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With the increasing usage rates of lithium ion batteries used in energy storage, the management of the resulting waste has also increasingly important. The short lifespan of lithium ion batteries and the precious metals they contain require careful management of these wastes from a technical, environmental and economic perspective. Therefore, in the context of the recovery of precious metals such as cobalt from waste lithium ion batteries, in this article, literature studies on the recovery of cobalt from commonly sed types of lithium ion batteries in the form of Nickel Manganese Cobalt and Lithium Cobalt Oxide have been evaluated. The literature review shows that the most commonly used methods are hydrometallurgical, pyrometallurgical and direct recovery methods. As the demand for lithium ion batteries increases in the coming years, the need to develop and optimize innovative methos for cobalt recovery will become even more important in achieving sustainability goals within energy storage systems. [ABSTRACT FROM AUTHOR]

New selective therapeutics are needed for the treatment of hepatocellular carcinoma (HCC), the 7th most common cancer. In this study, we compared the cytotoxic effect induced by the release of pH-dependent iron nanoparticles from nitrogen-doped graphene-coated mixed iron oxide nanoparticles (FexOy/N-GN) with the cytotoxic effect of nitrogen-doped graphene (N-GN) and commercial graphene nanoflakes (GN) in Hepatoma G2 (HepG2) cells and healthy cells. The cytotoxic effect of nanocomposites (2.5–100 ug/ml) on HepG2 and healthy fibroblast (BJ) cells (12–48 h) was measured by Cell Viability assay, and the half maximal inhibitory concentration (IC50) was calculated. After the shortest (12 h) and longest incubation (48 h) incubation periods in HepG2 cells, IC50 values of FexOy/N-GN were calculated as 21.95 to 2.11 µg.mL−1, IC50 values of N-GN were calculated as 39.64 to 26.47 µg.mL−1 and IC50 values of GN were calculated as 49.94 to 29.94, respectively. After 48 h, FexOy/N-GN showed a selectivity index (SI) of 10.80 for HepG2/BJ cells, exceeding the SI of N-GN (1.27) by about 8.5-fold. The high cytotoxicity of FexOy/N-GN was caused by the fact that liver cancer cells have many transferrin receptors and time-dependent pH changes in their microenvironment increase iron release. This indicates the potential of FexOy/N-GN as a new selective therapeutic. [ABSTRACT FROM AUTHOR]

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In this study, the upcycling and recycling applications for the management of waste printed circuit boards (PCBs) were compared through the sequential application of Streamlined Life Cycle Assessment (S-LCA) and Multi-Criteria Decision Making (MCDM) techniques. Upcycling applications were determined as gold, copper-tin alloy, lead, copper recovery and activated carbon production. And, portland cement, aggregate, sawdust, fiberglass and styrene butadiene rubber (SBR) productions were taken account as recycling applications. At the S-LCA stage, CML-IA baseline and ReCiPe 2016 methods were used for the characterization. For the MCDM study, environmental, technical and economic criteria were determined. Remarkable characterization results of S-LCA were used as the environmental criteria of MCDM. The Entropy method was used for the weighting of the criteria. TOPSIS method was used to compare the alternatives based on weighted criteria. S-LCA study shows that impact categories of Abiotic Depletion Potential (element basis), Total Ecotoxicity Potential and Human Toxicity Potential are the major impact categories. MCDM study shows that the gold recovery (0.9845) as an upcycling application and SBR production (0.7361) as a recycling application have been determined as the first applications to be applied to waste PCBs in terms of environmental, technical and economic aspects. [ABSTRACT FROM AUTHOR]

The aim of this study is the recovery of gold, copper, silver, and palladium from waste printed circuit boards (PCBs) by sequential adsorption with waste orange peel (OP)-derived bio-sorbents. First of all, adsorption tests on the gold and silver model solutions were carried out using native orange peels and modified orange peels by different methods in order to increase the adsorption capacity. These included saponification with sodium hydroxide, hydroxypropylation with propylene oxide, crosslinking with sodium trimetaphosphate and sodium tripolyphosphate, and acidification with citric acid. The optimum adsorption conditions were determined. Gold and silver adsorption was found appropriate to the Freundlich isotherm and pseudo-second-order model for isotherm and kinetic studies, respectively. After this, model solutions including gold, copper, silver, and palladium were prepared and the adsorption efficiencies were examined in the presence of different metals. Finally, waste printed circuit boards were pyrolyzed in a fixed bed stainless steel reactor to obtain an only-metal-containing solid product. Next, leaching of metals from the solid product was performed. For the last stage, adsorption studies on the leach solution were carried out under optimum conditions. As a result, 67.07% gold, 85.77% copper, 97.05% silver, and 75% palladium were adsorbed in total. [ABSTRACT FROM AUTHOR]

