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Micro-plastic and nano-particle have been the focal pollutants in environmental science. The printer toner is omitted micro-plastic and nano pollutant. It is comprised of micro polyacrylate styrene and nano-Fe 3 O 4 particles. Polyacrylate styrene and nano-metal were proved to be irreversibly toxic to biological cells. Therefore, toners have the potential environmental risk and healthy harm due to include micro plastics and nano-metal. To our knowledge, few studies provided the specific collection and treatment of micro-plastic pollutant. This paper has chosen a kind of micro-plastic and nano pollutant toxic toner and provided technical guidance and inspiration for controlling the micro-plastic and nano pollutants. The method of vacuum-gasification-condensation was adopted for controlling the micro-plastic and nano pollutant toner. We believe this review will open up a potential avenue for controlling micro-plastic and nano pollutants for environmental protection. [ABSTRACT FROM AUTHOR]

As a new kind of electronic waste, waste solar cells have posed a great threat to the environment. Solar cells contain a mass of hazardous organic components, such as ethylene-vinyl acetate copolymer and polyethylene glycol terephthalate. The degradation of ethylene-vinyl acetate copolymer and polyethylene glycol terephthalate may produce toxic substances to the environment. This paper proposed molecule co-fracture to dispose the organics in order to judge the hazard of degradation products to the environment. Co-fracture kinetics analysis showed that the heating rate with highest co-fracture efficient was 30 °C/min, at which the activation energy E had the largest value of 68.84 kJ/mol. The co-fracture products under different heating rates were tested. The main product was 1-hexadecanol, 2-methyl-, which had the highest yield of 44.66 wt % at the heating rate of 25 °C/min. Diisobutyl phthalate was the main hazardous product, which had highest yield was 9.75 wt % at the heating rate of 5 °C/min. Only at the heating rate of 30 °C/min, no hazardous substance was produced. Different energy supply in the system was the main reason for the different products. Molecule co-fracture was employed in this study to dispose organics in waste solar cells, which provides guidance for the disposal of waste solar cells to avoid environmental pollution. Image 1 • This paper provided a novel method of disposing EVA and PET in waste solar cells. • No hazardous substance was produced under heating rate at 30 °C/min. • The product differences depended on the different energy supply at different heating rates. [ABSTRACT FROM AUTHOR]

Quantities of waste solar cells have been produced due to their widespread sustainable energy applications. Due to the complicated composition of waste solar cells, the disposal of waste solar cells has been the hot spot of sustainable development and environmental protection research. To our knowledge, little information has been reported about the disposal of waste solar cells. For the safe disposal of waste solar cells, and to produce economic benefits, the present study applied the density functional theory to design the transformation pathways of organics in waste solar cells. The ethylene-vinyl acetate copolymer and polyethylene terephthalate of waste solar cells were transformed to 3,6,8,8-tetramethyl-2,3,4,7,8,8a-hexahydro-1H-3a,7-methanoazulene (cedrene). It is the precursor of precious wound-healing medicine. The transformation pathways exhibited a total energy barrier of 58.79 kcal/mol, and thermodynamic calculations indicated the temperature required for breaking this energy barrier was 777.50 K. 3,6,8,8-Tetramethyl-2,3,4,7,8,8a-hexahydro-1H-3a,7-methanoazulene was produced by vacuum heating at a temperature of 778.15 K, and the material had the most substantial proportion that accounted for 19.85 wt% in the products of vacuum heating. This paper provides insight into preparing the raw materials of medicine from the nonmetallic material of waste solar cells. Image 1 [ABSTRACT FROM AUTHOR]

The recovery trend of waste printed circuit boards has changed from stabilization to valued-added recovery, but the low value and complexity components of the nonmetallic resources greatly restrict its development. Therefore, the recovery of nonmetallic components deserves more attention and better guidance. This paper reviews the recent developments of the recycling techniques for nonmetallic components, including pyrolysis, supercritical fluid oxidation, chemical leaching, and direct recycling of synthetic materials. The clean production level, recycling efficiency, and economic value of these methods are the focus of this review. The key to improving the recycling technology for non-metallic component is to remove the harmful elements during the recovery process. In the direction of future development of e-waste recovery, environmental friendliness, value, and efficiency are important equally. The novel idea of debromination to reduce potential pollution prior to subsequent processing and enhance recovery value. It can effectively realize the valued-added preparation of environmental-friendly materials by combined process. The results are expected to give guidance for the future recycling process and provide reference for industrial development. • The latest research progress on recycling nonmetallic components in waste printed circuit boards is reviewed. • The low value and the potential secondary pollution will be the major problems during the nonmetal fraction recycling. • The debromination treatment before the valued-added recovery is the potential development direction. • A new optimized process of recycling nonmetallic components from waste printed circuit boards is proposed. [ABSTRACT FROM AUTHOR]

Biochar has been widely studied as an amendment for use in remediation of water and soil contaminated with heavy metals such as Pb2+ and Zn2+, but the effects of biochar characteristics, including stability, on the competitive adsorption of Pb2+ and Zn2+ by biochars from various sources are incompletely understood. In this work, biochars from three different feedstocks, including rice straw (RS), chicken manure (CM), and sewage sludge (SS), were prepared at two pyrolysis temperatures, 550 and 350 °C, and tested to investigate the influence of their stabilities and other characteristics on their adsorption of Pb2+ and Zn2+ in both single- and binary-metal systems. RS biochar had the highest carbon and hydrogen contents, greatest number of functional groups (e.g., O H and C=C/C=O), highest pH, most negative surface charge, and highest physical stability, and thus the highest adsorption capacity for Pb2+ and Zn2+. Pyrolysis at the higher temperature resulted in a slight decrease in aromatic functional groups on biochar surfaces but higher adsorption capacities for Pb2+ and Zn2+ due to the decreased biochar particle size and increased specific surface area. FTIR, XRD, and XPS analyses indicated that Pb2+ and Zn2+ were absorbed on the biochars primarily via chemical complexation with aromatic functional groups. Quantum chemistry calculations confirmed that these functional groups (e.g., –OH and-COOH) tended to bind more strongly with Pb2+ than with Zn2+ due to the former's lower binding energies, which also accounted for the notable decrease in adsorption of Zn2+ in the presence of Pb2+. In addition, compared to carboxyl groups, hydroxyl groups had smaller binding energies and stronger metal complexation. These findings provide a theoretical basis for improved understanding of potential applications of biochars in environmental remediation. Unlabelled Image • Six biochars were prepared using three feedstocks at two pyrolysis temperatures. • RS biochar had the most functional groups, resulting in higher adsorption capacity. • Biochar stability played an important role in adsorption of Pb2+ and Zn2+. • Biochars prepared at the higher pyrolysis temperature had higher affinities due to enhanced surface area. • Biochar had a greater affinity for Pb2+ than for Zn2+ due to the former's lower binding energy. [ABSTRACT FROM AUTHOR]