Physical Sciences and Mathematics Commons^™

Potential Degradation Of Hexabromocyclododecane (Hbcdd) In Sediments: Stereoisomer Specific Reaction Of Hbcdd With Reduced Sulfur Species Or Fe(Ii) Bound To Iron Oxides, Xianmiao Zhang

Dissertations, Theses, and Capstone Projects

The individual degradation rates of the three dominant stereoisomers (alpha, beta, gamma) of hexabromocyclododecane (HBCDD) with bisulfide and polysulfides were investigated at pH 9-10 in methanol/water solutions at two different temperatures (25 °C and 40 °C). alpha-HBCDD reacts significantly slower than beta-HBCDD and gamma-HBCDD. It was also observed that the reaction of HBCDD with polysulfides is faster than with bisulfide. For the reaction of HBCDD with bisulfide, the experiments were performed in 20% water/80% methanol, 50% water/50% methanol and 80% water/20% methanol at 40 °C. It was determined that the solvent polarity affects the reaction and the second-order rate constants …