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Oeza BR, Ahmad N, Ng KH, Widyastuti, Haile CT, Kuo CFJ. Enhanced efficiency of AgAlO 2/g-C 3N 4 binary composite to degrade organic pollutants for environmental remediation under visible light irradiation. CHEMOSPHERE 2024; 357:142116. [PMID: 38663674 DOI: 10.1016/j.chemosphere.2024.142116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/26/2024] [Accepted: 04/21/2024] [Indexed: 04/28/2024]
Abstract
This study explores the utilization of semiconductor-based photocatalysts for environmental remediation through photocatalytic degradation, harnessing solar energy for effective treatment. The primary focus is on the application of photocatalytic technology for the degradation of 2-chlorophenol and methylene blue, critical pollutants requiring remediation. The research involves the synthesis of binary AgAlO2/g-C3N4 nanocomposites through an exchange ion method, subsequent calcination, and sonication. This process enhances the transfer of photogenerated electrons from AgAlO2 to g-C3N4, resulting in a significantly increased reductive electron charge on the surface of g-C3N4. The photocatalytic activity of the synthesized composites is comprehensively examined in the degradation of 2-chlorophenol and methylene blue through detailed crystallographic, electron-microscopy, photoemission spectroscopy, electrochemical, and spectroscopic characterizations. Among the various composites, AgAlO2/20% g-C3N4 emerges as the most active photocatalyst, achieving an impressive 98% degradation of methylene blue and 97% degradation of 2-chlorophenol under visible light. Notably, AgAlO2/20% g-C3N4 surpasses bare AgAlO2 and bare g-C3N4, exhibiting 1.66 times greater methylene blue degradation and constant rate (k) values of 20.17 × 10-3 min-1, 4.18 × 10-3 min-1 and 3.48 × 10-3 min-1, respectively. The heightened photocatalytic activity is attributed to the diminished recombination rate of electron-hole pairs. Scavenging evaluations confirm that O2•- and h+ are the primary photoactive species steering methylene blue photodegradation over AgAlO2/g-C3N4 in the visible region. These findings present new possibilities for the development of efficient binary photocatalysts for environmental remediation.
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Affiliation(s)
- Bobby Refokry Oeza
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC; Department of Materials and Metallurgical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia
| | - Naveed Ahmad
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC
| | - Kim Hoong Ng
- Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC
| | - Widyastuti
- Department of Materials and Metallurgical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, 60111, Indonesia
| | - Cheru Talbachew Haile
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC
| | - Chung Feng Jeffrey Kuo
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC.
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Mohd Raub AA, Bahru R, Mohamed MA, Latif R, Mohammad Haniff MAS, Simarani K, Yunas J. Photocatalytic activity enhancement of nanostructured metal-oxides photocatalyst: a review. NANOTECHNOLOGY 2024; 35:242004. [PMID: 38484390 DOI: 10.1088/1361-6528/ad33e8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
Nanostructured metal oxide semiconductors have emerged as promising nanoscale photocatalysts due to their excellent photosensitivity, chemical stability, non-toxicity, and biocompatibility. Enhancing the photocatalytic activity of metal oxide is critical in improving their efficiency in radical ion production upon optical exposure for various applications. Therefore, this review paper provides an in-depth analysis of the photocatalytic activity of nanostructured metal oxides, including the photocatalytic mechanism, factors affecting the photocatalytic efficiency, and approaches taken to boost the photocatalytic performance through structure or material modifications. This paper also highlights an overview of the recent applications and discusses the recent advancement of ZnO-based nanocomposite as a promising photocatalytic material for environmental remediation, energy conversion, and biomedical applications.
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Affiliation(s)
- Aini Ayunni Mohd Raub
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, 43600, Selangor, Malaysia
| | - Raihana Bahru
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, 43600, Selangor, Malaysia
| | - Mohd Ambri Mohamed
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, 43600, Selangor, Malaysia
| | - Rhonira Latif
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, 43600, Selangor, Malaysia
| | | | - Khanom Simarani
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Kuala Lumpur, Malaysia
| | - Jumril Yunas
- Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia (UKM), Bangi, 43600, Selangor, Malaysia
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Wang C, Wu G, Zhu X, Xing Y, Yuan X, Qu J. Synergistic degradation for o-chlorophenol and enhancement of power generation by a coupled photocatalytic-microbial fuel cell system. CHEMOSPHERE 2022; 293:133517. [PMID: 34995621 DOI: 10.1016/j.chemosphere.2022.133517] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/24/2021] [Accepted: 12/31/2021] [Indexed: 06/14/2023]
Abstract
A hierarchically photocatalytic microbial fuel cell system (PMFC) coupled with TiO2 photoanode and bioanode was established to enhance the power generation based on single-chamber MFC. Compared with the conventional anaerobic mode, oxygen in the solution could be utilized by the photoanode of PMFC to improve the removal of o-chlorophenol (2-CP). The maximum power densities were increasing from 261 (MFC) to 301 mW/m2 (PMFC). The removal efficiency of 2-CP (5 mg/L) in PMFC was 76.20% and higher than that in MFC (19.33%) and by photocatalysis (49.23%). The electron-hole separation efficiencies were decreasing with the increasing of dissolved oxygen, causing a low efficiency of photocatalysis, due to the reduction of the current density of the systems. The abundance of Geobacter sp., PHOS-HE36 fam., and Pseudomonas sp. was increased with illumination, contributing to improve the electricity production and 2-CP degradation. The only detective intermediate of 1,2-dichlorobenzene in PMFC indicated that the microbes could regulate the degradation pathway of 2-CP in the coupling system. These findings provided an feasible method for the effective degradation of refractory organic compounds and simultaneous energy recovery by combining photocatalysis and microbial power generation.
