Application of soil magnetometry and geochemical methods to investigate soil contamination with antimony.

The aim of the study was an assessment of the pollution level and identification of the antimony sources in soils in areas subjected to industrial anthropopressure from: transport, metallurgy and electrical waste recycling. The combination of soil magnetometry, chemical analyzes using atomic spectrometry (ICP-OES and ICP-MS), Sb fractionation analysis, statistical analysis (Pearson's correlation matrix, factor analysis) as well as Geoaccumulation Index, Pollution Load Index, and Sb/As factor allowed not only the assessment of soil contamination degree, but also comprehensive identification of different Sb sources. The results indicate that the soil in the vicinity of the studied objects was characterized by high values of magnetic susceptibility and thus, high contents of potentially toxic elements. The most polluted area was in the vicinity of electrical waste processing plants. Research has shown that the impact of road traffic and wearing off brake blocks, i.e. traffic anthropopression in general, has little effect on the surrounding soil in terms of antimony content. Large amounts of Pb, Zn, As and Cd were found in the soil collected in the vicinity of the heap after the processing of zinc-lead ores, the average antimony (11.31 mg kg-1) content was lower in the vicinity of the heap than in the area around the electrical and electronic waste processing plant, but still very high. Antimony in the studied soils was demobilized and associated mainly with the residual fraction.

Persistent organic pollutants in feathers of various terrestrial and aquatic bird species: Interspecies difference and source apportionment.

Feathers are regarded as important nondestructive biomonitoring tools for bird pollutants. However, external contamination of feathers by different pollutants in different bird species remains unclear. In the present study, the feathers of 16 bird species, including terrestrial, freshwater, and marine birds, were analyzed for persistent organic pollutants (POPs). Bird feathers from an abandoned e-waste recycling site had higher POP concentrations and were more correlated with the POP muscle concentrations than those from the less polluted areas. The significant and positive POP correlations between the feathers and muscles of different species indicate that feathers are a good indicator of inter-species and spatial pollution. For individual species, the most hydrophobic POPs in feathers, such as hepta- to deca-polybrominated diphenyl ethers, had higher proportions than in muscles and worse correlations with muscle POPs compared with other POPs. Results of the chemical mass balance (CMB) model revealed that the gaseous phase, internal pollution, and atmospheric particle phase were the main contributors to low-, medium-, and high-hydrophobicity POPs in feathers, respectively. Overall, this study provides a preliminary but meaningful framework for distinguishing between internal and external contamination in feathers and gives information concerning the fitness of feathers as POP indicators with specific physicochemical properties.

Leaching of liquation-feeding furnace dross as a first step for germanium recovery.

OBJECTIVE: Germanium, an important component of electronics, is considered by many global economies as a critical raw material. Therefore, investigating its potential new sources is crucial for prospective technology development. This paper presents the investigation results on the leaching of liquation-feeding furnace dross using sulfuric and oxalic acid solutions. RESULTS: The dross contained mostly zinc (68.0% wt.) but also elevated germanium concentration (0.68% wt.). The influence of temperature, time, initial acid concentration, and liquid-to-solid phase ratio (L:S) was examined. It was found that germanium availability via leaching is limited-maximum leaching yields using aqueous solutions of sulfuric and oxalic acids were 60% (80 °C, 2 h, 15% wt. H2SO4, L:S 25:1) and 57% (80 °C, 3 h, 12.5% wt. H2C2O4, L:S 10:1), respectively.

Mechanism of PGMs capture from spent automobile catalyst by copper from waste printed circuit boards with simultaneous pollutants transformation.

The traditional pyrometallurgical recycling of nano-sized platinum group metals (PGMs) from spent automotive catalysts (SACs) is an energy-intensive process that requires the addition of large quantities of copper capture and slag-forming reagents. Similarly, pyro-recycling of valuable metals from waste printed circuit boards (WPCBs) is also an energy- and reagent-intensive process that and carries a risk of pollution emissions. Based on the complementarity of composition and similarity of recycling process, synergistic pyro-recycling of SACs and WPCBs allow copper in WPCBs to capture PGMs in SACs and oxides from two waste form slag jointly, which offers benefits of enhanced metal recovery, reduced reagent and energy consumption, and suppressed pollutant emissions. However, the mechanisms of PGMs capture and pollutant transformation in co-smelting remain unknown. Here, we investigated the sub-processes mechanisms of slag formation, brominates fixation, multi-metal distribution and kinetic settlement. Oxides in both wastes support SiO2-Al2O3-CaO slag formation with low melting point and viscosity, where CaO suppresses the emission of brominated pollutants. Copper (50-100 µm) from WPCBs facilitates nano-sized PGMs in SACs recovery through capture and settlement. The results of demonstration experiments indicated a recovery rate of 94.6 %, 96.8 %, 97.2 %, and 98.1 % for Cu, Pt, Pd, and Rh, respectively, with a debromination efficiency exceeding 98 %. The theoretical analysis provides support for the establishment of a synergistic pyro-recycling process for SACs and WPCBs and provides insights into the potential for a greener and more efficient co-recycling of multi urban mines.

