Metal contamination in recovered waste wood used as energy source in Sweden

Large amounts of recovered waste wood (RWW) originating from construction and demolition activities (C&DWW) and industrial activities (IWW) are annually generated in Sweden. RWW is also imported for use as an energy source at biofuel boilers. Increased use of biomass is one strategy to decrease environmental impact, in general, and the emissions of green house gases, in particular. This study addresses the environmental and resource implications of metal occurrence in RWW that is used as an energy source at biofuel boilers. RWW contains elevated concentrations of arsenic, chromium, copper, zinc, mercury, nickel, lead and possibly cadmium. The metal composition of Swedish and imported RWW differs in that Swedish RWW contains higher concentrations of arsenic, chromium, zinc, nickel and copper, while imported RWW contains higher concentrations of lead, mercury and cadmium. Ashes from combustion of RWW are nowadays generally disposed in landfills due to their elevated metal concentrations. This practice makes it impossible to use these ashes as filler material thereby replacing extraction of raw materials and decreasing the need for landfill space. Furthermore, landfilling leads to accumulation of hazardous heavy metals that poses a future environmental and health problem. If RWW from construction and demolition should contribute optimally to a sustainable energy system, cleaner waste wood flows are a prerequisite. The elementary measure is to track potential pollution sources in this waste stream and find out which are significant. Furthermore, since most of the RWW is untreated and unpolluted wood, there is a great environmental potential to separate this flow through the waste management system. Such an approach might lead to decreased environmental pollution of heavy metals and an improved resource management.
Researchers : J. Krook, A. Martensson and M. Eklund
Department of Mechanical Engineering, Linköpings University of Technology, SE-581 83, Linköping, Sweden
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· Site selection for hazardous wastes: A case study from the GAP area, Turkey

The increase in the popularity of using environmental design criteria in town and country planning has brought about the need to fully identify the principles to determine the best location of hazardous waste to be landfilled. This environmental management issue has received considerable attention because of its applications in urban and rural infrastructure planning, industrial development planning as well as health, housing, transportation and agricultural schemes. This paper explains a method to determine how to locate suitable sites for hazardous waste landfilling area by using the site screening study. It demonstrates how the criteria such as geology, topography, land use, climate, earthquake and other related factors can be introduced into the overlayer technique to determine the suitable site selection in a region. The research was undertaken in the Southeastern Anatolia Project (known as GAP in Turkey) region where identifying the land resources is crucial for agricultural and water management purposes. The paper also explains the validity of the method employed on the site selection process for hazardous wastes. The introduced method may enable more accurate design procedure for planning in environmental management in future.
Reseachers: Mehmet Irfan Yesilnacar,, Department of Environmental Engineering, Harran University, P.K. 153, Sanliurfa, Turkey and Hasan Cetin, Department of Geological Engineering, Cukurova University, Adana, Turkey
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· Global perspectives on e-waste
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Electronic waste, or e-waste is an emerging problem as well as a business opportunity of increasing significance, given the volumes of e-waste being generated and the content of both toxic and valuable materials in them. The fraction including iron, copper, aluminium, gold and other metals in e-waste is over 60%, while pollutants comprise 2.70%. Given the high toxicity of these pollutants especially when burned or recycled in uncontrolled environments, the Basel Convention has identified e-waste as hazardous, and developed a framework for controls on transboundary movement of such waste. The Basel Ban, an amendment to the Basel Convention that has not yet come into force, would go one step further by prohibiting the export of e-waste from developed to industrializing countries.
Section 1 of this paper gives readers an overview on the e-waste topic—how e-waste is defined, what it is composed of and which methods can be applied to estimate the quantity of e-waste generated. Considering only PCs in use, by one estimate, at least 100 million PCs became obsolete in 2004. Not surprisingly, wasteelectrical and electronic equipment (WEEE) today already constitutes 8% of municipal waste and is one of the fastest growing waste fractions.
Section 2 provides insight into the legislation and initiatives intended to help manage these growing quantities of e-waste. Extended Producer Responsibility (EPR) is being propagated as a new paradigm in waste management. The European Union's WEEE Directive, which came into force in August of 2004, makes it incumbent on manufacturers and importers in EU states to take back their products from consumers and ensure environmentally sound disposal.
WEEE management in industrializing countries has its own characteristics and problems, and therefore this paper identifies some problems specific to such countries. The risky process of extracting copper from printed wiring boards is discussed as an example to illustrate the hazards of the e-waste recycling industry in India.

The WEEE Knowledge Partnership programme funded by seco (Swiss State Secretariat for Economic Affairs) and implemented by Empa has developed a methodology to assess the prevailing situation, in order to better understand the opportunities and risks in pilot urban areas of three countries—Beijing-China, Delhi-India and Johannesburg-South Africa. The three countries are compared using an assessment indicator system which takes into account the structural framework, the recycling system and its various impacts. Three key points have emerged from the assessments so far: a) e-waste recycling has developed in all countries as a market based activity, b) in China and India it is based on small to medium-sized enterprises (SME) in the informal sector, whereas in South Africa it is in the formal sector, and c) each country is trying to overcome shortcomings in the current system by developing strategies for improvement.
Researchers: Rolf Widmer, Heidi Oswald-Krapf and Heinz Böni, Technology and Society Lab, Empa, Swiss Federal Laboratories for Materials Testing and Research, Lerchenfeldstr. 5, CH-9014 St. Gallen, Switzerland;Deepali Sinha-Khetriwal, A-502, Millennium Park, Akruti Niharika, N. S. Phadke Marg, Andheri, Mumbai-400069, India and Max Schnellmann, State Secretariat for Economic Affairs (seco), Economic Development Cooperation, Effingerstrasse 31, CH-3003 Berne, Switzerland
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· Key drivers of the e-waste recycling system: Assessing and modelling e-waste processing in the informal sector in Delhi

