Iron and manganese amended activated alumina - A medium for adsorption/oxidation of arsenic from water

In a laboratory study, iron and manganese amended activated alumina (IMAA) showed promise as an effective medium for removing arsenic [As(III) and As(V)] from groundwater. Batch adsorption/oxidation kinetic test indicated that the effectiveness of the IMAA medium was due to in situ oxidation of As(III) to As(V) and higher adsorption of As(V) by the medium. A home arsenic removal unit, containing 4 L of IMAA or AA and operated at 6 L/h, produced 2400 L and 2340 L or 1392 L and 1320 L of water in two cycles of runs when the influent arsenic concentration was 1.0 mg/L [0.6 mg/L of As(III) and 0.4 mg/L of As(V)]. The IMAA medium should be subjected to field trials to assess the long-term effects on performance, such as loss of medium capacity, attrition of the iron and manganese coating, fouling by organics, and pH and competing ion effects. © IWA Publishing 2007.