title: Photodegradation of ibuprofen by TiO2 co-doping with urea and functionalized CNT irradiated with visible light - Effect of doping content and pH.
abstract: Ibuprofen (IBP) is one kind of non-steroidal anti-inflammatory drugs (NSAIDs), which are classified as Pharmaceuticals and Personal Care Products (PPCPs). IBP possesses bioactive property and the substantial use of IBP results in a harmful impact on bioreceptors even in small concentrations. Accordingly, the treatment of these wastewaters is important before discharging them into the ecosystem. The photodegradation of IBP with TiO2 co-doped with functionalized CNTs (CNT-COOH and CNT-COCl) and urea, named as N-doping CNT/TiO2, irradiated with visible light of 410 nm was investigated in this study. The titanium tetrachloride was used as the precursor of Ti. The N-doping CNT-COCl/TiO2 photocatalysts exhibited a better crystalline structure and smaller crystal size than the N-doping CNT-COOH/TiO2 photocatalyst. It might largely ascribe to strong binding between acyl chloride functional group and TiO2. About 85.0%-86.0% of IBP was degraded with N-doping CNT/TiO2 within 120 min at natural condition, which obeyed the pseudo first order reaction and the rate constant was 4.45 × 10(-3)-1.22 × 10(-2) min(-1) and 5.03 × 10(-3)-1.47 × 10(-2) min(-1) for N-doping CNT-COOH/TiO2 and N-doping CNT-COCl/TiO2, respectively. The best IBP degradation of 87.9%-89.0% was found at pH 5, which indicated superoxide radicals (O2(-)) played a key role. The optimal pH was majorly dominated by the nature of IBP and N-doping CNT/TiO2. A successful synergy effect of TiO2 and dopants was exhibited and this mainly attributed to the strong binding strength by functional group of acyl chloride (COCl) and carboxylic acid (COOH). In summary, IBP could be effectively photodegraded by the fabricated N-doping CNT/TiO2 photocatalysts.
authors.affiliation: Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd, Nan-Tzu Dist., Kaohsiung City, 811, Taiwan. Electronic address: caroline@nuk.edu.tw.
authors.forename: Ching
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, No. 1, University Rd., Yenchau Dist., Kaohsiung, 824, Taiwan. Electronic address: jeremyh@ccms.nkfust.edu.tw.
authors.forename: Chung-Hsuang
authors.initials: CH
authors.lastname: Hung
authors.affiliation: Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd, Nan-Tzu Dist., Kaohsiung City, 811, Taiwan. Electronic address: chakey44@gmail.com.
authors.forename: Huei-Wen
authors.initials: HW
authors.lastname: Li
authors.affiliation: Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd, Nan-Tzu Dist., Kaohsiung City, 811, Taiwan. Electronic address: soillab@nuk.edu.tw.
authors.forename: Wei-Hsian
authors.initials: WH
authors.lastname: Chang
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen / Q000737:chemistry / Q000378:metabolism*; D008027:Light; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*; D014508:Urea / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D037742:Nanotubes, Carbon; C009495:titanium dioxide; D014508:Urea; D014025:Titanium; D007052:Ibuprofen
keywords: CNT; Ibuprofen; Photodegradation; TiO(2); Urea; Visible light