Biosorption potential of sugar beet pulp was significantly improved via grafting by quaternary ammonium salt. Initial pH, biosorbent dosage, contact time, temperature and flow rate were investigated as design parameters. A higher biosorption yield, shorter period of equilibrium time and lower amount of biosorbent were recorded as the main characteristics for batch mode decolorization. The pseudo-second-order model better fitted the kinetic data while Langmuir isotherm model is found to be best represent the biosorption equilibrium. Thermodynamic findings indicated that the nature of Reactive Red 2 (RR2) biosorption is endothermic and spontaneous. The modified sugar beet pulp was also successfully used in dynamic flow mode removal of RR2. Recovery of biosorbed RR2 from the modified biomaterial was investigated in alkaline solutions and good values were observed. IR, SEM, AFM, EDX, potentiometric titration and zeta potential studies were used to characterize the biosorbent structure in addition to real sample application of modified biomaterial. (c) 2013 Elsevier B.V. All rights reserved.