Abstract
A composite material was prepared by incorporating the clay (Kaolinite (Kao)) into a poly(acrylamide co-acrylic acid) (P(AAm-AA)) through the in situ polymerization method with cross-linker. The prepared composite adsorbent was firstly characterized by FTIR, SEM, XRD and Thermal analysis. After characterization, the composite adsorbent P(AAm-AA)/Kao was potentially studied for sorption of bromophenol blue (BPB) dye. Different factors that could affect the dye adsorption behavior were studied as time of contact dye concentration and temperature. The kinetic studies revealed that the adsorption results fitted well with Lagergren (pseudo first order reaction rate). The isotherm studies also display that the adsorption data fit with Freundlisch more than Langmuir isotherm model. Based on the effect of temperature the thermodynamic parameters were calculated and the free energy change (Delta G degrees) value of -110323 kJ/mol was obtained, referring to the feasibility and spontaneous nature of the sorption reaction. Also the relatively high negative value of entropy change Delta S degrees = -509.4 J mol(-1) K-1, suggests the chemical nature of the sorption reaction. (C) 2014 Elsevier B.V. All rights reserved.