Mythical soil ligand

The value of - the slope of the metal solubility as a function of pH - is often found to be between -0.5 and -0.7 for Cd + and (McBride et al., 1997 Salam and Helmke, 1998 Gray et al., 1999 Sauve et al., 2000). If we take —0.67 as a reasonable value for Cd, then metal solubility will show a 2 3 dependence on soil solution pH. This can be handled by having GEOCHEM-PC consider the formation of a mixed solid phase with a mythical soil ligand, the MSL ... 

Important parameters used to develop the mythical soil ligand (MSL) for input into Geochem-PC (Parker et al, 1995)... 

To test the ability of Fe(IIl) to compete for DMA with other metals, two-metal scenarios were modeled. The findings from this suggest that while Fe(III) is able to effectively compete with Zn, Cd, Cu or Ni at low pH and complex the majority of the DMA present, at higher pHs, the other metals predominate DMA complexation (see Fig. 3). Further GEOCHEM-PC simulations with 25 tiM concentrations of DMA, Fe(III), and Cd/Zn/Cu/Ni, and with neither precipitation nor mythical soil ligand, were of the same general shape as those in Fig. 1 but had... 

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See also in sourсe #XX -- [ , ]

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