title: Photocatalytic degradation of carbamazepine in wastewater by using a new class of whey-stabilized nanocrystalline TiO2 and ZnO.
abstract: Nanoscale photocatalysts have attracted much attention due to their high surface area to volume ratios. However, due to extremely high reactivity, TiO2 and ZnO nanoparticles prepared using different methods tend to either react with surrounding media or agglomerate, resulting in the formation of much larger flocs and significant loss in reactivity. This work investigates the photocatalytic degradation of carbamazepine (CBZ), a persistent pharmaceutical compound from wastewater (WW) using TiO2 and ZnO nanoparticles prepared in the presence of a water-soluble whey powder as stabilizer. The TiO2 and ZnO nanoparticles prepared in the presence of whey stabilizer displayed much less agglomeration and greater degradation power than those prepared without a stabilizer. Higher photocatalytic degradation of carbamazepine was observed (100%) by using whey stabilized TiO2 nanoparticles with 55 min irradiation time as compared to ZnO nanoparticles (92%). The higher degradation of CBZ in wastewater by using TiO2 nanoparticles as compared to ZnO nanoparticles was due to formation of higher photo-generated holes with high oxidizing power of TiO2. The photocatalytic capacity of ZnO anticipated as similar to that of TiO2 as it has the same band gap energy (3.2 eV) as TiO2. However, in the case of ZnO, photocorrosion frequently occurs with the illumination of UV light and this phenomenon is considered as one of the main reasons for the decrease of ZnO photocatalytic activity in aqueous solutions. Further, the estrogenic activity of photocatalyzed WW sample with CBZ and its by-products was carried out by yeast estrogen screen (YES) assay method. Based upon the YES test results, none of the samples showed estrogenic activity.
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec,Canada, G1K 9A9.
authors.forename: D P
authors.initials: DP
authors.lastname: Mohapatra
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec,Canada, G1K 9A9. Electronic address: satinder.brar@ete.inrs.ca.
authors.forename: S K
authors.initials: SK
authors.lastname: Brar
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec,Canada, G1K 9A9.
authors.forename: R
authors.initials: R
authors.lastname: Daghrir
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec,Canada, G1K 9A9.
authors.forename: R D
authors.initials: RD
authors.lastname: Tyagi
authors.affiliation: Phytronix Technologies, 4535 Boulevard Wilfrid Hamel, Québec,Canada, G1P 2 J7.
authors.forename: P
authors.initials: P
authors.lastname: Picard
authors.affiliation: US Environmental Protection Agency, P.O. Box 17-2141, Kansas City 66117,USA.
authors.forename: R Y
authors.initials: RY
authors.lastname: Surampalli
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec,Canada, G1K 9A9.
authors.forename: P
authors.initials: P
authors.lastname: Drogui
mesh_terms: D002220:Carbamazepine / Q000032:analysis / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D014025:Titanium / Q000032:analysis / Q000737:chemistry*; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D000067816:Whey Proteins; D015034:Zinc Oxide / Q000032:analysis / Q000737:chemistry*
chemical_list: D002220:Carbamazepine; D008894:Milk Proteins; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; D000067816:Whey Proteins; D015034:Zinc Oxide; C009495:titanium dioxide
keywords: Carbamazepine; Photocatalysis; Wastewater; Whey stabilizer; Yeast estrogen screen assay