Waste Management & Research: The Journal for a Sustainable Circular Economy

This article deals with assessment of the potential health risk posed by carcinogenic and non-carcinogenic substances, namely lead (Pb), cadmium (Cd), copper, chromium (CrVI), zinc, nickel and mercury, present in e-waste. A multi-objective, multi-stakeholder approach based on strategic game theory model has been developed considering cost, as well as human health risk. The trade-off due to cost difference between a hazardous substances-free (HSF) and a hazardous substance (HS)-containing desktop computer, and the risk posed by them at the time of disposal, has been analyzed. The cancer risk due to dust inhalation for workers at a recycling site in Bangalore for Pb, Cr(VI) and Cd was found to be 4, 33 and 101 in 1 million respectively. Pb and Cr(VI) result in a very high risk owing to dust ingestion at slums near the recycling site—175 and 81 in 1 million for children, and 24 and 11 in 1 million for adults respectively. The concentration of Pb at a battery workshop in Mayapuri, Delhi (hazard quotient = 3.178) was found to pose adverse health hazards. The government may impose an appropriate penalty on the land disposal of computer waste and/or may give an incentive to manufacturer for producing HSF computers through, for example, relaxing taxes, but there should be no such incentive for manufacturing HS-containing computers.

Municipal solid waste (MSW) recycling performance, both nationally and in Florida, USA, has shown little improvement during the past decade. This research examines variations in the MSW recycling program performance in Florida counties in an attempt to identify effective recycling programs. After reviewing trends in the MSW management literature, we conducted an empirical analysis using cross-sectional multiple regression analysis. The findings suggest that the convenience-based hypothesis was supported by showing that curbside recycling had a positive effect on MSW recycling performance. Financial (cost-saving) incentive-based hypotheses were partially supported meaning that individual level incentives can influence recycling performance. Citizen environmental concern was found to positively affect the amount of county recycling, while education and political affiliation yielded no significant results. In conclusion, this article discusses the implications of the findings for both academic research and practice of MSW recycling programs.

The waste and recycling sector has been identified as a green industry and, as such, jobs within this sector may be classed as ‘green jobs’. Many governments have seen green jobs as a way of increasing employment, particularly during the global financial crisis. However, the methods used to define and quantify green jobs directly affect the quantification of these green jobs. In December 2010, Queensland introduced a waste strategy that stated intent to increase green jobs within the waste sector. This article discusses the milieu and existing issues associated with quantifying green jobs within Queensland’s waste and recycling sector, and provides a review of the survey that has sought to quantify the true size of the Queensland industry sector. This research has identified nearly 5500 jobs in Queensland’s private waste management and recycling sector, which indicates that official data do not accurately reflect the true size of the sector.

An integrated formal collection and recycling network is a significant concern to achieve efficient management of waste electrical and electronic equipment (WEEE). This study, which aimed to investigate the present problems of WEEE recycling in China, proposes the application of a comprehensive solution approach to address a complete WEEE collection and transportation network in Shanghai, China. The methodologic steps regard three things: identification of WEEE collection sites and transit sites with quadratic optimizing models solved by exact algorithm; vehicle routing planning with a modified ant colony algorithm; and defining of minimum transportation cycles and proper shipping arrangements. The rounded WEEE collection network is presented as technical support and a demonstration of further planning and construction of the WEEE recycling system in China.

Plastics continue to be a challenge for recovering materials at the end-of-life for vehicles. However, it may be possible to improve the recovery of plastics by exploiting material characteristics, such as shape, or by altering their behavior, such as through temperature changes, in relation to recovery processes and handling. Samples of a 2009 Dodge Challenger front fascia were shredded in a laboratory-scale hammer mill shredder. A 2 × 2 factorial design study was performed to determine the effect of sample shape (flat versus curved) and sample temperature (room temperature versus cryogenic temperature) on the size of the particles exiting from the shredder. It was determined that sample shape does not affect the particle size; however, sample temperature does affect the particle size. At cryogenic temperatures, the distribution of particle sizes is much narrower than at room temperature. Having a more uniform particle size could make recovery of plastic particles, such as these more efficient during the recycling of end-of-life vehicles. Samples of Chrysler minivan headlights were also shredded at room temperature and at cryogenic temperatures. The size of the particles of the two different plastics in the headlights is statistically different both at room temperature and at cryogenic temperature, and the particles are distributed narrowly. The research suggests that incremental changes in end-of-life vehicle processing could be effective in aiding materials recovery.

