Processes in informal end-processing of e-waste generated from personal computers in Vietnam

Informal treatment of e-waste plays an important role in many countries which have no or weak formal waste management structures. One of the challenges for assessing informal e-waste recycling technologies is to identify their disadvantages and potential technology improvement. The analysis of informal recycling processes starts with a balance of input and output materials for each of the processes. Main obstacles are the fact that in most cases, mixed or variety materials serve as input and, secondly by nature, the informal sector does not systematically measure and monitor the process. This study presents the processes and available data for informal e-waste recycling of desktop personal computer as it consists of components made of plastic and many metals within the Vietnamese context. To identify the most relevant processes, critical flows and technology gap, two scenarios are compared: (1) current situation in which recycling activities are taken in recycling craft villages and (2) appropriately selected BAT. The selected materials from e-waste cover a wide range of recycling processes and technologies: Printed Circuit Board treatment, metal (ferrous metal, aluminum and copper) and plastic recycling.

     

Friction measurements on “anti-slip” floors under shoe sole,contamination, and inclination conditions

Friction measurements were conducted to study the effects of shoe sole, floor, contamination, and inclined angle of the floor surface on friction coefficient. The shoe sole samples included composite rubber outsole samples with and without V-shaped tread design. Unglazed ceramic tiles of both flat and tiles with molded profile design were tested. The contamination conditions included dry, wet, and glycerol-contaminated conditions. The inclined angles included 0°, 5°, and 10°. A Brungraber Mark II slipmeter was used. The results showed that all the four factors affected friction coefficient significantly (p < 0.0001). Flat rubber soles had higher friction coefficients than the soling samples with V-shaped tread design on all tested floors and inclined angles under wet conditions. Flat soles, however, had extremely low friction when tested on flat floors under glycerol-contaminated conditions. The floors with molded grooves perpendicular to friction measurement direction had the highest friction coefficients than all other floor conditions under both the wet and glycerol-contaminated conditions except the wet/flat sole/10° condition. A regression model with a cosine function was established to describe the relationship between friction coefficient and inclined angle of the floor under the experimental conditions. This model is statistically significant at p < 0.0001 with an R² of 0.97.     

Risk management for outsourcing biomedical waste disposal – Using the failure mode and effects analysis

Using the failure mode and effects analysis, this study examined biomedical waste companies through risk assessment. Moreover, it evaluated the supervisors of biomedical waste units in hospitals, and factors relating to the outsourcing risk assessment of biomedical waste in hospitals by referring to waste disposal acts. An expert questionnaire survey was conducted on the personnel involved in waste disposal units in hospitals, in order to identify important factors relating to the outsourcing risk of biomedical waste in hospitals. This study calculated the risk priority number (RPN) and selected items with an RPN value higher than 80 for improvement. These items included “availability of freezing devices”, “availability of containers for sharp items”, “disposal frequency”, “disposal volume”, “disposal method”, “vehicles meeting the regulations”, and “declaration of three lists”. This study also aimed to identify important selection factors of biomedical waste disposal companies by hospitals in terms of risk. These findings can serve as references for hospitals in the selection of outsourcing companies for biomedical waste disposal.     

Reactive Compatibilization of Biobased Polyurethane Prepolymer Toughening Polylactide Prepared by Melt Blending

Polylactide (PLA) is a major biodegradable polymer, which has received extensive interests over the past decades and holds great potential to replace several petroleum-based polymeric materials. Nevertheless, the inherent brittleness and low impact strength have restricted its invasion to niche markets. In this paper, the authors demonstrate that the entirely bio-sourced blends, namely PLA and castor oil-based polyurethane prepolymer (COPUP), were first melt-compounded in an effort to prepare novel biodegradable materials with an excellent balance of properties. NCO-terminated COPUP was successfully synthesized and subsequently mixed with variable concentration of PLA matrix using melt-compounded by twin-screw extrusion technique. The miscibility, phase morphology, mechanical properties, and thermal resistance of the blends were investigated. During FTIR analysis, it suggests that the interfacial compatibilization between COPUP and PLA phase occurred by the reaction of –NCO group of MDI with terminal hydroxyl group of PLA. DMA analysis showed that COPUP and PLA showed some limited miscibility with shifted glass transition temperature. The morphologies of fracture surface showed a brittle-to-ductile transition owing by the addition of COPUP. The crystallization behavior was studied by differential scanning calorimeter (DSC). The strain at break and notched impact strength of PLA/COPUP blends were increased more than 112–15.4 times elegant of neat PLA; the increase is superior to previous toughening effect by using petroleum-based tougheners. Furthermore, the thermal resistances and melt flow properties of the materials were also examined by analysis of the melt flow index and heat deflection temperature use in the work. With enhanced toughness, the PLA/COPUP blends could be used as replacements for some traditional petroleum-based polymeric materials.     

