Nickel-Catalyzed Growth of Carbon Nanofibers for Chromium Removal from Water

High Resolution Image Download MS PowerPoint Slide Exposure to hexavalent chromium [Cr(VI)] via oral intake, skin contact, or inhalation may lead to its accumulation in vital organs such as the liver, kidneys, heart, blood, and endocrine glands, leading to serious health issues and organ damage. This study evaluates the efficiency of Ni-CNF synthesized by CVD for the adsorptive removal of Cr(VI) from both aqueous solutions and Cr(VI)-spiked river water. The adsorption performance was found to be strongly dependent on contact time, solution pH, and the initial Cr(VI) concentration. The maximum adsorption capacity, estimated using the Liu isotherm model, was 98.18 ± 2.85 mg/g at pH 2, an adsorbent dosage of 0.25 mg/mL, an initial Cr(VI) concentration of 100 mg/L, and a temperature of 30 °C. The adsorption mechanisms under acidic conditions include electrostatic attraction, surface complexation between Cr(VI) and oxygen containing functional groups, reduction of Cr(VI) to Cr(III) via redox surface reactions, and pore-filling effects. Furthermore, the adsorption capacity of Ni-CNF decreased only moderately from 48.57 mg/g in the initial cycle to 40.52 mg/g after five adsorption−desorption cycles, indicating good regeneration efficiency and structural robustness. Overall, the findings demonstrate that Ni-CNF is a promising multifunctional material with significant potential for the removal of other dyes and heavy metals from wastewater.