P. Agamuthu

E-waste: a problem or an opportunity? Review of issues, challenges and solutions in Asian countries

Safe management of electronic and electrical waste (e-waste/WEEE) is becoming a major problem for many countries around the world. In particular, developing countries face a number of issues with the generation, transboundary movement and management of e-waste. It is estimated that the world generates around 20–50 million tonnes of e-waste annually, most of it from Asian countries. Improper handling of e-waste can cause harm to the environment and human health because of its toxic components. Several countries around the world are now struggling to deal with this emerging threat. Although the current emphasis is on end-of-life management of e-waste activities, such as reuse, servicing, remanufacturing, recycling and disposal, upstream reduction of e-waste generation through green design and cleaner production is gaining much attention. Environmentally sound management (ESM) of e-waste in developing countries is absent or very limited. Transboundary movement of e-waste is a major issue throughout the region. Dealing with the informal recycling sector is a complex social and environmental issue. There are significant numbers of such challenges faced by these countries in achieving ESM of e-waste. This article aims to present a review of challenges and issues faced by Asian countries in managing their e-waste in a sustainable way.

Phytoremediation of soil contaminated with used lubricating oil using Jatropha curcas

Soil contamination by used lubricating oil from automobiles is a growing concern in many countries, especially in Asian and African continents. Phytoremediation of this polluted soil with non-edible plant like Jatropha curcas offers an environmental friendly and cost-effective method for remediating the polluted soil. In this study, phytoremediation of soil contaminated with 2.5 and 1% (w/w) waste lubricating oil using J. curcas and enhancement with organic wastes [Banana skin (BS), brewery spent grain (BSG) and spent mushroom compost (SMC)] was undertaken for a period of 180 days under room condition. 56.6% and 67.3% loss of waste lubricating oil was recorded in Jatropha remediated soil without organic amendment for 2.5% and 1% contamination, respectively. However addition of organic waste (BSG) to Jatropha remediation rapidly increases the removal of waste lubricating oil to 89.6% and 96.6% in soil contaminated with 2.5% and 1% oil, respectively. Jatropha root did not accumulate hydrocarbons from the soil, but the number of hydrocarbon utilizing bacteria was high in the rhizosphere of the Jatropha plant, thus suggesting that the mechanism of the oil degradation was via rhizodegradation. These studies have proven that J. curcas with organic amendment has a potential in reclaiming hydrocarbon-contaminated soil.

Drivers of sustainable waste management in Asia

Drivers of sustainable waste management are defined as groups of related factors that influence the development (or lack thereof) of industry. There has been no attempt to reasonably list the drivers that influence sustainable waste management in Asia. In this review, four groups of drivers of sustainable waste management, specifically of Asia, are explained. The four groups of drivers consist of three human elements (human, economic and institutional) and the environment as a single driving group. Typically, the first three groups have been very influential, with the environment driver, noticeably, only considered when preceded by other groups of drivers. The interconnectedness of the drivers and neglect of the environment driver is discussed. It is concluded that while the essence of the four groups of drivers can be found all over Asia, each driving group must be investigated in a local context and all information combined to devise sustainable waste management policies or strategies.

Challenges and issues in moving towards sustainable landfilling in a transitory country - Malaysia

Malaysia disposes of 28 500 tonnes of municipal solid waste directly into landfills daily. This fact alone necessitates sustainable landfills to avoid adverse impacts on the population and the environment. The aim of the present study was to elucidate the issues and challenges faced by waste managers in moving towards sustainable landfilling in Malaysia. Various factors influence the management of a landfill. Among them is the human factor, which includes attitude and public participation. Although Malaysia’s economy is developing rapidly, public concern and awareness are not evolving in parallel and therefore participation towards sustainable waste management through the ‘reduce, reuse and recycle’ approach (3Rs) is severely lacking. Consequently, landfill space is exhausted earlier than scheduled and this is no longer sustainable in terms of security of disposal. Challenges also arise from the lack of funding and the increase in the price of land. Thus, most waste managers normally aim for ‘just enough’ to comply with the regulations. Investment for the establishment of landfills generally is minimized since landfilling operations are considered uneconomical after closure. Institutional factors also hamper the practice of sustainable landfilling in the country where 3Rs is not mandatory and waste separation is totally absent. Although there are huge obstacles to be dealt with in moving towards sustainable landfilling in Malaysia, recent developments in waste management policy and regulations have indicated that positive changes are possible in the near future. Consequently, with the issues solved and challenges tackled, landfills in Malaysia can then be managed effectively in a more sustainable manner.

Biodegradation of Used Motor Oil in Soil using Organic Waste Amendments

Soil and surface water contamination by used lubricating oil is a common occurrence in most developing countries. This has been shown to have harmful effects on the environment and human beings at large. Bioremediation can be an alternative green technology for remediation of such hydrocarbon-contaminated soil. Bioremediation of soil contaminated with 5% and 15% (w/w) used lubricating oil and amended with 10% brewery spent grain (BSG), banana skin (BS), and spent mushroom compost (SMC) was studied for a period of 84 days, under laboratory condition. At the end of 84 days, the highest percentage of oil biodegradation (92%) was recorded in soil contaminated with 5% used lubricating oil and amended with BSG, while only 55% of oil biodegradation was recorded in soil contaminated with 15% used lubricating oil and amended with BSG. Results of first-order kinetic model to determine the rate of biodegradation of used lubricating oil revealed that soil amended with BSG recorded the highest rate of oil biodegradation (0.4361 day−1) in 5% oil pollution, while BS amended soil recorded the highest rate of oil biodegradation (0.0556 day−1) in 15% oil pollution. The results of this study demonstrated the potential of BSG as a good substrate for enhanced remediation of hydrocarbon contaminated soil at low pollution concentration.

