A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection methods were suggested for equipment types that currently have no specific collection systems in Japan, particularly for video games, notebook computers, and mid-size ICT and audio/video equipment.     

Estimating the amount of WEEE generated in South Korea by using the population balance model

We estimated the amount of waste electrical and electronic equipment (WEEE) generated in South Korea by using the population balance model (PBM) based on a lifespan distribution analysis. This is the first study to apply PBM to estimate WEEE generation in South Korea. The lifespan distribution analysis of electrical and electronic equipment (EEE) was based on the results of a questionnaire survey of 1000 households, which were analyzed with the Weibull distribution. As a result, we could estimate the domestic service lifespan and lifespan distribution shape parameter for eight selected products. Using the lifespan distribution analysis and other data, such as the shipment volume and the number of products owned by households, we estimated the amount of WEEE generated for the eight selected items from 2000 to 2020. We found that 1.2 million air conditioners, 2.5 million televisions, 1.3 million microwave ovens, 1.2 million kimchi refrigerators, 17.0 million mobile phones, 1.7 million refrigerators, 2.0 million vacuum cleaners, and 1.4 million washing machines were generated as WEEE in 2010. We also compared our WEEE estimates with the number of items collected through the official WEEE recycling program from 2003 to 2009 and found that in 2009 washing machines had the highest collection rate (28%) and air conditioners had the lowest rate (7%).     

Exploring the linkages between river water chemistry and watershed characteristics using GIS-based catchment and locality analyses

A typology of land characteristics for the Humber catchment in central/eastern England is identified in relation to land use, hydrology and demographic, topographic and geological characteristics, using GIS and statistical analyses. Empirical relationships between land characteristics and water quality were examined in relation to the spatial variability in water quality across the Humber catchment. Analyses of relationships between land characteristics and water quality were undertaken at two hierarchical scales: (1) individual catchments and (2) localities of 10 km radius draining to each sampling site. The importance of urban and agricultural sources was identified, together with a hydrological component linked to dilution of point source inputs and mobilisation of specific sediment-associated contaminants in higher-energy (higher-flow) environments. High-solubility (dissolved) chemical determinands (such as B, Cl and SO₄), which undergo conservative transport through the river network, show the strongest linkages with land characteristics at the catchment scale. Cr, Zn and Ca show stronger correlations with land characteristics at the locality rather than the catchment scale, indicating that the concentrations of these determinands are more closely linked to the availability of localised sources. This work provides a starting point for investigating how changes in land use and management of drainage basins might impact river water quality at the regional scale and fluxes to the coastal zone, by providing a mechanism for examining linkages between regional-scale land characteristics and river water quality. The next step requires development of the approach within a more rigorous statistical framework and the extension of the regional analysis within a wider national and international context. Electronic Publication     

Evaluation by year of the valuable/hazardous material content of lithium-ion secondary battery cells and other components of notebook computer battery packs

Journal of Material Cycles and Waste Management - Our objective was to provide the information necessary to efficiently recover metals from end-of-life lithium-ion secondary batteries by assessing...     

Fate of metals contained in waste electrical and electronic equipment in a municipal waste treatment process

In Japan, waste electrical and electronic equipment (WEEE) that is not covered by the recycling laws are treated as municipal solid waste. A part of common metals are recovered during the treatment; however, other metals are rarely recovered and their destinations are not clear. This study investigated the distribution ratios and substance flows of 55 metals contained in WEEE during municipal waste treatment using shredding and separation techniques at a Japanese municipal waste treatment plant. The results revealed that more than half of Cu and most of Al contained in WEEE end up in landfills or dissipate under the current municipal waste treatment system. Among the other metals contained in WEEE, at least 70% of the mass was distributed to the small-grain fraction through the shredding and separation and is to be landfilled. Most kinds of metals were concentrated several fold in the small-grain fraction through the process and therefore the small-grain fraction may be a next target for recovery of metals in terms of both metal content and amount. Separate collection and pre-sorting of small digital products can work as effective way for reducing precious metals and less common metals to be landfilled to some extent; however, much of the total masses of those metals would still end up in landfills and it is also important to consider how to recover and utilize metals contained in other WEEE such as audio/video equipment.