Removal of an azo-metal complex textile dye from colored aqueous solutions using an agro-residue

The pine leaves which are an agricultural residue were used in its natural form as biosorbent for the removal of Acid Yellow 220 (AY 220) dye from aqueous solutions. The sorption experiments were carried out as a function of solution pH, biosorbent dosage, biosorbent size, dye concentration, temperature, contact time and ionic strength. The sorption isotherms closely followed the Langmuir model. The monolayer sorption capacity of the pine leaves for AY 220 was found as 40.00 mg g(-1). It was shown that pseudo-second order equation could best describe the sorption kinetics. The thermodynamic data indicated that the sorption system was spontaneous. endothermic and physical process. Based on the results of present investigation, the pine leaves could be used as a suitable alternative biosorbent for the elimination of AY 220 from aqueous solutions. (C) 2011 Elsevier B.V. All rights reserved.