Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Niigata 950-2181, Japan.
J Hazard Mater. 2012 Nov 30;241-242:355-62. doi: 10.1016/j.jhazmat.2012.09.054. Epub 2012 Oct 2.
Diphenylarsinic acid (DPAA) is known to be the major contaminant in soils where diphenylchloroarsine and diphenylcyanoarsine were abandoned after World Wars I and II. In this study, experimental model studies were performed to elucidate key factors regulating the transformation of DPAA under anaerobic soil conditions. The elimination of DPAA in Gleysol soils (Qiqihar and Shindori soils) was more rapid than in Mollisol and Regosol soils (Heihe and Ikarashi soils, respectively) during a 5-week incubation. No clear relationship between decreasing rates of DPAA concentrations and soil Eh values was found. The Ikarashi soil showed the slowest decrease in DPAA concentrations among the four soils, but the transformation of DPAA was notably enhanced by addition of exogenous sulfate together with acetate, cellulose or rice straw. Addition of molybdate, a specific inhibitor of sulfate reduction, resulted in the stagnation of DPAA transformation, suggesting that indigenous sulfate reducers play a role in DPAA transformation under anaerobic conditions. Arsenate, phenylarsonic acid, phenylmethylarsinic acid, diphenylmethylarsine oxide and three unknown compounds were detected as metabolites of DPAA. This is the first study to reveal enhancement of DPAA transformation under sulfate-reducing conditions.
二苯胂酸（DPAA）是在第一次和第二次世界大战期间，二苯氯胂和二苯氰胂被废弃后，在土壤中发现的主要污染物。在这项研究中，进行了实验模型研究，以阐明在厌氧土壤条件下调节 DPAA 转化的关键因素。在 5 周的培养过程中，Gleysol 土壤（齐齐哈尔和新堀土壤）中 DPAA 的消除速度比 Mollisol 和 Regosol 土壤（黑河和伊卡里希土壤）更快。DPAA 浓度下降率与土壤 Eh 值之间没有明显的关系。在这四种土壤中，伊卡里希土壤中 DPAA 浓度的下降最慢，但在外源硫酸盐与乙酸盐、纤维素或稻草一起添加时，DPAA 的转化明显增强。添加钼酸盐，一种硫酸盐还原的特异性抑制剂，导致 DPAA 转化停滞，表明在厌氧条件下，本地硫酸盐还原菌在 DPAA 转化中起作用。砷酸盐、苯胂酸、苯甲基胂酸、二苯甲基胂氧化和三种未知化合物被检测为 DPAA 的代谢物。这是首次揭示在硫酸盐还原条件下 DPAA 转化增强的研究。
