Chun Chan Lan, Hozalski Raymond M, Arnold William A
Department of Civil Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA.
Environ Sci Technol. 2005 Nov 1;39(21):8525-32. doi: 10.1021/es051044g.
Corrosion of iron pipes leads to the release of ferrous iron, Fe(II), and the formation of iron oxides, such as goethite and magnetite, on the pipe surface. Fe(II), a potent reductant when associated with iron oxide surfaces, can mediate the reduction of halogenated organic compounds. Batch experiments were performed to investigate the kinetics and pathways of the degradation of selected chlorinated disinfection byproducts (OBPs) by Fe(II) in the presence of synthetic goethite and magnetite. Trichloronitromethane was degraded via reduction, while trichloroacetonitrile, 1,1,1-trichloropropanone, and trichloroacetaldyde hydrate were transformed via both hydrolysis and reduction. Chloroform and trichloroacetic acid were unreactive. Observed pseudo-first-order reductive dehalogenation rates were influenced by DBP chemical structure and identity of the reductant. Fe(II) bound to iron minerals had greater reactivity than either aqueous Fe(II) or structural Fe(II) present in magnetite. For DBPs of structure Cl3C-R, reductive dehalogenation rate constants normalized by the surface density of Fe(II) on both goethite and magnetite correlated with the electronegativity of the -R group and with one electron reduction potential. In addition to chemical transformation, sorption onto the iron oxide minerals was also an important loss process for 1,1,1-trichloropropanone.
铁管的腐蚀会导致亚铁离子（Fe(II)）的释放，并在管道表面形成诸如针铁矿和磁铁矿之类的铁氧化物。当与氧化铁表面结合时，Fe(II)是一种强还原剂，能够介导卤代有机化合物的还原反应。进行了批次实验，以研究在合成针铁矿和磁铁矿存在的情况下，Fe(II)对选定的氯化消毒副产物（DBPs）降解的动力学和途径。三氯硝基甲烷通过还原反应降解，而三氯乙腈、1,1,1-三氯丙酮和三氯乙醛水合物则通过水解和还原反应进行转化。氯仿和三氯乙酸没有反应活性。观察到的伪一级还原脱卤速率受DBP化学结构和还原剂特性的影响。与铁矿物结合的Fe(II)比磁铁矿中存在的水相Fe(II)或结构Fe(II)具有更高的反应活性。对于结构为Cl3C-R的DBPs，通过针铁矿和磁铁矿上Fe(II)的表面密度归一化后的还原脱卤速率常数与-R基团的电负性和单电子还原电位相关。除了化学转化外，1,1,1-三氯丙酮在铁氧化物矿物上的吸附也是一个重要的损失过程。
