Immobilization of toxic metal cations on goethite-amended soils: a remediation strategy.

Autor: MOKWENYE, IFESINACHI I., DIAGBOYA, PAUL N., OLUOWOLABI, BAMIDELE I., ANIGBOGU, IKENNA O., OWAMAH, HILARY I.
Zdroj: Journal of Applied Sciences & Environmental Management; Jun2016, Vol. 20 Issue 2, p436-443, 8p
Abstrakt: The study investigates a simple and viable option to reduce toxic metals mobility and availability in four surface (0-30cm) soils with varying physicochemical properties amended by different percentages of goethite. Batch sorption experiments carried out to study the effectiveness of immobilizing Pb2+, Cu2+, Zn2+ and Cd2+ ions on these soils showed that goethite played vital role in the metals adsorption (≥10% increase in adsorption). Removal of soil iron oxides caused reduced Pb2+ adsorption on soils with high organic matter (≤10% decrease in adsorption) with no significant increase in adsorption upon amendment, while soils having low organic matter had enhanced adsorption with amendment. Cu2+ and Cd2+ adsorptions were not enhanced even at 10% goethite amendment. However, Zn2+ adsorption was interestingly different: the soils showed ≥55 % increases upon removal of inherent soil iron oxides without goethite amendment. Goethite amendments further enhanced Zn2+ adsorption on these soils. Generally, both whole and amended soils showed higher preference for Pb2+; the sorption trend is - Pb2+ >Cu2+ >Zn2+ >Cd2+. Goethite amendment of these soils improved Pb2+ and Zn2+ adsorption. Hence, goethite amendment may be an effective method for immobilizing Pb2+ and Zn2+ on these soils and thus reducing their availability to biota. The quantity of goethite required by a soil to attain maximum immobilization varies depending on the metal and the soil's physicochemical properties; however, Cu2+ and Cd2+ may not be effectively immobilized using goethite amendment. ' [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index