Adsorption mechanism of aqueous Cr(<scp>vi</scp>) by Vietnamese corncob biochar: a spectroscopic study
Duong Thuy Phuc Nguyen, Quoc-Bao Ly-Tran, Van‐Phuc Dinh, Bich‐Ngoc Duong, Thi-Phuong-Tu Nguyen, Phạm Nguyễn Kim Tuyến
Abstract
electrostatic mechanisms. Energy-dispersive X-ray (EDX) spectra combined with Fourier-transform infrared (FTIR) spectra demonstrate that two key adsorption mechanisms in this study are surface adsorption (Cr(vi)-biochar) followed by the reduction of Cr(vi) to Cr(iii), allowing ion exchange adsorption to occur. X-ray diffraction (XRD) patterns indicate no precipitation on the surface, and the material remains stable after four reuse cycles. These results suggest that CCBC can be used as an efficient, cost-effective, and environmentally friendly adsorbent for Cr(vi) removal from water. This is the first study to combine spectroscopic methods and theoretical models to gain deeper insights into the Cr(vi) adsorption mechanisms onto CCBC.