Soil contamination due to chlorinated organics prompts an important environmental problem; however, the iron-based reduction materials and complicated ground environment are the main barriers to implementation and promotion of in situ soil remediation. Therefore, this study aims to evaluate the reductants zero-valent iron (ZVI) and its activated carbon composite (AC-ZVI) in terms of their self-oxidation and selectivity in soil experiments. The results indicated that saturated moisture conditions were beneficial for degradation due to the dispersal of the pollutants from soil particles. Particularly, increasing the water/soil ratio to the over-saturated state would decrease the selectivity of ZVI and AC-ZVI. Meanwhile, increasing the reductant loading decreased the selectivity of ZVI and AC-ZVI, whereas the high initial concentration increased the selectivity of AC-ZVI. In addition, the self-oxidation of ZVI (3.0 ×10⁻³ h⁻¹) is 4.2 times higher than that of AC-ZVI (0.7 ×10⁻³ h⁻¹), and the selectivity of AC-ZVI (48%) is 6.9 times higher than that of ZVI (7%), which confirmed that AC-ZVI is a superior iron-based amendment in saturated moisture conditions. Therefore, this study provides a reliable and feasible evaluation method for in situ remediation process, and deepens the understanding of the effects of moisture contents.

氯化有机物造成的土壤污染引发了一个重要的环境问题；然而，铁基还原材料和复杂的地面环境是原位土壤修复实施和推广的主要障碍。因此，本研究旨在评估还原剂零价铁（ZVI）及其活性炭复合材料（AC-ZVI）在土壤实验中的自氧化和选择性。结果表明，由于污染物从土壤颗粒中分散，饱和水分条件有利于降解。特别是，将水土比提高到过饱和状态会降低 ZVI 和 AC-ZVI 的选择性。同时，增加还原剂负载量会降低 ZVI 和 AC-ZVI 的选择性，而高初始浓度增加了 AC-ZVI 的选择性。此外，ZVI 的自氧化 (3.0 ×10^-3 h ^{-1 )是AC-ZVI (0.7 ×10 -3} h ^-1 )的4.2倍，AC-ZVI的选择性(48%)是ZVI (7%)的6.9倍，这证实了 AC-ZVI 在饱和水分条件下是一种优越的铁基改良剂。因此，本研究为原位修复过程提供了一种可靠可行的评价方法，加深了对水分含量影响的认识。