Abstract

The effect of nutrient and sulfate additions on As mobility in contaminated soils was investigated under advective-flow anoxic columns in this study. The mobility of As in surface contaminated soils was investigated by the leaching of de-ionized water (DI-water), artificial ground water (AG-water) and AG-water + sulfate (Sulfate). After 144 d of experiments, compared to the DI-water column, the total As exported from the columns AG-water and Sulfate was enhanced by seven and eightfold, respectively. The results indicated that the nutrient and sulfate addition significantly enhanced the As mobility in contaminated soils. In low-sulfate soils (DI-water and AG-water systems), As mobilization was primarily attributed to As reduction and to the transformation of amorphous Fe(III) (oxy)hydroxides. In soil with sulfate addition (Sulfate system), besides As reduction and Fe(III) (oxy)hydroxides transformation, the dissolution of As sulfides and the formation of thioarsenic species under sulfidogenic condition were possibly important processes accelerating As release. In conclusion, the addition of the nutrient solution and sulfates may increase the mobility of As in contaminated soils, posing a potential threat to groundwater. (C) 2014 Elsevier Ltd. All rights reserved.

Keywords

Arsenic mobility; Reduction; Minerals transformation; Sulfidization; Speciation; Anoxic soils

Published in

Chemosphere
2015, Volume: 119, pages: 902-909
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

UKÄ Subject classification

Soil Science
Metallurgy and Metallic Materials


Publication identifier

DOI: https://doi.org/10.1016/j.chemosphere.2014.08.078

Permanent link to this page (URI)

https://res.slu.se/id/publ/85383