Profile distribution of As(III) and As(V) species in soil and groundwater in Bozanta area

The profile distribution of arsenic(III) and arsenic(V) species in soil and groundwater was investigated in the samples collected in 2005 from a hand-drilled well, in the Bozanta area, Baia Mare region, Romania. The total content of arsenic in the soil was in the range of 525 - 672 mg kg(-1) exceeding 21 - 27 times the action trigger level for sensitive soil. 0.9 - 11.3 % of the total content was soluble in water, 83.0 - 92.6 % in 10 mol dm(-3) HCl and 2.6 - 13.3 % was the residual fraction. Arsenic( V) was the dominant arsenic species in the soil in the range of 405 - 580 mg kg(-1). The distribution and mobility of arsenic species was governed by soil pH and contents of Al, Fe, and Mn. The mobility of arsenic( V) decreased with depth, while that of arsenic( III) was high at the surface and in the proximity of groundwater. The total concentration of arsenic in groundwater was ( 43.40 +/- 1.70) mu g dm(-3), which exceeded the maximum contaminant level of 10 mu g dm(-3).