Fate of aluminium and nickel in soil. Evaluation through lysimeters under laboratory conditions

ABSTRACT

Nanomaterials (Nms) applications and environmental deposition are continuously increasing. Aluminum (Al) and nickel (Ni) fate in soil, both from gamma alumina-based Nms and as chloride salts were evaluted through lysimeters. After 85 days of treatment, which included irrigation and collection of eluates, the soil of each lysimeter was divided into four sections. The metal concentration was analyzed in eluates, soil samples, and extracts. Al and iron (Fe) present in soil eluted from Control lysimeter. Al from Nms suspension treatment was quantified in the eluates since 30 days on. Ni eluted upon solid salt deposition on top of one device. These results indicate that Al and Ni applied under certain conditions on soil, could leach and reach groundwater. The total concentration and bioavailability (extractable metals) of Al and Fe in soils showed similar patterns. Ni was retained only in the soil of devices treated with chloride salts. Bioavailability % results were of concern for Ni under certain conditions of treatment: 15.57% and 11.08% in two chloride salt-treated lysimeters versus 0.55% and 0.47% of those in control and treated with Nms lysimeters. Conducting studies with different kinds of soil and longer treatment periods should be useful to understand Nms-metals fate in the environment. The results presented here constitute important evidences both for significant metal release from Nms and elution and for considerable Ni bioavailability, after deposition on soil in the form of Nms or as a chloride salt, respectively. Then, possible toxic effects could occur through exposure of aquatic and terrestrial organisms.