Abstract The transformation of iron sulfide to pyrite is an important process in anoxic environments that strongly influences the mobility of metal(loid)s such as As. It is, therefore, important to understand the fate of As in this process. In this study, batch experiments were conducted at 150 °C and 80 °C and pH 7.5 and 6.0 to examine the transfer of As in the transformation of amorphous FeS to pyrite. The solid phase was characterized using XRD, SEM-EDS, and XPS. The transformation of FeS to pyrite can be promoted in the presence of As(III). During the transformation of FeS loaded with As(III), dissolution of FeS occurs prior to pyrite formation. As(III) is first released in the stage of FeS dissolution, and then is incorporated into the newly formed pyrite. Both high temperature and low pH can promote As uptake by pyrite. XPS analysis indicated sorption as a pathway of As incorporation into pyrite. The contribution from the pathway of lattice substitution is proposed to become significant at high temperature. The results of this study show that As lost or gain in solid phases can occur depending on the As uptake ability by pyrite under different conditions and the initial As loading.

中文翻译：

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在无定形 FeS 转化为黄铁矿的过程中，FeS 结合的砷转化为黄铁矿

摘要 硫化铁向黄铁矿的转化是缺氧环境中的一个重要过程，它强烈影响金属（液体）如 As 的迁移率。因此，在此过程中了解 As 的命运非常重要。在这项研究中，在 150 °C 和 80 °C 以及 pH 7.5 和 6.0 下进行了批量实验，以检查在无定形 FeS 向黄铁矿的转化过程中 As 的转移。使用 XRD、SEM-EDS 和 XPS 表征固相。在 As(III) 的存在下，可以促进 FeS 向黄铁矿的转化。在负载 As(III) 的 FeS 的转化过程中，FeS 的溶解发生在黄铁矿形成之前。As(III) 在 FeS 溶解阶段首先释放，然后结合到新形成的黄铁矿中。高温和低 pH 值均可促进黄铁矿对砷的吸收。XPS 分析表明吸附是砷掺入黄铁矿的途径。来自晶格取代途径的贡献被认为在高温下变得显着。这项研究的结果表明，固相中砷的损失或增加可能取决于黄铁矿在不同条件下的砷吸收能力和初始砷负载。