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Affiliation(s)
- Chengzhi Wang
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China
| | - Guanlan Wu
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China
| | - Xiaolin Zhu
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China.
| | - Yi Xing
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China
| | - Xing Yuan
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China
| | - Jiao Qu
- School of Environment, Northeast Normal University, Changchun, Jilin, 130024, China.
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Ombaka LM, McGettrick JD, Oseghe EO, Al-Madanat O, Rieck Genannt Best F, Msagati TAM, Davies ML, Bredow T, Bahnemann DW. Photocatalytic H 2 production and degradation of aqueous 2-chlorophenol over B/N-graphene-coated Cu 0/TiO 2: A DFT, experimental and mechanistic investigation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114822. [PMID: 35255324 DOI: 10.1016/j.jenvman.2022.114822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/17/2022] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
Energy and environmental challenges are global concerns that scientists are interested in alleviating. It is on this premise that we prepared boron/nitrogen graphene-coated Cu0/TiO2 (B/N-graphene-coated Cu/TiO2) photocatalyst of varying B:N ratios with dual functionality of H2 production and 2-Chlorophenol (2-CP) degradation. In-situ coating of Cu0 with B/N-graphene is achieved via solvothermal synthesis and calcination under an inert atmosphere. All B/N-graphene-coated Cu/TiO2 exhibit higher photonic efficiencies (5.68%-7.06% at 300 < λ < 400 nm) towards H2 production than bare TiO2 (0.25% at 300 < λ < 400 nm). Varying the B:N ratio in graphene influences the efficiency of H2 generation. A B:N ratio of 0.08 yields the most active composite exhibiting a photonic efficiency of 7.06% towards H2 evolution and a degradation rate of 4.07 × 10-2 min-1 towards 2-chlorophenol (2-CP). Density functional theory (DFT) investigations determine that B-doping (p-type) enhances graphene stability on Cu0 while N-doping (n-type) increases the reduction potential of Cu0 relative to H+ reduction potential. X-ray photoelectron spectroscopy reveals that increasing the B:N ratio increases p-type BC2O while decreasing n-type pyridinic-N in graphene thus altering the interlayer electron density. Isotopic labelling experiments determine water reduction as the main mechanism by which H2 is produced over B/N-graphene-coated Cu/TiO2. The reactive species involved in the degradation of 2-CP are holes (h+), hydroxyl radical (OH•), and O2•-, of which superoxide (O2•-) plays the major role. This work displays B/N -graphene-coated Cu/TiO2 as a potential photocatalyst for large-scale H2 production and 2-CP degradation.
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Affiliation(s)
- Lucy M Ombaka
- Institut für Technische Chemie, Gottfried Wilhelm Leibniz Universität Hannover, Callinstrasse 3, Hannover, 30167, Germany; School of Chemistry and Material Science, Technical University of Kenya, P.O Box 52428-00200, Nairobi, Kenya.
| | - James D McGettrick
- SPECIFIC IKC, Materials Research Centre, College of Engineering, Swansea University, Bay Campus, Fabian Way, Swansea, SA1 8EN, UK
| | - Ekemena O Oseghe
- Institute for Nanotechnology and Water Sustainability, College of Science, Engineering and Technology, University of South Africa, Florida Campus, 1709, Johannesburg, South Africa
| | - Osama Al-Madanat
- Institut für Technische Chemie, Gottfried Wilhelm Leibniz Universität Hannover, Callinstrasse 3, Hannover, 30167, Germany
| | - Felix Rieck Genannt Best
- Institute for Physical Chemistry and Electrochemistry, Leibniz University Hannover, 30167, Hannover, Germany
| | - Titus A M Msagati
- Institute for Nanotechnology and Water Sustainability, College of Science, Engineering and Technology, University of South Africa, Florida Campus, 1709, Johannesburg, South Africa
| | - Matthew L Davies
- SPECIFIC IKC, Materials Research Centre, College of Engineering, Swansea University, Bay Campus, Fabian Way, Swansea, SA1 8EN, UK; School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Thomas Bredow
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, Bonn, Germany
| | - Detlef W Bahnemann
- Institut für Technische Chemie, Gottfried Wilhelm Leibniz Universität Hannover, Callinstrasse 3, Hannover, 30167, Germany; Laboratorium für Nano- und Quantenengineering, Gottfried Wilhelm Leibniz Universität Hannover, Schneiderberg 39, Hannover, 30167, Germany; Laboratory for Photoactive Nanocomposite Materials, Department of Photonics, Faculty of Physics, Saint-Petersburg State University, Ulianovskaia Str. 3, Peterhof, Saint-Petersburg, 198504, Russia
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Photocatalytic water purification under visible light using carbon nitride materials and β-Bi2O3 immobilized on electrospun polyvinyl acetate fibers. SN APPLIED SCIENCES 2022. [DOI: 10.1007/s42452-022-04945-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
AbstractWe report on the immobilization of carbon nitride (CN) materials and β-Bi2O3 on electrospun polyvinyl acetate (PVAc) fiber substrates using a dispersion based dip coating process. The spinning process was optimized by variation of several parameters to finally obtain continuous droplet-free fibers at 15 kV and a flow rate of 50 µL min−1 using a needle with 1.2 mm diameter. The polymer substrates were coated with the β-Bi2O3 and CN materials, which were characterized using SEM and applied in the photocatalytic degradation of organic pollutants such as Rhodamine B (RhB), ethinyl estradiol (EE2) and triclosan using visible light irradiation. The pollutants were degraded with up to 50% of the initial concentration within 8 h. Different amounts of CN material were deposited to evaluate the photocatalytic activity per mass. Immobilized CN materials were shown to be of higher activity (2.0 × 10−10 mol mg−1 min−1) than β-Bi2O3 (1.3 × 10−10 mol mg−1 min−1) and the mixture CN/β-Bi2O3 (1.6 × 10−10 mol mg−1 min−1). Reference samples with CN particles partially embedded in the polymer fleece showed minor degradaton rates (18% RhB degradation within 8 h) as compared to coated fiber substrates (47% RhB degradation within 8 h). Minor leaching of the carbon nitride material and no leaching of β-Bi2O3 occurs as shown by NPOC (non purgeable organic carbon) and ICP-MS measurements.
