Estimation of end of life mobile phones generation: the case study of the Czech Republic

Noncytotoxic WORM Memory Using Lysozyme with Ultrahigh Stability for Transient and Sustainable Electronics Applications

Biocompatibility and transient nature of electronic devices have been the matter of attention in recent times due to their immense potential for sustainable solutions toward hazardous e-wastes. In order to fulfill the requirement of high-density data-storage devices due to explosive growth in digital data, a resistive switching (RS)-based memory device could be the promising alternative to the present Si-based electronics. In this research work, we employed a biocompatible enzymatic protein lysozyme (Lyso) as the active layer to design a RS memory device having a device structure Au/Lyso/ITO. Interestingly the device showed transient, WORM memory behavior. It has been observed that the WORM memory performance of the device was very good with high memory window (2.78 × 102), data retention (up to 300 min), device yield (∼73.8%), read cyclability, as well as very high device stability (experimentally >700 days, extrapolated to 3000 days). Bias-induced charge trapping followed by conducting filament formation was the key behind such switching behavior. Transient behavior analysis showed that electronic as well as optical behaviors completely disappeared after 10 s dissolution of the device in luke warm water. Cytotoxicity of the as-prepared device was tested by challenging two environmentally derived bacteria, S. aureus and P. aeruginosa, and was found to have no biocidal effects. Hence, the device would cause no harm to the microbial flora when it is discarded. As a whole, this work suggests that Lyso-based WORM memory device could play a key role for the design of transient WORM memory device for sustainable electronic applications.

Generation estimation and metals recycling potentials evaluation of retired mobile phones in Korea

The goal of this work is to evaluate generation and metals recycling potentials of retired mobile phones in Korea. The generation estimation is conducted with the sales&new method and statistic data, such as sales of mobile phones and amount of the subscribers. The result shows that there are 17.99 million of mobile phones retired in 2022, compared 13.12 million in 2001. Accordingly, the deduced lifetime has minimum and maximum values in 2003 and 2020, which are 2.02 and 4.33 years, compared with 4.16 years in 2022 and 2.21 years in 2001. The deduced lifetime trends to increase with the increased values of subscribers and the fluctuated values of sales. The crosscheck testifies to the veracity of the result in comparison with the actual condition. The amount and dynamic of critical metals are also calculated with the content and amount of retired mobile phones.

Towards the definition of WEEE recycling targets in Ecuador. A case of study for mobile phones

The rise of consumption patterns of electrical and electronic equipment (EEE) and the generation of waste EEE (WEEE) has been strongly increasing globally. Recycling rates (RRs) are one of the main indicators for monitoring the progress towards a circular economy and establishing recovery and treatment schemes. For this reason, this study discusses the setting of recycling targets for WEEE in Ecuador, using mobile phones as a case study. Firstly, the generation of mobile phone waste from 2012 to 2018 is estimated based on literature review. The most appropriate model for estimating WEEE generation is selected according to the applicable market conditions, input requirements and available data. Then, the composition of a mobile phone is determined through an extensive literature review. Based on these results, the materials' environmental impact and potential economic value are approximated using the ReCiPe Endpoint (H, A) method and the prices of virgin materials, respectively. The estimation shows that in Ecuador an average of 2 million devices are discarded every year, which represents an interesting source of resources but currently does not have appropriate management. Ecuador has implemented regulatory frameworks in favour of the integral management of these wastes. However, mass-based collection targets still appear to be the only available measure. Therefore, national results on electronics recycling do not allow adequate monitoring of progress towards a circular economy and largely neglect environmental aspects and economic potential.

Mapping the social stock and spatiotemporal distribution of high-tech minerals from wasted mobile phones in China: 2001-2019

In the twenty-first century, mobile phones have become one of the most indispensable electronic products in the international community. The pollution of wasted mobile phones has become an urgent problem worldwide and needs special attention. In this paper, we applied the consumption and usage method to calculate the high-tech mineral elements in China from 2001 to 2019. To analyze the spatial distribution of per capita high-tech minerals in China, we proposed a model (3D GHM) through which a 3D grid of high-tech minerals in wasted mobile phones can be obtained in 1 km resolution. The results showed that the total amount of wasted mobile phones in China from 2001 to 2019 was 8.6 billion, with a growth rate of 1026.7% in 2019 compared with 2001. Moreover, the spatiotemporal distribution of wasted mobile phones is characterized by more in the east and less in the west. The total amount of cobalt, palladium, antimony, beryllium, neodymium, praseodymium, and platinum in wasted mobile phones from 2001 to 2019 reached 42,422.4 tons. Based on our results, we proposed a system for efficient collecting and recycling of wasted mobile phones in China.

Prediction of e-waste generation: Application of modified adaptive neuro-fuzzy inference system (MANFIS)

An accurate estimation of generated electronic waste (e-waste) plays a pivotal role in the development of any appropriate e-waste management plan. The present study aimed to exploit modified adaptive neuro-fuzzy inference system (MANFIS) for the estimation of generated e-waste. There are different parameters affecting e-waste generation, the most important of which need to be identified to achieve the accurate estimation. The MANFIS used for parameter selection involves evaluating multiple choices between twelve initially specified parameters. The MANFIS models with five inputs have the highest mean R²_(train) and R²_(test) (0.978 and 0.952, respectively, in training and testing stages). According to the results, the best combination of parameters was related to legal imports of electrical and electronic equipment (EEE), smuggling (illegal) imports of EEE, exports of EEE, accumulation of EEE in Tehran, and accumulation of EEE in Iran with RMSE_(train) and RMSE_(test) of 0.221 and 2.221, respectively. The findings showed that the model with three triangular membership functions had the best performance; R²_(train) and RMSE_(train) values were 0.981 and 1.371, as well as R²_(test) and RMSE_(test) values were 0.971 and 1.678, respectively. Finally, the developed model was successfully applied for prediction of monthly e-waste generation in Tehran for thirteen selected electronic items. The obtained consistent results emphasized that appropriate selection of the number of input parameters and their combination, along with identifying optimal structure of MANFIS, provides a proper, simple and accurate prediction of e-waste.

