Assessment of Copper and Lead Biosorption from Aqueous Solutions by Brewer's Yeast

Tania Mihăiescu, Andreea Stănilă, Antonia Odagiu, Radu Mihăiescu

Abstract


Adsorption of Cu(II) and Pb(II) ions by a non-conventional biosorbent, brewer's yeast (a waste by-product from the brewing industry) was investigated. Copper and lead ions were studied, taking into account their ubiquitous presences in various types of industrial waste waters. In order to determine the adsorption capacity (qe) of copper and lead ions by brewer's yeast, in accordance with the data present in specialty literature, experimental tests regarding the study of the concentrations dynamics of metal ions in synthetic aqueous solutions treated with known quantities of biosorbent were performed. The impacts of various parameters such as contact time, pH and biosorbent dose on the removal efficiency were assessed. The results demonstrate that the brewers yeast adsorption capacity of metals increases with yeast-metal solution contact time, however it appears that adsorption weakens after 60 minutes, proving that the systems reach equilibrium. It was determined that the pH of solutions is one of the important factors in biosorption. The increase of yeast concentration also affects the metal ions adsorption capacity (doubling the yeast concentration causes a decrease of qe values). The optimum results were obtained for the biosorbent concentration of 0.5% and contact time 60 min., copper at pH 6, and lead at pH 5 respectively.


Keywords


Biosorption, Brewery Yeast, Heavy Metal, Adsorption Capacity.

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