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1.
Environ Monit Assess ; 193(7): 416, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34120239

RESUMO

Spatial variations and mobility of mercury (Hg) and Hg associations with other potentially toxic elements (PTEs) were studied in soil samples from Alaba, the largest e-waste recycling site in Nigeria and West Africa. Total Hg concentration was determined in surface soil samples from various locations using cold vapour atomic absorption spectrometry (CVAAS) following microwave-assisted acid extraction, while sequential extraction was used to determine operationally defined mobility. The concentrations of the PTEs arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) metals were determined using inductively coupled plasma mass spectrometry (ICP-MS) following microwave-assisted digestion with aqua regia. Total Hg concentration ranged from < 0.07 to 624 mg/kg and was largely dependent on the nature and intensity of e-waste recycling activities carried out. Mobile forms of Hg, which may be HgO (a known component of some forms of e-waste), accounted for between 3.2 and 23% of the total Hg concentration, and were observed to decrease with increasing organic matter (OM). Non-mobile forms accounted for >74% of the total Hg content. In the main recycling area, soil concentrations of Cd, Cd, Cu, Hg, Mn, Ni, Pb and Zn were above soil guideline values (Environment Agency in Science Report, 2009; Kamunda et al., 2016). Strong associations were observed between Hg and other PTEs (except for Fe and Zn) with the correlational coefficient ranging from 0.731 with Cr to 0.990 with As in April, but these correlations decreased in June except for Fe. Hazard quotient values > 1 at two locations suggest that Hg may pose health threats to people working at the e-waste recycling site. It is therefore recommended that workers should be investigated for symptoms of Hg exposure.


Assuntos
Resíduo Eletrônico , Mercúrio , Metais Pesados , Poluentes do Solo , África Ocidental , Monitoramento Ambiental , Humanos , Mercúrio/análise , Metais Pesados/análise , Nigéria , Medição de Risco , Solo , Poluentes do Solo/análise
2.
Environ Sci Technol ; 55(12): 8203-8214, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34081443

RESUMO

Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.


Assuntos
Resíduo Eletrônico , Mercúrio , Nanopartículas , Taquicardia por Reentrada no Nó Atrioventricular , Idoso , Arritmias Cardíacas/induzido quimicamente , Nó Atrioventricular , Humanos , Resíduos Industriais , México , Titânio
3.
Chemosphere ; 279: 130862, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134434

RESUMO

Lead (Pb) entering the body through different channels can damage the function of intestinal mucosal barrier and cause the body stressful inflammatory response to enhance. This study conducted a cross-sectional study to investigate the effects of Pb exposure on intestinal permeability in children by measuring the level of bacterial endotoxin and index of inflammatory cell types in peripheral blood. From November to December 2018, we recruited 187 participants aged 3-6 years by stratified randomization, from an electronic-waste-exposed group (n = 82) and a referent group (n = 105). General demographic information, past history of the digestive system in child, and family situation were informed by children's guardians with questionnaires. Children in the exposed group showed lower weight, height, and body mass index while more diarrhea in a month. Blood Pb and plasma endotoxin were elevated in exposed children than referent children and the positive relationship between them was shown in all children [B (95% CI): 0.072 (0.008, 0.137), P = 0.033]. Peripheral monocyte counts and leukotriene B4 (LTB4) levels were significantly increased in the exposed group. Endotoxin levels were positively correlated with neutrophils, monocytes, and LTB4 [B (95% CI): 0.054 (0.015, 0.093), 0.018 (0.005, 0.031), and 0.049 (0.011, 0.087), respectively, P < 0.05]. To sum up, the exposed children showed lower physical growth levels, poorer gut health, and increased intestinal permeability, which was related to high blood Pb and peripheral inflammatory indices. These results suggest the possible adverse impact of environmental Pb exposure on the intestinal health of children.