Disposal of obsolete mobile phones: A review on replacement, disposal methods, in-use lifespan, reuse and recycling

Usage/consumption of mobile phones has increased rapidly around the world. As of April 2021, there were 5.27 billion mobile phone users. Meanwhile, the generation of obsolete mobile phones/mobile phone wastes is also increased mainly due to the replacement of mobile phones. The in-use lifespan of mobile phones is correspondingly getting decreased. The inappropriate disposal of obsolete mobile phones leads to adverse consequences on the environment, human health and on metal recovery. This review article provides an insight on findings from various articles on disposal of obsolete mobile phones by users/consumers. The various aspects, such as reasons for replacement, disposal methods adopted by users/consumers, impact due to the adoption of improper disposal methods such as handing them over to the informal recycling sector and storage/hibernation after its in-use lifespan, were covered. Along with this, the study even focuses on reduce, reuse and recycle (3Rs) of sustainability. Reduce means reduction of mobile phone replacement frequency. Storage of mobile phones post-in-use lifespan is the most opted disposal method, and it is one of the significant barriers to reuse, recycling and metal recovery. When it comes to recycling, the research undertaken on the recycling of obsolete mobile phones is not as in-depth when compared to the research done on recycling of e-waste in general. This article identifies future directions for sustainable end-of-life management of obsolete mobile phones.

Response to the Upcoming Emerging Waste: Necessity and Feasibility Analysis of Photovoltaic Waste Recovery in China

With the widespread photovoltaic deployment to achieve the net-zero energy goal, the resulting photovoltaic waste draws attention. In China, considerable steps have not been taken for photovoltaic waste management. The lack of relevant scientific information on photovoltaic waste brings difficulties to the establishment of photovoltaic waste regulatory systems. In this study, the necessity and feasibility of photovoltaic waste recovery were investigated. In China, the photovoltaic waste stream was quantified as 48.67-60.78 million t in 2050. In photovoltaic waste, indium, selenium, cadmium, and gallium were in high risk, judging by the metal criticality analysis, which meant that their recovery was significant to alleviate the resource shortage. The full recovery method was proved to reduce the environmental burdens most. For cost and benefit analysis, the net present value/size was -1.02 $/kg according to the current industrial status. However, it can be profitable with the recovery of silver. This study provides scientific and comprehensive information for photovoltaic waste management in China and is expected to promote the sustainable development of photovoltaic industry.

Generation estimation and material flow analysis of retired mobile phones in China

The generation estimation of retired mobile phones is launched with the sales and new method using the revised sales data and amount of the subscribers. Several assumptions have been made due to the insufficient sources of the data. The sales data of legal mobile phones are calculated with the authoritative and continuous official data. The sales data of smuggled and counterfeit mobile phones in China are also estimated based on the behavior data collected from the questionnaires. The results of generation estimation show that there are 636.52 million mobile phones retired in 2020, compared with 14.44 million in 1999 and several negative values in 2000, 2001, and 2008. The annual total mass of retired mobile phones in China escalated with the contributions of both the increasing generation amount and constant mass of the single unit. There are 50,921.60 ton of mobile phones retired in 2020 compared with 1155.20 ton in 1999, while the peak is 58,131.20 ton in 2019. There are 26,066.80 ton of retired mobile phones are stockpiled in 2020, while 16,152.40 ton and 8702.40 ton of retired mobile phones are reused as a whole unit and recycled, respectively. In the retired mobile phones that are recycled, 4600.50 ton material is recovered and 1216.50 ton components are reused, while 2885.40 ton residues need final disposal. The amount and dynamic characteristics of metals in the retired mobile phones are also calculated. Based on the results, several policy implications are made to improve sustainable management system of retired mobile phones in China.

Forecasting quantities of critical raw materials in obsolete feature and smart phones in Greece: A path to circular economy

Mobile phones represent an ever-increasing waste stream due to the increasing ownership and short lifetime. In particular, smartphones are among the most valuable e-waste because of their extremely high content of numerous key metals, specifically in the printed circuit board and magnets. As feature and smart phones contain different key metals at different concentrations, it is important to distinguish between the two phone types to make reliable estimations. This study presents estimations of obsolete mobile phones quantities, generated in Greece in 1995-2035 and the Critical Raw Materials (CRMs) and Precious Metals (PMs) embedded in them, making a differentiation between feature and smart phones. The dynamic material flow analysis is adopted, the lifespan is evaluated by the Weibull distribution and future sales are predicted by the logistic model incorporating phases of growth, saturation and decline. Then, the future wastes are predicted by the Market Supply A model. According to the results, the generation of obsolete smartphones is constantly increasing, while the waste flows of feature phones are declining. Efficient recycling of obsolete phones (1995-2020) can cover the demand for key metals (Au, Pd, Co) in the new smartphones for more than a decade in Greece, while the demand for Ag, Sb, Si, Zn, Be, Ti will be covered for more than 15 years. In 2020-2035 the accumulated amounts of CRMs and PMs, only from the smartphone waste, will be 1292.02 and 14.11 tonnes, respectively. The findings can contribute to the management of a valuable e-waste category closing the loop between resources-products-wastes.

Analysis of Households' E-Waste Awareness, Disposal Behavior, and Estimation of Potential Waste Mobile Phones towards an Effective E-Waste Management System in Dubai

During the recent decades, the world has seen ongoing economic and technological development which resulted in the generation of huge volumes of electrical and electronic waste (e-waste). In the Middle East, the United Arab Emirates (UAE) ranks among countries with large e-waste generation due to its consumers' high spending on electronic devices thereby resulting in a high obsolescence rate in the country. Accordingly, this study aims to analyze the e-waste management and recycling practices in the UAE. It takes Dubai as a case study and conducts a structured questionnaire to analyze households' awareness, consumption of electronic devices in general and mobile phones in particular, and the disposal behavior of e-waste. Waste mobile phones is taken as a key representative in this study, in which potential waste mobile phones is estimated using the Approximation 1 method in the period 2021-2030. Results from the survey illustrated gaps among households' awareness and disposal behavior of e-waste, where e-waste recycling rates were noticed to be low. Based on these gaps, strategies were proposed for an effective e-waste management system in the context of Dubai, and were supported by the proposal of an e-waste legislation framework in the UAE.