Informal E-waste dismantling activities accelerated the releasing of liquid crystal monomers (LCMs) in Pakistan: Occurrence, distribution, and exposure assessment.

Liquid crystal monomers (LCMs) are emerging contaminants characterized by their persistence, bioaccumulation potential, and toxicity. They have been observed in several environmental matrices associated with electronic waste (e-waste) dismantling activities, particularly in China. However, there is currently no information on the pollution caused by LCMs in other developing countries, such as Pakistan. In this study, we collected soil samples (n = 59) from e-waste dismantling areas with different functions in Pakistan for quantification analysis of 52 target LCMs. Thirty out of 52 LCMs were detected in the soil samples, with the concentrations ranging from 2.14 to 191 ng/g (median: 16.3 ng/g), suggesting widespread contamination by these emerging contaminants. Fluorinated LCMs (median: 10.4 ng/g, range: 1.27-116 ng/g) were frequently detected and their levels were significantly (P < 0.05) higher than those of non-fluorinated LCMs (median: 6.11 ng/g, range: not detected (ND)-76.7 ng/g). The concentrations and profiles of the observed LCMs in the soil samples from the four functional areas varied. The informal dismantling of e-waste poses a potential exposure risk to adults and infants, with median estimated daily intake (EDI, ng/kg bw/day) values of 0.0420 and 0.1013, respectively. Calculation of the hazard quotient (HQ) suggested that some LCMs (e.g., ETFMBC (1.374) and EDFPB (1.257)) may pose potential health risks to occupational workers and their families. Considering the widespread contamination and risks associated with LCMs, we strongly recommend enhancing e-waste management and regulation in Pakistan.

Lagging pollution of polycyclic aromatic hydrocarbons in the rebuilt e-waste site: From the perspective of characteristics, sources, and risk assessment.

Little information is known regarding how the lagged pollution of polycyclic aromatic hydrocarbon (PAH) influenced the environment and human health after an e-waste dismantling site was rebuilt. This study investigated the characteristics, sources, and risk assessment of PAHs in a rebuilt e-waste site and its surrounding farmland by analyzing the samples of soil, dust, water, and vegetable. Concentrations of PAHs in soil, vegetable and water in the rebuilt site were relatively higher than in its surrounding farmland. The concentrations in surface soils, soil columns, dust, vegetables, and water varied from 55.4 to 3990 ng g-1, 1.65 to 5060 ng g-1, 2190 to 2420 ng g-1, 2670 to 10,300 ng g-1, and 46.8 to 110 µg L-1 in the e-waste site, respectively. On the farmland, PAH concentrations in surface soils, vegetables, and water ranged from 41.5 to 2760 ng g-1, 506 to 7640 ng g-1, and 56.6 to 89.2 µg L-1, respectively. A higher proportion of high-molecular-weight PAHs (HMW-PAHs) appeared in all multimedia compared with low-molecular-weight PAHs (LMW-PAHs). Diagnostic ratio together with positive matrix factorization (PMF) revealed that vehicle emission was the primary source in this area, and the activity of e-waste disposal was another important source in the rebuilt e-waste site. Based on the deterministic health risks, people working in the reconstructed e-waste site were exposed to low risks, whereas the residents living near the surrounding farmland were exposed to low risk. Sensitivity analyses indicated that exposure frequency and PAH concentrations were the main factors that influenced exposure risk. This study provides valuable insight into the comprehension of the lagging pollution effects of PAH on the environment and human health after the e-waste site was rebuilt.

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.

Systematic literature review of heavy metal contamination of the Nigerian environment from e-waste management: Associated health and carcinogenic risk assessment.