Assuntos
Resíduo Eletrônico , Criança , Estudos Transversais , Resíduo Eletrônico/análise , Endotoxinas/toxicidade , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Chumbo/toxicidade , Permeabilidade , Reciclagem
4.
J Environ Manage ; 291: 112748, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33971514

RESUMO

Bimetallic (Ag-Pd/α-Al2O3) catalysts are essentially applied to naptha-cracking process with a controlled CO2 emission. After losing the catalytic properties in long run, the landfilling disposal of spent catalysts poses severe stress to the environment and deprivation of precious metals. Therefore, an innovative solvo-chemical recycling approach that involving the solid-liquid and liquid-liquid mass transfer phenomena was studied. The parametric variations for dissolving precious metals yielded >98% efficiency at a lixiviant concentration, 2.0 mol L-1 HCl; pulp density, 20% (wt./vol.); agitation speed, 300 rpm, temperature, 90 °C, and duration, 60 min. The activation energy of silver (6.9 kJ mol-1) and palladium (11.9 kJ mol-1) leaching indicated that the process was governed by a diffusion-controlled mechanism. Subsequently, silver and palladium were separated using 0.15 mol L-1 LIX 84-I at different acid concentration that yielding the maximum separation factor (ß(Ag/Pd) = 12,501) at 2.0 mol L-1 HCl. Stripping of separately (Ag/Pd)-loaded organic solutions with different solutions of HNO3, (NH4)2SO4, and CH4N2S showed higher affinity for thiourea, yielding 56%, 38%, and 87% efficiency, respectively. Thus the counter-current extraction at an organic-to-aqueous (O:A) ratio of 1:2.5 and stripping with 0.5 mol L-1 CH4N2S at an O:A ratio of 2:1 yielded a five-fold enrich solutions of precious metals (75.2 mg L-1 Ag and 188.5 mg L-1 Pd) with a purity of >99.9%. The process essentially aims to Goal 12 under the United Nations' Sustainable Development Goals for sustainable recycling of industrial wastes consequently conserving the natural mineral reserves.


Assuntos
Resíduo Eletrônico , Prata , Catálise , Resíduo Eletrônico/análise , Resíduos Industriais , Paládio , Reciclagem
5.
J Environ Manage ; 290: 112373, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33932756

RESUMO

The rapid consumption of advanced e-products has intensified problems for the linear economy; constantly diminishing natural resources employed in production processes have created a need of recycle and reuse. Although the transition to a circular economy proposes to end the loop of e-products, it needs the application of processes such as urban mining to recover resources as secondary raw material. The present study intends to examine the issues and challenges of electronic waste urban mining (EWUM) in India that need to be assessed for the development of a sustainable economy. To accomplish this, the current study employs integrated Multi-Criteria-Decision making methods (MCDM). Step-Wise Weight Assessment Ratio Analysis (SWARA) is used to prioritize issues and their possible solutions with Weighted Assessment Sum Product Assessment (WASPAS) methods introduced to explore these challenges and provide solutions for managing EWUM. There is an immediate need to acknowledge the issues confronted by stakeholders in urban mining processes for successful transition to a circular economy. A better understanding of the issues will help policy makers and decision makers to implement best practices to enhance the urban mining process in India. This study has shown that socio-economic (SE) issues are the most critical issues in EWUM in India. The possible solutions that would have most impact are to enhance awareness campaigns for people to educate themselves regarding e-waste, train staff to handle safe disposal of e-waste and produce eco-friendly electronic products.


Assuntos
Resíduo Eletrônico , Gerenciamento de Resíduos , Humanos , Índia , Mineração , Reciclagem
6.
Waste Manag ; 126: 497-507, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33838389

RESUMO

The complex composition of waste electrical and electronic equipment (WEEE) plastics represents a challenge during post-consumption plastic recycling. A single WEEE category, e.g. large household appliances (LHA), can contain several different plastic types with overlapping material properties, making the sorting of individual plastics a challenge. Significant increases in plastic recovery rates can be expected by clustering product categories, as clustering can avoid mixing of non-compatible plastics with overlapping material properties. For this purpose, a life cycle assessment (LCA) is conducted to investigate the influence of different clustering strategies on the environmental performance of waste treatment and the production of recycled plastic from LHA waste stream. To assure comparability between waste treatment scenarios a system expansion approach is applied, and to allocate the burden of shared processes over the first and second use cycle of the material partitioning is applied. Results show that an increased separation of product clusters by plastic type can improve the plastic recovery rate from 5.8% to 47.1% and reduce the overall environmental impact, quantified with the ReCiPe (2016) method, by up to 23%. The environmental impacts of using recycled plastics from LHA waste can be reduced by 27 to 38% compared to single-use plastic. The holistic approach used in this study demonstrates (1) the potential benefits of implementing product clustering strategies for LHA plastic recycling, (2) the relevance of different allocation procedures when integrating recycling into an LCA, (3) the importance of using less virgin material and avoiding final waste treatment, and (4) the limitation of the recycling system to reduce the environmental burden associated with products.