Dynamic estimation of future obsolete laptop flows and embedded critical raw materials: The case study of Greece

The coronavirus pandemic has turned school and university learning system from classroom-based to exclusively online all over the world. As this change is accompanied by a spike in demand of laptops, an excessive amount of obsolete devices will be witnessed in the near future. Laptops are the most valuable e-waste category containing a high content of numerous critical raw materials, thus their waste management is crucial. Considering the impact of the coronavirus pandemic on the laptop lifespan, the future quantities and pieces of obsolete laptops in Greece are estimated (2016-2040), as well as the critical raw materials (CRMs) and precious metals (PMs) embedded in them, to illustrate the potential of recovering useful resources, thus contributing to a circular economy. To this end, dynamic material flow analysis is adopted, lifespan distribution is evaluated and future sales are predicted by the logistic model utilizing a bounding analysis. Then the future End-of-Life (EoL) laptop quantities are estimated taking time-varying parameters into consideration such as penetration rate, population, laptop weight and lifespan. This study is a dynamic estimation that avoids using average values adopted from literature that are not country specific. The provided information is useful for implementing national plans, improving the management of the most valuable category, EoL laptops, enhancing resources efficiency and contributing to a circular economy. The coronavirus pandemic has a similar impact on laptop sales in other countries, affecting their future laptop waste as well.

On the influence of second use, future battery technologies, and battery lifetime on the maximum recycled content of future electric vehicle batteries in Europe

The European Union is promoting the uptake of low emission vehicles to reduce greenhouse gas emissions from transportation. However, this transition will increase the demand for five important battery raw materials; i.e. lithium, nickel, cobalt, copper, and graphite. Therefore, a substance flow analysis and forecasting model are proposed to investigate the flow of these materials through the different lifecycle stages of electric vehicle batteries. The model forecasts that by 2040, the vehicle stock will be from 72 to 78 million vehicles, while the second use stock will be from 3 to 11 million batteries. In addition, the annual recycling waste stream in 2040 will grow to roughly 3 million batteries with a capacity of 125 GWh. Results indicate that this waste stream could cover between 10% and 300% of future raw materials demand for electric vehicles. The width of this range is dominated by uncertainties on the rapidly evolving material composition of automotive batteries and the possible commercialization of cobalt-free battery technologies. The remaining uncertainty is attributed to the battery lifetime in vehicle use and potential second use of retired batteries.

Analyzing present and future availability of critical high-tech minerals in waste cellphones: A case study of India

Critical high-tech minerals (CHTMs) are raw materials that are essential for a future clean-energy transition and the manufacture of high-end products. Cellphones, one of the fastest growing electronic products, contain various CHTMs. Since 2019, India has surpassed the United States to become the second largest smartphone market in the world. An increasing and alarming number of excessive waste cellphones will be generated in India in the near future. In this study, the dynamic material flow analysis approach and the Weibull distribution are adopted to analyze the volumes of accumulated waste cellphones and the contained CHTMs based on the differentiation between smartphones and feature phones in India. Moreover, a market supply model is adopted to predict the future trends of CHTMs in waste cellphones. The results show a general upward tendency of waste cellphone volume in India, which indicates that various CHTMs contained in cellphone waste can be properly reused or recycled. Future implications based on the analysis results are provided for efficient cellphone management in India.

Fractional grey model based on non-singular exponential kernel and its application in the prediction of electronic waste precious metal content

Precious metal recovery is the main economic power of electronic waste (e-waste) recovery. The prediction of e-waste and its precious metal content is of great significance to the realisation of China's circular economy. In this work, the generation mechanism of e-waste is firstly deduced to determine model characteristics suitable for its prediction. Fractional derivative grey models base on a weak singular power kernel function (PFGM(q,1)) and a non-singular exponential kernel function (EFGM(q,1)) are established. Compared with the PFGM(q,1), the EFGM(q,1) has the advantages of simpler solution, lower calculation complexity and wider scope of application. Next, some data are selected to verify the validity. The EFGM(q,1) is used to predict mobile phone, laptop, desktop and television waste, and the weight of printed circuit boards (PCBs) in the waste and content of precious metals in these PCBs are calculated. Finally, the trend of e-waste and its precious metal contents are analysed and discussed based on the calculation results.

Cost-benefit analysis of waste photovoltaic module recycling in China

With the rapid development of renewable energy, the impact on environment and resource caused by waste photovoltaic modules has been realized gradually. To solve the problem, recycling becomes an effectual way. Therefore, the aim of this paper was to assess the economic feasibility of the photovoltaic modules recycling project in China by using cost-benefit analysis. It was found that, under the estimated treatment quantity will generate in China in 2020-2034, the recovery cost per kilowatt (kW) of photovoltaic modules will be 25.11 USD, the unit benefit is 25.68 USD/kW, and the unit net benefit is 0.57 USD/kW. The net present value (NPV) and benefit-cost ratio (BCR) are 21.14 million USD and 1.023. The sensitivity analysis indicated that the sale benefits of recycled materials and tax were the most sensitive factors affecting the project's economy. Finally, we proposed ways to improve the economy for the government and related enterprises.

A review of sustainable e-waste generation and management: Present and future perspectives

Studies on sustainable management of waste from electrical and electronic equipment (or e-waste) have gained increasing attention from researchers around the world in recent years, with investigations into various aspects of e-waste management were investigated. Studies on e-waste generation by previous papers have been reviewed to provide an overview of the current research progress and recommendations for future research. The relevant existing studies were collected from various databases. Using content analysis, three main aspects of the existing studies were evaluated: the distribution and trends of the publications, the scope and boundaries of the studies, and the current research practices and research applications. Although there was a significant increasing trend of the amount of research on the evaluation of e-waste generation, however, the number of publications based on the countries of origin was still small. Another limitation was found related to the differences in the selection of research subjects and the level of analysis resulted in variations in the scopes and boundaries of the existing studies. Various other research areas were investigated further based on their research findings, but the analysis of various methodological aspects was complicated due to the increasing number of newly developed methodologies and the lack of comprehensive and up-to-date reviews on this research area. Additionally, there was also a need to evaluate emerging and/or older technology, which led electrical appliances to be overlooked. We found that comprehensive and up-to-date reviews of the methodological aspects of e-waste generation are still lacking. Based on the research gaps and limitations discussed, recommendations for future research were made.

The Role of Chemists and Chemical Engineers in a Sustainable World

Where we fit in to the puzzle: The world is standing at a crossroads and with large-scale challenges and difficulties facing us all, the role of chemists in upcoming developments will continue to be a crucial one. In this article, the United Nations 17 Sustainable Goals are outlined and highlighted to show where chemists will fit into the puzzle of trying to reshape and reform the environment and industrial practices so that targets can be reached.

