Biosorption of reactive red 120 from aqueous solutions by using modified juglans regia L. LEAF.

In this study, biosorption of RR120 dye from aqueous solution by Juglans regia L. (walnut) leaf in natural (HCY) form and citric acid modified (MCY) form was investigated. The biomasses were characterized by means of FT-IR spectra, SEM images and zeta potantial analyses. The experiments were carried out in the batch system as a function of pH, biosorbent amount, inital dye concentration, contact time and temperature. The dye concentrations in the solutions were determined by UV-visible spectrophotometer. Biosorption data fits best with the Langmuir isotherm model for both biomasses. Monolayer maximum biosorption capacity at 50 ºC was determined as 135,16 mg/g and 181,21 mg/g for HCY and MCY, respectively. Experimental findings were applied to pseudo-first order and pseudo-second order kinetic models and it was concluded that the biosorption kinetics of RR120 on HCY and MCY could be explained by pseudo-second order kinetic model. Keywords: Biosorption, Biosorption kinetics, Juglans regia L. leaf, Freundlich isotherm, Langmuir isotherm, RR120.