Nutrient cycling within the developing oil palm - legume ecosystem.

Abstract Oil palms (Elaeis guineensis Jacq.) are normally planted in fields stripped of all other vegetation. Leguminous cover crops are planted simultaneously to protect the soil surface and to provide other, less tangible benefits. Nutrient cycling, especially of nitrogen, was followed in a commercial oil palm plantation and showed that: (a) legumes contribute about 150 kg nitrogen ha−1 year−1 to the system through nitrogen fixation; (b) during the early stages of oil palm growth the legumes absorb 149 kg nitrogen ha−1 year−1 from the soil; (c) with a loss of nitrogen through litter fall of 123 kg nitrogen ha−1 year−1, legumes accumulate a net amount of 176 kg nitrogen ha−1 year−1 in their foliage; (d) in comparison with “natural” covers, leguminous covers reduce leaching losses by 63 kg nitrogen ha−1 year −1 so that the total benefits of leguminous covers amount to 239 kg nitrogen ha−1 year−1; (e) the combined inputs from fertilization and oil palm debris in plots without legumes is 208 kg nitrogen ha−1 year−1; and (f) during the initial growth phase, oil palms need only 175 kg nitrogen ha−1 year−1. Since legumes fix nitrogen and thoroughly scavenge the soil for minerals they eventually provide more nitrogen to the oil palms than is needed for growth. This surplus nitrogen is “banked” in the legume foliage. Then, when the rooting system of the oil palms has grown under the inter-rows, competition for nutrients causes a gradual decline in the cover-crop. Nutrients “deposited” in the legumes are thus slowly re-released stimulating root-growth and general development of the oil palm.

Biodegradability of degradable plastic waste.

Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60°C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

Solidification and stabilization of asbestos waste from an automobile brake manufacturing facility using cement.

Currently, the generated brake lining waste dust, which contains asbestos as its major component, is disposed of into a secure landfill without any additional treatment. As an alternative to this, solidification/stabilization (S/S) disposal of the dust was investigated using Portland cement alone and Portland cement mixed with activated carbon (AC), as the binders. Toxicity Characteristics Leaching Procedure (TCLP) results on the solidified matrix showed that cement was able to immobilize the heavy metals, Ba, Zn, Cr, Pb, Cu and Fe, to within the limits set by the US EPA for TCLP. Addition of AC to the cement reduced the leaching of heavy metals by an additional 4-24% compared to cement alone. The pH of the TCLP leachate extracted from virgin cement, and from dust treated with cement with or without AC was found to increase to 10.9-12.5 as opposed to an initial value of 4.93 for the TCLP extract for the untreated dust. Results of ANS 16.1 (modified) leach protocol revealed that Ba in cement-treated samples showed the highest leach rate, followed by Zn, Pb, Cr, Cu and Fe. The leach rate of heavy metals decreased with progress in time. Cement mixed with AC exhibited similar leach characteristics, however, the leach rate was lower. The linear relationship between the cumulative fraction leached (CFL) and the square root of leaching time in all cement-based samples indicate that a diffusional process is the controlling transport mechanism for the leaching of the heavy metals. The obtained Leachability Indices (L(i)) of 7.6-9.1 and 8.3-9.5 for cement and cement with AC, respectively, were low but exceeded the guidance value of 6, which clearly indicates that all the heavy metals studied are retained well within solid matrices. Cement-based S/S hardening times increased from 30 to 96 h as the dust content increased from 40 to 70 wt.%. The resulting solid matrices exhibited a compressive strength ranging from 1 to 12 MPa, which was well above the specified limit of 414 kPa for such matrices. An economic analysis indicates that the disposal costs for the dust in the only available secure landfill would increase by 40.3% if one were to go for the cement S/S option. Addition of AC to the cement would escalate this by an additional 43.8%. Although the S/S of brake lining dust using cement effectively immobilized the heavy metals of concern, cost considerations may hinder the commercial adaptation of this technique for waste disposal unless new regulatory demands are implemented.

Policy trends of extended producer responsibility in Malaysia

This paper seeks to examine the provisions for extended producer responsibility (EPR) within the Malaysian environmental and waste management policies and to determine its existing practice and future prospects in Malaysia. Malaysian waste generation has been increasing drastically where solid waste generation was estimated to increase from about 9.0 million tonnes in 2000 to about 10.9 million tonnes in 2010, to about 12.8 million tonnes in 2015 and finally to about 15.6 million tonnes in 2020. Malaysian e-waste was estimated to be about 652 909 tonnes in 2006 and was estimated to increase to about 706 000 tonnes in 2010 and finally to about 1.2 million tonnes in 2020. The projected increasing generation of both solid waste and scheduled wastes is expected to burden the country’s resources and environment in managing these wastes in a sustainable manner. The concept of EPR is provided for in the Malaysia waste management system via the Environmental Quality Act 1974 and the Solid Waste and Public Cleansing Management Act 2007. However, these provisions in the policy are generic in nature without relevant regulations to enable its enforcement and as such the concept of EPR still remains on paper whereas the existing practice of EPR in Malaysia is limited through voluntary participation. In conclusion, policy trends of EPR in Malaysia seem to indicate that Malaysia may be embarking on the path towards EPR through the enactment of an EPR regulation.

Characterization and toxicological evaluation of leachate from closed sanitary landfill

Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys’ Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L−1, COD 10 234 ± 175 mg L−1, ammonical nitrogen of 880 ± 74 mg L−1, benzene 0.22 ± 0.1 mg L−1 and toluene 1.2 ± 0.4 mg L−1. The 50% lethality concentration (LC50) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.