Camellia oleifera Shell Derived Amino-Functionalized Carbonaceous Materials for Cr(VI) Removal in Wastewater

The objective of this study was to investigate the uptake of Cr(VI) from aqueous solutions using amino-functionalized carbonaceous materials synthesized through hydrothermal carbonization of Camellia oleifera shells in the presence of ammonia solution. The characterization of the carbonaceous materials was performed employing various techniques, including Fourier-transform infrared spectroscopy (FTIR), N2 adsorption–desorption analysis, elemental analysis and scanning electron microscopy (SEM). The adsorption capacity and kinetics of the prepared carbon-based materials for Cr(VI) in wastewater were investigated. The results showed as follows: adsorption kinetics can be elucidated by pseudo-second-order model, and the adsorption isotherm can be fitted by Langmuir equation. The maximum adsorption capacity for Cr(VI) by the amino-functionalized carbonaceous materials reached 483.52 mg g−1, which was approximately four times greater than that of unmodified carbonaceous materials (123.01 mg g−1). Furthermore, the as-prepared carbonaceous materials demonstrated an impressive ability to remove 99.71% of Cr(VI) ions from actual wastewater generated by the electroplating industry, thereby meeting the discharge standards established by regulatory authorities. These findings indicate that amino-functionalized carbonaceous materials hold significant potential as cost-effective adsorbents for the removal of Cr(VI) ions from aqueous solutions.