title: Sonocatalytical degradation enhancement for ibuprofen and sulfamethoxazole in the presence of glass beads and single-walled carbon nanotubes.
abstract: Sonocatalytic degradation experiments were carried out to determine the effects of glass beads (GBs) and single-walled carbon nanotubes (SWNTs) on ibuprofen (IBP) and sulfamethoxazole (SMX) removal using low and high ultrasonic frequencies (28 and 1000kHz). In the absence of catalysts, the sonochemical degradation at pH 7, optimum power of 0.18WmL(-1), and a temperature of 15°C was higher (79% and 72%) at 1000kHz than at 28kHz (45% and 33%) for IBP and SMX, respectively. At the low frequency (28kHz) H2O2 production increased significantly, from 10μM (no GBs) to 86μM in the presence of GBs (0.1mm, 10gL(-1)); however, no enhancement was achieved at 1000kHz. In contrast, the H2O2 production increased from 10μM (no SWNTs) to 31μM at 28kHz and from 82μM (no SWNTs) to 111μM at 1000kHz in the presence of SWNTs (45mgL(-1)). Thus, maximum removals of IBP and SMX were obtained in the presence of a combination of GBs and SWNTs at the low frequency (94% and 88%) for 60min contact time; however, >99% and 97% removals were achieved for 40 and 60min contact times at the high frequency for IBP and SMX, respectively. The results indicate that both IBP and SMX degradation followed pseudo-first-order kinetics. Additionally, the enhanced removal of IBP and SMX in the presence of catalysts was because GBs and SWNTs increased the number of free OH radicals due to ultrasonic irradiation and the adsorption capacity increase with SWNT dispersion.
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Yasir A J
authors.initials: YAJ
authors.lastname: Al-Hamadani
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Kyoung Hoon
authors.initials: KH
authors.lastname: Chu
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, USA.
authors.forename: Joseph R V
authors.initials: JRV
authors.lastname: Flora
authors.affiliation: Korea Environmental Industry & Technology Institute, 215 Jinheungno, Eunpyeong-gu, Seoul, South Korea.
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Environmental Engineering, Kwangwoon University, 447-1 Wolgye-Dong Nowon-Gu, Seoul, South Korea.
authors.forename: Min
authors.initials: M
authors.lastname: Jang
authors.affiliation: School of Civil and Environmental Enginering, Kookmin University, Seoul 02707, South Korea.
authors.forename: Jinsik
authors.initials: J
authors.lastname: Sohn
authors.affiliation: Department of Environmental Engineering, Kwangwoon University, 447-1, Wolgye-Dong, Nowon-Gu, Seoul 01897, South Korea.
authors.forename: Wanho
authors.initials: W
authors.lastname: Joo
authors.affiliation: Department of Civil and Environmental Engineering, University of South Carolina, Columbia, SC 29208, USA. Electronic address: yoony@cec.sc.edu.
authors.forename: Yeomin
authors.initials: Y
authors.lastname: Yoon
mesh_terms: D000327:Adsorption; D006861:Hydrogen Peroxide; D007052:Ibuprofen / Q000737:chemistry*; D037742:Nanotubes, Carbon; D013420:Sulfamethoxazole / Q000737:chemistry*; D014465:Ultrasonics
chemical_list: D037742:Nanotubes, Carbon; D006861:Hydrogen Peroxide; D013420:Sulfamethoxazole; D007052:Ibuprofen
keywords: Glass beads; Ibuprofen; Single-walled carbon nanotubes; Sonocatalytical degradation; Sulfamethoxazole