A study on the adsorption of chromium on laterite from Guizhou Province, China

Abstract

The adsorption behaviors of Cr(VI) on laterite from Guizhou Province were studied in this paper, and the adsorption mechanism was discussed as well. Results showed that different mineral compositions in the laterite would cause differences in the capacity of laterite to absorb Cr(VI). Gibbsite, iron oxide minerals and non-crystalloids are the main contributors to enhancing the capacity of laterite to absorb Cr(VI). The pH of the solution is an important factor affecting the adsorption of Cr(VI) on laterite. Acidic environment (pH=2-5) is favorable to the adsorption of Cr(VI). The amount of adsorbed Cr(VI) decreases with increasing pH of the solution. With increasing initial concentrations of Cr(VI), the amount of adsorbed Cr(VI) increases first, and then decreases. The optimal adsorption concentration of Cr(VI) on laterite is 250 μg/mL. The adsorption of Cr(VI) on laterite is a rapid process, about 80% Cr(VI) will be adsorbed within 2 hours. And the adsorption of Cr(VI) on kaolinite is a slow process.

Nickel contamination of laterite soil by hydraulic fracturing flowback water: Geochemical behaviour and policy implications

“…The laterite profile in this karst area usually has obvious vertical zonation. Four zones can be classified from top to bottom, depending on the weathering intensity (a) the surface soil zone, which has undergone the entire laterite development process; (b) the fully weathered zone, which may constitute more than 90% of the total thickness; (c) the moderately weathered zone, which is the laterite to carbonate rock transition zone with typically 0.1–0.2 m thickness; and (d) the bedrock zone (Yu et al., 2008; Yu et al, 2009; Zhu & Qi, 1997).…”