Product lifespan estimates are important information for understanding progress toward sustainable consumption and estimating the stocks and end-of-life flows of products. Publications reported ...actual lifespan of products; however, quantitative data are still limited for many countries and years. This study presents regional and longitudinal estimation of lifespan distribution of consumer durables, taking passenger cars as an example, and proposes a simplified method for estimating product lifespan distribution. We estimated lifespan distribution parameters for 17 countries based on the age profile of in-use cars. Sensitivity analysis demonstrated that the shape parameter of the lifespan distribution can be replaced by a constant value for all the countries and years. This enabled a simplified estimation that does not require detailed data on the age profile. Applying the simplified method, we estimated the trend in average lifespans of passenger cars from 2000 to 2009 for 20 countries. Average lifespan differed greatly between countries (9-23 years) and was increasing in many countries. This suggests consumer behavior differs greatly among countries and has changed over time, even in developed countries. The results suggest that inappropriate assumptions of average lifespan may cause significant inaccuracy in estimating the stocks and end-of-life flows of products.
Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate ...management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously.
► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for managing toxic metals in WEEE because the total amount is not negligible. ► Changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. ► The flows of toxic metals and valuable materials should be managed simultaneously in recycling and treatment of WEEE.
► End-of-life electrical and electronic equipment (EEE) as secondary metal resources. ► The content and the total amount of metals in specific equipment are both important. ► We categorized 21 EEE ...types from contents and total amounts of various metals. ► Important equipment types as secondary resources were listed for each metal kind. ► Collectability and possible collection systems of various EEE types were discussed.
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.
•Effects of product price rises on metal consumption, GHG, and sales are analyzed.•5% price rise reduces iron, copper, and aluminum use by 6, 1, and 2 thousand tons.•5% price rise increases GHG by ...506 KtCO2eq. and reduces sales by 56 billion JPY.•30% price increase can reduce both metal consumption and GHG emissions.•Business models should be developed to overcome the resulting decrease in sales.
This study examined the effects of product price increases on metal consumption, greenhouse gas (GHG) emissions, and product sales via changes in the product replacement decisions of consumers. A dynamic discrete choice model was applied to air conditioners (ACs) in Japan to determine these effects when product price is increased by from 5% to 30% in 5% increments. To illustrate, a 5% increase in air conditioners was shown to reduce consumption of iron, copper, and aluminum by six, one, and two thousand tons, respectively, while increasing GHG emissions by 506 kt-CO2 eq. and decreasing product sales by 56 billion Japanese yen. Thus, product price increases for ACs led to a reduction in material consumption while decreasing product sales. The effect on GHG emissions depends on the level of the product price increase. These interactions suggest that consumers will use products longer so long as the value of the product's enhanced durability and longevity matches the increased price of the product. Efforts to improve product durability and longevity, however, will require that AC companies explore new business models in order to cope with the anticipated decrease in product sales as the transition to a circular economy continues.
National accounts for material stocks and flows are reported regularly by an increasing number of countries to promote a sustainable use of our natural resources. In this research we build upon the ...work of Herman Daly and Donella Meadows and propose a framework that links material stocks and flows to a conceptual hierarchy of ends and means which are societal benefit and natural capital. We introduce a set of six indicators that link together to quantitatively relate material consumption and societal benefits: material productivity, primary material use rate, stock retention time, stock productivity, service productivity, and service utilization. We apply this analytical framework to accounts of the material stocks and flows of Japan for the period 1990 to 2015. We find that Japan’s material flow productivity doubled from 1.6 US$/kg to 3.2 US$/kg. This improvement can be primarily attributed to improvements in stock retention rates and circular material use, but has been offset by decreasing productivity of Japan’s material stocks from 0.2 US$/kg to 0.14 US$/kg. We discuss the future potential of our indicator framework to include additional indicators for specific sectors and argue for the need for proper measurements of societal services and human wellbeing to enhance the policy implications of the indicator framework.
•We present a framework of 6 indicators to study stocks, flows, and services.•The indicators address productivity, circularity, service provision, and wellbeing.•The framework quantifies the means-ends approach to sustainable development.•We apply this framework to new stock & flow accounts for Japan 1990–2015.•Japan’s material productivity improved due to circularity and stock retention.
Product replacement programs promote the replacement of durable goods such as automobiles, home appliances and houses with new energy-efficient products using financial incentives such as subsidies. ...Many countries have implemented such programs to reduce environmental loads. These programs affect the point in time at which the decision to replace a product is made (and acted on) by consumers, which, in turn, influences the overall effectiveness of the program. Thus, in order to improve the policy design of these replacement programs, it is necessary to consider the mechanism of the consumer product replacement decision. This study examines the effects of the Japanese Home Appliance Eco-Point Program on the timing of household air conditioner replacements and the resulting GHG emission reduction effects and assesses the program's cost-effectiveness using a dynamic discrete choice model and an input–output model. We found that the program increased the air conditioner replacement rate by 1.5%–1.9% and reduced GHG emissions by 28,516 tCO2eq. However, the cost per ton of CO2eq reduced was approximately 978 US dollars, which is quite high compared to the GHG emission reduction costs of other programs. We conclude that the Home Appliance Eco-Point Program as constituted in 2009–2010 was not a cost-effective means to reduce GHG emissions and that appropriate policy coordination needs to be conducted in order to improve the cost-effectiveness of such programs in the future.
