Hanoch R J, Shao H, Butler E C
School of Civil Engineering and Environmental Science, University of Oklahoma, 202 West Boyd, Room 334, Norman, OK 73019, USA.
Chemosphere. 2006 Apr;63(2):323-34. doi: 10.1016/j.chemosphere.2005.07.016. Epub 2005 Sep 9.
This study investigated the transformation of carbon tetrachloride (CT) by goethite, hematite, magnetite, and kaolinite treated with bisulfide to form coatings of iron monosulfide (FeS) and other Fe(II) species. These coatings contribute to abiotic natural attenuation in anaerobic environments. Batch kinetic experiments were performed under anoxic conditions at pH 8.0. Surface-area-normalized pseudo-first-order rate constants for CT transformation did not differ significantly for the three HS- treated iron oxides, but the rate of CT transformation by bisulfide-treated kaolinite was significantly lower, most likely due to kaolinite's lower iron content. The yield of chloroform (CF) from CT transformation was typically approximately 1%. There was negligible or only slight adsorption of several natural organic matter (NOM) model compounds to the surface of HS- treated goethite, and these compounds had no influence on CT transformation rate constants or CF yields. Juglone, on the other hand, adsorbed to a greater extent, and also significantly influenced the CF yield, increasing it by a factor of approximately 20 for HS- treated hematite. We speculate that juglone or its HS- addition product adsorbed to the mineral surface and acted as a hydrogen atom donor that reacted with the trichloromethyl radical intermediate, increasing the CF yield.
本研究调查了用二硫化物处理的针铁矿、赤铁矿、磁铁矿和高岭土对四氯化碳（CT）的转化，以形成硫化亚铁（FeS）和其他亚铁（Fe(II)）物种的涂层。这些涂层有助于厌氧环境中的非生物自然衰减。在缺氧条件下，于pH 8.0进行了间歇动力学实验。三种经HS处理的铁氧化物的CT转化的比表面积归一化准一级速率常数没有显著差异，但经二硫化物处理的高岭土的CT转化率显著较低，这很可能是由于高岭土的铁含量较低。CT转化生成氯仿（CF）的产率通常约为1%。几种天然有机物（NOM）模型化合物在经HS处理的针铁矿表面的吸附可忽略不计或仅有轻微吸附，并且这些化合物对CT转化率常数或CF产率没有影响。另一方面，胡桃醌的吸附程度更大，并且也显著影响CF产率，对于经HS处理的赤铁矿，CF产率提高了约20倍。我们推测，胡桃醌或其加HS产物吸附在矿物表面，并作为与三氯甲基自由基中间体反应的氢原子供体，提高了CF产率。
