Feng Jing, Zhu Bao-Wei, Lim Teik-Thye
School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, Republic of Singapore.
Chemosphere. 2008 Dec;73(11):1817-23. doi: 10.1016/j.chemosphere.2008.08.014. Epub 2008 Sep 21.
The influences of amphiphiles, including humic acid (HA) and various types of surfactants, on dechlorination of carbon tetrachloride (CTC) and chloroform (CF) by the nano-scale Fe particles were investigated. Since the amphiphiles would modify the surface tension between the liquid-liquid and solid-liquid interface, in the presence of amphiphile matrix solution the Fe corrosion rate and the parent compound dechlorination rate would be different from those in the ultrapure water. Among the four amphiphile solutions, Fe corrosion rate was the highest in the anionic surfactant sodium dodecyl sulfate (SDS) solution, presumably due to the existence of chemisorption between the hydrophilic head of SDS and Fe particles. The dechlorination rates of CTC and CF could be described with the pseudo-first order kinetic model. The influences of amphiphiles on the dechlorination reaction rate were related to the species of parent compound and concentration of the matrix solution. The influences of HA on the dechlorination of CTC and CF were the most significant compared to other matrix solutions. At relatively low HA concentration (<0.1 g L(-1)), the HA molecules (serving as electron transfer mediator) would significantly accelerate the dechlorination rate of CF. The two-parameter regression with energy of the lowest unoccupied molecular orbital (E(LUMO)) and HA concentration as the descriptors was developed to predict the specific reduction rate constants of chlorinated methanes in HA solution. The analysis of variance (ANOVA) indicated the existence of significant relationship between the dechlorination rate constants and the two descriptors.
研究了包括腐殖酸（HA）和各种类型表面活性剂在内的两亲性物质对纳米级铁颗粒脱氯四氯化碳（CTC）和氯仿（CF）的影响。由于两亲性物质会改变液 - 液和固 - 液界面之间的表面张力，在两亲性物质基质溶液存在的情况下，铁的腐蚀速率和母体化合物的脱氯速率将与超纯水中的不同。在四种两亲性物质溶液中，铁的腐蚀速率在阴离子表面活性剂十二烷基硫酸钠（SDS）溶液中最高，这可能是由于SDS的亲水头部与铁颗粒之间存在化学吸附。CTC和CF的脱氯速率可用伪一级动力学模型描述。两亲性物质对脱氯反应速率的影响与母体化合物的种类和基质溶液的浓度有关。与其他基质溶液相比，HA对CTC和CF脱氯的影响最为显著。在相对较低的HA浓度（<0.1 g L⁻¹）下，HA分子（作为电子转移介质）会显著加速CF的脱氯速率。建立了以最低未占分子轨道能量（E(LUMO)）和HA浓度为描述符的双参数回归模型，以预测HA溶液中氯代甲烷的特定还原速率常数。方差分析（ANOVA）表明脱氯速率常数与这两个描述符之间存在显著关系。