Potential of electronic waste recycling in Gulf Cooperation Council states: an environmental and economic analysis

This paper for the first time aims to valorize the environmental and economic values of electronic waste recycling for member states of the Gulf Cooperation Council (GCC) from the year 2018 up to 2040. GCC countries have a unique situation due to the significant economic growth with the resulting urbanization and population growth accompanied by high standards of living that in turn increase all types of waste. A direct link among the living standards and quantity of electronic waste production is observed in the GCC states. The annual growth of electronic waste in GCC is 3-5% while the current estimated electronic waste generation exceeds 52.2 million metric tonnes (Mt). In 2018, GCC states generated 857 kilotonnes (kt) electronic waste that would be 1.094 Mt by 2040. KSA, among the GCC states, generated the highest amount of electronic waste (533 kt) in 2018 that would be 675 kt by 2040. GCC countries are on the right track of developing policies and regulations for managing electronic waste. However, more efforts are required to ensure the implementation of these regulations. The findings of this study would be a base for the future studies in the electronic waste sector in the GCC region and a novel initiative for GCC to develop a unified free zone for the electronic waste recycling that will meet the local, regional, and international standards and regulations. This unified GCC initiative has substantial economic and environmental benefits for the region.

E-Waste Reverse Supply Chain: A Review and Future Perspectives

Electronic waste (e-waste) has become one of the fastest-growing waste, leading a globe issue. Reverse supply chain (RSC) is considered a potential way for e-waste management. Over the last two decades, RSC has received significant attention from industries, governments, experts, and researchers. A large number of studies have been published in the field of e-waste RSC. Most of the existing review papers concentrated on the general RSC models for all types of returned products. However, the review papers focusing on specific products, such as e-waste, are quite limited. To fill this gap published papers in the area of RSC for a specific product, e-waste, from 1999 to 2019 have been selected for review and analysis in this study. E-waste RSC studies have been divided into four main groups, namely, factors of implementation, performance evaluation and decision making, foresting product returns, and network design. Finally, some potential directions for e-waste RSC models have been suggested for future research.

Province-level estimation of waste mobile phones in China and location planning of recycling centers

This paper aims to uncover the spatial distribution of waste mobile phones and perform a preliminary optimization of the location of waste mobile phone recycling centers in China. This study first selects the best-suited among the logistic, Gompertz, and Bass models to forecast the per capita holding quantity of mobile phones. Combined with the population projected by the GM(1,1) and logistic models, the spatial distribution of waste mobile phones is uncovered through the stock-based model. Finally, a mixed-integer programming model is established to optimize the location of recycling centers upon the spatial distribution of waste mobile phones. Accordingly, the logistic model is concluded as the best-suited in terms of forecasting the per capita holding quantity of mobile phones for all 31 provinces in mainland China. The spatial distribution of waste mobile phones indicates the largest number in Guangdong, Shandong, and Jiangsu while the fewest are in Xizang, Qinghai, and Ningxia, in 2016. Furthermore, a remarkable increase in waste mobile phones from 2016 to 2036 in Guangdong and Beijing is projected. The location planning study indicates that a total of 175 recycling centers will be required to cover all waste mobile phones in China in 2036. Guangdong, Beijing and Zhejiang are the top three provinces regarding the number of recycling centers, with 29, 12, and 11 centers, respectively. The authors also propose the effective promoting of waste mobile phone recycling through regional cooperation and the establishment of regional management centers. The results of this study are expected to benefit waste mobile phone recycling in China.

Environmental performance of collection boxes for end of life mobile phones

Managing waste electrical and electronic equipment is currently one of the top priority challenges of waste management in the European Union. The collection and subsequent processing of waste electrical and electronic equipment are realized by means of the so-called collective systems that employ collection boxes varying in size and materials used for their production. This study focuses on quantifying and comparing environmental impacts of often-used collection boxes on the example of mobile phone collection. The comparison was based on volume (20 l, 60 l, and 70 l) and on the material used for the construction of the box (polypropylene, corrugated cardboard, and stainless steel). Other parameters, such as lifetime, material and energy performance for production, end of life stage, and waste generation were taken in account. The evaluation was carried out using the method of life cycle assessment with the characterization model CML 2001 created in GaBi 8. The goal of the study was to identify the box with the smallest environmental impact and to identify the hotspots in the life cycles of the individual collection boxes. The results of the study show that polypropylene boxes are the most environmentally suitable for collecting small waste electrical and electronic equipment as they produce the lowest environmental impacts in all of the impact categories evaluated, while boxes made of stainless steel have been found to represent the least environmentally friendly option. The results of the study provide and suggest to the collective system basic data for choosing the type of collection box.

Gold Bioleaching from Printed Circuit Boards of Mobile Phones by Aspergillus niger in a Culture without Agitation and with Glucose as a Carbon Source

Hydrometallurgical and pyrometallurgical processes to recover gold (Au) from cell-phone printed circuit boards (PCBs) have the disadvantage of generating corrosive residues and consuming a large amount of energy. Therefore, it is necessary to look for biological processes that have low energy consumption and are friendly to the environment. Among the biological alternatives for the recovery of Au from PCB is the use of cyanogenic bacteria and filamentous fungi in cultures with agitation. Considering that it is important to explore the response of microorganisms in cultures without agitation to reduce energy expenditure in the recovery of metals from PCB, the present investigation evaluated the capacity of Aspergillus niger MXPE6 and a fungal consortium to induce Au bioleaching from PCB in a culture medium with glucose as a carbon source and without agitation (pH 4.5). The results indicate that the treatments with PCB inoculated with the fungal consortium showed a considerable decrease in pH (2.8) in comparison with the treatments inoculated with A. niger MXPE6 (4.0). The fungal consortium showed a significantly higher Au bioleaching (56%) than A. niger MXPE6 (17%). Finally, the use of fungal consortia grown without agitation could be an alternative to recover metals from PCB, saving energy and material resources.

Investigating the reasons for storage of WEEE by residents - A potential for removal from households

Some categories of waste electrical and electronic equipment (WEEE) escape legal methods of disposal. The waste stream intended for recycling is sometimes disrupted because of the stockpiling of end of life (EOL) equipment in households. In some cases this equipment may be non-functional or broken but it is kept by the individuals. It is usually equipment of small dimensions that is involved in these instances. The main purpose of this study is to identify the reasons that individuals stockpile EOL equipment. A behavioural model of WEEE disposal by household individuals is proposed and tested with a survey. Results from questionnaires show the differences in behaviour for individual categories of WEEE included in the survey conducted in Poland. The results show the significance of education, age, gender and type of residence on behavioural patterns relating to disposal of waste equipment. The most likely to be stockpiled are computer accessories and other information technology equipment, comprising above 60% of responses, and mobile phones, being above 80% of responses. The most frequent reason for stockpiling is intended possible use of the equipment in the future. The results of this research can be used in campaigns aimed at increasing household awareness against stockpiling.

