Zinc, adsorption

Zinc adsorption can occur via exchange of Zn2+ and Zn(OH)+ with surface-bound Ca2+ on calcite (Zachara et al., 1988). Zinc and Ni form surface complexes on calcite as hydrate until they are incorporated into the structure via recrystallization (Zachara et al., 1991). The selectivity of metal sorption on calcite is as follows Cd > Zn > Ni (Zachara et al., 1991). The easily reducible oxide bound metals are primarily from Mn oxides (Chao, 1972 Shuman, 1982 and 1985a). At pH > 6, Zn sorption on Mn oxide abruptly increases because of hydroxylation of the ions (Loganathan et al., 1977), and a high soil pH in arid soil may favor Zn sorption on Mn oxides due to a great... 

Shuman L.M. Effect of removal of organic matter and iron or manganese-oxides on zinc adsorption by soil. Soil Sci 1988 146 248-254. 

Shuman L.M. Effect of roganic waste amendments on zinc adsorption by two soils. Soil Sci 1999 164 197-205. 

Shuman L.M. Zinc adsorption isotherms for soil clays with and without iron oxides removed. Soil Sci Soc Am J 1976 40 349-352. 

Fig. 16.5 Percent of dissolved As(lll), As(V)(3,j, and adsorbed As during As(III) oxidation kinetics on bimessite (suspension density 0.1 g Lin 0.01 M NaCl, and atmosphere) as a function of pH and initial As(lll) concentration, [As(lll)].. (a) pH 4.5, [As(lll)]. = lOOpM (b) pH 4.5, [As(III)]. = 300pM (c) pH 6.0, [As(lll)]. = lOOpM (d) pH 6.0, [As(lll)]. = 300pM. Reprinted with permission from Power LE, Arai Y, Sparks DL (2005) Zinc adsorption effect on arsenite oxidation kinetics at the bimessite water interface. Environ Sci Technol 39 181-187. Copyright 2005 American Chemical Society...

Zinc adsorption by goethite in the absence and presence of phosphate. Aust. J. 

Xue, J. Huang, P.M. (1995) Zinc adsorption-desorption on short-range ordered iron oxide as influenced by citric add during its formation. Geoderma 64 343—356 Yamada, K. Harato,T. Shiozaki,Y. (1980) Flocculation and sedimentation of red mud. Light Metals 39-50... 

The dissolved concentrations of zinc in the Yangtze, Amazon, and Orinoco rivers have been shown to strongly decrease with pH, between 5 and 8.5 (Shiller and Boyle, 1985). This decrease is similar to that obtained in an experiment in which the pH of unfiltered Mississippi River water was adjusted to various pH values, and to isotherms of zinc adsorption on various natural and synthetic metal oxides surfaces (Figure 23). According to Shiller and Boyle (1985), alkaline rivers have less dissolved zinc because they are more suspended sediment-rich that acidic rivers. values between adsorbed (acid-leachable) zinc and dissolved zinc approach 10 for the Mississippi, which indicates that the Mississippi transports 10 times more adsorbed zinc than dissolved zinc. 

With the diffuse-layer model and the sweep option in MINTEQA2, calculate the adsorption of zinc onto HFO at 0.5-pH-unit increments between pH 4 and 8.5 and determine corresponding surface speciation. Comment on the relationship of surface speciation to the pHpzNpc and on the behavior of surface charge and surface potential around the pHpzNPc- Finally, compute and plot for zinc adsorption from pH 4 to 8.5. Assume the same system conditions as in the previous problem, but with a total added zinc concentration of 10 M. System conditions include I = 0.01 M, Sa = 600 mVg, Cj = 8.9 x 10 g/L, and F = 2 x 10" mol active sites/L. 

Figure 6.4. Fit of tlie two surface Langmuir adsorption isotherm equation to zinc adsorption by two soil horizons. (From Shuman, 1975.)...

A CA approach described zinc adsorption on aquifer sand material from Cape Cod by assuming that the aluminum and iron phases present in the quartz grain coatings have a surface area and site density similar to those of poorly crystalline materials (Davis et al., 1998). A similar approach provided only a semiquantitative prediction of uranium adsorption on an alluvial aquifer sediment from Naturita, Colorado, depending on the assumptions made about the relative amounts of surface area of quartz, ferrihydrite, and goethite (Davis et al., 2004). In both of these studies, the surface complexation model considered... 

Marzal, P., Seco, A., and Gabaldon, C. (1996). Cadmium and zinc adsorption onto activated carbon influence of temperature, pH and metal/carbon ratio. J. Chem. Tech. Biotech., 66, 279—85. 

Kalbasi, M., Racz, G.J., and Loewen-Rudgers. L.A., Mechanism of zinc adsorption by iron and aluminum oxides, Soil Sci., 125, 146, 1978. 

Kandah M. (2001), Zinc adsorption from aqueous solutions using disposal sheep manure waste (SMW), Chemical Engineering Journal, 84, 543-549. 

Sanders JR, El Kherbawy Ml. 1987. The effect of pH on zinc adsorption equilibria and exchangeable zinc pools in soils. Environ Pollut 44 165-176. 

Sources of data C.-P. Huang and W. Stumm, Specific adsorption of cations on hydrous y-AbOa, /. Colloid Interface Sci. 43 409 (1973). B. Bar-Yosef, A. M. Posner, and J. P. Quirk, Zinc adsorption and diffusion in goethite pastes, /. Soil Sci. 26 1 (1975). L. C Bell, A. M. Posner, and J. P. Quirk, The point of zero charge of hydroxyapatite and fluorapatite in aqueous solutions, J. Colloid Interface Sci. 42 250 (1973). A. P. Ferris and W. B. Jepson, The exchange capacities of kaolinite and the preparation of homoionic clays, J. Colloid Interface Sci. 51 245 (1975). 

M.D.A. Bolland, A. M. Posner, and J. P. Quirk, Zinc adsorption by goethite in the absence and presence of phosphate, Aust. J. Soil Res. 15 279 (1977). M. M. Benjamin and N. S. Bloom, Effects of strong binding of anionic adsorbates on adsorption of trace metals on amorphous iron oxyhydroxide, in Adsorption from Aqueous Solutions (P. H. Tewari, ed.). Plenum, New York, 1981. 

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