Sand, iron-oxide-coated

Thirunavukkarasu OS, Viraraghavan T, Subramanian KS (2003) Arsenic removal from drinking water using iron oxide-coated sand. Water Air Soil Poll 142 95-111... 

Iron oxide-coated sand (IOCS), for arsenic removal, 3 279, 284-285 Iron oxide control, in industrial water treatment, 26 133 Iron oxide pastes, 19 402 Iron oxide pigments, 19 397-402 production of, 19 385 transparent, 19 412 economic aspects of, 14 557-559... 

Gupta, V.K., Saini, V.K. and Jain, N. (2005) Adsorption of As(III) from aqueous solutions by iron oxide-coated sand. Journal of Colloid and Interface Science, 288(1), 55-60. 

Joshi, A. and Chaudhuri, M. (1996) Removal of arsenic from ground water by iron oxide-coated sand. Journal of Environmental Engineering, 122(8), 769-71. 

Vaishya, R.C. and Gupta, S.K. (2004) Modeling arsenic(V) removal from water by sulfate modified iron-oxide coated sand (SMIOCS). Separation Science and Technology, 39(3), 645-66. 

Benjamin MM, Sletten RS, Bailey RP, Bennett T. Sorption and filtration of metals using iron-oxide-coated sand. Water Res 1996 30 2609-2620. 

Bunn, R.A. et al., Mobilization of natural colloids from an iron oxide-coated sand aquifer Effect of pH and ionic strength, Environ. Sci. Technol., 36, 314, 2002. 

Breakthrough curves from column experiments have been used to provide evidence for diffusion of As to adsorption sites as a rate-controlling mechanism. Darland and Inskeep (1997b) found that adsorption rate constants for As(V) determined under batch conditions were smaller than those necessary to model breakthrough curves for As(V) from columns packed with iron oxide coated sand the rate constants needed to model the breakthrough curves increased with pore water velocity. For example, at the slowest velocity of 1 cm/h, the batch condition rate constant was 4 times smaller than the rate constant needed to model As adsorption in the column experiment. For a velocity of 90 cm/h, the batch rate constant was 35 times smaller. These results are consistent with adsorption limited by diffusion of As(V) from the flowing phase to sites within mineral aggregates. Puls and Powell (1992) also measured more retardation and smaller rate constants for As(V) at slower flow velocities where there was sufficient time for diffusion to adsorption sites. 

Azizian, M.P. and Nelson, P.O., Lead sorption, chemically enhanced desorption, and equilibrium modeling in an iron-oxide-coated sand and synthetic groundwater system, in Adsorption of Metals by Geomedia, Jenne, E., ed.. Academic Press, New York, 1998, p. 165. 

Szecsody, J.E., Zachara, J.M., and Bruckhart, P.L., Adsorption-dissolution reactions affecting the distribution and stability of Co EDTA in iron oxide-coated sand. Environ. Sci. Technol., 28, 1706, 1994. 

Metal-oxide adsorption using packed beds of activated alumina, modified activated alumina, granular ferric hydroxide, iron-oxide coated sands, and other specialty adsorbents... 

The granular metal-oxide adsorbents discussed in this chapter are activated alumina (AAl), modified activated aluminas, iron-oxide-coated sand (IOCS), granular ferric hydroxide (GFH or GEH), and proprietary filter media such as ADI. Although they differ in physical appearance, they all involve hydrous oxides of iron or aluminum that remove arsenic by a process of ligand exchange. Generally, they are employed in packed beds or small filters containing 28 X 48 mesh (0.6-... 

Three of the recently introduced arsenic adsorbents, iron-doped alumina, iron-oxide coated sand, and granular ferric hydroxide, merit a brief discussion here because of their demonstrated effectiveness in removing arsenic. Because ferric hydroxide has a higher capacity for arsenic than does an equivalent surface area of aluminum hydroxide, iron-doped aluminas have been designed for the purpose of improving their arsenic capacity. One such adsorbent is Alcan AAFS-50, a brown-colored promoted alumina that is advertised to have five times the arsenic capacity and less pH sensitivity than conventional activated aluminas (6). Unlike conventional aluminas, AAFS-50 cannot be regenerated, but it reportedly can be landfilled without special treatment. Our recent research (7) showed... 

Iron-oxide-coated sand is another recently introduced arsenic adsorbent that has been shown to have promise for arsenic removal (8,9). However, because the effective adsorption area is only on the surface of the particle, minimal capacity should be expected compared with adsorbents that are pure hydrated iron oxide and are truly porous. An example of the latter type of adsorbent is granular ferric hydroxide (5). 

Ryan, J.N., M. Elimelech, R.A. Ard, R.W. Harvey, and P.R. Johnson. 1999. Bacteriophage PRD I and solica colloid transport and recovery in an iron oxide-coated sand aquifer. Envimn. Sci. Technol. 33 63-73. 

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