A model for estimation of potential generation of waste electrical and electronic equipment in Brazil

Potential of metal recovery from printed circuit boards in Brazil

In this study, the generation of domestic waste electrical and electronic equipment (WEEE) and waste printed circuit board (WPCB) were estimated, from 2015 to 2030. Based on the number of EEE put on the Brazilian market, the possession rate in the Brazilian households and obsolescence amounts of five EEE types were estimated using time series. The results show that, between 2015 and 2030, the quantity of WEEE generated per year will increase from 131.87 kt to 195.22 kt. In this period, WPCB generation will stay around 10% of WEEE generation. Additionally, this study shows that the urban mining potential of the materials recoverable from WPCB can be an important revenue source, with environmental benefits deriving from energy savings and a reduction in CO2 emissions. The results of this study provide a quantitative basis that may help decision makers develop strategic policies for WEEE management, considering material circularity.

Identification of hazardous organic compounds in e-waste plastic using non-target and suspect screening approaches

End-of-life electric and electronic devices stand as one of the fastest growing wastes in the world and, therefore, a rapidly escalating global concern. A relevant fraction of these wastes corresponds to polymeric materials containing a plethora of chemical additives. Some of those additives fall within the category of hazardous organic compounds (HOCs). Despite the significant advances in the capabilities of analytical methods, the comprehensive characterization of WEEE plastic remains as a challenge. This research strives to identify the primary additives within WEEE polymers by implementing a non-target and suspect screening approach. Gas chromatography coupled to time-of-flight mass spectrometry (GC-QTOF-MS), using electron ionization (EI), was applied for the detection and identification of more than 300 substances in this matrix. A preliminary comparison was carried out with nominal resolution EI-MS spectra contained in the NIST17 library. BPA, flame retardants, UV-filters, PAHs, and preservatives were among the compounds detected. Fifty-one out of 300 compounds were confirmed by comparison with authentic standards. The study establishes a comprehensive database containing m/z ratios and accurate mass spectra of characteristic compounds, encompassing HOCs. Semi-quantification of the predominant additives was conducted across 48 WEEE samples collected from handling and dismantling facilities in Galicia. ABS plastic demonstrated the highest median concentrations, ranging from 0.154 to 4456 μg g-1, being brominated flame retardants and UV filters, the families presenting the highest concentrations. Internet router devices revealed the highest concentrations, containing a myriad of HOCs, such as tetrabromobisphenol A (TBBPA), tribromophenol (TBrP), triphenylphosphate (TPhP), tinuvin P and bisphenol A (BPA), most of which are restricted in Europe.

Concentrations and legislative aspects of PBDEs in plastic of waste electrical and electronic equipment in Brazil

Brominated flame retardants (BFRs) have been widely used as additives in polymeric products such as electronic and electrical equipment (EEE) to help meet fire safety regulations. However, some BFRs like polybrominated diphenyl ethers (PBDEs), are now listed under the Stockholm Convention on persistent organic pollutants (POPs) and banned in many countries, due to their adverse health impacts, environmental persistence, and capacity for bioaccumulation and long-range atmospheric transport. Despite this, in Brazil, only a few studies exist of the presence of these contaminants in the environment, and even fewer in waste EEE (WEEE). Against this backdrop, this study measured the presence of PBDEs in samples (n = 159) of WEEE in the metropolitan region of Sorocaba, Sao Paulo, Brazil. PBDEs were detected in 149 samples, with concentrations in 18 samples exceeding the European Union's Low POP Content Limit (LPCL) of 1000 mg/kg. Decabromodiphenyl ether (BDE-209) was the congener present at the highest concentration in most samples, with those of other PBDEs such as BDE-47 much lower. In general, samples containing >1000 mg/kg are those categorised as display items and miscellaneous EEE (n = 15.27 %), comprising: parts from cathode ray tube TVs (n = 11), audio systems (n = 2), and LCD TVs (n = 2). In addition, in 5 % (n = 3) of IT and telecommunications equipment samples (computer parts) PBDE concentrations exceeded 1000 mg/kg. Our results show the need for greater control and monitoring of the presence of these pollutants in WEEE before recycling and final disposal, to prevent PBDEs entering the recycling stream.

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.

