Effect of silica, phosphate and humic substances on sorption of As to commercially available granulated iron minerals and biogenic Fe(Ⅲ)(hydr)oxides

摘要

In spite of extensive research on the sorption or coprecipitation of arsenic (As) species in Fe-rich systems, the factors influencing their immobilization and removal from drinking water are still not fully understood. Even less is known about the efficiency of biogenic Fe minerals for As sorption and co-precipitation. In various aqueous systems, aerobic Fe(Ⅱ)-oxidizing, anaerobic Fe(Ⅲ)-reducing, and anaerobic Fe(Ⅱ)-oxidizing bacteria can influence Fe speciation and cycling (Fig. 1). The role of these microorganisms in the formation or dissolution of Fe(Ⅲ) (hydr)oxides in As sequestration and the factors affecting this interaction has hereto not been elucidated.