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Ji H, Hu C, Zhang S, Zhang L, Yang X. BiO(OH) xI 1-x solid solution with rich oxygen vacancies: interlayer guest hydroxyl for improved photocatalytic properties. J Colloid Interface Sci 2021; 605:1-12. [PMID: 34303921 DOI: 10.1016/j.jcis.2021.07.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/07/2021] [Accepted: 07/11/2021] [Indexed: 12/14/2022]
Abstract
A series of BiO(OH)xI1-x solid solution (SS) catalysts were successfully prepared by ion exchange of I- and OH- between the [Bi2O2]2+ layers. The morphology and microstructure were studied in depth using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) method, etc. Tunable absorption in the visible-light region was achieved by changing the proportion of OH- to I-. Due to the etching effect of OH-, oxygen vacancies (OVs) greatly increased for the SS catalysts, and were confirmed by X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and electron paramagnetic spectroscopy (EPR). The unique composition of OH-, I-, OV, and [Bi2O2]2+ layers in BiO(OH)xI1-x materials resulted in diverse photoexcitations. The BiO(OH)0.45I0.55 photocatalyst displayed a 10-fold-improved 2-chlorophenol (2-CP) degradation rate compared to BiOI. The interfacial reaction process by the photoinduced valence-band holes and conduction-band electrons proved to be a more efficient pathway for organic pollutant degradation by the BiO(OH)xI1-x SS photocatalyst. The OVs in the SS photocatalyst facilitated photoexcited and electron migration and transformation.
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Affiliation(s)
- Huanhuan Ji
- College of Urban and Rural Construction, Hebei Agricultural University, Baoding 071001, China
| | - Chun Hu
- Institute of Environmental Research at Greater Bay; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China.
| | - Sai Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Lili Zhang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaozhuo Yang
- College of Urban and Rural Construction, Hebei Agricultural University, Baoding 071001, China
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7
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Köwitsch I, Mehring M. Coatings of magnetic composites of iron oxide and carbon nitride for photocatalytic water purification. RSC Adv 2021; 11:14053-14062. [PMID: 35423917 PMCID: PMC8697677 DOI: 10.1039/d1ra00790d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/07/2021] [Indexed: 12/03/2022] Open
Abstract
Magnetic composites of iron oxide (α-Fe2O3 and Fe3O4) and carbon nitride materials (CN) were synthesized via a microwave assisted hydrothermal method starting from iron salts and CN, which was obtained by thermal decomposition of dicyandiamide. The as-prepared composites with iron oxide loadings of 0.5 ω%-6 ω% were characterized by powder X-ray diffraction (PXRD), diffuse reflectance UV-vis spectroscopy, magnetization measurements, nitrogen adsorption measurements and thermogravimetric analyzes (TGA). The composites were examined for the degradation rate of an aqueous rhodamine B (RhB) solution under visible light irradiation. The magnetic composite α-Fe2O3(3 ω%)/CN enables 82% degradation of RhB within 90 min. Therefore, this material was selected for an immobilization approach and deposited using a spray coating technique on a magnetic polymer substrate. Coatings with loadings from 1.1 mg to 3.6 mg were compared with regard to their activity for the photocatalytic degradation of RhB under visible light irradiation. The substrate loaded with 0.4 mg cm-2 catalyst enables a RhB degradation of 61% within 8 h. Photocatalytic degradation of triclosan and ethinyl estradiol was also successful and both compounds were degraded with up to 46% of the initial concentration within 8 h. ICP-MS measurements of the pollutant solutions after photocatalytic treatment showed that leaching does not occur.
