Iminodiacetate Resins Mercury

Iminodiacetate resins are clearly more selective among the transition metals than are weak acid

Figure 1 Chelating functionalities: (A) iminodiacetic acid and (B) aminophosphonic acid.

resins. Adsorption of all metal cations decreases with decreasing pH, and uptake of moderately preferred ions such as Ni2 + and Zn2 + becomes negligible at pH 1-2, but Hg2 + and Cu2 + are still strongly adsorbed. For Hg2 + in sulfuric acid, D + 2 L g_1 at pH 1. The advantage of this high selectivity is illustrated by some results for treatment of a highly acidic, mercury-containing smelter wastewater. Simulated wastewater containing Hg(II), Zn(II), Fe(III), Cd(II) and Pb(II) salts at pH 1.5 was treated with an iminodiacetate resin in bench-scale column runs. Table 4 and Figure 2 show the composition of the column effluent over 157 bed volumes. Uptake of Hg(II) was close to 100%, while most of the other cations were not significantly adsorbed. Adsorption of mercury can be represented by:

It appears that a small amount of Pb(II) is adsorbed initially, then displaced by Hg(II). Fe(III) is adsorbed more strongly than Pb(II), but still less strongly than Hg(II). Uptake of iron can essentially be eliminated by reducing Fe(III) to Fe(II), which is not significantly adsorbed at this low pH.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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