Goethite arsenate adsorption

Arsenate is readily adsorbed to Fe, Mn and Al hydrous oxides similarly to phosphorus. Arsenate adsorption is primarily chemisorption onto positively charged oxides. Sorption decreases with increasing pH. Phosphate competes with arsenate sorption, while Cl, N03 and S04 do not significantly suppress arsenate sorption. Hydroxide is the most effective extractant for desorption of As species (arsenate) from oxide (goethite and amorphous Fe oxide) surfaces, while 0.5 M P04 is an extractant for arsenite desorption at low pH (Jackson and Miller, 2000). 

Violante A, Krishnamurti GSR, Pigna M (2008) Mobility of trace elements in soil environments. In Violante A, Huang PM and Gadd G (eds) Wiley-JUPAC series on biophysico-chemical processes of metals and metalloids in soil environments. John Wiley Sons, Hoboken, USA Waltham AC, Eick MJ (2002) Kinetic of arsenic adsorption on goethite in the presence of sorbed silicic acid. Soil Sci Soc Am J 66 818-825 Waychunas GA, Fuller CC, Rea BA, Davis J (1996) Wide angle X-ray scattering (WAXS) study of two-line ferrihydrite structure Effect of arsenate sorption and counterion variation and comparison with EXAFS results. Geochim Cos-mochim Acta 60 1765-1781... 

O Reilly, S. E., Strawn, D. G., and Sparks, D. L., 2001, Residence time effects on arsenate adsorption/desorption mechanisms on goethite Soil Science Society of America Journal, v. 65, p. 67-77. 

Zhang, J.S., Stanforth, R., and Pehkonen, S.O., Proton-arsenic adsorption ratios and zeta potential measurements Implication for protonation of hydroxyls on the goethite surface, 7. Colloid Interf. Sci., 315, 13, 2007. 

Figure 4.8. Adsorption evelopes for phosphate on goethite, arsenate on amorphous aluminium hydroxide, and borate on amorphous iron hydroxide. The ordinate values should be multiplied by ten for the arsenate data.

FIG. 19 Arsenate adsorption to goethite at pH = 3.5 in 0.1 M NaCl. Normalization of uptake and total arsenite concentration is done by the relative molar charge concentration of the bare goethite surface at pH = 3.0. 

Liu F, De Cristofaro A, Violante A (2001) Effect of pH phosphate and oxalate on the adsorption/desorption of arsenate on/from goethite. Soil Sci 166 197-208 Livesey NT, Huang PM (1981) Adsorption of arsenate by soils and its relation to selected properties and anions. Soil Sci 131 88-94 Manceau A (1995) The mechanism of anion adsorption on iron oxides Evidence for the bonding of arsenate tetrahedra on free Fe(0, OH)6 edges. Geochim Cosmochim Acta 59 3647-3653. 

Sun X, Doner, HE (1996) An investigation of arsenate and arsenite bonding structures on goethite by FTIR. Soil Sci 161 865-872 Sun X, Doner HE (1998) Adsorption and oxidation of arsenite on goethite. Soil Sci 163 278-287... 

Trace metal adsorption on goethite is reportedly increased by the presence of sulphate ions (Balistrieri and Murray, 1982). Arsenate and antimony oxyanions enhance uptake of cobalt on ferrihydrite and hematite, respectively (Benjamin and Bloom,... 

Phosphate must be applied as fertilizer to the soil. Ideally it is added in quantities sufficient to guarantee optimal yields, but not in excess in order to avoid P transportation into other compartments of the ecosystem. The amount added should be based on an accurate estimation of the plant-available fraction of P already present in a soil.This is an old and difficult task and a large number of extraction methods have been used since intensive land use was practised. Recently methods have been worked out in which a strip of filter paper impregnated with an Fe oxide (2-line ferri-hydrite) is dipped into a soil suspension and the amount of P adsorbed by the paper is taken as being plant-available (Sissingh,1988 Van der Zee et ah, 1987 Sharpley, 1993 Sharpley et ah,1994 Kuo and Jellum, 1994 Myers et ah 1997). Anion and cation resins extracted more P from four heavily fertilized soils than from goethite (Delgado Torrent, 2000). Other oxyanions adsorbed by soil Fe oxides are silicate, arsenate, chromate, selenite ( ) and sulphate. Adsorption of sulphate led to a release of OH ions and was substantially lowered once the Fe oxides were selectively removed (Fig.16.17). 

Manning, B.A. Goldberg, S. (1996) Modeling competitive adsorption of arsenate with phosphate and molybdate on oxide minerals. Soil Sci. Soc. Am. J. 60 121-131 Manning, B.A. Fendorf S.E. Goldberg, S. (1998) Surface structures and stability of ar-senic(lll) on goethite spectroscopic evidence for inner-sphere complexes. Environ. Sci. Techn. 34 2383-2388... 

Gao, Y. and Mucci, A. (2001) Acid base reaction, phosphate and arsenate complexation, and their competitive adsorption at the surface of goethite in 0.7M NaCl solution. Geochimica et Cosmochimica Acta, 65(14), 2361-78. 

Luengo, C., Brigante, M. and Avena, M. (2007) Adsorption kinetics of phosphate and arsenate on goethite. A comparative study. Journal of Colloid and Interface Science, 311(2), 354-60. 

Zhang, J. and Stanforth, R. (2005) Slow adsorption reaction between arsenic species and goethite (a -FeOOH) diffusion or heterogeneous surface reaction control. Langmuir, 21(7), 2895-901. 

Grafe, M Eick, M.J. and Grossl, P.R. (2001) Adsorption of arsenate (V) and arsenite (III) on goethite in the presence and absence of dissolved organic carbon. Soil Science Society of America Journal, 65(6), 1680-87. 

Charge distribution multisite complexation model (CD-MUSIC) A surface complexation model for explaining ion adsorption on the surfaces of adsorbents. Hiemstra and van Riemsdijk (1999) used the model to explain the adsorption of arsenate oxyanions on goethite. 

Figure 8.2. Desorption of (a) As(lII) and ( ) As(V) from goethite on the onset of dynamic flow conditions. Goethite-coated quartz sand was loaded with arsenic at various fractions of the adsorption maxima, as determined by batch incubations and Langmuir isotherm tits, and then subjected to continuous injection of minimal groundwater medium.

Antelo J. et al.. Effects of pH and ionic strength on the adsorption of phosphate and arsenate at the goethite-water interface, J. Colloid Interf. Sci., 285, 476, 2005. 

Lakshmipathiraj, P. et al.. Adsorption of arsenate on synthetic goethite from aqueous solutions, 7. Hazard. Mater. B, 136, 281, 2006. 

These observations indicate that reduction of As(V) to As(III) does not, in itself, result in the mobilization of arsenic. This conclusion is supported by laboratory adsorption studies showing similar affinities of As(III) and As(V) for hydrous ferric oxide, goethite, and magnetite.16 However, outstanding questions remain regarding the factors that control the rate and extent of the reductive dissolution of iron in these sediments and whether the arsenic (and iron) that is released into the porewater is (re)sorbed onto the residual iron oxyhydroxides in... 

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