Analysis of national policies for Circular Economy transitions: Modelling and simulating the Brazilian industrial agreement for electrical and electronic equipment

Public policies, incentives, and infrastructure are top-down instruments that can align stakeholders' roles and expectations for Circular Economy (CE) transitions, but it is crucial to analyse the possible effects of such instruments before implementation. This research investigates the Brazilian Industrial Agreement for Electrical and Electronic Equipment (BIAEEE) that governs the responsibilities and targets for nationwide collection and treatment of Waste from Electrical and Electronic Equipment (WEEE). A system dynamics simulation model is adapted for the use of smartphones in Brazil, and interventions focused on the collection of end-of-life products are examined against the BIAEEE targets. Twelve policy scenarios investigate three aspects of EEE collection: coverage increase, distribution of collection points and rewards. All scenarios show improvement in the EEE collection, but only one meets the BIAEEE targets. This research demonstrates how modelling and simulation can inform strategic decision-making in public policies for CE transitions.

Leaching kinetics and interface reaction of LiNi0.6Co0.2Mn0.2O2 materials from spent LIBs using GKB as reductant

The application of green reductant is signification to recycling of cathode materials from spent lithium ions batteries. Here, ginkgo biloba was developed for enhancing leaching of spent LiNi_0.6Co_0.2Mn_0.2O₂ materials with systematically analysis of leaching kinetics and interface reaction. The leaching efficiencies of Ni, Mn, Co, and Li reach respectively 98.65 %, 98.25 %, 98.41 % and 99.99 % under optimal condition of 1.8 mol/L H₂SO₄ concentration, 9 g/L ginkgo biloba, 80 °C leaching temperature, 40 min time and 15 g/L pulp density. The apparent activation energies for leaching of Ni, Co, Mn and Li determined as 74.63, 79.33, 73.14 and 23.43 kJ/mol, respectively, indicates that the leaching process was controlled by the surface chemical reaction during the leaching process. Meanwhile, the regenerated material with better electrochemical performance was obtained by co-precipitation and calcination from leachate. Finally, the process is environmental friendly and economical feasible for recycling of spent lithium-ion batteries.

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.

Bioleaching metals from waste electrical and electronic equipment (WEEE) by Aspergillus niger: a review

In the twenty-first century, the increasing demand for electrical and electronic equipment (EEE) has caused its quick update and the shortening of its service life span. As a consequence, a large number of waste electrical and electronic equipment (WEEE) needs to be processed and recycled. As an environmentally friendly method, biometallurgy has received extensive attention in the disposal of WEEE in recent years. Aspergillus niger is an acid-producing fungus with a potential applicability to improve metals' recycling efficiency. This review article describes the latest statistical status of WEEE and presents the latest progress of various metallurgical methods involved in WEEE recycling for metal recovery. Moreover, based on the summary and comparison towards studies have been reported for bioleaching metals from WEEE by A. niger, the bioleaching mechanisms and the bioleaching methods are explained, as well as the effects of process parameters on the performance of the bioleaching process are also discussed. Some insights and perspectives are provided for A. niger to be applied to industrial processing scale.

Electronic Waste, an Environmental Problem Exported to Developing Countries: The GOOD, the BAD and the UGLY

Electronic waste (e-waste) is a rapidly developing environmental problem particularly for the most developed countries. There are technological solutions for processing it, but these are costly, and the cheaper option for most developed countries has been to export most of the waste to less developed countries. There are various laws and policies for regulating the processing of e-waste at different governance scales such as the international Basel Convention, the regional Bamoko Convention, and various national laws. However, many of the regulations are not fully implemented and there is substantial financial pressure to maintain the jobs created for processing e-waste. Mexico, Brazil, Ghana Nigeria, India, and China have been selected for a more detailed study of the transboundary movements of e-waste. This includes a systematic review of existing literature, the application of the Driver, Pressure, State, Impact, Response (DPSIR) framework for analysing complex problems associated with social ecological systems, and the application of the Life Cycle Assessment (LCA) for evaluating the environmental impact of electronic devices from their manufacture through to their final disposal. Japan, Italy, Switzerland, and Norway have been selected for the LCA to show how e-waste is diverted to developing countries, as there is not sufficient data available for the assessment from the selected developing countries. GOOD, BAD and UGLY outcomes have been identified from this study: the GOOD is the creation of jobs and the use of e-waste as a source of raw materials; the BAD is the exacerbation of the already poor environmental conditions in developing countries; the UGLY is the negative impact on the health of workers processing e-waste due to a wide range of toxic components in this waste. There are a number of management options that are available to reduce the impact of the BAD and the UGLY, such as adopting the concept of a circular economy, urban mining, reducing loopholes and improving existing policies and regulations, as well as reducing the disparity in income between the top and bottom of the management hierarchy for e-waste disposal. The overarching message is a request for developed countries to help developing countries in the fight against e-waste, rather than exporting their environmental problems to these poorer regions.

