Waste collection widely depends on the route optimization problem that involves a large amount of expenditure in terms of capital, labor, and variable operational costs. Thus, the more waste collection route is optimized, the more reduction in different costs and environmental effect will be. This study proposes a modified particle swarm optimization (PSO) algorithm in a capacitated vehicle-routing problem (CVRP) model to determine the best waste collection and route optimization solutions. In this study, threshold waste level (TWL) and scheduling concepts are applied in the PSO-based CVRP model under different datasets. The obtained results from different datasets show that the proposed algorithmic CVRP model provides the best waste collection and route optimization in terms of travel distance, total waste, waste collection efficiency, and tightness at 70-75% of TWL. The obtained results for 1 week scheduling show that 70% of TWL performs better than all node consideration in terms of collected waste, distance, tightness, efficiency, fuel consumption, and cost. The proposed optimized model can serve as a valuable tool for waste collection and route optimization toward reducing socioeconomic and environmental impacts.
The purpose of this study is to review the relationship between the highly anticipated concept of circular economy (CE) and sustainable development goals (SDGs). These two sustainability principles have transformed organizations and countries in their quest to achieve sustainable development. Despite their importance to the business and corporate realm, the discussion of these two concepts has been developed in silos, arbitrarily connected. Through a bibliometric approach, this study reviewed 226 journal publications and 16,008 cited references from the Web of Science (WoS) to understand the past, present and future trends of the two concepts and their impact on the sustainability development. The bibliometric approach of citation, co-citation and co-word analysis uncovers the relevant and significant themes and research streams. Theoretical and practical implications were discussed within the broader business and governance perspective to develop a substantial triple bottom line in creating a sustainable future for civil society.
In Malaysia, most municipal wastes currently are disposed into poorly managed 'controlled tipping' systems with little or no pollution protection measures. This study was undertaken to assist the relevant governmental bodies and service providers to identify an improved waste disposal management strategy. The study applied the choice experiment technique to estimate the nonmarket values for a number of waste disposal technologies. Implicit prices for environmental attributes such as psychological fear, land use, air pollution, and river water quality were estimated. Compensating surplus estimates incorporating distance from the residences of the respondents to the proposed disposal facility were calculated for a number of generic and technology-specific choice sets. The resulting estimates were higher for technology-specific options, and the distance factor was a significant determinant in setting an equitable solid waste management fee.
Malaysia is facing an increase in the generation of waste and of accompanying problems with the disposal of this waste. In the last two decades, extensive building and infrastructure development projects have led to an increase in the generation of construction waste material. The construction industry has a substantial impact on the environment, and its environmental effects are in direct relation to the quality and quantity of the waste it generates. This paper discusses general characteristics of the construction contractors, the contractors' willingness to pay (WTP) for improved construction waste management, determining factors which affect the amount of their willingness to pay, and suggestions and policy implications in the perspective of construction waste management in Malaysia. The data in this study is based on contractors registered with the construction industry development board (CIDB) of Malaysia. Employing the open ended contingent valuation method, the study assessed the contractors' average maximum WTP for improved construction waste management to be RM69.88 (1US$=3.6 RM) per tonne of waste. The result shows that the average maximum WTP is higher for large contractors than for medium and small contractors. The highest average maximum WTP value is RM88.00 for Group A (large contractors) RM78.25 for Group B (medium-size contractors) and RM55.80 for Group C (small contractors). One of the contributions of this study is to highlight the difference of CIDB registration grade in the WTP for improved construction waste management. It is found that contractors' WTP for improved waste collection and disposal services increases with the increase in contractors' current paid up capital. The identified factors and determinants of the WTP will assist the formulation of appropriate policies in addressing the construction waste problem in Malaysia and indirectly improve the quality of construction in the country.
The provision of appropriate waste management is not only an indicator of development but also of broader sustainability. This is particularly relevant to expanding cities in developing countries faced with rising waste generation and associated environmental health problems. Despite these urgent issues, city authorities often lack the evidence required to make well-informed decisions. This study evaluates the carbon and economic performance of low-carbon measures in the waste sector at a city level, within the context of a developing country. Palembang in Indonesia is used as a case of a medium-sized city in a newly industrialized country, with relevance to other similar cities in the developing world. Evidence suggests that the waste sector can achieve substantial carbon emission reductions, and become a carbon sink, in a cost effective way. Hence there is an economic case for a low carbon development path for Palembang, and possibly for other cities in developing and developed countries facing similar challenges.
The preparation of chars and activated carbon as low-cost elemental mercury adsorbents was carried out through the carbonisation of coconut husk (pith and fibre) and the activation of chars with potassium hydroxide (KOH), respectively. The synthesised adsorbents were characterised by using scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption/desorption analysis. The elemental mercury removal performance was measured using a conventional flow type packed-bed adsorber. The physical and chemical properties of the adsorbents changed as a result of the carbonisation and activation process, hence affecting on the extent of elemental mercury adsorption. The highest elemental mercury (Hg°) adsorption capacity was obtained for the CP-CHAR (3142.57 µg g(-1)), which significantly outperformed the pristine and activated carbon adsorbents, as well as higher than some adsorbents reported in the literature.
