Adsorption performances of branched aminated waste polyacrylonitrile fibers: experimental versus modelling study

Abstract

Synthesis of branched aminated waste polyacrylonitrile (PAN) fibers, realized in a three addition/amidation successive steps, was performed in order to obtain AS3-PAN adsorbent. Influence of various operating parameters such as pH, contact time, adsorbent mass and initial concentration of pollutants, on adsorption capacity has been studied. Design of the experimental plan of adsorption experiments, defined by response surface methodology (RSM), rationalized the number of necessary experiments. The calculated adsorption capacities for AS3-PAN, obtained by Langmuir model, were 58.94, 41.07, 34.51, 24.54 and 29.61 mg g(-1) for Pb2+, Cd2+, Ni2+, Cr(VI) and As(V) ion, respectively. The results of pseudo-second-order reaction rate and Weber-Morris kinetic model indicated significant resistance due to intra-particle (pore) diffusion. The experimental results were compared with the theoretically calculated ones, obtained by RSM prediction model, and validation of applied methodology was performed by testing the quality of the regression analysis with analysis of variance test.