The influence of in situ synthesized biocomposite consisted of Phragmites australis (Pha) - common reed and emeraldine base (Emb) on the removal of copper ion from aqueous media is discussed. The biocomposites were prepared with two different ratios of common reed/aniline (samples Pha/Emb1 and Pha/Emb2, respectively. Physicochemical parameters such as initial copper ion concentration, composite dosage and contact time between the composites and Cu(II) ions in aqueous solution were studied. An assessment of the equilibrium and the kinetics of sorption of copper ions has been made. Removal efficiency of 99.6 % was achieved with Pha/Emb1 and 91.9 % with Pha/Emb2, respectively. The experimental results were fitted to the isotherms of Langmuir, Freundlich, Temkin and DubininRadushkevich. It was established that the Langmuir isotherm is more suitable for the case of emeraldine base and for composite Pha/Emb1, while the Dubinin-Radushkevich isotherm is more suitable for the case of Pha/Emb2 (with higher content of common reed). The influence of the plant quantity in the biocomposite is important for the mechanism of Cu2+ removal. Physical adsorption and ion exchange are dominant in the case of Pha/Emb1, and Emb, while in the case of Pha/Emb2 the chemical interaction is predominant. The kinetics of Cu(II) adsorption onto biocomposites followed pseudo-second-order model.
Key words: In situ polymerization, polyaniline, Phragmites australis, copper ions adsorption.
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