Resumo

SHAMA, S.A.; MOUSTAFA, M.E.  e  GAD, M.A.. Removal of Heavy Metals Fe³⁺, Cu²⁺, Zn²⁺, Pb²⁺, Cr³⁺ and Cd²⁺ from Aqueous Solutions by Using Eichhornia Crassipes. Port. Electrochim. Acta [online]. 2010, vol.28, n.2, pp.125-133. ISSN 0872-1904.

The adsorption capacity of Eichhornia Crassipes towards metal ions such as Fe³⁺, Cu²⁺, Zn²⁺, Pb²⁺, Cr³⁺ and Cd²⁺, was studied. The adsorption capacity was investigated by batch experiments. The results showed that the removal percentages increased as the weight of sorbent increased, except for Fe³⁺ and Zn²⁺. The effect of contact time was also studied and the results showed that the removal percentages increased as the contact time increased for Cr³⁺, Zn²⁺ and Pb²⁺, but for Fe³⁺, Cu²⁺ and Cd²⁺ the removal decreased. The effect of pH of the solution was also studied and the removal percentages increased as pH increased. Also the effect of the initial concentration of metal ions was studied at four different concentrations (5, 10, 30, 50 mg/L); in case of metal ions (Cu²⁺, Zn²⁺ and Cd²⁺) the removal percentages increased by increasing initial concentration. But, for the other metal ions it decreased by increasing initial concentration over 30 mg/L. The order of increasing removal percentages of metal ions at pH=4.86, initial concentration of metal ions 30 mg/L, and after four hours of shaking was: Cu²⁺< Cr³⁺ <Cd²⁺< Zn²⁺ <Pb²⁺ <Fe³⁺.

Palavras-chave : heavy metals; eichhornia crassipes; atomic absorption; spectrophotometer.

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