Assuntos
Resíduo Eletrônico , Utensílios Domésticos , Gerenciamento de Resíduos , Análise por Conglomerados , Conservação dos Recursos Naturais , Plásticos , Reciclagem
7.
Waste Manag ; 126: 517-526, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33839403

RESUMO

The efficient recycling of spent anode material (SAM) from spent lithium-ion batteries (LIBs) is generally critical in terms of electronic waste recyclingas well as increasing resource shortage and environmental problems. This research reported a novel and green method to recycle lithium, copper foil, and graphite from SAM by water leaching treatment. The results indicated that 100% of graphite was exfoliated from the anode material and 92.82% leaching efficiency of lithium was obtained under the optimal conditions of 80 °C, 60 g/L, 300 rpm, and 60 min, respectively. This finding revealed that the SAM got a full liberation characteristic due to the removal of binder, which produced an ideal leaching lithium efficiency rivaling the acids' performance. The mechanism of the liberation of SAM and lithium leaching is presented based on the analysis of results. The graphite was purified and recovered after water leaching treatment. Besides, lithium was recovered in the form of lithium carbonate (Li2CO3), and the copper foil was recovered in a sheet. This study endeavors to develop an economical and environmentally feasible plan to recycle graphite, copper, and lithium from SAM.


Assuntos
Resíduo Eletrônico , Lítio , Fontes de Energia Elétrica , Eletrodos , Reciclagem
8.
Front Public Health ; 9: 657784, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33889561

RESUMO

Airborne microorganisms in the waste associated environments are more active and complex compared to other places. However, the diversity and structure of airborne bacteria in waste-associated environments are still not clearly understood. The purpose of this study was to assess airborne bacterial community in electronic waste dismantling site and a waste transfer station based on culture-dependent and culture-independent methods. A total of 229 isolates were obtained from four airborne sites collected from residential area, electronic industrial park, and office area in or near an electronic waste dismantling site and a waste transfer station in Southern China in the morning, afternoon, and evening. Most of the isolates were isolated from air for the first time and 14 potentially novel species were identified by Sanger sequencing. Bacterial communities in waste-associated bioaerosols were predominated by Proteobacteria and Bacteroidetes. Abundant genera (>1%) included Paracaedibacteraceae (uncultured EF667926), Ralstonia, Chroococcidiopsis, Chitinophagaceae (uncultured FN428761), Sphingobium, and Heliimonas. One-third of the species in these genera were uncultured approximately. Differences community structure existed in airborne bacterial diversity among different sampling sites. These results showed that waste-associated environments have unique bacterial diversity. Further studies on such environments could provide new insights into bacterial community.


Assuntos
Resíduo Eletrônico , Microbiota , Aerossóis/análise , Bactérias/genética , China
9.
Artigo em Inglês | MEDLINE | ID: mdl-33805282

RESUMO

The recycling of electronic waste (e-waste) contaminates ecosystems with metals, though a compilation of data from across sites worldwide is lacking, without which evidence-based comparisons and conclusions cannot be realized. As such, here, a systematic review of the literature was conducted to identify peer-reviewed studies concerning e-waste sites (published between 2005 and 2017) that reported on the concentration of heavy metals (Cd, Hg, As, Pb and Cr) in soil, water and sediment. From 3063 papers identified, 59 studies from 11 countries meeting predefined criteria were included. Reported metal concentrations were summarized, and a narrative synthesis was performed. This review summarized 8286 measurements of the aforementioned metals in soils (5836), water (1347) and sediment (1103). More than 70% of the studies were conducted in Asia. In nearly all cases, the average metal concentrations in a particular medium from a given site were above guideline values; suggesting soils, water and sediment at, or near, e-waste recycling sites are contaminated. Across all media, concentrations of Pb were generally highest, followed by Cr, As, Cd and Hg. The synthesized information demonstrates that e-waste sites worldwide are contaminated with metals, that geographic data gaps exist, that the quality of most studies can be improved and that action is needed to help reduce such levels to protect human health and the environment.