E-waste -the aftermath of large amount of electrical and electronic equipment ferried into Africa from which Nigeria receives a significant chunk, is composed of components known to be hazardous to health. Composition of series of heavy metals (HMs) in e-waste is traceable to many health conditions including cancer which is hitherto incompletely understood. This study harmonizes primary data on HMs from e-waste in different Nigerian environmental media including the air, soil, surface dust, water and plant. We estimated the possible health implications, single and aggregative soil and water pollution indices both in adult and children categories, carcinogenic and non-carcinogenic risks secondary to HM exposure and mapped out the possible mechanism of carcinogenesis. Analysis showed that soil, water, surface dust and plant matrices in Nigerian environment are variedly but considerably contaminated with combination of HMs. The significantly high values of the hazard quotient and hazard index of both water and surface dust matrices are indicative of adverse health effect of the non-carcinogenic risk. The highest HQ is generated by Pb and Cr through dermal exposure to soil and surface dust with mean values of 1718.48, 1146.14, 1362.10 and 1794.61 respectively among Nigerian children followed by the oral exposure. This pattern of observation is similar to that obtained for adult category. HI due to Pb and Cr in soil constitutes the highest HI (2.05E+03 and 1.18E+03 respectively) followed by surface dust. However, this study precipitates the observation that children are more at health risk than adults in contaminated environment. Carcinogenic risk also follows the same pattern of expression in the Nigerian environment. We conclude that exposure to e-waste poses significant carcinogenic and non-carcinogenic health risks and the induction of toxicity may be mediated via DNA damage, oxidative stress and inflammatory/immune cells dysfunction in Nigerian environment.

Tetrabromobisphenol-A/S and their derivatives in surface particulates from workshop floors of three representative e-waste recycling sites in China.

Surface particulates collected from the workshop floors of three major e-waste recycling sites (Taizhou, Qingyuan, and Guiyu) in China were analyzed for tetrabromobisphenol A/S (TBBPA/S) and their derivatives to investigate the environmental pollution caused by e-waste recycling activities. Mean concentrations of total TBBPA/S analogs in surface particulates were 31,471-116,059 ng/g dry weight (dw). TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most frequently detected in particulates with average concentration ranges of 17,929-78,406, 5601-15,842, and 5929-21,383 ng/g dw, respectively. Meanwhile, TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most abundant TBBPA/S analogs, accounting for around 96% of the total. The composition profiles of TBBPA/S analogs differed significantly among three e-waste sites. Similarly, principal component analysis uncovered different pollution patterns among different sites. The discrepancy in the profiles of TBBPA/S analogs largely relied on the e-waste types recycled in different areas. E-waste recycling led to the release of TBBPA/S analogs, and TBBPA/S analogs produced differentiation during migration from source (surface particulates) to nearby soil. More researches are necessary to find a definite relationship between pollution status and e-waste types and study differentiation behavior of TBBPA/S analogs in migration and diffusion from source to environmental medium.

The potential impact of the new 'Right to Repair' rules on electrical and electronic equipment waste: A case study of the UK.

Every year an estimated two million tonnes of waste electrical and electronic equipment (WEEE) are discarded by householders and companies in the United Kingdom (UK). While the UK has left the European Union (EU), its waste-related policies still mirror those of the EU, including the WEEE-related policies. Motivated by the recent introduction the so-called 'Right to Repair' policy for electrical and electronic equipment (EEE) across the EU and UK, this paper aims to demonstrate that, depending on the commitment and behavioural changes by the consumers and the government, the future of the WEEE management of the UK will vary. To this end, focusing on landfilled WEEE reduction we develop a generic system dynamics model and apply it to eleven WEEE categories. They depict the flow of EEE and WEEE representing the interaction among the stakeholders (e.g., consumers and producers of EEE) and relevant government regulations of the UK. Our four scenario analyses find that longer use of EEE and better WEEE collection seem to be effective in reducing landfilled WEEE, while more reuse and more recycling and recovery have negligible impacts, despite excluding the additional generation of landfilled WEEE as a result of recycling and recovery. Comparing with the business-as-usual scenario, one year longer EEE use and 10% more of WEEE collection could at maximum reduce landfilled WEEE by 14.05% of monitoring and control instruments and 93.93% of display equipment respectively. Backcasting scenario analyses reveal that significant efforts are required to reduce the targeted amounts.

Chromoproduct approach to achieve environmentally sound management of e-waste plastics: Colombian project case.

