorbents require the time and energy taken up in grinding...     

Ethanol production from alkali-pretreated oil palm empty fruit bunch by simultaneous saccharification and fermentation with mucor indicus

Oil palm empty fruit bunch (OPEFB) is a potential raw material for production of lignocellulosic bioethanol. The OPEFB was pretreated with 8% sodium hydroxide (NaOH) solution at 100°C for 10 to 90 min. Enzymatic digestion was carried out using cellulase and β-glucosidase at 45°C for 24 h. It was then inoculated with Mucor indicus spores suspension and fermented under anaerobic conditions at 37°C for 96 h. Sodium hydroxide pretreatment effectively removed 51–57% of lignin in the OPEFB and also its hemicellulose (40–84%). The highest glucan digestibility (0.75 g/g theoretical glucose) was achieved in 40-min NaOH pretreatment. Fermentation by M. indicus resulted in 68.4% of the theoretical ethanol yield, while glycerol (16.2–83.2 mg/g), succinic acid (0–0.4 mg/g), and acetic acid (0–0.9 mg/g) were its by-products. According to these results, 11.75 million tons of dry OPEFB in Indonesia can be converted into 1.5 billion liters of ethanol per year.     

Source apportionment of surfactants in marine aerosols at different locations along the Malacca Straits

This study aims to determine the source apportionment of surfactants in marine aerosols at two selected stations along the Malacca Straits. The aerosol samples were collected using a high volume sampler equipped with an impactor to separate coarse- and fine-mode aerosols. The concentrations of surfactants, as methylene blue active substance and disulphine blue active substance, were analysed using colorimetric method. Ion chromatography was employed to determine the ionic compositions. Principal component analysis combined with multiple linear regression was used to identify and quantify the sources of atmospheric surfactants. The results showed that the surfactants in tropical coastal environments are actively generated from natural and anthropogenic origins. Sea spray (generated from sea-surface microlayers) was found to be a major contributor to surfactants in both aerosol sizes. Meanwhile, the anthropogenic sources (motor vehicles/biomass burning) were predominant contributors to atmospheric surfactants in fine-mode aerosols.     

Quantitative assessment of people-oriented forestry in Bangladesh: a case study in the Tangail forest division

Forests represent more than just a livelihood to many people in developing countries. In Bangladesh, for example, overwhelming poverty and socio-economic pressures have resulted in an unstable situation where intensive pressure on forest resources is having increasingly negative consequences for the population. Some studies have evaluated the benefits of people-oriented forestry activities from an investment, as well as a participant, point of view. In the study area located in the Tangail Forest Division, a total of 11,854 ha of woodlot, 2704 ha of agroforestry and 945 km of strip plantations have been raised in a benefit-sharing program that is inclusive of land encroachers and other economically disadvantaged people. Since 2000-2001, a total of 3716 ha of woodlot, 890 ha of agroforestry and 163 km of strip plantations have been harvested to the benefit of 6326 individuals. Investment analysis indicates that woodlot plantation is not financially viable but agroforestry is the most profitable. These results were somewhat unexpected since initial analysis suggested that the woodlot plantation profit would be greater than, or at least equal to, that of the agroforestry plantation if the number of planted seedlings per unit area was taken into account. The per unit area net present value (NPV) was highest in the agroforestry plantation ($1662) and negative in the woodlot plantation (-$397). The benefit cost ratio (BCR) was also highest in the agroforestry plantation (1.64) and lowest in the woodlot plantation (0.86). This study also showed that some individuals who were formally classified as encroachers have now become vital stakeholders. On average, participants received $800, $1866 and $1327 over the course of 13 years from strip, agroforestry and woodlot plantations, respectively. Average annual return per participant was $62, $144 and $102, respectively, which was in addition to each individual's yearly income. This added income is a significant contribution to monetary resources and improves socio-economic conditions at a grass roots level. Overall then this program can be considered a financial success as a plantation raising strategy. However, despite this financial progress, the program cannot be considered a true form of participatory people-oriented forestry because it shows serious deviations from the original concept or model for participatory people-oriented forestry that is outlined in the project document. These discrepancies are especially notable with regard to (i) beneficiary selection, (ii) gender equity, (iii) professional attitude and corruption, (iv) funding and (v) program approach. However, other countries faced with similar challenges of forest overuse and degradation may adopt this practice for achieving self-reliance and environmental stability.