Assuntos
Resíduo Eletrônico , Metais Pesados , Poluentes do Solo , Ásia , China , Ecossistema , Resíduo Eletrônico/análise , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Reciclagem , Solo , Poluentes do Solo/análise
10.
J Environ Manage ; 288: 112380, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33831638

RESUMO

This review details the current information on e-waste treatment using plasma technology. The current status of e-waste treatment via plasma technology from the scientific literature is presented herein, namely, moist paste battery, galvanic sludge, resin, printed circuit board, and semiconductor industries. The concept of plasma technology, classification of e-waste, contaminants of e-waste (metals, metalloids, and VOCs), and vitrification of the final product are presented herein. This review paper focuses on fusing flux agents to vitrify e-waste. Furthermore, this paper covers laboratory-scale investigations, plasma technology benefits, and reuse of material from plasma post-treatment. The use of plasma technology combined with flux agents could be recommended to eliminate contaminants from e-waste. Materials from plasma post-treatment may also be applied in environmental reuse applications.


Assuntos
Resíduo Eletrônico , Resíduo Eletrônico/análise , Metais , Plasma , Reciclagem , Esgotos , Tecnologia
11.
Environ Sci Technol ; 55(9): 5984-5992, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33877816

RESUMO

Liquid-crystal monomers (LCMs), especially fluorinated biphenyls and analogues (FBAs), are considered to be a new generation of persistent, bioaccumulative, and toxic organic pollutants, but their emissions from liquid-crystal display (LCD)-associated e-waste dismantling remain unknown. To fill this knowledge gap, a broad range of 46 LCMs, including 39 FBAs and 7 biphenyls/bicyclohexyls and analogues (BAs), were investigated by a dedicated target analysis in e-waste dust samples. Of 39 target FBAs, 34 were detected in LCD dismantling-associated dust. Among these 34 detectable FBAs, 9 were detected in 100% of the samples and 25 were frequently detected in >50% of the samples. The total concentrations of these 34 FBAs (∑34FBAs) detected in LCD e-waste dust were in the range of 225-976,000 (median: 18,500) ng/g, significantly higher than those in non-LCD e-waste dust (range: 292-18,500, median: 2300 ng/g). In addition to FBAs, six of seven BAs were also frequently detected in LCD e-waste dust with total concentrations (∑6BAs) of 29.8-269,000 (median: 3470) ng/g. Very strong and significant correlations (P < 0.01) were identified in all frequently detected LCMs, indicating their common applications and similar sources. Our findings demonstrate that e-waste dismantling contributes elevated emissions of FBAs and BAs to the ambient environment.


Assuntos
Resíduo Eletrônico , Poluentes Ambientais , Cristais Líquidos , Bifenilos Policlorados , China , Poeira/análise , Resíduo Eletrônico/análise , Monitoramento Ambiental , Poluentes Orgânicos Persistentes
12.
Environ Pollut ; 283: 117033, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33887669

RESUMO

Waste residues and acidic effluents (post-processing of E-waste) released into the local surroundings cause perilous environmental threats and potential risks to human health. Only limited research and information are available toward the sustainable management of waste residues generated post resource recovery of E-waste components. In the present study, the manual processing of obsolete computer (keyboard, monitor, CPU, and mouse) and chemical leaching of waste printed circuit boards (WPCBs) (motherboard, hard drive, DVD drive, and power supply) were performed for urban mining. The toxicity characteristics of typical pollutants in the residues of the WPCBs (post chemical leaching) were studied by toxicity characteristics leaching procedure (TCLP) test. Manual dismantling techniques resulted in an efficient urban mining concept with an overall average profit estimation of INR 2513.73/US$ 34.59. The chemical leaching of WPCBs showed a high concentration of metal leaching like Cu (229662 ± 575.3 mg/kg) and Pb (36785.67 ± 13.07 mg/kg) in the motherboard after stripping epoxy coating. The toxicity test revealed that the concentration of Cu (245.746 ± 0.016 mg/l) in the treated waste residue and Cu (430.746 ± 0.0015 mg/l) and Pb (182.09 ± 0.0035 mg/l) in the non-treated waste residue exceeded the threshold limit. The concentrations of other elements As, Cd, Co, Cr, Ag, Mn, Zn, Ni, Fe, Se, and In were within the permissible limit. Hence, the waste residue stands non-hazardous except Cu and Pb. Stripping out the epoxy coating of WPCBs enhances the metal leaching concentrations. The study highlighted that efficient and appropriate E-waste urban mining has immense potential in tracing the waste scrap into secondary resources. This study also emphasized that the final processed waste residue (left unattended or discarded due to lack of appropriate skill and technology) can be taken into consideration and exploited for value-added materials.