Research to prevent releases of brominated flame retardants listed as persistent organic pollutants by the Stockholm Convention (POP-BFRs) was conducted through an international cooperation project in Colombia. Six waste electrical and electronic equipment (WEEE) management facilities implemented: 1) sorting e-waste by product type and color (black, white, and other; henceforth called chromoproducts), 2) sampling test products and their plastic fraction (called sets, separated by polymer type), 3) monitoring mass, bromine and antimony contents by hand-held X-ray fluorescence (XRF) and POP-BFRs such as polybrominated diphenyl ethers (PBDEs) by gas chromatography and mass spectrometry (GC-MS), and 4) differentiated treatment according to categories that used the Restriction of Hazardous Substances in Electrical and Electronic Equipment Directive (RoHS) hazardousness threshold of 1000 mg ∑PBDEs/kg. This scheme led to the proposal of a methodology for WEEE management called the "chromoproduct approach". 994,230 products were managed and grouped into 222 chromoproducts, from which 77 were analyzed: 50 below RoHS hazardousness (BRH), 16 above RoHS hazardousness (ARH), and 11 unknown RoHS hazardousness (URH). XRF indicators using bromine and antimony contents could rule out pollution in BRH chromoproducts; however, categorization still required GC-MS. One ARH plastics sample had 3620 mg ∑PBDEs/kg, while no POP-BFRs were found in the BRH plastics sample. The implementation of the chromoproduct approach traced 153.6 tonnes of ARH plastics. BRH plastics composition was estimated and used in a pilot-scale closed-loop economic activity. The chromoproduct approach seems promising for avoiding POP-BFR releases and promoting the upcycling of recyclable e-waste plastics.

Spatiotemporal variation of 6PPD and 6PPDQ in dust and soil from e-waste recycling areas.

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its derivative 6PPDQ have been detected in various environmental media, with harmful consequences for both ecosystems and biological health. However, the distribution of 6PPD and 6PPDQ in areas around e-waste recycling areas is currently unknown. We collected soil and dust samples from areas around a traditional e-waste recycling zone, an emerging recycling park, and a reference area. Higher levels of 6PPD were found in dust from residential areas around the traditional e-waste recycling zone compared to the reference area (median: 108.99 versus 33.57 ng/g, P < 0.01). Lower levels of 6PPDQ were detected in dust samples from around the emerging e-waste recycling parks compared to traditional e-waste recycling zones (median: 15.40 versus 46.37 ng/g, P < 0.05). The median concentrations of 6PPD and 6PPDQ were higher in the dust samples than in the soil samples (P < 0.001). The concentrations of 6PPD and 6PPDQ in the dust and soil varied seasonally, with the highest total concentrations occurring in the winter. Results from a multiple linear regression analysis indicate that 6PPDQ is negatively correlated with temperature and positively correlated with 6PPD, O3, and radiation. This study confirms that e-waste is a potential contributor to 6PPD and 6PPDQ. In residential areas, 6PPD and 6PPDQ are more likely to accumulate in dust than in soil. The emerging e-waste recycling parks have greatly improved the local 6PPDQ pollution situation. Further studies are necessary to understand the distribution of newly found substances in various settings.

Process and systematic study of gold recovery from flexible printed circuit boards (FPCBs) using a choline chloride-ethylene glycol system.

The traditional hydrometallurgy technology has been widely used to recover precious metals from electronic waste. However, such aqueous recycling systems often employ toxic/harsh chemicals, which may cause serious environmental problems. Herein, an efficient and environment-friendly method using a deep eutectic solvent (DES) mixed system of choline chloride-ethylene glycol-CuCl2·2H2O is developed for gold (Au) recovery from flexible printed circuit boards (FPCBs). The Au leaching and precipitation efficiency can reach approximately 100 % and 95.3 %, respectively, under optimized conditions. Kinetic results show that the Au leaching process follows a nucleation model, which is controlled by chemical surface reactions with an apparent activation energy of 80.29 kJ/mol. The present recycling system has a much higher selectivity for Au than for other base metals; the two-step recovery rate of Au can reach over 95 %, whereas those of copper and nickel are < 2 %. Hydrogen nuclear magnetic resonance spectroscopy (HNMR) and density functional theory (DFT) analyses confirm the formation of intermolecular hydrogen bonds in the DES mixed system, which increase the system melting and boiling points and facilitate the Au leaching process. The Au leaching system can be reused for several times, with the leaching efficiency remaining > 97 % after five cycles. Moreover, ethylene glycol (EG) and choline chloride (ChCl) act as aprotic solvents as well as coordinate with metals, decreasing the redox potential to shift the equilibrium to the leaching side. Overall, this research provides a theoretical and a practical basis for the recovery of metals from FPCBs.