A study was conducted to investigate the levels of plant nutrients, heavy metals, parasites and fecal coliform bacteria in Bangkok-produced sewage sludge and finished compost products for potential agricultural application, as well as to compare the quality of compost under different composting conditions. The results indicated that digested sewage sludge had high fertilizing values for organic matter (19.01 ± 0.09%), total nitrogen (2.17 ± 0.07%), total phosphorus (2.06 ± 0.06%) and total potassium (1.16 ± 0.22%), but it was contaminated with human pathogens, including fecal coliform bacteria, viable helminthes egg and active forms of parasite cysts. Thus, fresh sewage sludge should not be disposed on land unless it has undergone pathogen reduction. It is proven that the quality of the sludge mixed with grass clippings at a ratio of 6:1 volume/volume after having passed a windrow composting process for 8 weeks can be classified as class A biosolids as the levels of remaining fecal coliforms were < 3 most probable number g⁻¹ dry solid and all human parasites were destroyed. Concentrations of organic matter, total nitrogen, total phosphorus and total potassium in the finished compost were 16.53 ± 1.25%, 1.39 ± 0.06%, 0.42 ± 0.10% and 1.53 ± 0.05% respectively. The total copper concentration was rather high (2291.31 ± 121.77 mg kg⁻¹), but all heavy metal concentrations were also well below the United States Environmental Protection Agency pollutant limits for land application. The finished compost products can be considered as a soil conditioner as they have relatively low essential plant nutrient concentrations. It is recommended to be initially used for gardening and landscaping to ensure safety utilization.

During the last decade, the European Union has enforced the diversion of organic wastes and recyclables to waste management companies operating incineration plants, composting plants and recycling units instead of landfills. The temporary storage sites have been established as a buffer against fluctuations in energy demand throughout the year. Materials also need to be stored at temporary storage sites before recovery and recycling. However, regulations governing waste fuel storage and handling have not yet been developed, and, as a result, companies have engaged in risky practices that have resulted in a high number of fire incidents. In this study, a questionnaire survey was distributed to 249 of the 400 members of Avfall Sverige (Swedish Waste Management Association), which represents the waste management of 95% of the Swedish population. Information regarding 122 storage facilities owned by 69 companies was obtained; these facilities were responsible for the storage of 47% of the total treated waste (incineration + digestion + composting) in 2010 in Sweden. To identify factors related to fire frequency, the questionnaire covered the amounts of material handled and burnt per year, financial losses due to fires, storage duration, storage method and types of waste. The results show that 217 fire incidents corresponded to 170 kilotonnes of material burnt and cumulative losses of 49 million SEK (€4.3 million). Fire frequency and amount of material burnt per fire was found to be dependent upon type of management group (waste operator). Moreover, a correlation was found between fire frequency and material recycled during past years. Further investigations of financial aspects and externalities of fire incidents are recommended.

The article summarises the main results of the ‘Gestione Rifiuti in Lombardia: Analisi del ciclo di vita’ (Waste management in Lombardia region: Life cycle assessment; GERLA) project. Life cycle assessment (LCA) has been selected by Regione Lombardia as a strategic decision support tool in the drafting of its new waste management programme. The goal was to use the life cycle thinking approach to assess the current regional situation and thus to give useful strategic indications for the future waste management. The first phase of the study consisted of the LCA of the current management of municipal waste in the Lombardia region (reference year: 2009). The interpretation of such results has allowed the definition of four possible waste management scenarios for the year 2020, with the final goal being to improve the environmental performance of the regional system. The results showed that the current integrated waste management of Lombardia region is already characterised by good energy and environmental performances. However, there is still room for further improvement: actions based, on the one hand, on a further increase in recycling rates and, on the other hand, on a series of technological modifications, especially in food waste and residual waste management, can be undertaken to improve the overall system.

The recovery of aluminium (Al) scraps from waste incineration bottom ash is becoming a common practice in waste management. However, during the incineration process, Al in the waste undergoes oxidation processes that reduce its recycling potential. This article investigates the behaviour of Al scraps in the furnace of two selected grate-fired waste-to-energy plants and the amount recoverable from the bottom ash. About 21–23% of the Al fed to the furnace with the residual waste was recovered and potentially recycled from the bottom ash. Out of this amount, 76–87% was found in the bottom ash fraction above 5 mm and thus can be recovered with standard eddy current separation technology. These values depend on the characteristics and the mechanical strength of the Al items in the residual waste. Considering Al packaging materials, about 81% of the Al in cans can be recovered from the bottom ash as an ingot, but this amount decreases to 51% for trays, 27% for a mix of aluminium and poly-laminated foils and 47% for paper-laminated foils. This shows that the recovery of Al from the incineration residues increases proportionally to the thickness of the packaging.

The purpose of this study was to evaluate the physical and mechanical properties of particleboard made   with pruning wastes from Ipê (Tabebuia serratifolia) and Chapéu-de-Sol (Terminalia catappa) trees. Particleboards were prepared with both wood species, using all the material produced by grinding the pruning wastes. The particleboards had dimensions of 45×45 cm, a thickness of approximately 11.5 mm and an average density of 664 kg/m³. A urea–formaldehyde adhesive was used in the proportion of 12% of the dry particle mass. The particleboards were pressed at a temperature of 130°C for 10 mins. The physical and mechanical properties analyzed were density, moisture content, thickness swelling, percentage of lignin and cellulose, modulus of resilience, modulus of elasticity and tensile strength parallel to the grain, accordingly to the standards NBR 14810 and CS 236-66 (1968). The particleboards were considered to be of medium density. The particle size significantly affected the static bending strength and tensile strength parallel to the grain. Ipê presented better results, demonstrating a potential for the production and use of particleboard made from this species.