Progress on Redox Characteristics of an Iron Oxide-Ferrous System in the Hyporheic Zone

The hyporheic zone is a critical zone for the interaction between groundwater and surface water. The heterogeneous system composed of iron oxides and ferrous in the low-permeability zone of the hyporheic zone is vital for the abiotic natural attenuation of pollutants. This review summarized the universality, reduction ability, and influencing factors of the iron oxides and ferrous in groundwater. Chlorinated hydrocarbons are taken as typical pollutants to indicate the role of iron oxide and ferrous system in their abiotic natural attenuation process. The review indicates that the reducing ability of the iron oxide and ferrous system can be expressed by Eh which is influenced by pH, ferrous concentration, and natural organic matter. Whereas the rate constant of abiotic natural attenuation of pollutants can be quantitatively described by Eh. So far, the rapid and accurate determination of Eh and the establishment of quantitative relationships between various pollutants and Eh under complex hydrochemical conditions will be the key to evaluating the abiotic natural attenuation of pollutants in aquifers. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202309090150.