Tandem Efficient Bromine Removal and Silver Recovery by Resorcinol-Formaldehyde Resin Nanoparticles.

Halogen wastewater greatly threatens the health of human beings and aquatic organisms due to its severe toxicity, corrosiveness, and volatility. Efficient bromine removal is therefore urgently required, while existing Br2-capture materials often face challenges from limited water stability and possible halogen leaking. We report a facile and efficient aqueous Br2 removal method using submicron resorcinol-formaldehyde (RF) resin nanoparticles (NPs). The abundant aromatic groups dominate the Br2 removal by substitution reactions. An excellent Br2 conversion capacity of 7441 mg gRF-1 was achieved by RF NPs that outperform state-of-the-art materials by ∼2-fold, along with advantages including good water stability, low cost, and easy fabrication. Two recycling-coupled (electrochemical or H2O2-involved) Br2 removal routes further reveal the feasibility of in-depth halogen removal by RF NPs. The brominated resin can be downstream upcycled for silver recovery, realizing the harvesting of precious metal, reducing of heavy-metal pollution, and resource utilization of brominated resin.