Abstract

Afaf Amara-Rekkab, Mohamed Amine Didi*

DOI : http://dx.doi.org/10.13005/ojc/310122

A sensitive, simple method for the determination of amounts of mixture of Hg²⁺and  Cd²⁺ by spectrophotometry was described based on the formation of the Hg²⁺- Cd²⁺- PAN complex in water media. Optimal conditions such as reagent amounts, and pH for the Hg²⁺- Cd²⁺ determination were reported. It was found that the 2:1 PAN- Hg²⁺- Cd²⁺ complex dominate at pH 13.0. In another hand, the sorption of mixture mercury (II) and cadmium (II) from aqueous medium on a chelating resin Chelex 100 was studied in batch mode. Since the extraction kinetic was obtained, with a mixture of 0.1 g of resin and 5 mL of mixture at 1 mmol/L of initial concentration, extraction equilibrium was reached within 20 min of mixing. The influence of some parameters such as initial mixture ions concentrations, initial pH of aqueous solution, ion strength  and the amounts of resin have been studied at fixed temperature (20±1°C). The optimum pH value level for quantitative sorption was up to 2.6. The best performance obtained was 97.1% of extraction yield equivalent to 15.65 mg/g of resin. The pseudo-first- order, pseudo-second-order models and the intra-particle diffusion model were used to describe the kinetic data and rate constants were evaluated.

Mercury; Cadmium; spectrophotometry; PAN; Chelex 100

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