This paper deals with a system of integration of Radio Frequency Identification (RFID) and communication technologies for solid waste bin and truck monitoring system. RFID, GPS, GPRS and GIS along with camera technologies have been integrated and developed the bin and truck intelligent monitoring system. A new kind of integrated theoretical framework, hardware architecture and interface algorithm has been introduced between the technologies for the successful implementation of the proposed system. In this system, bin and truck database have been developed such a way that the information of bin and truck ID, date and time of waste collection, bin status, amount of waste and bin and truck GPS coordinates etc. are complied and stored for monitoring and management activities. The results showed that the real-time image processing, histogram analysis, waste estimation and other bin information have been displayed in the GUI of the monitoring system. The real-time test and experimental results showed that the performance of the developed system was stable and satisfied the monitoring system with high practicability and validity.
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.
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.
This study employed contingent valuation method to estimate the willingness to pay (WTP) of the households to improve the waste collection system in Kuala Lumpur, Malaysia. The objective of this study is to evaluate how household WTP changes when recycling and waste separation at source is made mandatory. The methodology consisted of asking people directly about their WTP for an additional waste collection service charge to cover the costs of a new waste management project. The new waste management project consisted of two versions: version A (recycling and waste separation is mandatory) and version B (recycling and waste separation is not mandatory). The households declined their WTP for version A when they were asked to separate the waste at source although all the facilities would be given to them for waste separation. The result of this study indicates that the households were not conscious about the benefits of recycling and waste separation. Concerted efforts should be taken to raise environmental consciousness of the households through education and more publicity regarding waste separation, reducing and recycling.
Research interests in addressing construction and demolition (C&D) waste management issues have resulted in a large amount of publications during the last decade. This study demonstrates that there is no systematic examination on the research development in literature in the discipline of C&D waste management. This study presents the latest research trend in the discipline through analyzing the publications from 2000 to 2009 in eight major international journals. The analysis is conducted on the number of papers published annually, main authors' contributions, research methods and data analysis methods adopted, and research topics covered. The results exhibit an increasing research interest in C&D waste management in recent years. Researchers from developed economies have contributed significantly to the development of the research in the discipline. Some developing countries such as Malaysia and China have also been making good efforts in promoting C&D waste management research. The findings from this study also indicate that survey and case study are major methods for data collection, and the data are mostly processed through descriptive analysis. It is anticipated that more future studies on C&D waste management will be led by researchers from developing economies, where construction works will remain their major economic activities. On the other hand, more sophisticated modeling and simulating techniques have been used effectively in a number of studies on C&D waste management research, and this is considered a major methodology for future research in the discipline. C&D waste management will continue to be a hot research topic in the future, in particularly, the importance of human factors in C&D waste management has emerged as a new challenging topic.
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.
This paper analyses some of the higher education and research capacity building experiences gained from 1998-2006 by Danish and Malaysian universities. The focus is on waste management, directly relating to both the environmental and socio-economic dimensions of sustainable development. Primary benefits, available as an educational legacy to universities, were obtained in terms of new and enhanced study curricula established on Problem-oriented Project-based Learning (POPBL) pedagogy, which strengthened academic environmental programmes at Malaysian and Danish universities. It involved more direct and mutually beneficial cooperation between academia and businesses in both countries. This kind of university reach-out is considered vital to development in all countries actively striving for global and sustainable development. Supplementary benefits were accrued for those involved directly in activities such as the 4 months of field studies, workshops, field courses and joint research projects. For students and academics, the gains have been new international dimensions in university curricula, enhanced career development and research collaboration based on realworld cases. It is suggested that the area of solid waste management offers opportunities for much needed capacity building in higher education and research, contributing to sustainable waste management on a global scale. Universities should be more actively involved in such educational, research and innovation programmes to make the necessary progress. ISWA can support capacity building activities by utilizing its resources--providing a lively platform for debate, securing dissemination of new knowledge, and furthering international networking beyond that which universities already do by themselves. A special challenge to ISWA may be to improve national and international professional networks between academia and business, thereby making education, research and innovation the key driving mechanisms in sustainable development in solid waste management.
Construction and demolition waste continues to sharply increase in step with the economic growth of less developed countries. Though the construction industry is large, it is composed of small firms with individual waste management practices, often leading to the deleterious environmental outcomes. Quantifying construction and demolition waste generation allows policy makers and stakeholders to understand the true internal and external costs of construction, providing a necessary foundation for waste management planning that may overcome deleterious environmental outcomes and may be both economically and environmentally optimal. This study offers a theoretical method for estimating the construction and demolition project waste generation rate by utilising available data, including waste disposal truck size and number, and waste volume and composition. This method is proposed as a less burdensome and more broadly applicable alternative, in contrast to waste estimation by on-site hand sorting and weighing. The developed method is applied to 11 projects across Malaysia as the case study. This study quantifies waste generation rate and illustrates the construction method in influencing the waste generation rate, estimating that the conventional construction method has a waste generation rate of 9.88 t 100 m(-2), the mixed-construction method has a waste generation rate of 3.29 t 100 m(-2), and demolition projects have a waste generation rate of 104.28 t 100 m(-2).