Cr(VI) reduction at the magnetite-zero-valent iron/water interface

Abstract:

Chemical reduction of highly mobile Cr(VI) to immobile Cr(III) is one of the most utilized methods to remediate Cr(VI)-contaminated environments. The mineral magnetite provides an adequate reducing capacity but the surface-driven reaction is passivated by consumption of available surface Fe(II), which is oxidized to Fe(III), and the reduction yields obtained are not optimal. Its mixture with metallic Fe(0) appears to provide an appropriate medium for replenishment of the Fe(II) lost at the surface. The goals of the present work were (1) to investigate this reduction yield as a function of time, particle size, and proportion of magnetite/Fe(0), and (2) to test the performance of a natural magnetite sample containing small particle sizes, in this process. It was found that a very small (1-5% weight) proportion of Fe(0) increases considerably both the Cr(VI) reduction rate and yield, which are directly proportional to the available magnetite surface area. © 2010 Taylor & Francis Group, London.

Año de publicación:

2010

Keywords:

Fuente:

scopus