Liver Metallothionein Level and Metal Content in Fish of Chung-Kung Stream,Taiwan-Tilapia and Liza Macrolepsis

A survey of Chung-Kung sttream fish was undertaken on six occasions from March 1994 to August 1995. Tilapia (Oreochromis hybrid) and Liza macrolepsis were the major species found downstream and were chosen as the target species for metallothionein (MT) analysis of liver tissue. in total MT of 77 tilapia and 48 Liza macrolepsis liver samples were analyzed. Significantly higher values (p >0.05) were found for the August 1995 samples than for samples taken earlier at site B (6 km from the sea) for tilapia and at site A (estuary) for Liza macrolepsis. Liver zinc, copper and cadmium were analyzed for the 1995 samples. for tilapia, liver MT concentration was found to correlate well with zinc concentration (r = 0.84, p > 0.001). for Liza macrolepsis, good correlation was found for MT with both zinc (r = 0.89, p > 0.001) and copper (r = 0.90, p > 0.001). These results indicate that in the Chung-Kung stream, zinc and copper may be the major inducers of fish liver MT. Since these two species are ubiquitous in tropical areas, they would provide a good biomarker for evaluation of integrated metal exposure in the tropical aquatic environment.     

Remote sensing of global change: growth in China's Jiangsu Province

SUMMARY

This paper examines how remote-sensing data and regional social and economic data can be used together to identify changes in land-use patterns in particular regions. Study of the spatiotemporal dynamics of remote-sensing data can identify trends in competing uses of land, water and other natural resources for agriculture, industrial development and urban settlements. When combined with information on trends in industrial production, population, agricultural production, pollutant releases, water usage and natural forest coverage, these data reveal patterns of anthropogenic disturbance that can provide early signals of problems in resource decline or land-use management. This study focuses on land-cover changes in southern Jiangsu Province of the People's Republic of China between 1976 and 1984. This region, to the west of Shanghai and to the south of the Yangtze River, experienced unprecedented economic growth after the end of the Cultural Revolution. Remote-sensing imagery reveals the rapid growth of urban centres, commensurate declines in surface water area, and changing patterns of agriculture. The observed changes cast doubt on the ability of the region to sustain such rapid and intense land-use conflicts over a long period.     

Evolutionary governance choice for corporate social responsibility: a forestry campaign case in South Korea

Firms select different governance types (e.g. internalisation, outsourcing or collaboration) for corporate social responsibility (CSR) activities. This paper examined how the choice of CSR governance type is influenced by social factors and organisational experiences and how changes in these factors affect the governance choice. These questions are especially meaningful in the context of developing countries with weak institutional environments and recent social change. With the unique phenomenon that is not readily explainable in terms of the extant theoretical groundwork on CSR governance choice, a case study of a South Korean forestry campaign by Yuhan-Kimberly was analysed. It was found that social circumstances triggered Yuhan-Kimberly's initiation of forestry projects, but the absence of social infrastructure limited the choice of governance type early on. Lack of experience also constrained the governance choice. Over time, environmental change and the accumulation of organisational knowledge caused the choice of governance to evolve. This study contributes to the CSR governance choice literature by exploring social and organisational determinants other than economic efficiency and by applying a dynamic perspective.     

Direct production of hydroxymethylfurfural from raw grape berry biomass using ionic liquids and metal chlorides

We report for the first time the direct conversion of raw grape berry biomass to hydroxymethylfurfural (HMF) using ionic liquid solvents with metal chloride catalysts. Exploiting raw plant biomass as a biorefinery feedstock is innovative for sustainable chemical industry. The use of the raw biomass to synthesize compounds can indeed lead to less energy consumption and less CO₂ emissions. Using raw plant biomass skips pretreatment steps that are required to produce biomaterials such as carbohydrates or cellulosic biomass. Here, grape berry biomass was used as a raw chemical feedstock for the production of hydroxymethylfurfural, a key platform intermediate for syntheses of future renewable biofuels. We examined 3 ionic liquid solvents, 3 reaction temperatures, 5 chloride catalysts, and 5 concentrations of HCl. We found an increasing HMF yields depending on reaction conditions. 1-octyl-3-methylimidazolium chloride was most effective for HMF synthesis. Addition of HCl or metal chlorides alone showed little improvement. The highest HMF yield of about 100 mg HMF per mL of grape biomass extract was obtained using 0.3 M HCl, [OMIM]Cl, and CrCl₂ at 100°C for 3 h. Our study provides a model system of sustainable production of valuable compounds from raw plant biomass.