BAEZ German David
congresos y reuniones científicas
Lead removal from water by adsorption on pre - treated biomass (Saccharomyces cerevisiae)
MAULIÓN, EVANGELINA; BÁEZ, GERMÁN; BALLERINI, GRISELDA; MORO, ANDREA; DELORENZI, NÉSTOR; BUSTI, PABLO
Congreso; XII. Congreso, XXX Reunión anual de la Sociedad de Biología Rosario 2010; 2010
Water pollution with heavy metals is an important issue and ordinary methods to remove these contaminants are expensive. This situation has led to the development of new technologies. Bioadsorption is a property of microorganisms to bind metals and it can be improved trough physicochemical treatments. The use of dead Saccharomyces cerevisiae is an attractive alternative because: i) it does not need nutrients, ii) it is not affected by the contaminant toxicity and iii) it is an industrial fermentation waste. In this work, Pb2+ maximum bioadsorption capacity of yeast (qmax) was optimized. Treated yeast were prepared by suspending cells in H2O2 (pH 4.50) and heating for one hour at 3 atm. The conditions were established through a central composite design by the software Design Expert? 6.0. The temperature was ranged from 19.80 to 55.20 ºC and H2O2 concentration from 1.01 to 199.99 vol. The yeast was washed with distilled water, dried and milled. Batch equilibrium was performed shaking 100 mL of Pb2+ solution with 300 mg of biomass during two hours. Initial lead concentration was ranged between 50 and 400 ppm. Remaining metal concentration was measured by the dithizone method. The parameter qmax was predicted by the Langmuir equation and the value of untreated biomass was 53 mg g-1. Surface response method generated a mathematical model that forecasted the qmax of treated biomass. It suggested that suspending yeast in H2O2 30 vol at 50 ºC would generate an optimal qmax. Batch experiment was assayed with that biomass and qmax value was 72.32 mg g-1. Therefore, Pb2+ maximum bioadsorption capacity was increased 45% compared with untreated biomass.