Evaluation and microanalytical study of ZVI/scoria zeolite mixtures for treating acid mine drainage using reactive barriers - Removal mechanisms

Hematite and Goethite minerals were formed in ZVI upon its exposure to AMD during the mine water treatment. The VS that was exposed to AMD showed enhancement of Diopside and Augite along with the formation of two new phases comprising Forsterite and Ferroan. Geochemical changes and microanalytical investigations altogether showed pH-dependent chemical precipitation to be the main mechanism of heavy metal removal by ZVI, while adsorption and cation exchange processes were found to be responsible for pollutant removal by VS.