Decontamination of Post-Consumer WEEE Plastics: Evaluation of Extraction Methods for Brominated Flame Retardant Removal and Their Effects on Polymer Mechanical Properties

High Resolution Image Download MS PowerPoint Slide Electrical and electronic equipment waste (WEEE) plastics contamination is a major environmental and health issue due to the presence of brominated flame retardants (BFRs), which may have prevented the recycling of 50% of 180 kt of plastics in 2020 in Europe. This study evaluates three BFR extraction techniques on real post-consumer WEEE plastics: Soxhlet extraction (butanol, 12 h), microwave-assisted extraction (MAE; butanol, 30 min), and supercritical fluid extraction (sc CO 2, 3 h; isopropanol co solvent). The batches investigated were 1-BB-PAM (dominant polymers: acrylonitrile−butadiene styrene/polycarbonate (ABS/PC) and polyamide-6 (PA-6)) and 2-BB-CRT (dominant polymer: ABS/PC). Targeted BFRs were tetrabromobisphenol A (TBBPA), polybrominated diphenyl ethers (PBDEs; including decaBDE (DBDE) and hexabrominated congeners (HBDE)), and hexabromocyclododecane (HBCDD), selected because they are restricted under EU RoHS and/or listed under POPs or because of their toxicity. Initial and residual compound-specific concentrations were quantified by GC/MS, and total bromine was screened by XRF to relate molecular data to elemental bromine. Soxhlet extraction permitted removal of TBBPA up to 99.1%, DBDE up to 63.4%, and total BFR reduction of 83.8−85.7% (as, for 1-BB-PAM: TBBPA 34.5 mg/kg, DBDE 370 mg/kg, HBDE 30 mg/kg, compliant with EU thresholds); sc-CO 2 achieved 46.2% total BFR reduction with 80% TBBPA removal (to 771 mg/kg) but showed negligible DBDE removal under the tested conditions; MAE achieved 77% total BFR reduction under butanol/30 min/80 °C. The mechanical characterization (tensile and impact) indicates no deleterious influence of the treatments on material performance, supporting the recovery of treated plastics as usable recyclates.