Destruction of decabromodiphenyl ether (BDE-209) in a ternary carbonate molten salt reactor

摘要

Soil contamination by PBDEs has become a significant environmental concern and requires appropriate remediation technologies. In this study, the destruction of decabromodiphenyl ether (BDE-209) in a ternary molten salt (Li, Na, K)_2 CO_3 reactor was evaluated. The effects of reaction temperature, additive amount of BDE-209 and salt mixture, on off-gas species, were investigated. The salt mixture after reaction was characterized by XRD analysis and a reaction pathway proposed. The results showed that the amounts of C_2H_6, C_2H_4, C_4H_8 and CH_4 in the off-gas decreased with increases in temperature, while the CO_2 level increased. When the reaction temperature reached 750 ℃, incomplete combustion products (PICs) were no longer detected. Increasing BDE-209 loading was not helpful for the reaction, as more PICs were produced. Larger amounts of salt mixture were helpful for the reaction and PICs were not observed with the mole ratio 1: 2000 of BDE-209 to carbonate melt. XRD analysis confirmed the capture of bromine in BDE-209 by the molten salt.