Fate of low arsenic concentrations during full-scale aeration and rapid filtration

Abstract

Arsenic (As) mobility during full-scale aeration and rapid filtration was investigated. As(III) remained largely mobile during aeration and as supernatant water and was not efficiently immobilized. In the filter bed however, oxidation of As(III) was complete within 2 min of contact time and As removal efficiency improved. Therefore, the overall conclusion is that not aeration and supernatant storage, but the filter bed is the crucial treatment step for rapid As(III) removal, indicating the importance to control the oxidation sequence of Fe and As for achieving improved As removal efficiencies.