Bioaccessibility of halogenated flame retardants and organophosphate esters in settled dust: Influences of specific dust matrices from informal e-waste and end-of-life vehicle processing areas in Vietnam.

Bioaccessibility of halogenated flame retardants (HFRs) and organophosphorus esters (OPEs) is necessarily investigated to provide more accurate risk assessment and information about absorption behavior of these pollutants. In this study, total and bioaccessible concentrations of HFRs (including legacy and alternative substances) and OPEs were determined in settled dust samples collected from Vietnamese e-waste and end-of-life vehicle (ELV) processing areas. Concentrations of both HFRs and OPEs were significantly higher in the e-waste dust than ELV dust. Bioavailability of HFRs and OPEs in dust was determined by using an in vitro assay with human-simulated digestive fluids, dialysis membrane, and Tenax® TA sorptive sink. Bioaccessibility of HFRs was markedly lower than that of OPEs, which could be largely due to higher hydrophobicity of HFRs compared to OPEs. Bioaccessibility of almost hydrophobic compounds were markedly lower in the e-waste dust (containing micronized plastic debris) than in the ELV dust (containing oily materials), suggesting the influence of specific dust matrices on pollutant bioaccessibility. Although the daily uptake doses of selected HFRs and OPEs from dust were markedly higher in the e-waste sites compared to the ELV sites, the direct exposure risk was not significant. Our results suggest that bioaccessibility can partly explain the differences between dust and uptake profiles, which may relate to accumulation profiles of HFRs and OPEs in human samples.

A hybrid thermal-biological recycling route for efficient extraction of metals and metalloids from end-of-life liquid crystal displays (LCDs).

Waste liquid crystal displays (LCDs) are one of the most substantial and rapidly growing e-waste streams that contain a notable amount of critical, precious, and toxic elements. This study presented a novel thermal-biological hybrid method for resource recovery from waste LCDs. Through the design of a multistage thermal treatment process with the addition of optimized 20 wt% B2O3 to waste, the LCD's glass structure was separated into two interconnected phases, resulting in the transfer of metals from the LCD's glass phase to the B2O3 phase that can solubilize in the acid solution. Following the thermal treatment step, the biometabolites of Aspergillus niger were used for bioleaching of In, Sr, Al, and As from the obtained thermally treated product. The optimal bioleaching parameters were a pulp density of 10 g/L, temperature of 70 °C, and leaching time of 2 days, which led to the highest extraction of 82.6% Al, 70.8% As, 64.5% In, and 36.2% Sr from thermally treated LCD waste, representing a multifold increase in Al, As, and Sr extraction levels compared to untreated waste. This study demonstrated that the proposed hybrid method could successfully overcome waste complexities and ensure effective element extraction from discarded LCDs.

Recovery of non-metallic useable materials from e-waste.

Tremendous amounts of electric and electronic wastes (e-waste) are generated daily, and their indiscriminate disposal may cause serious environmental pollution. The recovery of non-metallic materials from e-waste is a strategy to not only reduce the volume of e-waste but also avoid pollutant emissions produced by indiscriminate disposal of e-waste. Pyrolysis, sub/supercritical water treatment, chemical dissolution, and physical treatment (e.g., ball milling, flotation, and electrostatic separation) are available methods to recover useable non-metallic materials (e.g., resins, fibers, and various kinds of polymers) from e-waste. The e-waste-derived materials can be used to manufacture a large variety of industrial and consumer products. In this regard, this work attempts to compile relevant knowledge on the technologies that derive utilizable materials from different classes of e-waste. Moreover, this work highlights the potential of the e-waste-derived materials for various applications. Current challenges and perspectives on e-waste upcycling to useable materials are also discussed.

Debromination of novel brominated flame retardants using Zn-based additives: A viable thermochemical approach in the mitigation of toxic effects during e-waste recycling.

