Effective removal of Cr(vi) through adsorption and reduction by magnetic mesoporous carbon incorporated with polyaniline

Abstract

Magnetic mesoporous carbon incorporated with polyaniline (PANI–Fe/OMC) is developed for enhanced adsorption and reduction of toxic Cr(vi) to non-toxic Cr(iii).

Nanoporous carbon synthesized from grass for removal and recovery of hexavalent chromium

“…The peak at 1570 cm -1 in Af-NPC corresponds to the C=C stretching vibration of the graphitic carbon skeleton, which shifted to 1542 cm -1 . The vibrational mode appearing at 874 cm -1 is due to the Cr-O bond of hexavalent chromium after adsorption [17]. The peak due to aliphatic C-H str.…”

Multifunctional hierarchical cabbage-like nZVI-Fe 3 O 4 /C composites for efficient chromium (VI) removal

“…That is to say the main speciation of Cr(VI) ions is anionic. In addition, HCrO 4 − could adsorb preferentially on the carbon surface because of its low adsorption free energy [34] . At the pH values ranged from 3 to 7, the surface of Fe/CCMs-800 became highly protonated and positively charged, which was benefited to the uptake of Cr(VI) through electrostatic interaction.…”

Negative impact of oxygen molecular activation on Cr(VI) removal with core–shell Fe@Fe2O3 nanowires

“…Both Fe 0 and Fe(II) are capable of reduction and precipitation of Cr(VI) to the sparingly soluble Fe(III)-Cr(III) (oxy) hydroxide phase in aqueous environment [15][16][17][18][19][20]. Inevitably, Fe 0 and Fe(II) as electron donors could also react with other substances like humic acids, phenols, quinones, and oxygen in aquatic environment [21,22].…”

“…According to nZVI's environmental benignancy, Cr(VI) sequestration by nZVI has been widely studied [1,[8][9][10][11][14][15][16][17][18]. Cr(VI) removal by nZVI is a complex process associated with both physical adsorption and chemical reduction reactions.…”