AWWA ACE61609

ArsenXsupnp/sup, a novel hybrid (i.e., inorganic/organic) sorbent, has been developed bySolmeteX, Inc. to combine the arsenic affinity of an iron-based media with theruggedness of a polymeric ion exchange resin bead. ArsenXsupnp/sup consists of spherical,porous, polymeric anion exchanger beads within which hydrous iron oxide nano-particleshave been uniformly and irreversibly dispersed. The size of the polymeric beads rangesfrom 300 to 1200 microns in diameter and they typically contain around 25% elementaliron based on dry weight. The ArsenXsupnp/sup sorbent utilizes well-established iron chemistryin combination with conventional ion exchange processes to adsorb arsenic species fromwater with minimal competition from other anions, such as sulfate, bicarbonate andchloride. Additionally, the durable nature of the polymer substrate makes ArsenXsupnp/sup moreconvenient to handle compared to friable iron-based sorbents like GFH and E33.ArsenXsupnp/sup has been certified by the National Sanitary Foundation (NSF) for potable wateruse and is NSF-61 compliant. Recently, an iron-impregnated cation exchange sorbent hasalso been developed, but showed only a limited arsenic capacity in model water(DeMarco et al. 2003). The purpose of this study was to perform field and laboratorybased evaluations of ArsenXsupnp/sup for the removal of arsenic from drinking waters usingpacked bed systems. Specific objectives included: characterization of physico-chemicalproperties of ArsenXsupnp/sup; evaluation of arsenic treatability in pilot testings;implementation of rapid small-scale column tests (RSSCTs) to simulate pilot columnperformance; and, estimation of arsenic desorption under several regenerationconditions and to determine the regeneration potential. A series of laboratory and fieldbased batch and column experiments were carried out to accomplish the above-mentionedobjectives. Includes 38 references, tables, figures.



Keywords: Arsenic; Iron; Ion Exchange; Laboratories; Regeneration; Modeling; Testing; Desorption; Resins