Investigation of adsorbability of basic blue 41 dye by anaerobic and activated sludge biomass

In this study, the adsorption of Basic Blue 41 (BB41) dye onto live activated sludge and anaerobic sludge was investigated. The results showed that both sludge were good adsorbents for BB41 dye; however, it was found that the adsorption capacity of activated sludge (Qmax=437,0 mg/g) was higher than that of anaerobic sludge (Qmax=232,6 mg/g). The adsorption isotherms of both adsorbents were described by Freundlich isotherm (activated sludge; R=0,957, Kf=ll,06, n=l,285) (anaerobic sludge; R=0,998, Kf=3,806, n=l,209) better than Langmuir isotherm. Kinetics of both adsorption processes was best described by pseudo-second order model. The pseudo isotherms of both adsorption processes were also studied with the help of pseudo second order constants and it was concluded that the real isotherms described the anaerobic sludge/BB41 process better than the pseudo isotherms, but pseudo Freundlich isotherm (R=0,9714) described the activated sludge/BB41 process better than the real isotherms. The thermodynamic calculations showed that Gibbs free energies of both processes (activated sludge, AG= -5,44 kJ/mol; anaerobic sludge, AG= -5,33 kJ/mol) have negative values indicating the spontaneous nature of the processes.Keywords: Biosorption, kinetics, pseudo isotherm, thermodynamics.