Organophosphate flame retardants emitted from thermal treatment and open burning of e-waste.

Graphical abstract Highlights • Crude e-waste recycling was simulated in closed chamber. • Emissions of OPFRs were large in both thermal treatment and open burning. • OPFRs were probably emitted in association with particles. • The abundances of OPFRs were lower in coarse particles than in fine particles. Abstract Organophosphate flame retardants (OPFRs) have been increasingly produced and consumed since the gradual phase-out of polybrominated diphenyl ethers. Primitive recycling of e-waste can be a significant input source of OPFRs to the environment. Thermal treatment and open burning of typical e-wastes were conducted in a closed chamber to examine the emissions and the size distribution patterns of particle-bound OPFRs from these processes. The sum emission factors of OPFRs were 3.70 × 104–3.65 × 105 ng g−1 by thermal treatment and 5.22 × 103–9.27 × 104 ng g−1 by open burning. The output-input mass ratios of OPFRs for plastic casings were 0.030–116 and 0.012–7.1 by thermal treatment and open burning, respectively, and were 0.11–40 and 0.0014–6.7 for printed circuit boards. The size distribution patterns of OPFRs were characterized by one unimodal peak (0.56–1.0 μm) for thermal treatment and bimodal peaks (0.56–1.0 or 1.0–1.8 and 10–18 μm) for open burning. Particle-bound OPFRs appeared to form in affiliation with particles rather than by adsorption or deposition from the gaseous phase to particulate organic matter. With increasing amounts of OPFRs used in a variety of consumer products, the emissions of OPFRs to the environment are expected to increase continuously in the future. [ABSTRACT FROM AUTHOR]