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Affiliation(s)
- Isabel Köwitsch
- Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie Professur Koordinationschemie Straße der Nationen 62 09107 Chemnitz Germany
- Center for Materials, Architectures and Integration of Nanomembranes (MAIN) Rosenbergstraße 6 09126 Chemnitz Germany
| | - Michael Mehring
- Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie Professur Koordinationschemie Straße der Nationen 62 09107 Chemnitz Germany
- Center for Materials, Architectures and Integration of Nanomembranes (MAIN) Rosenbergstraße 6 09126 Chemnitz Germany
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8
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A novel CuO–Cu2O/Ag–Ag3PO4 nanocomposite: Synthesis, characterization, and its application for 2-chlorophenol decontamination under visible light. J Taiwan Inst Chem Eng 2020. [DOI: 10.1016/j.jtice.2020.10.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Examination of Photocatalyzed Chlorophenols for Sequential Photocatalytic-Biological Treatment Optimization. Catalysts 2020. [DOI: 10.3390/catal10090985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Given the known adverse effect of chlorophenols for the aquatic environments which they can reach, the development of efficient methods both technically and economically to remove them has gained increasing attention over time. The combination of photocatalytic oxidation with biological treatment can lead to high removal efficiencies of chlorophenols, while reducing the costs associated with the need to treat large volumes of aqueous solutions. Therefore, the present paper had as its main objective the identification of the minimum photocatalytic oxidation period during which the aqueous solutions of 4-chlorophenol and 2,4-dichlorophenol can be considered as readily biodegradable. Thus, the results of photocatalytic oxidation and biodegradability tests showed that, regardless of the concentration of chlorophenol and its type, the working solutions become readily biodegradable after up to 120 min of irradiation in ultraviolet light. At this irradiation time, the maximum organic content of the aqueous solution is less than 40%, and the biochemical oxygen demand and chemical oxygen demand (BOD/COD) ratio is much higher than 0.4. The maximum specific heterotrophic growth rate of activated sludge has an average value of 4.221 d−1 for 4-chlorophenol, and 3.126 d−1 for 2,4-dichlorophenol. This irradiation period represents at most half of the total irradiation period necessary for the complete mineralization of the working solutions. The results obtained were correlated with the intermediates identified during the photocatalytic oxidation. It seems that, working solutions initially containing 4-chlorophenol can more easily form readily biodegradable intermediates.
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Graphene oxide supported La/Co/Ni trimetallic nano-scale systems for photocatalytic remediation of 2-chlorophenol. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111605] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Boruah B, Gupta R, Modak JM, Madras G. Enhanced photocatalysis and bacterial inhibition in Nb 2O 5 via versatile doping with metals (Sr, Y, Zr, and Ag): a critical assessment. NANOSCALE ADVANCES 2019; 1:2748-2760. [PMID: 36132720 PMCID: PMC9418613 DOI: 10.1039/c9na00305c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/30/2019] [Indexed: 05/18/2023]
Abstract
Unique optical properties render semiconductor Nb2O5 nanoparticles suitable for light harvesting and photocatalytic applications. This study focuses on determining optical properties such as the band gap, conduction band edge, valence band edge and work function of as-prepared solution combustion synthesized Nb2O5 nanoparticles with the help of UV-vis Diffuse Reflectance spectroscopy (DRS) and ultraviolet photoelectron spectroscopy (UPS) techniques. Phase purity and the oxidation states of the elements present in the material were confirmed from X-ray diffraction (XRD) patterns and X-ray photoelectron spectra (XPS), respectively. Doping semiconductors with different metal ions impacts the activity of the material, and therefore efforts were made to understand the effect on the photocatalytic performance of Nb2O5 due to the incorporation of metal dopants viz. Sr, Y, Zr, and Ag. Lattice parameters were obtained from Rietveld refinement of the XRD patterns. Parameters which are closely related to the photoactivity of the catalysts such as the presence of surface defects, oxygen vacancies, surface area, and charge carrier dynamics were determined from photoluminescence (PL) analysis, Brunauer-Emmett-Teller (BET) surface area measurements and time-resolved fluorescence (TRF) analysis respectively. In addition, the dopant concentrations were optimised for enhanced photocatalytic activity. The doped Nb2O5 nanoparticles showed significant activity towards targeted degradation of organic pollutants like 2-chlorophenol (2-CP) and dye contaminants like methylene blue (MB), orange G (OG) and indigo carmine (IC). This strategy yielded a robust response towards inactivation of E. coli and S. aureus as well. Adsorption and photodegradation of MB followed Lagergren's pseudo 1st order reaction model and the Langmuir Hinshelwood model respectively. Bacterial inactivation and OG, IC and 2-CP photodegradation followed 1st order kinetics. The reusability of the catalyst for 5 cycles was demonstrated. Finally, a plausible mechanism is proposed based on radical trapping experiments and combined analysis of the characterization techniques.
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Affiliation(s)
- Bhanupriya Boruah
- Department of Chemical Engineering, Indian Institute of Science Bangalore 560012 India +91 80 23600683 +91 80 22932321
| | - Rimzhim Gupta
- Department of Chemical Engineering, Indian Institute of Science Bangalore 560012 India +91 80 23600683 +91 80 22932321
| | - Jayant M Modak
- Department of Chemical Engineering, Indian Institute of Science Bangalore 560012 India +91 80 23600683 +91 80 22932321
| | - Giridhar Madras
- Department of Chemical Engineering, Indian Institute of Science Bangalore 560012 India +91 80 23600683 +91 80 22932321
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Liu J, Zhang X, Li Y, Li W, Hang C, Sharma VK. Phototransformation of halophenolic disinfection byproducts in receiving seawater: Kinetics, products, and toxicity. WATER RESEARCH 2019; 150:68-76. [PMID: 30508715 PMCID: PMC6390291 DOI: 10.1016/j.watres.2018.11.059] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 05/14/2023]
Abstract
Flushing toilet with seawater is an effective method for preserving freshwater resources, but it introduces iodide and bromide ions into domestic wastewater. During chlorine disinfection, iodide and bromide ions in the saline wastewater effluent lead to the formation of iodinated and brominated aromatic disinfection byproducts (DBPs). Examples of aromatic DBPs include iodophenolic, bromophenolic and chlorophenolic compounds, which generally display substantially higher toxicity than haloaliphatic DBPs. This paper presented for the first time the rates of phototransformation of 21 newly identified halophenolic DBPs in seawater, the receiving waterbody of the wastewater effluent. The phototransformation rate constants (k) were in the range from 7.75 × 10-4 to 4.62 × 10-1 h-1, which gave half-lives of 1.5-895 h. A quantitative structure-activity relationship was established for the phototransformation of halophenolic DBPs as logk=-0.0100×ΔGf0+5.7528×logMW+0.3686×pKa-19.1607, where ΔGf0 is standard Gibbs formation energy, MW is molecular weight, and pKa is dissociation constant. This model well predicted the k values of halophenolic DBPs. Among the tested DBPs, 2,4,6-triiodophenol and 2,6-diiodo-4-nitrophenol were found to exhibit relatively high risks on marine organisms, based on toxicity indices and half-lives. In seawater, the two DBPs underwent photonucleophilic substitutions by bromide, chloride and hydroxide ions, resulting in the conversion to their bromophenolic and chlorophenolic counterparts (which are less toxic than the parent iodophenolic DBPs) and to their hydroxyphenolic counterparts (iodo(hydro)quinones, which are more toxic than the parent iodophenolic DBPs). The formed iodo(hydro)quinones further transformed to hydroxyl-iodo(hydro)quinones, which have lower toxicity than the parent compounds.