Determination of Metal Content of Waste Mobile Phones and Estimation of Their Recovery Potential in Turkey

Waste mobile phones constitute one of the fastest growing Waste Electrical and Electronic Equipment (WEEE) types all over the world due to technological innovations and shortening of their life span. They contain a complex mix of various materials, such as basic metals, precious metals and rare earth elements and represent an important secondary raw metal source. The main objectives of this study were to characterize the metal concentration of waste mobile phones by optimizing the inductively coupled plasma optical emission spectrometer (ICP-OES) operation parameters and estimate the metal recovery potential of waste mobile phones in Turkey. Therefore, selected mobile phone samples collected from a recycling center in Turkey were analyzed to determine their metal concentrations. Then, the theoretical recovery potentials of precious and rare earth metals from waste mobile phones were estimated for Turkey. The analytical methods optimized in this study can help further research activities to obtain comprehensive data for determination of the critical metals (precious metals and rare earth elements) in WEEE samples so that proper recycling and recovery strategies can be selected and implemented.

Estimating the generation of household e-waste in municipalities using primary data from surveys: A case study of Sao Jose dos Campos, Brazil

Estimating the generation of Waste from Electrical and Electronic Equipment (WEEE) in municipalities is relevant for the adequate planning of take-back systems. However, current WEEE estimation studies have focused primarily at the country level, and relied mostly on secondary data from literature, especially when adopting discrete average lifespans for each type of appliance. This paper aims at developing and applying a WEEE estimation method in a Brazilian city, by obtaining primary data that reflects the differences in WEEE generation among the various social and economic profiles in the city. A survey with a stratified sample was carried out to collect representative data from each city Zone. Results show that lifespan distributions are most desirable for WEEE estimation studies than discrete averages, and that the lifespan profiles in the city are considerably different than previous values adopted in other Brazilian studies. Results also show significant variations of lifespan profiles for different types of WEEE among the different Zones of the city, which reflect the social and economic differences.

Estimating the Evolution of Urban Mining Resources in Hong Kong, Up to the Year 2050

Rapid urban metabolism is causing many resources to flow from consumption to waste. But many of these wastes could be secondary resources, and cities could become urban mines and an increasing supply of future resources. Hong Kong, one of the most developed and populated cities in the world, has demonstrated a completely metabolic evolution to be an urban mine, since the 1970s. Covering 14 types of e-waste and eight types of end-of-life vehicles, this study first investigates Hong Kong's evolution as an urban mine. The potential output weight of the urban mine quickly grew from 117 kt in 2000 to 368 kt in 2014, and it is estimated to remain in the range of 300-350 kt over the years 2015-2050, with 40-50 kg/cap/year. The economic potential of urban mining, for 18 metals, plastic, glass, and rubber tires, will be approximately US$2 billion annually, mainly contributed by precious and rare metals. All the obtained results contribute to Hong Kong's waste management and promise to have positive impact on urban mining and circular economy for other, less-developed cities or regions.

Government and Intermediary Business Engagement for Controlling Electronic Waste in Indonesia: A Sustainable Reverse Logistics Theory through Customer Value Chain Analysis

Environmental pollution caused by the improper processing of electronic waste, especially from mobile phones, has increased drastically. Governments in developing countries, including Indonesia, have not been ready to face this problem. Informal groups are reacting very fast, growing and spreading evenly in many places to profit through reverse logistics activities. They dominate the markets of used electronic products. Today, eradicating these groups is impossible due to poverty, low education, and unemployment problems. Competing with them is also useless. Therefore, this research aims to find an engagement model between government and intermediary businesses, both formal and informal, for a sustainable purpose. Before determining the model, we must understand the intermediary businesses’ expectations. Therefore, we interviewed eight respondents that represent each business group and used customer value chain analysis to map them. We found forty-one expectations. Seven are the most common but are difficult to realize since they contradict government regulations. To cope with the urgency of the current situation, we concluded that the government should engage directly with the needs of these businesses, and we recommend three models of engagement i.e., empowerment, collaboration, and involvement.

Recycling Potentials of Precious Metals from End-of-Life Vehicle Parts by Selective Dismantling

Recycling of some minor but essential scarce metals used in vehicles may serve as an important strategy to strengthen sustainable management of natural resources. Accordingly, this study focused on five precious metals (PMs): Au, Ag, Pt, Pd, and Rh, in both end-of-life conventional and next-generation vehicles. To explore their recycling potentials in Japan, we developed substance flow and scenario analyses based on estimations of PM contents per end-of-life vehicle (ELV) and ELV generations. The study predicts that in Japan, from 2015 to 2040, the content of PMs per ELV will range from 2 to 6 g, and the annual amount of PMs in ELVs will remain largely stable, at 14-15 t, but the proportions of PMs utilized in different vehicles, parts, and components will gradually change; in particular, increased proportions will occur in the printed wiring boards (PWBs) of next-generation vehicles. The results also show that, in Japan, totals of 33-53% of PMs in ELVs were recycled in 2015, and that by selective dismantling of PWBs and heating wires in the rear windows of ELVs, the recycling potentials of PMs could be optimally increased to a maximum of 62-83% by 2040.

The Dynamic Equilibrium Mechanism of Regional Lithium Flow for Transportation Electrification

To assess changes in the lithium supply chain resulting from the development of the electric vehicle industry and corresponding impacts, this study established a regional dynamic flow model of the entire anthropogenic life cycle of lithium in China from 2000 to 2050. Based on historical data, this model provides output data including production, consumption and international trade of lithium embodied in five types of commodities. Results indicate that the amount of lithium flow in 2050 will be 13-20 times greater than that in 2015. The lithium applied in electric vehicles will account for the largest proportion of in-use stocks of lithium starting in 2022. Lithium recovery will not play a big role in reducing supply pressure until 2030. Comparing all types of lithium-containing commodities, import dependence on minerals will remain the greatest within the temporal boundary. This factor reflects a nonnegligible risk to the supply demand balance considering the high concentration of mineral import structure in China currently. Several policy recommendations are offered for the optimization of China's flow structure. On the demand side, limited capacity expansion and cutting overcapacity of downstream commodities should be under consideration to distribute lithium import more reasonably. On the supply side, the potential oversupply issues caused by low-grade scrap require further development of recycling technology.