Assuntos
Resíduo Eletrônico , Poluentes Ambientais , Metais Pesados , Computadores , Resíduo Eletrônico/análise , Poluentes Ambientais/análise , Metais , Metais Pesados/análise , Mineração
13.
Environ Pollut ; 283: 117059, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33845288

RESUMO

Non-invasive human biomonitoring methods using hair and fingernails as matrices are widely used to assess the exposure of organic contaminants. In this work, a total of 72 human fingernails were collected from workers and near-by residents from a typical electronic waste (e-waste) dismantling site, and were analyzed for human exposure to polycyclic aromatic hydrocarbons (PAHs) and their mono-hydroxyl metabolites (OH-PAHs). The concentrations of PAHs and OH-PAHs were obtained as 7.97-551 and 39.5-3280 ng/g for e-waste workers (EW workers), 7.05-431 and 27.3-3320 ng/g for non-EW workers, 7.93-289 and 124-779 ng/g for adult residents, and 8.88-1280 and 181-293 ng/g for child residents, respectively. The composition profiles of PAHs in the human fingernails of the four groups were similar, with isomers of Phe, Pyr and Fluo being the predominated congeners, while 2-OH-Nap accounted for more than 70% of the total OH-PAHs. These contaminants were found most in the fingernails of EW workers, followed by non-EW workers, adult residents, and child residents, indicating e-waste dismantling activities are the major sources of PAH exposure. However, significantly higher levels of PAHs with 4-6 rings were observed only in workers as opposed to the residents, and a significant correlation between 3-OH-Flu (p < 0.05) and 2-OH-Phe (p < 0.01) in the fingernails and urine was observed, but no significant correlation was found between the concentration of OH-PAHs in matched hair and fingernail samples. In addition, the levels of PAHs in fingernails increased with the age of EW workers. This is the first study to explore the accumulation and distribution of PAHs and OH-PAHs in human fingernails, which would provide valuable insight into non-invasive biomonitoring and health risk assessment of PAHs.


Assuntos
Resíduo Eletrônico , Hidrocarbonetos Policíclicos Aromáticos , Adulto , Monitoramento Biológico , Criança , Monitoramento Ambiental , Humanos , Unhas/química , Hidrocarbonetos Policíclicos Aromáticos/análise
14.
Chemosphere ; 279: 130478, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33857646

RESUMO

The effects of polybrominated biphenyls (PBBs) on human health have previously attracted much attention, but recent studies of PBBs have been focused on BB-153 and a few other congeners. PBB concentrations in serum samples from residents of an area containing an electronic waste dismantling site were determined in this study. The total PBB concentrations (i.e., the sums of the concentrations of the 35 PBB congeners) were 229-1360 ng/g lipid. The BB-153 concentrations were markedly higher in the samples from people living in the electronic waste dismantling area than in samples from people living in a nearby control area. BB-153 was found in all of the samples from the study exposure area but the concentrations were relatively low (0.07-4.70 ng/g lipid). High BB-1 concentrations were found for the first time in serum from people living in both the electronic waste dismantling and control areas. The BB-1 concentrations were 211-1280 ng/g lipid. The retention times of the 35 PBB standards and PCBs (polychlorinated biphenyls) with similar structures were used to predict the retention times of unidentified PBB congeners to allow the PBB distributions in the serum samples to be identified. A total of 26 previously unidentified PBB congeners were identified in the human serum samples. BB-5, BB-35, BB-79, and BB-109 were found in >50% of the samples. The PBB patterns in the serum samples were different from the patterns previously found in serum after a PBB contamination incident in 1973, so the health risks currently posed by PBBs are worth studying.


Assuntos
Resíduo Eletrônico , Poluentes Ambientais , Bifenil Polibromatos , Bifenilos Policlorados , China , Resíduo Eletrônico/análise , Poluentes Ambientais/análise , Humanos , Bifenil Polibromatos/análise , Bifenilos Policlorados/análise
15.
Waste Manag ; 127: 37-47, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33930684

