Department of Basic Sciences and Environment, University of Copenhagen , Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
Environ Sci Technol. 2012 Mar 20;46(6):3390-7. doi: 10.1021/es204368u. Epub 2012 Mar 7.
The reductive dechlorination of carbon tetrachloride (CT) by Fe(II)-Fe(III) hydroxide (green rust) intercalated with dodecanoate, Fe(II)(4)Fe(III)(2)(OH)(12)(C(12)H(23)O(2))(2) · yH(2)O (designated GR(C12)), at pH ~ 8 and at room temperature was investigated. CT at concentration levels similar to those found in heavily contaminated groundwater close to polluted industrial sites (14-988 μM) was reduced mainly to the fully dechlorinated products carbon monoxide (CO, yields >54%) and formic acid (HCOOH, yields >6%). Minor formation of chloroform (CF), the only chlorinated degradation product, was also detected (yields <6.3%). Reactions carried out with excess GR followed pseudo first-order kinetics with respect to CT with rate constants ranging from 6.5 × 10(-2) to 0.47 h(-1). These rate constants are comparable to those measured for CT dechlorinations mediated by zerovalent iron. Reduction of the highest concentration of CT (1.4 mM) proceeds until 56% of the Fe(II) sites of GR(C12) was consumed. This reaction ceased after 10 h due to surface passivation of GR(C12).
层状双金属氢氧化物（GR）插层十二烷酸盐 Fe(II)(4)Fe(III)(2)(OH)(12)(C(12)H(23)O(2))(2)·yH(2)O（GR(C12)）内的 Fe(II)-Fe(III)氢氧化物将四氯化碳（CT）还原脱氯，在 pH 值约为 8 且温度为室温的条件下进行了研究。CT 的浓度水平类似于受污染工业场地附近重度污染地下水的浓度水平（14-988 μM），主要还原为完全脱氯产物一氧化碳（CO，产率>54%）和甲酸（HCOOH，产率>6%）。还检测到少量氯仿（CF）的形成，这是唯一的氯化降解产物（产率<6.3%）。用过量的 GR 进行的反应对 CT 具有准一级动力学，反应速率常数范围从 6.5×10(-2)到 0.47 h(-1)。这些速率常数与零价铁介导的 CT 脱氯测量值相当。GR(C12)中 56%的 Fe(II)位被消耗，最高浓度的 CT（1.4 mM）的还原进行到 56%。由于 GR(C12)的表面钝化，该反应在 10 小时后停止。