An Effectiveness Assessment of China's WEEE Treatment Fund

Policy is essential to the management of waste electrical and electronic equipment (WEEE). In order to present valuable findings for policy improvement, we performed a quantitative effectiveness assessment of China’s WEEE treatment fund from 2012 to 2015. The achievement of the general goal of the WEEE treatment fund was evaluated with various indicators. We calculated the values of all indicators and analyzed the changes in them. The results show that the WEEE treatment fund was important in promoting WEEE collection and recycling activities and has provided great benefits in the form of resources and the environment. Moreover, the authorized enterprises also experienced progress in their development. In a word, the WEEE treatment fund was effective to some extent. However, because of the limited subsidies and other factors, the WEEE treatment fund had different effects on five categories of WEEE. We found that its approach worked best for the TV set. Although the promotional effects on the other four categories of WEEE have been increasingly significant since 2014, there is room for improvement. Fortunately, the subsidy rates have been adjusted by administrations and new subsidies were provided in 2016. As it is crucial for the effectiveness of the WEEE treatment fund, new subsidy rates should be evaluated regularly.

A survey on consumers' attitude towards storing and end of life strategies of small information and communication technology devices in Spain

This study analyses the current habits and practices towards the store, repair and second-hand purchase of small electrical and electronic devices belonging to the category of information and communication technology (ICT). To this end, a survey was designed and conducted with a representative sample size of 400 individuals through telephone interviews for the following categories: MP3/MP4, video camera, photo camera, mobile phone, tablet, e-book, laptop, hard disk drive, navigator-GPS, radio/radio alarm clock. According to the results obtained, there is a tendency to store disused small ICT devices at home. On average for all the small ICT categories analysed, 73.91% of the respondents store disused small ICT devices at home. Related to the habits towards the repair and second-hand purchase of small ICT devices, 65.5% and 87.6% of the respondents have never taken to repair and have never purchased second-hand, respectively, small ICT devices. This paper provides useful and hitherto unavailable information about the current habits of discarding and reusing ICT devices. It can be concluded that there is a need to implement awareness-raising campaigns to encourage these practices, which are necessary to reach the minimum goals established regarding preparation for reuse set out in the Directive 2012/19/EU for the category small electrical and electronic equipment.

Present status of recycling waste mobile phones in China: a review

A large number of waste mobile phones have already been generated and are being generated. Various countries around the world have all been positively exploring the way of recycling and reuse when facing such a large amount of waste mobile phones. In some countries, processing waste mobile phones has been forming a complete industrial chain, which can not only recycle waste mobile phones to reduce their negative influence on the environment but also turn waste into treasure to acquire economic benefits dramatically. However, the situation of recycling waste mobile phones in China is not going well. Waste mobile phones are not formally covered by existing regulations and policies for the waste electric and electronic equipment in China. In order to explore an appropriate system to recover waste mobile phones, the mobile phone production and the amount of waste mobile phones are introduced in this paper, and status of waste mobile phones recycling is described; then, the disposal technology of electronic waste that would be most likely to be used for processing of electronic waste in industrial applications in the near future is reviewed. Finally, rationalization proposals are put forward based on the current recovery status of waste mobile phones for the purpose of promoting the development of recycling waste mobile phones in developing countries with a special emphasis on China.

Use, Storage, and Disposal of Electronic Equipment in Switzerland

Electronic devices contain important resources, including precious and critical raw materials. For an efficient management of these resources, it is important to know where the devices are located, how long they are used and when and how they are disposed of. In this article, we explore the past and current quantities of electronic devices in the in-use stock and storage stock in Switzerland and quantify the flows between the use, storage and disposal phase with dynamic material flow analysis (MFA). Devices included are mobile phones, desktop and laptop computers, monitors, cathode ray tube and flat panel display televisions, DVD players, and headphones. The system for the dynamic MFA was developed as a cascade model dividing the use phase in first, second and further use, with each of these steps consisting of an in-use stock and a storage stock for devices. Using a customized software tool, we apply Monte Carlo simulation to systematically consider data uncertainty. The results highlight the importance of the storage stock, which accounts for 25% (in terms of mass) or 40% (in terms of pieces) of the total stock of electronic devices in 2014. Reuse and storage significantly influence the total lifetime of devices and lead to wide and positively skewed lifetime distributions.

The hibernating mobile phone: Dead storage as a barrier to efficient electronic waste recovery

Hibernation, the dead storage period when a mobile phone is still retained by the user at its end-of-life, is both a common and a significant barrier to the effective flow of time-sensitive stock value within a circular economic model. In this paper we present the findings of a survey of 181 mobile phone owners, aged between 18-25years old, living and studying in the UK, which explored mobile phone ownership, reasons for hibernation, and replacement motives. This paper also outlines and implements a novel mechanism for quantifying the mean hibernation period based on the survey findings. The results show that only 33.70% of previously owned mobile phones were returned back into the system. The average duration of ownership of mobile phones kept and still in hibernation was 4years 11months, with average use and hibernation durations of 1year 11months, and 3years respectively; on average, mobile phones that are kept by the user are hibernated for longer than they are ever actually used as primary devices. The results also indicate that mobile phone replacement is driven primarily by physical (technological, functional and absolute) obsolescence, with economic obsolescence, partly in response to the notion of being 'due an upgrade', also featuring significantly. We also identify in this paper the concept of a secondary phone, a recently replaced phone that holds a different function for the user than their primary phone but is still valued and intentionally retained by the user, and which, we conclude, should be accounted for in any reverse logistics strategy.

