Removal of chromium(VI) and naphthalenesulfonate from textile wastewater by photocatalysis combining ionic exchange membrane processes

New Advances in Heterogeneous Photocatalysis for Treatment of Toxic Metals and Arsenic

“…Cr(VI) photocatalytic reduction continues to be a very rich and interesting study system, and extensive work has been carried out in recent years, either with the aim of water treatment or as a practical system for the evaluation of the photocatalytic activity of several SC samples in the aqueous phase [121][122][123][124][125][126][127][128][129][130][131][132]. Most of the recent papers use the HP Cr(VI) reduction reaction as a model system for testing new photocatalysts; this is the case of immobilized nanotubular TiO 2 electrodes [130], wO 3 -doped long TiO 2 nanotube arrays [133], and Au/TiO 2 heterojunction nanotube composites [126], among other materials.…”

“…Kim and Choi [123] investigated the formation of surface complexes between TiO 2 and electron donors such as methanol, formic acid, acetic acid, triethanolamine, or edTA, which can absorb visible light through a ligand-to-metal charge transfer (LMCT) mechanism; the TiO 2 -edTA complex, especially, showed an outstanding visible light activity for Cr(VI) reduction. Another example is simultaneous Cr(VI) removal and naphthalenesulfonate (NS) oxidation in textile wastewater by the combination of visible light photocatalysis and ion exchange membrane processes (electrodialysis) [122]. Another example is simultaneous Cr(VI) removal and naphthalenesulfonate (NS) oxidation in textile wastewater by the combination of visible light photocatalysis and ion exchange membrane processes (electrodialysis) [122].…”

Removal of Chromium(III) and Other Physical Parameters from Chrome Tan Wastewater and Recovery of Chromium from the Precipitating Sludge

“…A little amount of chromium is necessary for glucose, lipid and protein metabolism of mammals but long-time exposure can lead to various adverse health effects. There are several methods of removal of chromium from the wastewater, like electrochemical precipitation [22,23,24], cation exchange membrane [25], solvent extraction, coagulation, membrane process and filtration [26], ion exchange [27,28] and adsorption [29][30][31][32][33]. With the exception of the precipitation method, most of the purification methods are costly in terms of installation and maintenance.…”

Simultaneous Reduction of Vanadium (V) and Chromium (VI) in Wastewater by Nanosized ZnWO<SUB>4</SUB> Photocatalysis

“…17 Recently, the photocatalytic properties of MWO 4 toward the degradation of organic contaminants under UV and visible-light irradiation have been reported, [18][19][20][21][22][23] among which ZnWO 4 presents the highest photocatalytic activity in the degradation of methylene blue (MB) and methyl orange (MO). [24][25][26] Although the photocatalytic reduction of individual Cr(VI) has been investigated, [27][28][29] and there has paper about the individually photocatalytic reduction of V(V) has been published recently. 30 Until now, the simultaneously photocatalytic reduction of V(V) and Cr(VI) has not been reported, and further investigation is needed in order to bridge the existing gaps.…”