Assessment of the economic recycling potential of a glycolysis treatment of rigid polyurethane foam waste: A case study from Thailand

This research assessed the economic feasibility of recovering polyol from rigid polyurethane foam (RPUF) waste, collected from dismantled, discarded refrigerators, by a single-phase glycolysis recycling process using domestic crude glycerol (a byproduct of biodiesel production) as a transesterification agent. The study, conducted in Thailand, took into account benefits from the added value of the recovered product, the investment and related operating costs of the process, demand (the need for the recovered product) and supply (the amount of RPUF waste). The results showed that the production of recovered polyol from RPUF waste is economically feasible, with a net present value of 1,113,018 USD, an internal rate of return (IRR) of 22.9%, and a payback period of 4.4 years. Due to the high IRR, project investment should be attractive to both the government and private sector investors. In addition, a sensitivity analysis was conducted to assess the economic resilience of the process to uncertainties in key factors, including the prices of the machinery, recovered polyol, crude glycerol and stannous octoate, and the amount of RPUF waste available. The sensitivity analysis showed that the economic feasibility was most sensitive to the price of the recovered polyol, followed by the amount of RPUF waste and the prices of the machinery, crude glycerol and stannous octoate. Based on these results, technological, operational, financial, and regulatory policy recommendations were also presented.

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.

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.

Domestic flow of e-waste in São Paulo, Brazil: Characterization to support public policies

Understanding the domestic flow of e-waste is essential for efficient waste management in urban contexts. However, diagnosis of domestic e-waste flow is complex due to its diffuse generation and dependence on consumer behavior. Here, we characterized domestic e-waste flow in São Paulo, Brazil (a megacity with roughly 11 million inhabitants in 3.5 million households), describing the stages of product acquisition, out-of-use storage, and end-of-life destination, via a population-based cross-sectional study using a statistically representative sample. We conducted household interviews using a structured questionnaire, with questions on characteristics, quantities, and behaviors of acquisition, replacement, storage, repair, and destination for 26 electric and electronic equipment (EEE) categories. Each household had on average 21 EEE (95% confidence interval [CI]: 19.7-21.7), of which 18 were in use and 3 were out-of-use. Out-of-use storage was common, occurring in 72.6% of households. Discarded EEE (i.e., e-waste) was destined for intended reuse (59.5%; 95% CI: 57.4-61.5%), recycling (20.4%; 95% CI: 18.8-22.1%), and, particularly for small EEE, municipal waste (16.0%; 95% CI: 14.5-17.6%). Other aspects of domestic e-waste flow (e.g., place and time of acquisition, second-hand acquisition, donation, intention to repair damaged EEE, and storage) were quantified and related to actions for public policies. This research shows that household surveys are useful for obtaining primary data to verify consumer behavior toward EEE. We expect the findings of this study to support decision-making for public policies related to e-waste management, particularly in countries where reverse logistics systems are in the initial phase of implementation.

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.

Factors influencing community participation in the management of household electronic waste in West Surabaya, Indonesia

The objective of the study was to determine the factors that influence community participation in the management of electronic waste. A survey of community willingness to participate in the management of electronic waste was conducted using questionnaires. Survey locations covered western areas of the city of Surabaya, Indonesia, where 238 respondents were selected proportionally from high-, medium-, and low-income groups during 2014. The group was divided by land and building taxes, which represents the socio-economic conditions of the community. Processing and statistical data analysis were performed with structural equation modeling. Results showed that one factor influencing the willingness of communities to manage e-waste was behavior, while factors influencing the willingness of communities to pay more included behavior, attitudes, and knowledge. Strategies to increase community participation can be applied through education and community assistance, the provision of recycling facilities, and applied regulations about e-waste management and extended producer responsibility.

