Related Experiment Video
Updated: Feb 14, 2026

Implementation of a Hyperbolic Vortex Plasma Reactor for the Removal of Micropollutants in Water
Published on: July 25, 2025
Reduction and Removal of Chromium VI in Water by Powdered Activated Carbon
Yanan Chen1,2, Dong An3,4, Sainan Sun5,6
1Department of Environmental Science & Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China. 16210740021@fudan.edu.cn.
Abstract:
Cr adsorption on wood-based powdered activated carbon (WPAC) was characterized by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The highest Cr(VI) adsorption (40.04%) was obtained under acidic conditions (pH 3), whereas Cr removal at pH 10 was only 0.34%. The mechanism of Cr(VI) removal from aqueous solutions by WPAC was based on the reduction of Cr(VI) to Cr(III) with the concomitant oxidation of C-H and C-OH to C-OH and C=O, respectively, on the surface of WPAC, followed by Cr(III) adsorption. Raman spectroscopy revealed a change in the WPAC structure in terms of the D/G band intensity ratio after Cr(VI) adsorption. SEM-EDS analysis showed that the oxygen/carbon ratio on the WPAC surface increased from 9.85% to 17.74%. This result was confirmed by XPS measurements, which showed that 78.8% of Cr adsorbed on the WPAC surface was in the trivalent state. The amount of oxygen-containing functional groups on the surface increased due to the oxidation of graphitic carbons to C-OH and C=O groups.
Related Concept Videos
The Carbon Cycle
Oxidation-Reduction Reactions
Carbon Skeletons
Water and Mineral Acquisition
States of Water
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Carbonation Shrinkage
The concrete's permeability is slightly reduced as calcium carbonate produced during the reaction fills its pores. Furthermore, its strength is slightly enhanced as the water released during the reaction...