The reduction of the sent to landfill amount of municipal solid waste (MSWs) and municipal sewage sludges (SSs) is of great importance both for the circular economy concept, which has been on the agenda in recent years, and more careful management of MSW and SS. Pyrolysis method is one of the most suitable methods that can be utilized to treat these wastes together. In this study, it was evaluated to convert these wastes into useful products by co-pyrolyzing MSW and SS, and obtained liquid products were characterized. Samples were prepared by mixing different percentages (wt. 25-75%) from these wastes. The values of moisture content, ash content, volatile matter, and fixed carbon of prepared samples before the pyrolysis process were determined. The prepared samples were co-pyrolyzed at 400 °C. Elemental analysis (C, H, O, N, S), heating value measurement, FT-IR, and 1H-NMR analysis were carried out to make the characterization of the obtained liquid products after the co-pyrolysis process. According to analysis results, it was observed that M1 (25% of MSW and 75% of SS) showed the highest liquid yield. For all liquid products, it has been determined that most of the pyrolysis liquid products consist of aliphatic compounds. For sustainable municipal solid waste management, valorizing these wastes together instead of sending them to landfill sites, the co-pyrolysis process converts them to valuable products, it also might be considered an option contributing economic and environmental aspects. [ABSTRACT FROM AUTHOR]

This paper summarizes our work aimed at applying different methods sequentially in the evaluation of GFRP (glass fiber reinforced polyester) waste, which is a composite waste according to circular economy assumptions. For this aim, the management alternatives that are defined as mechanical recycling, chemical recycling, pyrolysis, and incineration methods are compared using the ANP (Analytic Network Process) and the VIKOR (Vise Kriterijumska Optimizacija I Kompromisno Resenje) methods. To show the applicability of the pyrolysis, which was determined as the most appropriate method, experiments were carried out at different temperatures. After the general characterization of the products was conducted, the solid product was used to reproduce GFRP. After a tensile strength test of the GFRP, which was produced using fibers obtained from pyrolysis at 500°C, it was found that it had approximately 43.15% more tensile strength than polyester cast without fiber. Following a further oxidation step, the tensile strength increased by 61.50%. The liquid products have the potential to be used as fuel oil, and the gas product is sufficient to provide the energy requirements of a process plant. Pyrolysis proved to be a profoundly feasible method for not only recovering glass fiber, but also energy from GFRP waste. [ABSTRACT FROM AUTHOR]

Summary: A variety of polymer matrices, based on thermoplastic resins are used to produce shape stabilized phase change material (SSPCM) with a large range of chemical and mechanical properties. In order to reduce global environmental problems and conserve natural resources, instead of raw polymers, waste thermoplastics can be utilized as encapsulation material to produce SSPCM. Low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP) are the most preferred polymers for use as encapsulation materials. However, utilization of waste forms of these thermoplastics is important as SSPCM depends on various parameters that cannot be easily compared manually. In this study, based on this idea, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR), two different multi‐criteria decision methods, are used to select the most appropriate waste polymers to be used as encapsulation material to produce SSPCM in terms of thermal, mechanical and waste properties. These properties are detailed in seven criteria; melting temperature, degradation temperature, thermal conductivity, specific heat, elasticity modulus, waste cost, and supply of waste. The weighting of these criteria is carried out by decision‐makers and the analytic hierarchy process (AHP). According to the TOPSIS and VIKOR results, LDPE was chosen as the best alternative (Ci+: 0.5860 and Qi: 0.0000 with the decision‐makers' approach and Ci+: 0.6336 and Qi: 0.0000 with AHP method, respectively) for the average values of the decision matrix. Sensitivity analysis, performed with the lowest and highest values of the decision matrix, verified the ranking of LDPE as the most appropriate waste thermoplastic for SSPCM applications. [ABSTRACT FROM AUTHOR]

Paratransit modes dominate the public transportation industry in the majority of developing countries, especially those in Sub‐Saharan Africa. The number of these modes has increased rapidly over the years. Authorities have not yet been able to provide a better alternative for passengers, whose demand is ever‐growing. In this research, the main modes of public transport in a Sub‐Saharan African city, Kampala, have been studied. Here we used multi‐criteria decision‐making methods to find out which among the four major public transport modes in Kampala, Uganda, are best from a transportation operator's perspective. The evaluation of alternatives was conducted using Analytic Network Process (ANP) and Elimination Et Choice Translating Reality (ELECTRE III) methods. Both the ANP and the ELECTRE III analysis results demonstrate that alternative "Coaster" is the most appropriate alternative from a public transport operator's point of view. A sensitivity analysis consisting of four different scenarios was considered in the changing of weighting percentages (for benefit, cost, and risk clusters) in the ANP and the ELECTRE III analyses, to show the robustness of the ranking results. According to the sensitivity analysis results, there was no change in the final ranking. The findings of this paper are crucial to policymakers within the transportation sectors of developing countries. Integr Environ Assess Manag 2022;18:25–38. © 2021 SETAC KEY POINTS: Four different transport modes were ranked via two Multi‐Criteria Decision‐Making methods considering 15 different criteria.Global warming potential and fossil fuel based abiotic depletion potential (ADPff) criteria values were obtained by using the Life Cycle Assessment methodology.The Analytic Network Process and Elimination Et Choice Translating Reality (ELECTRE III) methods indicate that "Coaster" is the best alternative compared to the other three modes of transport.Safety is the most important assessment criterion followed by tiresomeness for drivers (driver exhaustion). [ABSTRACT FROM AUTHOR]