Material flow analysis (MFA) as a strategic tool in E-waste management: Applications, trends and future directions

Material flow analysis (MFA) is one of the most widely accepted and utilized tools in the industrial-ecology discipline, that measures the input-output materials and examines the pathways and flux of each material flow within the whole system. The application of MFA in e-waste management has recently increased and quite a few academic articles have been published on this issue providing decision support at the policy level. However, there is a need to understand the dynamics of MFA methodology, the data requirements (as well as the data sources used in the previous studies) and the lessons learnt from the studies, so that countries where such an E-waste-MFA study has not yet been performed can apply the international experience of such an emerging research technique. This comprehensive review article presents the recent applications, trends, characteristics, research gaps and challenges of the MFA method that may help e-waste management with an overview of the need for a such tool to be applied. A country-wise analysis is presented and MFA models complemented by various associated methods are summarized with national-level, regional-level, product-level, and element-level assessment. The highlighted future research perspectives discussed in this study will help to analyze e-waste management systems more critically, including the hidden and known flows of waste products and associated materials, economic assessment of material recovery and the role of responsible authorities. This invaluable contribution will help future researchers, particularly from the data collection techniques and previously applied MFA models complemented by various associated methods.

Estimation of electronic waste using optimized multivariate grey models

Rapid and revolutionary changes in technology and rising demand for consumer electronics have led to staggering rates of accumulation of electrical and electronic equipment waste, viz., WEEE or e-waste. Consequently, e-waste has become one of the fastest growing municipal solid waste streams in the United States making its efficient management crucial in supporting the efforts to create and sustain green cities. Accurate estimations on the amount of e-waste might help in increasing the efficiency of waste collection, recycling and disposal operations that have become more complicated and unpredictable. Early work focusing on prediction of e-waste generation includes a wide range of methodologies. Among these, grey forecasting models have drawn attention due to their capability to provide meaningful results with relatively small-sized or limited data. The performance of grey models heavily rely on their parameters. The purpose of this study is to present a novel forecasting technique for e-waste predictions with multiple inputs in presence of limited historical data. The proposed nonlinear grey Bernoulli model with convolution integral NBGMC(1,n) improved by Particle Swarm Optimization (PSO) demonstrates superior accuracy over alternative forecasting models. The proposed model and its findings are delineated with the help of a case study utilizing Washington State e-waste data. The results indicate that population density has a major impact on the generated e-waste followed by household income level. The findings also show that the e-waste generation forms a saturated distribution in Washington State. These results can help decision makers plan for more effective reverse logistics infrastructures that would ensure proper collection, recycling and disposal of e-waste.

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.

Atmospheric Concentrations of New Persistent Organic Pollutants and Emerging Chemicals of Concern in the Group of Latin America and Caribbean (GRULAC) Region

A special initiative was run by the Global Atmospheric Passive Sampling (GAPS) Network to provide atmospheric data on a range of emerging chemicals of concern and candidate and new persistent organic pollutants in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale data for a range of flame retardants (FRs) including polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs), and a range of alternative FRs (novel FRs) are reported over 2 years of sampling with low detection frequencies of the novel FRs. Atmospheric concentrations of the OPEs were an order of magnitude higher than all other FRs, with similar profiles at all sites. Regional-scale background concentrations of the poly- and perfluoroalkyl substances (PFAS), including the neutral PFAS (n-PFAS) and perfluoroalkyl acids (PFAAs), and the volatile methyl siloxanes (VMS) are also reported. Ethyl perfluorooctane sulfonamide (EtFOSA) was detected at highly elevated concentrations in Brazil and Colombia, in line with the use of the pesticide sulfluramid in this region. Similar concentrations of the perfluoroalkyl sulfonates (PFAS) were detected throughout the GRULAC region regardless of location type, and the VMS concentrations in air increased with the population density of sampling locations. This is the first report of atmospheric concentrations of the PFAAs and VMS from this region.

Status of electronic waste recycling techniques: a review

The increasing use of electrical and electronic equipment leads to a huge generation of electronic waste (e-waste). It is the fastest growing waste stream in the world. Almost all electrical and electronic equipment contain printed circuit boards as an essential part. Improper handling of these electronic wastes could bring serious risk to human health and the environment. On the other hand, proper handling of this waste requires a sound management strategy for awareness, collection, recycling, and reuse. Nowadays, the effective recycling of this type of waste has been considered as a main challenge for any society. Printed circuit boards (PCBs), which are the base of many electronic industries, are rich in valuable heavy metals and toxic halogenated organic substances. In this review, the composition of different PCBs and their harmful effects are discussed. Various techniques in common use for recycling the most important metals from the metallic fractions of e-waste are illustrated. The recovery of metals from e-waste material after physical separation through pyrometallurgical, hydrometallurgical, or biohydrometallurgical routes is also discussed, along with alternative uses of non-metallic fraction. The data are explained and compared with the current e-waste management efforts done in Egypt. Future perspectives and challenges facing Egypt for proper e-waste recycling are also discussed.

