To gain insight into the processes of transformations in zero valent iron systems, electrolytic iron (EI) has been used as a surrogate for the commercial products actually used in barriers. This substitution facilitates mechanistic studies, but may not be fully representative of all the relevant processes at work in groundwater remediation. To address this concern, the kinetic iron model (KIM) was used to investigate sorption and reactivity differences between EI and Connelly brand GI, using TCE as a probe compound. It was observed that retardation factors (R_app) for GI varied non-linearly with influent concentrations to the columns (C_o), and declined significantly as GI aged. In contrast, R_app values for EI were small and insensitive to C_o, and changed minimally with iron aging. Moreover, although declines in the rate constants (k) and increases in the sorption coefficients were observed for both iron types, they were most pronounced in the case of EI. SEM scans of the EI surface before and after aging (90 days) established the appearance of carbon on the older surface. This work provides evidence that iron with a higher surface carbon content outperforms pure iron, suggesting that the carbon is actively involved in promoting TCE reduction.

为了深入了解零价铁系统中的转化过程，已将电解铁（EI）用作屏障中实际使用的商业产品的替代品。这种替代方法有助于进行机理研究，但可能不能完全代表地下水修复工作中的所有相关过程。为了解决这个问题，使用TCE作为探针化合物，使用动铁模型（KIM）来研究EI和Connelly品牌GI之间的吸附和反应性差异。观察到，GI的阻滞因子（R _app）与进水浓度（C _o）呈非线性变化，并且随着GI的老化而显着下降。相比之下，R _appEI的值很小，并且对C _o不敏感，并且随着铁的老化而变化很小。此外，尽管在两种铁类型中均观察到速率常数（k）的下降和吸附系数的增加，但在EI的情况下最为明显。老化（90天）之前和之后的EI表面的SEM扫描确定了较老的表面上有碳的外观。这项工作提供了具有较高表面碳含量的铁优于纯铁的证据，表明该碳积极参与了促进TCE降低的工作。