RESUMO

In emerging economies, electronic waste is an important problem, because it negatively affects the health of staff and people, and causes pollution. Moreover, the location of the collection center has a crucial role in sustainable supply chains. Therefore, in this study, a framework was proposed to identify the location of sustainable collection centers for e-waste. The criteria set includes 3 main criteria, and 23 sub-criteria, and 7 different location options. The main criteria cover economic, social, and environmental criteria, which are organized as the Triple-Bottom-Line dimensions. Alternatives are Manisa, Menemen, Gaziemir, Kemalpasa, Torbali, Çigli, and Akhisar. Fuzzy Best-Worst Method (BWM) and Fuzzy TOPSIS methods are used to calculate the weights of criteria and rankings of the alternatives, respectively. Transportation cost was found as the most important criterion for sustainable collection center selection, followed by collection cost, storage/holding cost, land cost, greenhouse gas emissions, energy cost, tax, and investment cost, respectively. Among other alternatives, Çigli was found as the best alternative for sustainable collection center, followed by Gaziemir, and Manisa. Managerial implications were presented based on the findings.


Assuntos
Resíduo Eletrônico , Lógica Fuzzy , Humanos , Transportes
16.
J Environ Manage ; 289: 112517, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33836437

RESUMO

Ureolytic bacteria can be a promising mediator used for the immobilization of potentially toxic elements via microbially-induced carbonate precipitation (MICP) process from biodegradable ions to carbonate form. Electronic waste (E-waste) environment is very complex compared to general metal contaminated soil, however, MICP has not been studied under such an environment. In this study, three bacterial strains were successfully isolated from an E-waste area in Guiyu, China, and indicated to have positive ureolytic behavior with significant heavy metal resistance (specific to Cu and Pb), among which, a strain of Lysinibacillus sp. was proven to show a great persistence in heavy metal immobilization. This featured strain can tolerate up to 100 ppm copper and 1000 ppm lead according to minimal inhibitory concentration (MIC) results, and its urease activity was well-adapted to metal effects. Results also revealed the positive correlation (R2 = 0.9819) between metal concentrations and surface layer protein content present in bacterial cells. The underlying mechanism on the role of S-layer protein in heavy metal immobilization during biocalcification was elucidated. The metabolic system of heavy metal resistance for these E-waste derived isolates is novel and represents a point of interest for possible environmental applications to immobilize toxic heavy metals from electronic waste sites.


Assuntos
Resíduo Eletrônico , Metais Pesados , Poluentes do Solo , Bactérias/genética , China , Solo , Poluentes do Solo/toxicidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-33669889

RESUMO

Informal recycling of electrical and electronic waste (e-waste) has myriad environmental and occupational health consequences, though information about the chronic musculoskeletal health effects on workers is limited. The aim of this study was to examine the prevalence and intensity of self-reported musculoskeletal disorder (MSD) symptoms among e-waste workers at Agbogbloshie in Ghana-the largest informal e-waste dumpsite in West Africa-relative to workers not engaged in e-waste recycling. A standardized musculoskeletal discomfort questionnaire was administered to 176 e-waste workers (73 collectors, 82 dismantlers, and 21 burners) and 41 workers in a reference group. The number of body parts with musculoskeletal discomfort were 1.62 and 1.39 times higher for collectors and dismantlers than burners, respectively. A 1-week discomfort prevalence was highest for collectors (91.8%) followed by dismantlers (89%), burners (81%), and the reference group (70.7%). The discomfort prevalence for e-waste workers was highest in the lower back (65.9%), shoulders (37.5%), and knees (37.5%). Whole-body pain scores (mean ± SE) were higher for collectors (83.7 ± 10.6) than dismantlers (45.5 ± 7.6), burners (34.0 ± 9.1), and the reference group (26.4 ± 5.9). Differences in prevalence, location, and intensity of MSD symptoms by the e-waste job category suggest specific work-related morbidity. Symptom prevalence and intensity call attention to the high risk for MSDs and work disability among informal e-waste workers, particularly collectors and dismantlers.


Assuntos
Resíduo Eletrônico , Doenças Musculoesqueléticas , Exposição Ocupacional , Gana/epidemiologia , Humanos , Doenças Musculoesqueléticas/epidemiologia , Exposição Ocupacional/análise , Reciclagem
18.
Chemosphere ; 275: 130022, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33647682