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Affiliation(s)
- Jiaqi Liu
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China; Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, USA
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China.
| | - Yu Li
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Wanxin Li
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Chen Hang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Virender K Sharma
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX, USA
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Castro J, Paz S, Mena N, Urresta J, Machuca-Martinez F. Evaluation of heterogeneous catalytic ozonation process for diclofenac degradation in solutions synthetically prepared. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:4488-4497. [PMID: 29951767 DOI: 10.1007/s11356-018-2582-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
Sodium diclofenac (DCF) is a common analgesic and anti-inflammatory drug, which has become an environmental problem due to its growth and accumulation into water bodies. In this work, commercial (with excipients) and analytical (pure) DCF mineralization was studied by means of heterogeneous catalytic ozonation. The process was carried out with magnetite (Fe3O4) as a catalyst, which preserves its physical and chemical properties during the process. The best results of mineralization were obtained after a 40-min treatment of 35 mg/L analytical DCF solution, with a 0.5 g/L catalyst concentration. These results showed the highest organic load decrease, measured as dissolved organic carbon (DOC) and chemical oxygen demand (COD), with 94 and 89%, respectively. In addition, the percentage of organic load decrease was compared between the conventional and the catalyzed process. Besides, reaction products were identified by gas chromatography-mass spectrometry (GC-MS) and the catalytic properties were identified by Mössbauer spectroscopy, which showed the catalyst maintained its nature after the process. Finally, the results obtained show that the heterogeneous catalytic process could be an efficient degradation treatment for emerging contaminants such as DCF.
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Affiliation(s)
- Jenny Castro
- Grupo de Investigación de Procesos Avanzados para Tratamientos Químicos y Biológicos (GAOX), Universidad del Valle, Calle 13 No. 100-00, Cali, Colombia.
| | - Santiago Paz
- Grupo de Investigación de Procesos Avanzados para Tratamientos Químicos y Biológicos (GAOX), Universidad del Valle, Calle 13 No. 100-00, Cali, Colombia
| | - Natali Mena
- Laboratorio de Investigación en Catálisis aplicada y Procesos (LICAP), Universidad del Valle, Calle 13 No. 100-00, Cali, Colombia
| | - Julián Urresta
- Laboratorio de Investigación en Catálisis aplicada y Procesos (LICAP), Universidad del Valle, Calle 13 No. 100-00, Cali, Colombia
| | - Fiderman Machuca-Martinez
- Grupo de Investigación de Procesos Avanzados para Tratamientos Químicos y Biológicos (GAOX), Universidad del Valle, Calle 13 No. 100-00, Cali, Colombia
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Elghniji K, Zougari-Elwedi B, Elaloui E, Moussaoui Y. Photodegradation of 2-Chlorophenol in TiO2/UV System: Phytotoxicity Assessment of Treated Solutions Against Seedling Growth of Turnip and Tomato. J WATER CHEM TECHNO+ 2019. [DOI: 10.3103/s1063455x18060085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Ramachandran S, Sivasamy A. Synthesis of nanocrystalline bismuth oxide and its visible photocatalytic activity in the degradation of an organic dye. INORG NANO-MET CHEM 2018. [DOI: 10.1080/24701556.2018.1504071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Saranya Ramachandran
- Chemical Engineering Area, CSIR-Central Leather Research Institute, Chennai, India
| | - Arumugam Sivasamy
- Chemical Engineering Area, CSIR-Central Leather Research Institute, Chennai, India
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Wang WL, Wu QY, Huang N, Xu ZB, Lee MY, Hu HY. Potential risks from UV/H 2O 2 oxidation and UV photocatalysis: A review of toxic, assimilable, and sensory-unpleasant transformation products. WATER RESEARCH 2018; 141:109-125. [PMID: 29783164 DOI: 10.1016/j.watres.2018.05.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/04/2018] [Accepted: 05/05/2018] [Indexed: 06/08/2023]
Abstract
UV based advanced oxidation processes (UV-AOPs) that efficiently eliminate organic pollutants during water treatment have been the subject of numerous investigations. Most organic pollutants are not completely mineralized during UV-AOPs but are partially oxidized into transformation products (TPs), thereby adding complexity to the treated water and posing risks to humans, ecological systems, and the environment. While the degradation kinetics and mechanisms of pollutants have been widely documented, there is little information about the risks associated with TPs. In this review, we have collated recent knowledge about the harmful TPs that are generated in UV/H2O2 and UV photocatalysis, two UV-AOPs that have been studied extensively. Toxic and assimilable TPs were ubiquitously observed in more than 80% of UV-AOPs of organic pollutants, of which the toxicity and assimilability levels changed with variations in the reaction conditions, such as the UV fluence and oxidant dosage. Previous studies and modeling assessments showed that toxic and assimilable TPs may be generated during hydroxylation, dealkylation, decarboxylation, and deamination. Among various reactions, TPs generated from dealkylation and decarboxylation were generally less and more toxic than the parent pollutants, respectively; TPs generated from decarboxylation and deamination were generally less and more assimilable than the parent pollutants, respectively. There is also potential concern about the sensory-unpleasant TPs generated by oxidations and subsequent metabolism of microorganisms. In this overview, we stress the need to include both the concentrations of organic pollutants and the evaluations of the risks from TPs for the quality assessments of the water treated by UV-AOPs.
