Biosorption of acidic textile dyestuffs from aqueous solution by Paecilomyces sp. isolated from acidic mine drainage

Abstract

Removal of textile dyestuffs from aqueous solution by biosorption onto a dead fungal biomass isolated from acidic mine drainage in the Çanakkale Region of Turkey was investigated. The fungus was found to be a promising biosorbent and identified as Paecilomyces sp. The optimal conditions for bioremediation were as follows: pH, 2.0; initial dyestuff concentration, 50 mg l(-1) for Reactive Yellow 85 and Reactive Orange 12, and 75 mg l(-1) for Reactive Black 8; biomass dosage, 2 g l(-1) for Reactive Yellow 85, 3 g l(-1) for Reactive Orange 12, 4 g l(-1) for Reactive Black 8; temperature, 25 °C; and agitation rate, 100 rpm. Zeta potential measurements indicated an electrostatic interaction between the binding sites and dye anions. Fourier transform infrared spectroscopy showed that amine, hydroxyl, carbonyl, and amide bonds were involved in the dyestuff biosorption. A toxicity investigation was also carried out before and after the biosorption process. These results showed that the toxicities for the reactive dyestuffs in aqueous solutions after biosorption studies decreased. The Freundlich and Langmuir adsorption models were used for the mathematical description of the biosorption equilibrium, and isotherm constants were evaluated for each dyestuff. Equilibrium data of biosorption of RY85 and RO12 dyestuffs fitted well to both models at the studied concentration and temperature.

Talaromyces aculeatus from acidic environment as a new fungal biosorbent for removal of some reactive textile dyes

“…However, there is no peak referring aromatic group in the FTIR spectra of RB13-loaded biosorbent. To remove of acidic dyes from aqueous solutions, the electrostatic interactions were also proposed in this study as well as the studies of Colak and co-workers [26], Cengiz et al [27] and Çabuk et al [18]. This may be explained by the electrostatic attraction between the positively charged surface (NH3 + , -COOH2 + ) and the negative sulfonate (-SO2O − ) groups of the dyestuff molecule in acidic environment.…”

“…For all textile dyes in this study, the biosorption percentages of fungal biosorbent decreased with enhancing pH (after pH 2), indicating the important forces between dye anion molecules and the dye binding regions of the positively charged bioadsorbent surface. In other words, the negative charge density on the biosorbent surface enhanced when the pH was increased; therefore biosorption was decreased [17][18][19].…”

“…could produce a number of commercial enzymes including cellulases, amylases and chitinases [15,16] and it represents a fungal biomass potential source for use in biosorptive technology. These organisms exhibiting tolerance to strong acidic conditions have important potential for use in applications of biotechnology, including acidic textile dye wastewater decolorization [3,[17][18][19].…”