RESUMO

The dismantling of electrical and electronic waste (e-waste) can release various Volatile organic compounds (VOCs), impacting the surrounding ambient environment. We investigated the spatio-temporal characteristics and health risks of the ambient VOCs emitted in a typical e-waste dismantling region by conducting multi-site sampling campaigns in four seasons. The pollution of benzene, toluene, ethylbenzene, and xylenes (BTEX) in the e-waste dismantling park has relation to e-waste dismantling by seasonal trend analysis. The highest concentrations of most VOCs occurred in winter and autumn, while the lowest levels were observed in summer and spring. The spatial distribution map revealed the e-waste dismantling park to be a hotspot of BTEX, 1,2-dichloropropane (1,2-DCP), and 1,2-dichloroethane (1,2-DCA), while two major residential areas were also the hotspots of BTEX. The e-waste emission source contributed 20.14% to the total VOCs in the e-waste dismantling park, while it was absent in the major residential and rural areas. The cancer risk assessment showed that six VOCs exceeded 1.0 × 10-6 in the e-waste dismantling park, while only three or four compounds exceeded this risk in other areas. The noncancer risks of all compounds were below the safety threshold. This study supplements the existing knowledge on VOC pollution from e-waste dismantling and expands the research scope of chemical pollution caused by e-waste.


Assuntos
Poluentes Atmosféricos , Resíduo Eletrônico , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Humanos , Estações do Ano , Tolueno/análise , Compostos Orgânicos Voláteis/análise
19.
Waste Manag ; 126: 119-132, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33743338

RESUMO

A huge increase of waste of electrical and electronic equipment (WEEE) is observing everywhere in the world. Plastic component in this waste is more than 20% of the total and allows important environmental advantages if well treated and recycled. The resource recovery from WEEE plastics is characterised by technical difficulties and environmental concerns, mainly related to the waste composition (several engineering polymers, most of which containing heavy metals, additives and brominated flame retardants) and the common utilisation of sub-standard treatments for exported waste. An attributional Life Cycle Assessment quantifies the environmental performances of available management processes for WEEE plastics, those in compliance with the European Directives and the so-called substandard treatments. The results highlight the awful negative contributions of waste exportation and associated improper treatments, and the poor sustainability of the current management scheme. The ideal scenario of complete compliance with European Directives is the only one with an almost negligible effect on the environment, but it is far away from the reality. The analysed real scenarios have strongly negative effects, which become dramatic when exportation outside Europe is included in the waste management scheme. The largely adopted options of uncontrolled open burning and illegal open dumping produce huge impacts in terms of carcinogens (3.5·10+7 and 3.6·10+4 person⋅year, respectively) and non-carcinogens (1.7·10+8 and 2.0·10+6 person⋅year) potentials, which overwhelm all the other potential impacts. The study quantifies the necessity of strong reductions of WEEE plastics exportation and accurate monitoring of the quality of extra-Europe infrastructures that receive the waste.


Assuntos
Resíduo Eletrônico , Retardadores de Chama , Resíduo Eletrônico/análise , Eletrônica , Europa (Continente) , Plásticos , Reciclagem
20.
Waste Manag ; 126: 231-238, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33774583

RESUMO

A large amount of waste printed circuit boards (WPCBs) that contain valuable metals, namely gold and copper, are produced annually. WPCBs are constituted by a multi-layer structure reinforced by a brominated epoxy resin (BER), which is very difficult to separate into the metallic and non-metallic components. The main aim of this work was to evaluate the ability of microwave for assisting in the delamination of WPCBs by organic swelling of the BER. Additionally, its performance was compared with other strategies (thermostatic and ultrasonic baths) previously described in the literature. Firstly, a library of solvents [dimethyl formamide (DMF), dimethyl acetamide (DMAc), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), cyclohexanone (CH), γ-butyrolactone (GBL), tetrahydrofurfuryl alcohol (TFA) and dimethyl malonate (DM)] was selected based on the calculation of Hansen solubility parameters plus others exclusion parameters and their performance to detach all components of WPCBs (25 mm2) was tested by microwave (200 °C for 10 min), thermostatic (153 °C for 10 min) and ultrasonic (60 °C for 25 h) baths. Microwave showed to be the most efficient approach and the delamination order for WPCBs was: NMP > DMSO >DMF > DMAc. Subsequent optimization of key parameters (dimensions of WPCBs and reaction time) were obtained: dimensions of 225 mm2 using NMP (solid/liquid ratio of 300 g/L) at 200 °C with 2 cycles of 10 min. In conclusion, microwave-assisted swelling revealed to be more efficient and faster process to delaminate WPCBs into metallic and non-metallic components, which are important advantages when envisaging a future industrial waste management implementation.


Assuntos
Resíduo Eletrônico , Resinas Epóxi , Micro-Ondas , Reciclagem , Solventes
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