ABSTRACT
In recent years the health impacts of prolonged exposure to low concentrations of arsenic (As) have been established. Dutch drinking water companies, with a proactive vision towards potential changes in legislation of As concentrations in drinking water, actively try to reduce As concentrations under 1 µg/L. In this research the implementation of ferric chloride dosing combined with membrane filtration at the terminal end of a drinking treatment plant as As removal technique has been studied. The study aimed to assess the effect of phosphate, silica and dissolved organic matter on ferric hydroxide formation, growth and As adsorption in both synthetic and natural groundwater. Moreover, two partial treated drinking waters were used to assess the effectiveness of the combined co-precipitation/membrane filtration method. As shown in the results, DOC significantly affected particle formation and growth which subsequently reduced As adsorption. Arsenic removal was influenced Si and P while particle growth was not significantly affected. The study concluded that FeCl3 dosing combined with membrane filtration suffices as a treatment method to reduce As concentrations below 1 µg/L in drinking water.
