Removal of Ni(II) from aqueous system by chemically modified sunflower biomass

Abstract

This study reports the removal of Ni(II) onto boiled sunflower head (BSH) and formaldehyde sunflower head (FSH) adsorbents by batch technique. The adsorbents were characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The results showed that Ni(II) adsorption was dependent on process operating conditions including pH of the solution, adsorbent dosage, temperature, and initial Ni(II) ion concentration in the solution. The optimum pH for Ni(II) was 6.0. Maximum nickel adsorption was 65.5 and 75.9%, respectively, by BSH and FSH at adsorbent dose = 20.0 g/L, initial Ni(II) concentration = 100 mg/L, temperature = 25 ± 1°C. Langmuir and Freundlich isotherm models were used to analyze the equilibrium adsorption data. Freundlich isotherm fitted the data well with R2 values >0.99 for both the adsorbents. The results also showed that pseudo-second-order kinetic model correlated well with the adsorption data with R2 values >0.99 for both the adsorbents.