土壤铁氧化物-亚铁的相互作用及其环境影响研究进展

Soil Iron Oxide-Ferrous Interaction and Its Environmental Effects:A Review

铁氧化物和溶液相亚铁常在厌氧土壤环境中共存。铁氧化物能够加快亚铁的氧化速率,且控制亚铁氧化成矿产物的类型,同时,亚铁与铁氧化物组成的系统是一种良好的还原剂,能够有效还原重金属及降解有机污染物。另一方面,亚铁能够催化铁氧化物晶相转变,导致铁氧化物结构和表面性质发生改变,进而影响相关重金属、有机质的环境行为。本文综述了铁氧化物催化亚铁氧化成矿、铁氧化物–亚铁系统还原污染物以及亚铁催化铁氧化物相变的反应机制及影响因素,最后,对未来在自然土壤中研究铁氧化物–亚铁界面反应及其环境影响进行了展望。

Iron(hydr)oxides(hereafter termed iron oxides)catalyzed oxidation of aqueous Fe(Ⅱ)is an important process in soil environments not only because the two phases often coexist but also because the reactions are frequently coupled with the reduction of organic and inorganic contaminants.Concurrently,recrystallization of iron oxides in the presence of aqueous Fe(Ⅱ)plays a critical part in the iron geochemical cycling as the process leads to changes in the structure and surface properties of iron oxides to alter the ensuing adsorption of heavy metals and organic matter in soils and sediments.In this paper,we reviewed the recent progresses in understanding the interactions of iron oxides and aqueous ferrous with a focus on the reaction mechanism and controlling factors for:1)iron oxide-catalyzed Fe(Ⅱ)oxidation;2)contaminants reduction by the aqueous Fe(Ⅱ)-iron oxides system;and 3)Fe(Ⅱ)-catalyzed recrystallization of iron oxides.In addition,we provide a perspective for the future research of the iron oxide-aqueous Fe(Ⅱ)interface reaction and related environmental impact in soils.