Complexation by humic substances

3 Complexation by humic substances. The average equilibrium quotients for fulvic and 

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Filella, M. and Town, R. M. (2001). Heterogeneity and lability of Pb(II) complexation by humic substances practical interpretation tools, Fresenius J. Anal. Chem., 370, 413 118. 

The Scatchard model23,24 is perhaps the best-known quasiparticle description of complexation by humic substances. The quasiparticles in this case are hypothetical polymeric molecules bearing one class of functional group that forms a 1 1 complex with a cation. The conditional stability constant for the complexation of 1 mol of a metal by 1 mol of a given class of Scatchard quasiparticles can be expressed as... 

The same considerations apply to rate laws developed to describe the kinetics of Al3 complexation by humic substances. This fact can be illustrated by the associative metal-exchange reaction 11,... 

There is no doubt that metal complexation by humic substances is significant in the natural environment, but for any given stream the relative importance of organic to inorganic metal binding can be determined only after a horough evaluation of stream chemistry. Mantoura et al. (1978) included... 

Metal complexation by humic substances in estuaries has received little systematic attention. Only a few metals have been studied, with most of the emphasis on copper because of its obvious importance to plant production. 

In the spectrum of the Cu -humic acid complex (Fig. 12B) the intensity of the 1710 cm band has decreased considerably compared to that of the humic acid. This provides direct evidence for the participation of carboxyl groups in complexation by humic substances in the aqueous environment. 

Perdue EM, Lytle CR (1986) Chemical equilibrium modeling of metal complexation by humic substances. In Carlisle D, Berry WL, Kaplan IR, Watterson JR (eds) Minerals exploration biological systems and organic matter. Prentice-Hall, Englewood Cliffs, pp 428-444... 

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