Abstract
The reactivity of copper smelter dust enriched in arsenic (53% As), predominantly composed of arsenolite (As2O3), was investigated by an in situ weathering experimental approach. The dust placed in perforated experimental bags (1 μm mesh) was incubated for 6, 12, 18 and 24 months in different depths of four contrasting soils developed under different vegetation covers.
Total concentrations and speciation of As were measured in soils and soil pore water. Mass losses increased over time from 4 to 42% and As concentration in soil increased to 849 mg/kg.
Soil pore water contained up to 13 mg/l and As(V) was predominant species. SEM and XRD investigation indicated that arsenolite was highly weathered especially in Cambisols developed under the beech cover and complex Ca-Pb-Cu-Fe-Zn-As-S phase formed as a secondary alteration product.