A white rot basidiomycete Phanerochaete chrysosporium immobilized in loofa sponge was evaluated and characterized as a new biosorbent of dyes. Effects of biosorption process parameters on dye uptake capacity of loofa sponge-immobilized fungal biomass (LSIFB) were studied and compared with free fungal biomass (FFB). Remazol Brilliant Blue R (RBBR), a reactive dye, uptake from aqueous solution was found to be influenced by solution pH, temperature and initial dye concentration. Biosorption of RBBR by both FFB and LSIFB increased as the initial dye concentration increased in the medium. No loss to biosorption capacity of LSIFB was found due to the presence of loofa sponge (LS), indeed as compared to FFB an increase of 18.60% was noted in the biosorption capacity of FBILS. Maximum biosorption capacities for LSIFB and FFB at equilibrium were found as 101.06 +/- 2.52 and 85.21 +/- 2.98 mg RBBR g(-1) biomass at pH 2.0, respectively, whereas the amount of dye adsorbed on naked LS was 5.84 +/- 0.20 mg g(-1). The kinetics of dye removal was fast reaching at equilibrium in about 40 min for LSIFB and 60 min for FFB. The Langmuir and Freundlich adsorption models were used for mathematical description of the sorption equilibrium. Equilibrium data fitted very well to the Langmuir model in the studied concentrations (10-500 mg 1(-1)) The pseudo-first and second-order kinetic models were applied to the experimental data. The sorption data was found to follow the second-order kinetic model with r(2) of 0.99. The study points to the potential of a new use of LSIFB as an effective biosorbent for the removal of reactive dyes from wastewater. (C) 2007 Elsevier Ltd. All rights reserved.