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Affiliation(s)
- Wen-Long Wang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), and School of Environment, Tsinghua University, Beijing 100084, PR China; Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China
| | - Qian-Yuan Wu
- Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, PR China.
| | - Nan Huang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), and School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Zi-Bin Xu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), and School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Min-Yong Lee
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), and School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Hong-Ying Hu
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), and School of Environment, Tsinghua University, Beijing 100084, PR China; Shenzhen Environmental Science and New Energy Technology Engineering Laboratory, Tsinghua-Berkeley Shenzhen Institute, Shenzhen 518055, PR China.
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17
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Lin JCT, Sopajaree K, Jitjanesuwan T, Lu MC. Application of visible light on copper-doped titanium dioxide catalyzing degradation of chlorophenols. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2017.09.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Duan X, Zhao C, Liu W, Zhao X, Chang L. Fabrication of a novel PbO2 electrode with a graphene nanosheet interlayer for electrochemical oxidation of 2-chlorophenol. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.04.114] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Ba-Abbad MM, Takriff MS, Kadhum AAH, Mohamad AB, Benamor A, Mohammad AW. Solar photocatalytic degradation of 2-chlorophenol with ZnO nanoparticles: optimisation with D-optimal design and study of intermediate mechanisms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:2804-2819. [PMID: 27837474 DOI: 10.1007/s11356-016-8033-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/01/2016] [Indexed: 06/06/2023]
Abstract
In this study, the photocatalytic degradation of toxic pollutant (2-chlorophenol) in the presence of ZnO nanoparticles (ZnO NPs) was investigated under solar radiation. The three main factors, namely pH of solution, solar intensity and calcination temperature, were selected in order to examine their effects on the efficiency of the degradation process. The response surface methodology (RSM) technique based on D-optimal design was applied to optimise the process. ANOVA analysis showed that solar intensity and calcination temperature were the two significant factors for degradation efficiency. The optimum conditions in the model were solar intensity at 19.8 W/m2, calcination temperature at 404 °C and pH of 6.0. The maximum degradation efficiency was predicted to be 90.5% which was in good agreement with the actual experimental value of 93.5%. The fit of the D-optimal design correlated very well with the experimental results with higher values of R 2 and R 2adj correlation coefficients of 0.9847 and 0.9676, respectively. The intermediate mechanism behaviour of the 2-chlorophenol degradation process was determined by gas chromatography-mass spectrometry (GC-MS). The results confirmed that 2-chlorophenol was converted to acetic acid, a non-toxic compound.
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Affiliation(s)
- Muneer M Ba-Abbad
- Research Centre For Sustainable Process Technology, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
- Department of Chemical Engineering, Faculty of Engineering and Petroleum, Hadhramout University of Science & Technology, Mukalla, Hadhramout, Yemen.
| | - Mohd S Takriff
- Research Centre For Sustainable Process Technology, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Abdul Amir H Kadhum
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Abu Bakar Mohamad
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
- Fuel Cell Institute, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
| | - Abdelbaki Benamor
- Gas Processing Centre, Qatar University, P. O. Box 2713, Doha, Qatar
| | - Abdul Wahab Mohammad
- Research Centre For Sustainable Process Technology, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
- Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia
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Meenakshi G, Sivasamy A. Synthesis and characterization of zinc oxide nanorods and its photocatalytic activities towards degradation of 2,4-D. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 135:243-251. [PMID: 27744194 DOI: 10.1016/j.ecoenv.2016.10.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/03/2016] [Accepted: 10/06/2016] [Indexed: 06/06/2023]
Abstract
Semiconductor zinc oxide nanorods (NRZnO) were prepared by sol-gel technique using zinc acetate as the precursor and ammonia as the precipitating agent. The prepared photocatalyst were characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), UV-Visible diffuse reflectance spectroscopy (UV-Vis-DRS), X-ray photoelectron spectroscopy (XPS), Field Emission-Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), High Resolution-Tunneling Microscope (HR-TEM), Brunauer, Emmett and Teller (BET) and electron paramagnetic resonance spectroscopy (EPR) analysis. Particle size of the prepared photocatalyst was established by XRD and FE-SEM analysis. The morphology and the formation of uniform NRZnO was controlled by the temperature, entire concentration of precursors, duration of aging process. High surface roughness and porosity confirmed by AFM analysis. Band gap energy of the synthesized photocatalyst (3.2eV) was determined by using diffuse reflectance spectroscopy. The in-situ production of OH radicals by the prepared photocatalyst was confirmed by electron paramagnetic resonance spectroscopy (EPR) spin trapping technique. The photocatalytic activity of prepared NRZnO was evaluated by photo degradation of 2, 4-dichlorophenoxyacetic acid (2, 4-D) under UV and visible light irradiations. Experimental parameter such as effect of pH, catalyst dosage, initial 2, 4- D concentrations and addition of different electrolytes on the degradation of 2, 4-D was also studied in detail. Neutral pH was found to be the optimum and catalyst dosage of 30mg/10ml resulted in higher percentage of degradation. The photo degraded samples were analyzed by chemical oxygen demand (COD) analysis, UV-Visible spectroscopy. Reusability of the prepared photocatalyst was tested upto three cycles without affecting its performance. The experimental shown the rate of degradation follows pseudo-first order rate kinetics with respect to 2, 4 D.
