Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been investigated and modeled. Effect of manganese and iron loading on manganese removal and rate of oxidation of adsorbed iron and manganese have been studied.
Aquamandix and IOCS demonstrated iron and manganese adsorption capacity that increases with increasing pH under oxic and anoxic conditions. Manganese loading and low filtration rate using feedwater with no nitrite favour non-uniform development of catalytic manganese oxide on media that subsequently enhances manganese removal.