Equilibrium, kinetic and thermodynamic analysis petroleum oil adsorption from aqueous solution by magnetic activated carbon

A potential magnetized adsorbent was developed by a simple chemical process using iron oxide and banana stem based activated carbon for the treatment of petroleum oil. For batch experiment, pH (2-10), adsorbent dose (0.5 g/L -15 g/L), initial concentration (200-4500 ppm), agitation (50-150 rpm), temperature (25-45 °C) parameters were investigated. XRD, FTIR and FESEM analysis confirm the significant reflux of iron particles on prepared magnetic activated carbon. Data analysis calculated a removal of more than 95% at 1000 ppm petroleum oil within first 30 min of contact time. Freundlich, Langmuir, Temkin and Dubinin Radushkevich isotherm models were studied. The obtained data was found to fit well with Pseudo second order kinetic model and Freundlich isotherm model with a good correlation factor (R²) of 0.9998 and 0.9914, respectively. Thermodynamic parameters expressed the exothermic nature of the adsorption process and the result shows maximum adsorption capacity of 1.90 g/g (approx.) at 25 °C. The composite adsorbent shows a good oil adsorption capacity with rapid kinetics and able to be recovered along with adsorbed oil by applying an external magnet. Hence, the prepared adsorbent is proved to be an effective candidate for the fast removal of petroleum oil spills by magnetic separation.