Estimation of obsolete cellular phones generation: A case study of China

Rapid development of electronic technique has led to decreasing lifespan of electronic products. Meanwhile, the amount of waste electrical and electronic equipment (WEEE) is rapidly growing in recent years especially in China. The generation amount of WEEE is one of the basic information for waste management. In our study, the generation of obsolete cellular phones and metals containing of cellular phones were estimated from 1997 to 2025. The future average possession in per 100 inhabitants of cellular phones was predicted using logistic model. Moreover, the lifespan distribution of cellular phones was analyzed using Weibull distribution. Meanwhile, the generation amount of obsolete cellular phones and its metals containing were estimated by using population balance model (PBM) and substance flow analysis (SFA), respectively. The estimated results indicate that the average possession in per 100 inhabitants will reach to 111.2 and 118.3 units in 2020 and 2025, respectively, which is about two times higher than the average possession in 2010. In addition, the total possession amount of cellular phones are expected to exceed 1.64 billion units in 2025. Moreover, the estimated results show that 781 million units obsolete cellular phones were generated in 2015, and the number will grow up to 877 and 937 million units in 2020 and 2025, respectively. In 2025, the total weight of annual generation amount of obsolete cellular phones will exceed 140Gg. The precious metals such as silver, gold contains in obsolete cellular phones will reach 56,250 and 28,130kg, respectively, in 2025. The obsolete cellular phones are the typical secondary metal resources especially for precious metals. In order to improve the recycling efficiency, it is necessary to establish a comprehensive system of waste management.

The situation of waste mobile phone management in developed countries and development status in China

With the rapid development of electronic industry and improvement of living standards, a large number of waste mobile phones were generated. According to statistics, approximately 400million waste mobile phones are generated each year in the world, and 25% of that are contributed by China. Irregular disposal of waste mobile phones will do great harm to environment and human health, while at the same time recycling of them has the potential for high profits. Given the enormous quantity, great harm and resource properties, developed countries have taken necessary measures to manage waste mobile phones. As the largest developing country, China has also set out to pay close attention to waste mobile phones. This paper reviewed the situation ofwaste mobile phone management in the developed countries, focused on the development of waste mobile phone management in China, and analyzed existing problems. In light of the successful experience of the developed countries, some suggestions were proposed to promote the waste mobile phone management in China and worked as a valuable reference for other countries.

Estimation of the Unregistered Inflow of Electrical and Electronic Equipment to a Domestic Market: A Case Study on Televisions in Vietnam

Waste electrical and electronic equipment (WEEE) constitutes one of the most problematic waste streams worldwide, and accurately estimating the scale of WEEE can assist in tackling its associated issues. However, obtaining an accurate estimation of WEEE remains a challenge because a share of the waste is difficult to calculate. This share stems from the administratively unregistered (so-called "invisible") inflow of electrical and electronic equipment (EEE) into the domestic market. As a first attempt to qualitatively and quantitatively investigate this invisible inflow, this study discusses the nature of this flow in detail and proposes a calculation pathway for quantifying its magnitude. The size of the invisible inflow to a domestic market (assumed equal to invisible sales) is calculated by subtracting the registered, also called "visible", sales from the total sales. The total sales are modeled, whereas the visible sales are derived from statistical data. The method is illustrated by a case study on televisions (TVs) in Vietnam. The results show that from 2002 to 2013, the invisible TV inflow contributed, on average, 15% to the total TV sales (coefficient of variation: 0.21). This average share would increase by approximately 1.0% when the maximum number of TVs used per household increased by 1.0%. However, it would decrease by 1.7% when the visible sales increased by 1.0%. Additionally, the average share of the invisible TV inflow would change from 15% to 27% when an unadjusted constant instead of an adjusted time-varying lifespan is employed. This first estimation of the invisible EEE inflow to the domestic market can be improved with additional knowledge and data in the future.

Out with the old, out with the new--The effect of transitions in TVs and monitors technology on consumption and WEEE generation in Sweden 1996-2014

The recycling of Waste Electrical and Electronic Equipment (WEEE) is important due to its content of valuable and hazardous compounds. This study investigates the case of the recent technology change within television sets (TVs) and monitors, its impact on the generation of WEEE, and the implications for the recycling industry. In particular, material flow analysis for the time series of 1996-2014 for TVs and monitors by type of technology (CRT, Plasma and LCD) in physical units is combined with empirical data on product lifespans. The number of consumed TVs and monitors has grown exponentially. As a result, despite a 3-fold reduction in the weight of the products, the weight of the corresponding WEEE is also growing exponentially. Out with the old, out with the new - a peak in WEEE from both CRT and flat-screen displays is expected during 2014-2020, due to the simultaneous obsolesce of the last wave of CRT products and the short-lived flat-screen products that substituted the CRTs. The lifespans of LCD and LED TVs were found to be three times shorter than of the CRT TVs, with many TVs discarded while still functional. This is the consequence of two events - replacement of the CRT TVs in combination with lifestyle purchases of TVs, i.e. the premature replacement of flat-screen displays with new sets with extra-large screens and/or new features. The throughput of TVs and monitors consumed has been estimated annually from 2014 until 2040, by quantity and type of device, as well as by component and material type. The annual economic value of the corresponding secondary materials, by material type, has also been estimated. The point in time when the final disposal of CRT products is likely to take place has been identified and should be noted by the recycling industry. Among the important contributions of this study to the accounting and predicting of amounts and types of WEEE are the lifespan distributions, size and weight distributions, and material composition for TVs and monitors of different technology. Directions for method application in other countries are given.

Mobile phone waste management and recycling: Views and trends

There is an enormous growth in mobile phone consumption worldwide which leads to generation of a large volume of mobile phone waste every year. The aim of this review is to give an insight on the articles on mobile phone waste management and recycling, published in scientific journals, major proceedings and books from 1999 to 2015. The major areas of research have been identified and discussed based on available literature in each research topic. It was observed that most of these articles were published during the recent years, with the number of articles increasing yearly. Material recovery and review on management options of waste are found to be the leading topics in this area. Researchers have proved that economically viable refurbishing or recycling of such waste is possible in an environmentally friendly manner. However, the literatures indicate that without proper consumer awareness, a recycling system cannot perform to its maximum efficiency. The methodologies followed and analytical techniques employed by the researchers to attain their objectives have been discussed. The graphical representations of available literature on current topic with respect to year of publication, topics and location have also been explored.

