Kinetics and Thermodynamics of Adsorption of Rhodamine B onto Bentonite Supported Nanoscale Zerovalent Iron Nanocomposite

Bentonite clay supported nanoscale zerovalent iron (BC-nZVI) composite was successfully prepared. BC-nZVI was characterized by physicochemical and spectroscopic techniques. Surface area as determined by sear's method is 291.2 cm2. Adsorption operational parameters were investigated in a batch technique. At 500 mg/L initial concentration, 120 minutes contact time and pH 3, 454.81 mg/g quantity was adsorbed. The highest adsorption percentage removal efficiency was obtained at room temperature. Kinetic data fitted best to pseudo second order and the mechanism was diffusion governed. The kinetic models were further validated by sum of square error (SSE) and non-linear Chi-square statistical models (X2). The values of the thermodynamic parameters: standard enthalpy change ΔH (-10.597 Jmol−1)to (-5558 Jmol−1.), standard entropy change, ΔS (-277.804 J mol−1 K−1)- to (-139.2595 J mol−1K−1) and the Gibbs free energy (ΔG) revealed that the adsorption process was feasible, spontaneous and exothermic in nature. The performance of BC-nZVI enlisted it as a great potential adsorbent for effective removal of Rhodamine B and therefore recommended for application in industrial effluent treatment.