Biological As(III) oxidation in rapid sand filters

The objective of this study was to investigate whether arsenic-oxidising bacteria (AsOB) will grow and survive in rapid sand filters. Additionally, the interdependence of other groundwater constituents (Fe(II), Mn(II), NH₄) with biological As(III) oxidation was investigated. For this purpose As(III) oxidation was monitored in pilot...

Effect of supernatant water level on As removal in biological rapid sand filters

Current groundwater treatment facilities, mostly relying on aeration-filtration configurations, aim at the removal of iron (Fe), ammonia (NH ₄ ⁺ ) and manganese (Mn). However, recently water companies expressed the ambition to also reduce arsenic (As) concentrations in these rapid sand filters. The aim of this study was...

As(III) oxidation by MnO₂ during groundwater treatment

The top layer of natural rapid sand filtration was found to effectively oxidise arsenite (As(III)) in groundwater treatment. However, the oxidation pathway has not yet been identified. The aim of this study was to investigate whether naturally formed manganese oxide (MnO₂), present on filter grains, could abiotically be responsible...