Removal of Copper and Zinc from Ground Water by Granular Zero-Valent Iron: A Mechanistic Study

Abstract

Designing water treatment systems with contaminant removal based on zero-valent iron (ZVI) requires an understanding of the formation of a series of iron oxyhydroxides produced during corrosion of the thermodynamically unstable ZVI core. X-ray diffractometry (XRD) and geochemical modelling were used to investigate the mechanisms of copper and zinc removal and the formation of iron oxyhydroxides in batch experiments at 4 and 25°C, over a period of 349 days. Copper removal was predominantly associated with a mineral product, which was unstable in an aerobic environment. Zinc and some copper were sequestered into the iron oxyhydroxide structure and did not redissolve when the pH was reduced. X-..