► The fate of 55 metals during shredding and separation of WEEE was investigated. ► Most metals were mainly distributed to the small-grain fraction. ► Much of metals in WEEE being treated as ...municipal waste in Japan end up in landfills. ► Pre-sorting of small digital products reduces metals to be landfilled at some level. ► Consideration of metal recovery from other middle-sized WEEE is still important.
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.
•Consumers need to pay attention to the specific collection rules for each type of battery in each municipality in Japan.•6–10% of zinc carbon and alkaline batteries discarded in Japan currently ...could be regarded as containing mercury.•Despite announcements by producers and municipalities, only 2.0% of discarded cylindrical dry batteries were insulated.•Batteries made up an average of 4.6% of the total collected small WEEE under the small WEEE recycling scheme in Japan.•Exchangeable batteries were used in almost all of mobile phones, but the removal rate was as low as 22% for mobile phones.
To clarify current collection rules of waste batteries in municipal waste management in Japan and to examine future challenges for hazardous substance control and safety, we reviewed collection rules of waste batteries in the Tokyo Metropolitan Area. We also conducted a field survey of waste batteries collected at various battery and small waste electric and electronic equipment (WEEE) collection sites in Tokyo. The different types of batteries are not collected in a uniform way in the Tokyo area, so consumers need to pay attention to the specific collection rules for each type of battery in each municipality. In areas where small WEEE recycling schemes are being operated after the enforcement of the Act on Promotion of Recycling of Small Waste Electrical and Electronic Equipment in Japan in 2013, consumers may be confused about the need for separating batteries from small WEEE (especially mobile phones). Our field survey of collected waste batteries indicated that 6–10% of zinc carbon and alkaline batteries discarded in Japan currently could be regarded as containing mercury. More than 26% of zinc carbon dry batteries currently being discarded may have a lead content above the labelling threshold of the EU Batteries Directive (2006/66/EC). In terms of safety, despite announcements by producers and municipalities about using insulation (tape) on waste batteries to prevent fires, only 2.0% of discarded cylindrical dry batteries were insulated. Our field study of small WEEE showed that batteries made up an average of 4.6% of the total collected small WEEE on a weight basis. Exchangeable batteries were used in almost all of mobile phones, digital cameras, radios, and remote controls, but the removal rate was as low as 22% for mobile phones. Given the safety issues and the rapid changes occurring with mobile phones or other types of small WEEE, discussion is needed among stakeholders to determine how to safely collect and recycle WEEE and waste batteries.
► We estimated the amount of E-waste in South Korea from 2000 to 2020. ► The population balance model was applied based on a lifespan distribution analysis. ► The result was compared with the number ...of items collected through recycling program. ► Washing machine had the highest and air conditioners had the lowest collection rate. ► Distribution shape parameter of electronic appliances ranged from 1.49 to 2.43.
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 1.2million air conditioners, 2.5million televisions, 1.3million microwave ovens, 1.2million kimchi refrigerators, 17.0million mobile phones, 1.7million refrigerators, 2.0million vacuum cleaners, and 1.4million 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%).
Front face fluorescence spectroscopy of typical Japanese soil powders (soil A: Typic Hapludand; soil H: Typic Hydraquent; soil Y: Typic Paleudult) has been conducted. Three dimensional ...excitation-emission matrix fluorescence spectra of the 100 wt% soils showed similar fluorescence patterns to each other. The fluorescence patterns were similar between the soil samples and their residues after extraction by NaOH solution for 60 min. In order to examine fluorescence extinction from a view point of whiteness of the soils, the soil powders were mixed with white and black diluents (Al2O3 and Fe3O4) and fluorescence spectra of the mixtures were measured at 450 nm excitation. At low levels of dilution with Al2O3 (2–100 wt% of A; 50–100 wt% of H and Y), the fluorescence intensities increased with dilution. At high levels of dilution with Al2O3, the fluorescence intensities decreased with dilution. On the other hand, fluorescent intensities decreased by dilution with Fe3O4. These results suggested inner filter effect-like fluorescence extinction by (1) large amount of blackish organic compounds giving high total carbon value and (2) blackish non-fluorescent mineral compounds. In order to correct the fluorescence intensities of the mixtures containing the sample soils and the diluents, we preliminary applied a correction method based on the Kubelka-Munk theory using diffuse reflectance. The corrected fluorescence intensities of samples with white diluents (Al2O3) were described by a simple fluorescence response model having saturation values.
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•Front face fluorescence spectroscopy of typical Japanese soil powders was performed.•The soil powders showed 3D-EEM fluorescence patterns.•Inner filter effect-like fluorescence extinction by blackish compounds was suggested.•The extinction could be partly corrected by incorporating diffuse reflection.
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