title: Monitoring simultaneous photocatalytic-ozonation of mixture of pharmaceuticals in the presence of immobilized TiO2 nanoparticles using MCR-ALS: Identification of intermediates and multi-response optimization approach.
abstract: The present study has focused on the degradation of a mixture of three pharmaceuticals, i.e. methyldopa (MDP), nalidixic acid (NAD) and famotidine (FAM) which were quantified simultaneously during photocatalytic-ozonation process. The experiments were conducted in a semi-batch reactor where TiO2 nanoparticles (crystallites mean size 8nm) were immobilized on ceramic plates irradiated by UV-A light in the proximity of oxygen and/or ozone. The surface morphology and roughness of the bare and TiO2-coated ceramic plates were analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). An analytical methodology was successfully developed based on both recording ultraviolet-visible (UV-Vis) spectra during the degradation process and a data analysis using multivariate curve resolution with alternating least squares (MCR-ALS). This methodology enabled the researchers to obtain the concentration and spectral profiles of the chemical compounds which were involved in the process. A central composite design was used to study the effect of several factors on multiple responses namely MDP removal (Y1), NAD removal (Y2) and FAM removal (Y3) in the simultaneous photocatalytic-ozonation of these pharmaceuticals. A multi-response optimization procedure based on global desirability of the factors was used to simultaneously maximize Y1, Y2 and Y3. The results of the global desirability revealed that 8mg/L MAD, 8mg/L NAD, 8mg/L FAM, 6L/h ozone flow rate and a 30min-reaction time were the best conditions under which the optimized values of various responses were Y1=95.03%, Y2=84.93% and Y3=99.15%. Also, the intermediate products of pharmaceuticals generated in the photocatalytic-ozonation process were identified by gas chromatography coupled to mass spectrometry.
authors.affiliation: Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Mehrangiz
authors.initials: M
authors.lastname: Fathinia
authors.affiliation: Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran. Electronic address: a_khataee@tabrizu.ac.ir.
authors.forename: Alireza
authors.initials: A
authors.lastname: Khataee
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Abdolhosein
authors.initials: A
authors.lastname: Naseri
authors.affiliation: Research Laboratory of Environment Protection Technology, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
authors.forename: Soheil
authors.initials: S
authors.lastname: Aber
mesh_terms: D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D045424:Complex Mixtures / Q000032:analysis* / Q000493:pharmacokinetics; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D015738:Famotidine / Q000737:chemistry / Q000493:pharmacokinetics; D016018:Least-Squares Analysis; D008750:Methyldopa / Q000737:chemistry / Q000493:pharmacokinetics; D015999:Multivariate Analysis; D009268:Nalidixic Acid / Q000737:chemistry / Q000493:pharmacokinetics; D053758:Nanoparticles / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D062065:Wastewater / Q000032:analysis / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000493:pharmacokinetics / Q000528:radiation effects
chemical_list: D020099:Coated Materials, Biocompatible; D045424:Complex Mixtures; D015738:Famotidine; D008750:Methyldopa; D009268:Nalidixic Acid; D010100:Oxygen; D010126:Ozone; D014025:Titanium; D062065:Wastewater; D014874:Water Pollutants, Chemical; C009495:titanium dioxide
keywords: Multi-response optimization; Multivariate curve resolution; Nanocatalyst; Ozonation; Pharmaceutical; Photocatalysis