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Bench-scale studies were conducted to evaluate the performance of the GranularFerric Hydroxide (GFHTM) media for removing arsenic from contaminatedgroundwater in the presence of silica and vanadium. The effects of reaction pH,adsorbent dosage, and the concentrations of arsenic, vanadium, and silica wereinvestigated. The concentrations of dissolved arsenic (V) and vanadium (V) wereanalyzed using the Inductively Coupled Plasma - Mass Spectroscopy (ICP-MS)method, and the Inductively Coupled Plasma - Atomic Emission Spectroscopy(ICP-AES) method was used to determine the concentration of silicon (Si).Additionally, the concentration of molybdate - reactive silica, an index ofmonomeric soluble silica, was also measured.The results reveal that GFH is capable of removing arsenic in the presence of vanadium and soluble silica. The presence of a colloidal form of silica has asignificant inhibitory impact than the soluble silica. At a lower pH (7.0), GFHremoved more arsenic than vanadium. However, the performance of the media isaffected at higher pH (8.0) conditions. A competition for adsorption sites takesplace when more than one contaminant is present. Results of the U. S. Environmental Protection Agency'sToxic Characteristics Leaching Procedure (TCLP) test showed that theconcentrations of arsenic in the TCLP extracts were less than the regulatory limitof 5 mg/L. The spent media is environmentally friendly and can be disposed of as anon-hazardous material. Includes 20 references, tables, figures.

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Edition: Vol. - No. Published: 11/15/2004 Number of Pages: 15File Size: 1 file , 490 KB