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Recycling process for waste TV sets mainly consists of dismantling, printed wiring board (PWB) heating, PWB recycling, and plastic crushing in formal recycling plant. Polybrominated diphenyl ethers (PBDEs) contained in waste TV sets are released to indoor air. Air samples at 4 different workshops were collected to measure the PBDEs concentrations in both gaseous and particulate phases. The mean concentrations of ∑PBDEs in indoor air were in the range of 6780–2,280,000 pg/m 3 . The highest concentration in gaseous phase (291,000 pg/m 3 ) was detected in the PWB heating workshop. The ∑ 12 PBDEs concentrations in PM 2.5 and PM 10 at the 4 workshops ranged in 6.8–6670 μg/g and 32.6–6790 μg/g, respectively. The gas-particle partitioning of PBDEs was disrupted as PBDEs were continuously released during the recycling processes. Occupational exposure assessment showed that only the exposure concentration of BDE-47 (0.118 μg/kg/day) through inhalation in the PWB heating workshop for workers without facemask exceeded the reference dose (0.1 μg/kg/day), posing a health hazard to workers. All the results demonstrated that recycling of TV sets was an important source of PBDEs emission, and PBDEs emission pollution was related to the composition of TV sets, interior dust, and recycling process. [ABSTRACT FROM AUTHOR]

Abstract: Fiberglass–resin powder (FR powder), a mixture of resin powder and glass fibers reclaimed from pulverized waste printed circuit boards (PCBs), is used as a partial substitute of wood flour in the production of modified phenolic molding compound (MPMC). The results show that incorporation of FR powder into MPMC as a filler enhances the thermal stability represented by heat deflection temperature (HDT). MPMC with FR powder smaller than 0.07mm shows better properties, with a flexural strength of 73MPa, a charpy notched impact strength of 3.0kJ/m2, a HDT of 167°C, and a dielectric strength of 3.7MV/m, all of which meet the standard data. Thermogravimetric analysis shows that thermal degradation of MPMC mainly includes three steps, and over 55% weight loss of MPMC occurs between temperatures of 370°C and 575°C. Phenol is the main volatile compound released from molding powder during the production of molding product. After molding powder cures to molding product, low level of residual phenol is detected. All the results indicate that the MPMC can be used as a new type of molding compound. [Copyright &y& Elsevier]

• Thermal degradation behavior varied with the composition of organic substances. • HCl, benzene, and toluene were detected from pyrolysis of capacitor scarfskin. • Generous amount of particulate matter emitted from the heating of WPCB. • Phenol is one of the main VOCs from the heating of board resin. Waste printed circuit boards mounted with electronic components (WPCB-ECs) are generated from electronic waste dismantling and recycling process. Air-borne pollutants, including particulate matter (PM) and volatile organic compounds (VOCs), can be released during thermal treatment of WPCB-CEs. In this study, organic substances from WPCB-ECs were pyrolyzed by both thermo-gravimetric analysis (TGA) and in a quartz tube furnace. We discovered that board resin and solder coating were degraded in a one-stage process, whereas capacitor scarfskin and wire jacket had two degradation stages. Debromination of brominated flame retardants occurred, and HBr and phenol were the main products during TGA processing of board resin. Dehydrochlorination occurred, and HCl, benzene and toluene were detected during the pyrolysis of capacitor scarfskin. Benzene formation was found only in the first degradation stage (272–372 °C), while toluene was formed both in the two degradation stages. PM with bimodal mass size distributions at diameters of 0.45–0.5 and 4–5 μm were emitted during heating WPCB-ECs. The PM number concentrations were highest in the size ranges of 0.3–0.35 μm and 1.6–2 μm. The research produced new data on pollutant emissions during thermal treatment of WPCB-ECs, and information on strategies to prevent toxic exposures that compromise the health of recyclers. [ABSTRACT FROM AUTHOR]

• Large amount of fine particles were generated during thermal process. • Size distribution of particle-bound PBDEs inside recycling workshops were studied. • The abundance patterns of PBDE congeners in two workshops were different. • Exposure risk of inhaled PBDEs was low compared with reference dose. The emission characteristics of respirable particulate matter (PM 10), and polybrominated diphenyl ether (PBDE) size distribution, gas-particle partitioning and occupational exposure in two e-waste recycling workshops (manual and thermal dismantling workshop: ManuDW and TherDW) were investigated. The PM 10 mass concentration was higher but the number concentration was lower in the ManuDW than in the TherDW. The gaseous phase PBDE concentration (40.5 ng/m3) was higher in the ManuDW than in the TherDW (10.6 ng/m3) while the particulate phase PBDE concentration was just reverse (57.7 vs 156 ng/m3). The size distribution of particle was similar for two workshops but the size distribution of particle-bound PBDE exhibited remarkable differences. BDE-209 was the dominant congener in particle-bound PBDE in the TherDW, while Tri-, Tetra-, and Deca-BDE were the three most abundant homologues in the ManuDW. The size distribution of particle-bound PBDE homologue profile in the ManuDW was also distinct from that in the TherDW. The PBDE exposure doses were 13.9 and 15.3 ng/kg/day in the ManuDW and the TherDW, far lower than reference doses. Gaseous and particle phase have same contribution to the total doses in the ManuDW but the exposure doses in the TherDW mainly come from the particle phase. [ABSTRACT FROM AUTHOR]