EVALUATION OF FIELD DEBRIS OF CHICKPEA HUSK AS A LOW-COST BIOSORBENT FOR REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTIONS

In the present study, an important agricultural waste, chickpea straw, was evaluated as biosorbent material for the removal of basic dyes from aqueous solutions. Effects of solution pH, biosorbent dosage, initial dye concentration, contact time and solution temperature on biosorption process were investigated. In addition, equilibrium, kinetic and thermodynamic studies were carried out for the methylene blue biosorption. It was determined that equilibrium data were in accordance with Freundlich isotherm and pseudo second order kinetic model was the best model to express the biosorption kinetics. Calculated thermodynamic parameters showed that, biosorption was a spontaneous endothermic process between 20 and 50 degrees C. The maximum monolayer biosorption capacity of chickpea husk was determined as 108.7 mg/g for methylene blue biosorption. As a result, chickpea straw could be used as an environmentally friendly, cheap and effective biosorbent material for the removal of methylene blue from aqueous solutions.