The management and recycling of waste electrical and electronic equipment WEEE was assessed in the city of Delhi, India. In order to do this, the personal computer was defined as the tracer for which a model was designed. The model depicts the entire life cycle of the tracer, from production through sale and consumption—including reuse and refurbishment—to the material recovery in the mainly informal recycling industry. The field work included interviews with the relevant stakeholders, transect walks and literature study, which was followed by a software-supported material flow analysis (MFA) of the whole life cycle chain of the tracer item. In addition to the MFA, several economic aspects of the recycling system were investigated. The study revealed that the life span of a personal computer has considerable influence upon the system, most notably in the following two aspects: (i) a prolonged life span creates value by means of refurbishing and upgrading activities, and (ii) it slows down the flow rate of the whole system. This is one of the simplest ways of preventing an uncontrolled increase in environmentally hazardous emissions by the recycling sector. The material recovery of the system is mainly driven by the precious metal content of personal computers. A first estimate showed that precious metal recovery contributes to over 80% of the personal computer materials' market value, despite the small quantity of them found in computers.
Researchers: Martin Streicher-Porte, Swiss Federal Institute of Technology, ETH Landscape and Environmental Planning (LEP) at ETH Zurich Regional Resource Management, P.O. BOX 171, Wolfgang Pauli Street 15, ETH Hoenggerberg, HIL H 29.1, CH-8093 Zurich, Switzerland ; Rolf Widmer, Technology and Society Lab. Empa, Swiss Federal Laboratories for Materials Testing and Research, Lerchenfeldstr. 5CH-9014 St. Gallen, Switzerland ; Amit Jain, IRG Systems South Asia Pvt. Ltd., Ist Floor, K-71, Hauz Khas Enclave, New Delhi 110016, India ; Hans-Peter Bader, Modeling of Anthropogenic Material Flows, Development of models to describe anthropogenic substance flows and their dynamic, EAWAG, Swiss Federal Institute for Environmental Science and Technology, Überlandstr. 133, P.O. Box 611, CH-, 8600 Dübendorf, Switzerland; Ruth Scheidegger, Modeling of Anthropogenic Material Flows, Modeling and evaluation of anthropogenic caused substance flows on different scales. EAWAG, Swiss Federal Institute for Environmental Science and Technology, Überlandstr. 133, P.O. Box 611, CH-8600 Dübendorf, Switzerland and Susanne Kytzia ,Swiss Federal Institute of Technology, ETH, Landscape and Environmental Planning (LEP) at ETH Zurich, Wolfgang-Pauli-Str. 15, ETH Hoenggerberg, HIL H 28.3, CH-8093 Zurich, Switzerland
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· A reverse logistics cost minimization model for the treatment of hazardous wastes

A cost-minimization model for a multi-time-step, multi-type hazardous-waste reverse logistics system has been developed. A discrete-time linear analytical model is formulated that minimizes total reverse logistics operating costs subject to constraints that take into account such internal and external factors as business operating strategies and governmental regulations. Application cases are presented to demonstrate the feasibility of the proposed approach. By using the proposed model coupled with operational strategies, it is shown that the total reverse logistics costs for the applications cases can be reduced by more than 49%.
Researchers: Tung-Lai Hu Department of Industrial Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan, ROC
Jiuh-Biing Sheu Institute of Traffic and Transportation, National Chiao Tung University, 4F, 114 Chung Hsiao W. Rd., Sec. 1, Taipei 10012, Taiwan, ROC
Kuan-Hsiung Huang Department of Transportation, Warehousing and Logistics, National Kaohsiung First University of Science and Technology, 1 University Road, Yuanchau, Kaohsiung 824, Taiwan, ROC
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· Setting information priorities for remediation decisions at a contaminated-groundwater site

Many sites of contamination due to inappropriate disposal of hazardous materials or wastes have been found. These sites have the potential of damaging the environment and human health and thus need to be evaluated as to whether and what actions should be initiated. In the decision on whether a contaminated site should be subject to management, the knowledge concerning important parameters that would influence the decision will be beneficial to planning of data collection to support the decision. This paper presents a case study of contaminated site located in northern Taiwan, where the groundwater is contaminated by chlorinated hydrocarbons including trichloroethylene (TCE) and tetrachloroethylene (PCE). A site-specific multimedia risk assessment is performed to estimate the total risk resulting from the contamination. In addition, Monte Carlo simulation, rank correlation coefficients, and decision criteria are combined to develop a methodology for assessing the important of parameters in terms of their influence on the decision. It is found that TCE concentration, vegetable yield, deposition interception fraction of vegetables, and plant surface loss constant, are the four parameters important to the decision-making of the case problem.
Researchers: Hwong-wen Ma and Chung-Da Ton, Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei 106, Taiwan, ROC; Kuen-Yuh Wu Department of Occupational Safety and Health, China Medical College, No. 91, Hsuesh-Shih Road, Taichung, Taiwan, ROC

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