Abstract
The leaching of arsenic from contaminated sediments was investigated using flow injection-hydride generation-atomic fluorescence spectrometry as reported in the previous paper of this journal. Leached arsenite (As(III)) and arsenate (As(V)) were monitored with high time resolution (2 min), low sample consumption (120 µL) and high sensitivity. Investigations were carried out using contaminated sediments sampled along a river near an old arsenic mine to characterize the kinetic behavior of arsenic leaching. The effect of phosphate was also examined under aerobic conditions at neutral pH. The obtained results indicated that the leaching of arsenate increased with phosphate addition in the suspension until equilibrium was reached. Leaching processes were characterized according to kinetic investigations. As(V) leaching was slower, but the amount of leaching was much higher compared with that of As(III).
