Co-treatment of brominated epoxy resin waste, copper-based spent catalysts, and dimethylformamide wastewater: Pollutants degradation and resource recovery

Brominated epoxy resin (BER) is the main nonmetallic component of E-waste. Copper-based spent catalyst (CBSC) derived from the industrial process is a typical type of hazardous waste. N, N-dimethylformamide (DMF) wastewater is a typical organic wastewater. In this study, the DMF wastewater was used to construct a subcritical DMF wastewater (SDW) system for the synergistic co-treatment of BER and CBSC. The inter-conversion of copper species with different valence released from CBSC could promote the generation of hydroxyl radicals (·OH), which significantly improved the decomposition of DMF and debromination of BER. The decomposition products of DMF (CO₂, NH₄⁺, dimethylamine (DMA), methylamine (MA)) could promote the debromination of BER and the release of copper species from CBSC. The HBr produced by debromination of BER could promote the release of copper species from CBSC and the degradation of DMF wastewater. Under the optimal conditions, 98.79 % of bromine was removed from BER and 99.08 % of DMF was degraded. Simultaneously, high-purity (58.94 %) phenol could be obtained and 62.97 % of copper could be leached/recovered from CBSC. The results of life cycle assessment (LCA) indicated that the SDW process proposed in this study was a green and low-carbon co-treatment strategy for BER, CBSC, and DMF wastewater.