E-waste management and sustainability: a case study in Brazil

The advancement of technology and development of new electronic and electrical equipment with a reduced life cycle has increased the need for the disposal of them (called Waste of Electric and Electronic Equipment or simply e-waste) due to defects presented during use, replacement of obsolete equipment, and ease of acquisition of new equipment. There is a lack of consumer awareness regarding the use, handling storage, and disposal of this equipment. In Brazil, the disposal of post-consumer waste is regulated by the National Solid Waste Policy, established by Law No. 12305 and regulated on the 23rd December 2010. Under this legislation, manufacturers and importers are required to perform a project for the Reverse Logistics of e-waste, though its implementation is not well defined. This work focuses on the verification of the sustainability of reverse logistics suggested by the legislation and the mandatory points, evaluating its costs and the possible financial gain with recycling of the waste. The management of reverse logistics and recycling of waste electrical and electronic equipment, or simply recycling of e-waste, as suggested by the government, will be the responsibility of the managing organization to be formed by the manufacturers/importers in Brazil.

Generation of domestic waste electrical and electronic equipment on Fernando de Noronha Island: qualitative and quantitative aspects

The accelerated growth trajectory of waste electrical and electronic equipment (WEEE) is a matter of concern for governments worldwide. In developing countries, the problem is more complex because municipal waste management is still a challenge for municipalities. Fernando de Noronha Island, an environmentally protected area, has a transfer station for solid waste before it is sent to the final destination abroad, which is different waste management model to most urban areas. In order to check the specifics of management of WEEE, this study aimed to qualitatively and quantitatively evaluate the generation of this type of waste on the main island of Fernando de Noronha, taking into consideration aspects related to consumption habits and handling of waste. During the in situ research, a questionnaire was applied to a sample of 83 households. The results provide a picture of the generation of WEEE for a period of 1 year, when a production of 1.3 tons of WEEE was estimated. Relationships between education level and monthly income and between education level and number of plasma/LCD TVs and washing machines were confirmed. Another important result is that only two socioeconomic variables (monthly income and education level) are related to two recycling behavior variables. In addition, the population and government treat WEEE as ordinary waste, ignoring its contaminant potential. Despite the existence of relevant legislation concerning the treatment and disposal of WEEE, additional efforts will be required by the government in order to properly manage this type of waste on the island.

Technologies and decision support systems to aid solid-waste management: a systematic review

Population growth associated with population migration to urban areas and industrial development have led to a consumption relation that results in environmental, social, and economic problems. With respect to the environment, a critical concern is the lack of control and the inadequate management of the solid waste generated in urban centers. Among the challenges are proper waste-collection management, treatment, and disposal, with an emphasis on sustainable management. This paper presents a systematic review on scientific publications concerning decision support systems applied to Solid Waste Management (SWM) using ICTs and OR in the period of 2010-2013. A statistical analysis of the eighty-seven most relevant publications is presented, encompassing the ICTs and OR methods adopted in SWM, the processes of solid-waste management where they were adopted, and which countries are investigating solutions for the management of solid waste. A detailed discussion on how the ICTs and OR methods have been combined in the solutions was also presented. The analysis and discussion provided aims to help researchers and managers to gather insights on technologies/methods suitable the SWM challenges they have at hand, and on gaps that can be explored regarding technologies/methods that could be useful as well as the processes in SWM that currently do not benefit from using ICTs and OR methods.

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.

Sustainability assessment and prioritisation of e-waste management options in Brazil

Brazil has an increasing rate of e-waste generation, but there are currently few adequate management systems in operation, with the largest share of Waste Electrical and Electronic Equipment (WEEE) going to landfill sites or entering informal chains. The National Solid Waste Policy (2010) enforces the implementation of reverse logistics systems under the shared responsibility of consumers, companies and governments. The objective of this paper is to assess sustainability and prioritise system alternatives for potential implementation in the metropolitan region of Rio de Janeiro. Sustainability criteria and decision alternatives were defined by elicitation of stakeholders. The adopted multicriteria approach combines Life Cycle Assessment with qualitative evaluations by a small sample of regional experts with knowledge of the problem. The recommended system consists of a hybrid WEEE collection scheme with delivery points at shops, metro stations and neighbourhood centres; a pre-treatment phase with the involvement of private companies, cooperatives and social enterprises; and full recycling of all components in the country.