Forecasting waste compositions: A case study on plastic waste of electronic display housings

Because of the rapid succession of technological developments, the architecture and material composition of many products used in daily life have drastically changed over the last decades. As a result, well-adjusted recycling technologies need to be developed and installed to cope with these evolutions. This is essential to guarantee continued access to materials and to reduce the ecological impact of our material consumption. However, limited information is currently available on the material composition of arising waste streams and even less on how these waste streams will evolve. Therefore, this paper presents a methodology to forecast trends in the material composition of waste streams. To demonstrate the applicability and value of the proposed methodology, it is applied to forecast the evolution of plastic housing waste from flat panel display (FPD) TVs, FPD monitors, cathode ray tube (CRT) TVs and CRT monitors. The results of the presented forecasts indicate that a wide variety of plastic types and additives, such as flame retardants, are found in housings of similar products. The presented case study demonstrates that the proposed methodology allows the identification of trends in the evolution of the material composition of waste streams. In addition, it is demonstrated that the recycling sector will need to adapt its processes to deal with the increasing complexity of plastics of end-of-life electronic displays while respecting relevant directives.

Electronic waste recovery in Finland: Consumers' perceptions towards recycling and re-use of mobile phones

This paper examines consumers' awareness and perceptions towards mobile phone recycling and re-use. The results are based on a survey conducted in the city of Oulu, Finland, and analysed in the theoretical framework based on the theories of planned behaviour (TPB) and value-belief-norm (VBN). The findings indicate that consumers' awareness of the importance and existence of waste recovery system is high; however, awareness has not translated to recycling behaviour. The survey reveals that 55% of respondents have two or more unused mobile phones at homes. The more phones stored at homes, the more often reasons 'I don't know where to return' and/or 'have not got to do it yet' were mentioned. This indicates that proximity and the convenience of current waste management system are inadequate in promoting the return of small waste electrical and electronic equipment (WEEE). To facilitate re-use, and the highest level of recovery, consumers will need to be committed to return end-of-use electronics to WEEE collection centres without delays. Further, the supply and demand of refurbished mobile phones do not meet at this moment in Finland due to consumer's storing habits versus expectations of recent features under guarantee and unrealistic low prizes. The study also points out that, in order to change current storing habits of consumers, there is an explicit need for more information and awareness on mobile phone collection in Finland, especially on regarding retailers' take-back.

An in-depth literature review of the waste electrical and electronic equipment context: trends and evolution

The consumption of electrical and electronic equipment (EEE) is continuously increasing worldwide and, consequently, so is the amount of waste electrical and electronic equipment (WEEE) it generates at its end-of-life. In parallel to this growth, legislation related to this issue has been passed in different countries with the aim of improving the management of WEEE. In order to raise awareness about the situation in which the generation, composition, management or final treatment of this kind of waste currently finds itself, an extensive number of articles have been published around the world. The aim of this paper is to define and analyse the main areas of research on WEEE by offering a broader analysis of the relevant literature in this field published between 1992 and August 2014. The literature researched comprises 307 articles, which are analysed according to the topic they focus on (WEEE management, WEEE generation, WEEE characterisation, social aspects of WEEE, re-use of EEE or economic aspects of WEEE). In addition, a deeper analysis is also presented, which takes into account the temporal evolution (globally and by topic), location of the study, categories and subcategories analysed, etc.

Estimation of retired mobile phones generation in China: A comparative study on methodology

Due to the rapid development of economy and technology, China has the biggest production and possession of mobile phones around the world. In general, mobile phones have relatively short life time because the majority of users replace their mobile phones frequently. Retired mobile phones represent the most valuable electrical and electronic equipment (EEE) in the main waste stream because of such characteristics as large quantity, high reuse/recovery value and fast replacement frequency. Consequently, the huge amount of retired mobile phones in China calls for a sustainable management system. The generation estimation can provide fundamental information to construct the sustainable management system of retired mobile phones and other waste electrical and electronic equipment (WEEE). However, the reliable estimation result is difficult to get and verify. The priority aim of this paper is to provide proper estimation approach for the generation of retired mobile phones in China, by comparing some relevant methods. The results show that the sales&new method is in the highest priority in estimation of the retired mobile phones. The result of sales&new method shows that there are 47.92 million mobile phones retired in 2002, and it reached to 739.98 million in China in 2012. It presents an increasing tendency with some fluctuations clearly. Furthermore, some discussions on methodology, such as the selection of improper approach and error in the input data, are also conducted in order to improve generation estimation of retired mobile phones and other WEEE.

Overview of the WEEE Directive and Its Implementation in the Nordic Countries: National Realisations and Best Practices

Electronic devices and mobile applications have become a part of everyday life. Fast technological progress and rapid product obsolescence have led to the rapid growth of waste electrical and electronic equipment (WEEE). Due to hazardous substances and also substantial amounts of valuable materials contained in electrical and electronic equipment, the European Union has implemented Directives related to WEEE, in order to reduce negative environmental and health impacts and to improve material recovery of valuable substances from WEEE. This paper provides an overview of the WEEE Directive and its implementation to national legislations in Finland, Sweden, and Norway and, further, describes how the nationwide WEEE recovery infrastructures in the Nordic countries have been built. The Nordic WEEE management systems are evaluated from the point of resource efficiency and best practices. Evidently, the WEEE management systems as established in the Nordic countries have advantages because the WEEE collection rates in 2012 were 12 kg/inhab./year, in Finland, 16 kg/inhab./year, in Sweden, and 27 kg/ inhab./year, in Norway, despite their sparsely populated nature. The Swedish and Norwegian experiences, especially, with long history of WEEE recovery indicate that increasing consumer awareness leads to more environmentally sound behaviour and improves recovery efficiency.

Enhancing e-waste estimates: improving data quality by multivariate Input-Output Analysis

Waste electrical and electronic equipment (or e-waste) is one of the fastest growing waste streams, which encompasses a wide and increasing spectrum of products. Accurate estimation of e-waste generation is difficult, mainly due to lack of high quality data referred to market and socio-economic dynamics. This paper addresses how to enhance e-waste estimates by providing techniques to increase data quality. An advanced, flexible and multivariate Input-Output Analysis (IOA) method is proposed. It links all three pillars in IOA (product sales, stock and lifespan profiles) to construct mathematical relationships between various data points. By applying this method, the data consolidation steps can generate more accurate time-series datasets from available data pool. This can consequently increase the reliability of e-waste estimates compared to the approach without data processing. A case study in the Netherlands is used to apply the advanced IOA model. As a result, for the first time ever, complete datasets of all three variables for estimating all types of e-waste have been obtained. The result of this study also demonstrates significant disparity between various estimation models, arising from the use of data under different conditions. It shows the importance of applying multivariate approach and multiple sources to improve data quality for modelling, specifically using appropriate time-varying lifespan parameters. Following the case study, a roadmap with a procedural guideline is provided to enhance e-waste estimation studies.