Adsorptive removal of heavy metals from oil well produced water using citrullus lanatus peel: Characterization and optimization

Abstract

The effects of adsorbent dosage, reaction time, temperature and pH on the adsorption of Pb2+, Zn2+, Fe2+ and Cu2+ from produced water using activated carbon prepared from Citrullus lanatus peel via calcination at 681.10 °C for 2.61 h were studied. L9 orthogonal Taguchi approach was used for the parametric optimization. Activated carbon was characterized using scanning electron microscopy, Brunauer-Emmett-Teller analysis, X-ray diffraction, X-ray fluorescence and Fourier transform infrared spectroscopy and; exhibited a porous-graphite-crystalline structure, presence of different metal oxides and active functional groups with large surface area of 1249.7 m2/g. Batch adsorption experiments revealed the efficacy of prepared activated carbon to remove heavy metals from produced water. At optimum points, predicted values were 76.31, 59.3, 69.91 and 84.08% for Pb2+, Zn2+, Fe2+ and Cu2+ removed respectively. The values of R2, Adj-R2 and pred-R2 revealed reasonable agreements between experimental and predicted data which proved developed models to be effective.