Disassembly properties and material characterisation of household small waste electric and electronic equipment

This paper is focused on characterising small waste electric and electronic equipment, specifically small household appliances, from two different points of views: disassembly properties and material identification. The sample for this characterisation was obtained from a selective collection campaign organised in Castellón de la Plana (Spain). A total amount of 833.7kg (749 units) of small waste electric and electronic equipment was collected, of which 23.3% by weight and 22.4% by units belonged to the subcategory household equipment. This subcategory, composed of appliances such as vacuum cleaners, toasters, sandwich makers, hand blenders, juicers, coffee makers, hairdryers, scales, irons and heaters, was first disassembled in order to analyse different aspects of the disassembly process for each equipment type: type of joints, ease of identification of materials, ease of access to joints for extracting components, ease of separation of components from the whole, uniformity of tools needed for the disassembly process and possibility of reassembly after disassembly. Results show that the most common joints used in these equipment types are snap-fits and screws, although some permanent joints have also been identified. Next, the material composition of each component of each appliance belonging to each equipment type was identified visually and with additional mechanical trials and testing. It can be observed that plastic and electric/electronic components are present in all the equipment types analysed and are also the material fractions that appear with higher percentages in the material composition: 41.1wt% and 39.1wt% for the plastic fraction and electric/electronic components, respectively. The most common plastics are: polypropylene (PP), acrylonitrile butadiene styrene (ABS) and polycarbonate (PC), while the most common electric/electronic components are: cable, plug and printed circuit boards. Results also show that disassembly properties and material characterisation vary widely from one equipment type to another.

Recovery of cobalt from spent lithium-ion batteries using supercritical carbon dioxide extraction

Continuing technological development decreases the useful lifetime of electronic equipment, resulting in the generation of waste and the need for new and more efficient recycling processes. The objective of this work is to study the effectiveness of supercritical fluids for the leaching of cobalt contained in lithium-ion batteries (LIBs). For comparative purposes, leaching tests are performed with supercritical CO2 and co-solvents, as well as under conventional conditions. In both cases, sulfuric acid and H2O2 are used as reagents. The solution obtained from the supercritical leaching is processed using electrowinning in order to recover the cobalt. The results show that at atmospheric pressure, cobalt leaching is favored by increasing the amount of H2O2 (from 0 to 8% v/v). The use of supercritical conditions enable extraction of more than 95wt% of the cobalt, with reduction of the reaction time from 60min (the time employed in leaching at atmospheric pressure) to 5min, and a reduction in the concentration of H2O2 required from 8 to 4% (v/v). Electrowinning using a leach solution achieve a current efficiency of 96% and a deposit with cobalt concentration of 99.5wt%.

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.

Uncovering the Recycling Potential of "New" WEEE in China

Newly defined categories of WEEE have increased the types of China's regulated WEEE from 5 to 14. Identification of the amounts and valuable-resource components of the "new" WEEE generated is critical to solving the e-waste problem, for both governmental policy decisions and recycling enterprise expansions. This study first estimates and predicts China's new WEEE generation for the period of 2010-2030 using material flow analysis and the lifespan model of the Weibull distribution, then determines the amounts of valuable resources (e.g., base materials, precious metals, and rare-earth minerals) encased annually in WEEE, and their dynamic transfer from in-use stock to waste. Main findings include the following: (i) China will generate 15.5 and 28.4 million tons WEEE in 2020 and 2030, respectively, and has already overtaken the U.S. to become the world's leading producer of e-waste; (ii) among all the types of WEEE, air conditioners, desktop personal computers, refrigerators, and washing machines contribute over 70% of total WEEE by weight. The two categories of EEE-electronic devices and electrical appliances-each contribute about half of total WEEE by weight; (iii) more and more valuable resources have been transferred from in-use products to WEEE, significantly enhancing the recycling potential of WEEE from an economic perspective; and (iv) WEEE recycling potential has been evolving from ∼16 (10-22) billion US$ in 2010, to an anticipated ∼42 (26-58) billion US$ in 2020 and ∼73.4 (44.5-103.4) billion US$ by 2030. All the obtained results can improve the knowledge base for closing the loop of WEEE recycling, and contribute to governmental policy making and the recycling industry's business development.

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.