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Affiliation(s)
- G Meenakshi
- Chemical Engineering Area, CSIR-Central Leather Research Institute, Adyar, Chennai 600020, India
| | - A Sivasamy
- Chemical Engineering Area, CSIR-Central Leather Research Institute, Adyar, Chennai 600020, India.
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Salah N, Hameed A, Aslam M, Babkair SS, Bahabri FS. Photocatalytic activity of V doped ZnO nanoparticles thin films for the removal of 2- chlorophenol from the aquatic environment under natural sunlight exposure. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 177:53-64. [PMID: 27082257 DOI: 10.1016/j.jenvman.2016.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 06/05/2023]
Abstract
Vanadium doped ZnO powders were used as precursors to deposit thin films of V(5+) incorporated ZnO nanoparticles on glass substrates by the pulsed laser deposition technique. The observed variations in Raman signals, visible region shift in the diffuse reflectance spectra along with a small shift in the (101) reflections of the X-ray diffraction (XRD) confirmed the insertion of V(5+) ions in ZnO lattice. No other additional reflection in the XRD results other than ZnO further endorsed the occupation of lattice positions by V entities rather than independent oxide formation. The asymmetric XPS peaks of Zn2p and V2p core levels confirmed the existence of both in the vicinity. The existence of minimal proportion of V(3+) along with V(5+) states varied the alteration of the oxidation states V in the synthetic route. The SEM images at various resolutions displayed the uniform distribution identical nanoparticles without the presence of additional phases in the deposited films. The SEM cross-section measurements revealed the uniform thickness of ∼90 nm of each film, whereas the surface studies of the films were performed by AFM. The as-synthesized films were tested for photocatalytic activity in sunlight illumination for the removal of 2-chlorophenol. The unique feature of the study was the estimation of the photocatalytic activity 20 ppm of 2-chlorophenol by exposing the low exposed area. The degradation of the substrate was measured by liquid phase UV-vis spectroscopy, whereas total organic carbon measurement revealed the mineralization of the substrate. The released Cl(-) ions were also measured by ion chromatography. The estimated flatband potentials and pHzpc values of the V doped materials, by Mott-Schottky analysis and zeta potential measurements respectively, were correlated with the photocatalytic activity. The kinetics of the photocatalytic degradation/mineralization process was estimated and results were correlated with the plausible mechanism.
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Affiliation(s)
- Numan Salah
- Center of Nanotechnology, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
| | - A Hameed
- Center of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah, 21589, Saudi Arabia; National Centre for Physics, Quaid-e-Azam University, Islamabad 44000, Pakistan
| | - M Aslam
- Center of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Saeed S Babkair
- Department of Physics, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - F S Bahabri
- Sciences Faculty for Girls, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
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Barik AJ, Gogate PR. Degradation of 4-chloro 2-aminophenol using a novel combined process based on hydrodynamic cavitation, UV photolysis and ozone. ULTRASONICS SONOCHEMISTRY 2016; 30:70-78. [PMID: 26597540 DOI: 10.1016/j.ultsonch.2015.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 06/05/2023]
Abstract
The degradation of 4-chloro 2-aminophenol (4C2AP), an acute toxic organic compound, has been studied using different approaches based on the hydrodynamic cavitation (HC) with orifice plate as cavitating device, photolysis (UV) and ozonation (O3). The dependency of extent of degradation on operating parameters like operating pressure (2-5 bar), initial pH (3-8) and temperature (30-38 °C) have been established initially to maximize the efficacy of hydrodynamic cavitation. Subsequently the degradation has been studied using combined treatment strategies as HC+UV, HC+O3, UV+O3 and HC+UV+O3 at the established optimum parameters of operating temperature as 30 °C, initial pH of 6 and inlet pressure of 4 bar. The maximum extent of degradation as 96.85% and 73.6% reduction in TOC has been obtained using hydrodynamic cavitation in combination with UV photolysis and ozonation under the optimized operating conditions. The degradation products of 4C2AP have been identified using GC-MS. The present work has clearly established the efficacy of combined treatment approach (HC+UV+O3) for the removal of organic pollutant for the first time.
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Affiliation(s)
- Arati J Barik
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400 019, India
| | - Parag R Gogate
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai 400 019, India.
