AWWA ACE59832

Nano-structured commercially available porous GFH, E33 and emerging MetsorbG have been experimented for arsenic removal in drinking water systems. Rapid small-scale column tests (RSSCTs) have been employed to evaluate the performance using groundwater of central Arizona. Column adsorption densities (qcolumn) for the water tested on dry mass basis obtained in RSSCTs range 1 ~ 1.2μg As/mg for E33 and 0.5 ~ 0.6μg As/mg for GFH for the water tested. MetsorbG showed lower arsenic treatability than GFH. Microscopic analysis of exhausted medias with SEM and EDX showed relative silica and calcium (i.e. Si : Ca) occupancy with a trend of GFH (4.5 : 1) > E33 (3 : 1) > MetsorbG (1 : 1). Adsorbed calcium can be extracted from the exhausted surface by acid rinsing, whereas adsorbed silica can be removed by both acid and base wash. But batch experiments with E33 showed that exhausted media when washed at pH 12 could remove only 15-30% of arsenate. Includes 16 references, tables, figures.