Ligand-assisted degradation of carbon tetrachloride by microscale zero-valent iron.

摘要: Abstract Degradation of carbon tetrachloride (CT) by microscale zero-valent iron (ZVI) was investigated in batch systems with or without organic ligands (ethylenediaminetetraacetic acid (EDTA), citric acid, tartaric malic and oxalic acid) at pHs from 3.5 to 7.5. The results demonstrated that 25 °C, the dechlorination CT ZVI is slow absence ligands, a pseudo-first-order rate constant 0.0217 h −1 pH being further dropped 0.0052 h However, addition significantly enhanced rates extents removal, as indicated increases 39, 31, 32, 28 18 times presence EDTA, respectively, 25 °C. effect EDTA most significant; an initial concentration 20 mg l increased 16.3% (no ligands) 89.1% (with EDTA) end 8 h reaction. degradation primarily attributed elimination surface passivation layer Fe(III) (hydr)oxides on through chelating Fe(III), which maintained exposure active sites CT.