Waste electrical and electronic equipment (WEEE) estimation: A case study of Ahvaz City, Iran

The development of new technologies and the increasing consumption of electronic and electrical equipment have led to increased generation of e-waste in the municipal waste streams. This waste due to the presence of hazardous substances in its composition needs specific attention and management. The present study was carried out in Ahvaz metropolis using a survey method in 2011. For estimating the amount of waste electrical and electronic equipment (WEEE) generated, the "use and consumption" method was used. In order to determine the amounts of the electrical and electronic equipment that were used and their lifetime, and for investigating the current status of e-waste management in Ahvaz, an appropriate questionnaire was devised. In 2011, the total number of discarded electronic items was 2,157,742 units. According to the average weight of the equipment, the total generation of e-waste was 9952.25 metric tons per year and was 9.95 kg per capita per year. The highest e-waste generated was related to air conditioners, with 3125.36 metric tons per year, followed by the wastes from refrigerators and freezers, washing machines, and televisions. The wastes from desktop computers and laptops were 418 and 63 metric tons/year, respectively, and the corresponding values per capita were 0.42 and 0.063 kg, respectively. These results also showed that 10 tons fixed phones, 25 tons mobile phones, and by considering an average lifetime of 3 years for each lamp about 320 tons lamps were generated as e-waste in Ahvaz in the year 2011. Based on this study, currently there is not an integrated system for proper management of WEEE in Ahvaz, and this waste stream is collected and disposed of with other municipal waste. Some measures, including a specific collection system, recycling of valuable substances, and proper treatment and disposal, should be done about such waste.

IMPLICATIONS

Ahvaz is one of the most important economic centers of Iran, and to the best of our knowledge, no study has been carried out to estimate the generation of waste electrical and electronic equipment (WEEE) in this city. Therefore, the authors estimated the generation of the WEEE by the "use and consumption" method. The results of this study can be useful not only for decision-making organizations of Ahvaz to manage and recycle this type of waste but also can be used as a method to estimate the generation of e-waste in different locations of the world, especially in places where the generation of such waste could be a risk to human health and the environment.

Children's health in Latin America: the influence of environmental exposures

BACKGROUND

Chronic diseases are increasing among children in Latin America.

OBJECTIVE AND METHODS

To examine environmental risk factors for chronic disease in Latin American children and to develop a strategic initiative for control of these exposures, the World Health Organization (WHO) including the Pan American Health Organization (PAHO), the Collegium Ramazzini, and Latin American scientists reviewed regional and relevant global data.

RESULTS

Industrial development and urbanization are proceeding rapidly in Latin America, and environmental pollution has become widespread. Environmental threats to children's health include traditional hazards such as indoor air pollution and drinking-water contamination; the newer hazards of urban air pollution; toxic chemicals such as lead, asbestos, mercury, arsenic, and pesticides; hazardous and electronic waste; and climate change. The mix of traditional and modern hazards varies greatly across and within countries reflecting industrialization, urbanization, and socioeconomic forces.

CONCLUSIONS

To control environmental threats to children's health in Latin America, WHO, including PAHO, will focus on the most highly prevalent and serious hazards-indoor and outdoor air pollution, water pollution, and toxic chemicals. Strategies for controlling these hazards include developing tracking data on regional trends in children's environmental health (CEH), building a network of Collaborating Centres, promoting biomedical research in CEH, building regional capacity, supporting development of evidence-based prevention policies, studying the economic costs of chronic diseases in children, and developing platforms for dialogue with relevant stakeholders.

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.

Analysis of Material and Information Flows and Formulation of an ICT Waste Management Model

The generation and accumulation of waste of electrical and electronic equipment (WEEE) is growing fast, becoming one of the most complex waste streams the modern world faces. The effective and efficient management of this waste stream raises the interest of the global scientific and business community. The purpose of this paper is to analyze the flow in an e-waste management system, present the main processes included and detect the information procedures that affect the operation of the system. For its research, first a detailed literature review is presented and second the critical information flows are analyzed. The findings indicate five critical informational procedures of managerial concern: (a) defining the infrastructure, technological systems, and investments that are needed to optimize an e-waste management network, (b) minimizing the total cost of the e-waste management system, (c) estimating ICT waste quantities as precisely as possible, (d) selecting the appropriate strategy for ICT waste treatment, and (e) redesigning the IT and telecommunication products in order to improve their recycling characteristics. The study concludes with the formulation and presentation of a material and information flow diagram of ICT waste management system.

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.