Brominated flame retardants (BFRs) are bromine-bearing additives added to the polymeric fraction in various applications to impede fire ignition. The Stockholm Convention and various other legislations abolished legacy BFRs usage and hence, the so-called novel BFRs (NBFRs) were introduced into the market. Recent studies spotlighted their existence in household dust, aquifers and aquatic/aerial species. Co-pyrolysis of BFRs with metal oxides has emerged as a potent chemical recycling approach that produces a bromine-free stream of hydrocarbon. Herein, we investigate the debromination of two prominent two NBFRs; namely tetrabromobisphenol A 2,3-dibromopropyl ether (TD) and tetrabromobisphenol A diallyl ether (TAE) through their co-pyrolysis with zinc oxide (ZnO) and franklinite (ZnFe2O4). Most of the zinc content in electrical arc furnace dust (EAFD) exists in the form of these two metal oxides. Conversion of these metal oxides into their respective bromides could also assist in the selective extraction of the valuable zinc content in EAFD. The debromination potential of both oxides was unveiled via a multitude of characterization studies to analyze products (char, gas and condensates). The thermogravimetric analysis suggested a pyrolytic run up to 500 °C and the TAE treatment with ZnO produced only a trivial amount of brominated compounds (relative area, 0.83%). Phenol was the sole common compound in condensable products; potentially formed by the ß-scission debromination reaction from the parental molecular skeleton. Inorganic compounds and methane were the major constituents in the gaseous products. The pyrochar analyses confirmed the presence of metal bromides retained in the residue, averting the bromine release into the atmosphere. The ion chromatography analysis portrayed <8% of HBr gas release into the atmosphere upon pyrolysis with ZnO. The ZnO dominance herein envisaged further probes into other spinel ferrites in combating brominated polymers.

A sustainable approach toward mechanical recycling unsortable post-consumer WEEE: Reactive and non-reactive compatibilization.

While near-infrared (NIR) spectroscopy in post-consumer waste electrical and electronic equipment (WEEE) recycling accurately separates white or clear polymers, 40% containing dark plastics, termed 'unsortable WEEE,' are excluded from sorting lines and therefore incinerated or landfilled, causing environmental concerns. This study investigates the potential of using non-reactive and reactive copolymers as compatibilizers to enhance the performance of unsortable WEEE plastics free of brominated flame retardants. To the best of our knowledge, this is the first time that such copolymers have been explored as a solution for improving the compatibility of unsortable WEEE polymer blends. Initial trials with 4% of styrene-ethylene-butylene-styrene copolymer (SEBS-13) and SEBS-30-g-(maleic anhydride) copolymer (SEBS-30-g-MA MA) as compatibilizers showed insufficient results compared to virgin commercial polymers. However, the addition of higher concentrations of compatibilizers (i.e. up to 20 wt%) and the use of a SEBS having a higher styrene content (i.e. SEBS-30) improved the mechanical properties of the material, causing it to transition from brittle to ductile. This behavior was found more pronounced for the 20% non-reactive SEBS-30, for which the SEM analysis showed reduced phase segregation and revealed a more homogeneous fracture surface. This was further supported by Differential Scanning Calorimetry (DSC) analysis, which showed evidence of an interaction between one or more polymer phases. With a room temperature performance equivalent to that of virgin conventional polymers, the SEBS-30 compatibilization approach has made it possible to consider using unsortable WEEE streams as recycled materials in commercial applications.

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe.

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe. The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum. Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 µg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population. This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Advances in natural polysaccharides for gold recovery from e-waste: Recent developments in preparation with structural features.

The increasing demand for gold because of its high market price and its wide use in the electronic industry has attracted interest in gold recovery from electronic waste (e-waste). Gold is being dumped as solid e-waste which contains gold concentrations ten times higher than gold ores. Adsorption is a widely used approach for extracting gold from e-waste due to its simplicity, low cost, high efficiency, and reusability of adsorbent material. Natural polysaccharides received increased attention due to their natural abundance, multi-functionality, biodegradability, and nontoxicity. In this review, a brief history, and advancements in this technology were evaluated with recent developments in the preparation and mechanism advancements of natural polysaccharides for efficient gold recovery. Moreover, we have discussed some bifunctional modified polysaccharides with detailed gold adsorption mechanisms. The modified adsorbent materials developed from polysaccharides coupled with inorganic/organic functional groups would demonstrate an efficient technology for the development of new bio-based materials for efficient gold recovery from e-waste. Also, future views are recommended for highlighting the direction to achieve fast and effective gold recovery from e-waste in a friendly and sustainable manner.