Author(s)

A. M. Gottinger, D. J. Wild, D. McMartin, B. Moldovan & D. Wang

Abstract

The current study examined the use of a ZVI (zero valent iron)/sand filter for the removal of arsenic (As) from Canadian Prairie ground water sources. Batch isotherm data indicated a favourable reaction represented by the Langmuir isotherm equation with loading capacities of 5000 and 2000 mg As/kg ZVI. Column experiments using arsenate-spiked RO water (50 μg/L) and varying volumetric ratios of ZVI to sand indicated no statistical difference in arsenicremoval performance above a ZVI/sand ratio of 20/80 (%, v/v) with removal efficiencies of greater than 98%. A second column study using two ground water sources with 50/50 and 40/60 ZVI/sand filters achieved 89 – 96% As removal. A pilot study using a 50/50 ZVI/sand filter integrated into the existing smallscale biological system showed arsenic removal efficiency of approximately 99.7%. By incorporating this ZVI/sand filter into existing biological treatment, it was capable of removing As to concentrations below 0.1 μg/L and reducing the concentrations of other contaminants, such as ammonia, iron and manganese. The overall performance of the pilot system indicates the ZVI/sand filter is a viable option for arsenic removal from drinking water for small communities (populations < 5000). Keywords: arsenic, ZVI/sand filter, adsorption isotherm, slow sand filtration.

Keywords

arsenic, ZVI/sand filter, adsorption isotherm, slow sand filtration