Development Of A Rapid Small Scale Column Testing Procedure For The Evaluation Of Arsenic Adsorption Media PDF Download

Potable water supplies drawn from groundwater with high levels of arsenic are a serious public heath concern all over the world. Although adsorption technology has been recognized as one of the promising technologies to remove arsenic, few quantitative studies have been conducted to elucidate the influence of water quality on arsenic removal by adsorption technology. In this study, the extended triple layer model (ETLM), a surface complexation model consistent with spectroscopic and theoretical molecular evidence, was first systematically tested for its capability to predict arsenic adsorption on a common goethite-based granular porous adsorptive media (Bayoxide E33®) under wide range of solution conditions. Adsorption equilibrium constants of arsenate, phosphate, and carbonate were determined in single-solute systems, and these constants were used to predict competitive interactions of those ions in dual-solute systems. The ETLM successfully predicted the competitive interactions using the adsorption equilibrium constants determined in single-solute systems. The arsenate (As(V)) removal performance of a fixed-bed adsorber packed with a goethite-based adsorbent was also systematically studied at different pH, initial arsenate concentration, and empty bed contact time (ECBT) in the absence and presence of competing ions (silicate, phosphate, and vanadate). Rapid small scale column tests (RSSCTs) were extensively conducted with synthetic waters in which water quality was controlled within the environmentally relevant range. The column study quantitatively elucidates influence of water quality and operating conditions on arsenate removal by fixed-bed iron oxide adsorber. Iron oxide nanoparticles were synthesized using the inverse flame synthesis method to develop a novel adsorbent that has higher adsorption capacity than commonly used commercial adsorbents. The iron oxide nanoparticles were synthesized and fabricated using the different inverse flame conditions. The developed iron oxide nanoparticle has much higher adsorption capacity than a widely-used commercial adsorbent, Bayoxide E33. Since the inverse flame synthesis is a cost effective and suitable for large production, it can be used to synthesis adsorbent for potable water treatment or environmental remediation.