Study on Adsorbing Chromium(VI) Ions in Wastewater by Aureobacidium pullulans Secretion of Melanin
Heavy water is a class of highly contaminated waste water, even if the concentration is small, it can cause harm, and the toxicity is long-term sustainability.In this paper, Aureobasidium pullulans secretion of melanin were used for adsorption of Cr6+ ions in waste water.Aureobasidium pullulans strain were activated, cultured for seed and fermented, so that secreted melanin. The Aureobasidium pullulans secretion of melanin were made of dry cell, four factors such as pH, time, amount of bacteria,temperature and three level orthogonal experimental made for adsorption of chromium metal.Results showed, adsorption of chromium metal by dry cells for the best conditions: control temperature 30 , pH 3, the adsorption time was 2 hours, the absorption rate was 27%; and reached the four factors on the adsorption of Cr6+ for Aureobasidium pullulans followed the order: pH> bacteria amount> of time> temperature. In the best adsorption conditions were wet cell assay for adsorption of chromium metal. With 4% (V/V) hydrogen peroxide of 0.01ml/mg bleaching for the dry and wet cell, then for its adsorption of chrome metal. The results showed that the order of effect on adsorption of heavey metal ions by Aureobasidium were: the dry cells secretion of melanin> the wet cells secretion of melanin > decolorized dry cells> decolorized wet cells. It showed that adsorption ability of heavy metals by Aureobasidium pullulans was related to its secretion of melanin.
Jingtao Han, Zhengyi Jiang and Sihai Jiao
X. H. Yu et al., "Study on Adsorbing Chromium(VI) Ions in Wastewater by Aureobacidium pullulans Secretion of Melanin", Advanced Materials Research, Vols. 156-157, pp. 1378-1384, 2011