Characterization of corrosion products in the permeable reactive barriers

The impact of geochemical processes and microbial activity has been a major concern for the long-term performance of reactive iron barriers because co rrosion products and precipitates during the water treatment with reactive materials will decrease the reactivity and permeability of the iron bed. Th is study characterizes corrosion products in reactive iron barrier as well as evaluates the effect of the iron corrosion products and precipitates on iron wall performance during contaminated-water treatment under varying con ditions. Major phases in the reactive iron barrier include iron oxides, car bonates, iron sulfides, and elemental sulfur, depending on the degree of ir on oxidation, groundwater chemistry, and microbial activity. Detailed geoch emical and mineralogical characteristics are imperative for long-range pred ictions of the reactive iron wall performance on water treatment because th e surface coating materials reduce the effectiveness of the zero-valent iro n media.