As(III) removal in rapid filters: Effect of pH, Fe(II)/Fe(III), filtration velocity and media size

In the top layer of aerated rapid sand filtration systems, uncharged As(III) is biologically converted to charged As(V). Subsequently, the main removal mechanism for As(V) is adsorption onto oxidised, flocculated Fe(III) (hydrous ferric hydroxides; HFO). The aim of this research was to understand the interactions between As and Fe in...

Arsenic oxidation and removal with Manganese oxides in filters

The actual European Union (EU) guidelines for allowed concentration of arsenic (As) in drinking water fix a maximum of 10 ?g/L. However, this limit is expected to become more stringent: the recommended health related limitation from the US Natural Resources Defense Council is below 1 ?g/L. In Dutch groundwater treatment plants, the produced...