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Enhancement of 2-chlorophenol photocatalytic degradation in the presence Co2+-doped ZnO nanoparticles under direct solar radiation. RESEARCH ON CHEMICAL INTERMEDIATES 2015. [DOI: 10.1007/s11164-015-2352-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rashid J, Barakat M, Salah N, Habib SS. ZnO-nanoparticles thin films synthesized by RF sputtering for photocatalytic degradation of 2-chlorophenol in synthetic wastewater. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.08.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Taleb MFA. Adsorption and photocatalytic degradation of 2-CP in wastewater onto CS/CoFe2O4 nanocomposite synthesized using gamma radiation. Carbohydr Polym 2014; 114:65-72. [DOI: 10.1016/j.carbpol.2014.07.061] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/10/2014] [Accepted: 07/29/2014] [Indexed: 11/28/2022]
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26
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Ansari SA, Khan MM, Ansari MO, Lee J, Cho MH. Visible light-driven photocatalytic and photoelectrochemical studies of Ag–SnO2 nanocomposites synthesized using an electrochemically active biofilm. RSC Adv 2014. [DOI: 10.1039/c4ra03448a] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ag–SnO2 nanocomposites (1 mM and 3 mM) were synthesized in water at room temperature using an electrochemically active biofilm.
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Affiliation(s)
- Sajid Ali Ansari
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan-si, South Korea
| | | | - Mohd Omaish Ansari
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan-si, South Korea
| | - Jintae Lee
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan-si, South Korea
| | - Moo Hwan Cho
- School of Chemical Engineering
- Yeungnam University
- Gyeongsan-si, South Korea
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Heterogeneous photocatalytic degradation of 4-chlorophenol by immobilization of cobalt tetrasulphophthalocyanine onto MCM-41. KOREAN J CHEM ENG 2013. [DOI: 10.1007/s11814-013-0223-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Zhang J, Ma C, Sun Y, Ren X. Hydroxyl radical reactions with 2-chlorophenol as a model for oxidation in supercritical water. RESEARCH ON CHEMICAL INTERMEDIATES 2013. [DOI: 10.1007/s11164-012-1015-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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29
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Photocatalytic degradation of chlorophenols under direct solar radiation in the presence of ZnO catalyst. RESEARCH ON CHEMICAL INTERMEDIATES 2012. [DOI: 10.1007/s11164-012-0731-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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30
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Sharma S, Mukhopadhyay M, Murthy Z. Rate parameter estimation for 4-chlorophenol degradation by UV and organic oxidants. J IND ENG CHEM 2012. [DOI: 10.1016/j.jiec.2011.11.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Elghniji K, Hentati O, Mlaik N, Mahfoudh A, Ksibi M. Photocatalytic degradation of 4-chlorophenol under P-modified TiO2/UV system: kinetics, intermediates, phytotoxicity and acute toxicity. J Environ Sci (China) 2012; 24:479-87. [PMID: 22655362 DOI: 10.1016/s1001-0742(10)60659-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A series of phosphorus-modified titanium dioxide samples with varying P/Ti atomic ratio were conveniently prepared via a conventional solgel route. The effects of phosphorus content and calcination temperature on the crystalline structure, grain growth, surface area, and the photocatalytic activity of P-modified TiO2 were investigated. The XRD results showed that P species slow down the particle growth of anatase and increase the anatase-to-rutile phase transformation temperature to more than 900 degrees C. Kinetic studies on the P-modified TiO2 to degraded 4-chlorophenol had found that the TP5(500) prepared by adopting a P/Ti atomic ratio equal to 0.05 and calcined at 500 degrees C had an apparent rate constant equal to 0.0075 min(-1), which is superior to the performance of a commercial photocatalyst Degussa P25 K(app) = 0.0045 min(-1) and of unmodified TiO2 (TP0(500)) K(app) = 0.0022 min(-1). From HPLC analyses, various hydroxylated intermediates formed during oxidation had been identified, including hydroquinone (HQ), benzoquinone (BQ) and (4CC) 4-chlorocatechol as main products. Phytotoxicity was assessed before and after irradiation against seed germination of tomato (Lycopersicon esculentum) whereas acute toxicity was assessed by using Folsomia candida as the test organism. Intermediates products were all less toxic than 4-chlorophenol and a significant removal of the overall toxicity was accomplished.
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Affiliation(s)
- Kais Elghniji
- University of Sfax, Laboratoire Eau, Energie et Environnement ENIS, B.P 1173, 3038 Sfax, Tunisia
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Palmisano L, Augugliaro V, Bellardita M, Di Paola A, García López E, Loddo V, Marcì G, Palmisano G, Yurdakal S. Titania photocatalysts for selective oxidations in water. CHEMSUSCHEM 2011; 4:1431-1438. [PMID: 21957017 DOI: 10.1002/cssc.201100196] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 06/30/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Leonardo Palmisano
- "Schiavello-Grillone" Photocatalysis Group, Dipartimento di Ingegneria Elettrica, Elettronica e delle Telecomunicazioni, University of Palermo, Viale delle Scienze, Ed. 9, 90128 Palermo, Italy.
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Shriwas AK, Gogate PR. Intensification of Degradation of 2,4,6-Trichlorophenol Using Sonochemical Reactors: Understanding Mechanism and Scale-up Aspects. Ind Eng Chem Res 2011. [DOI: 10.1021/ie200817u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Akshaykumar K. Shriwas
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai-40019, India
| | - Parag R. Gogate
- Chemical Engineering Department, Institute of Chemical Technology, Matunga, Mumbai-40019, India
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Kusic H, Juretic D, Koprivanac N, Marin V, Božić AL. Photooxidation processes for an azo dye in aqueous media: modeling of degradation kinetic and ecological parameters evaluation. JOURNAL OF HAZARDOUS MATERIALS 2011; 185:1558-1568. [PMID: 21093983 DOI: 10.1016/j.jhazmat.2010.10.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 10/14/2010] [Accepted: 10/20/2010] [Indexed: 05/30/2023]
Abstract
Three photooxidation processes, UV/H(2)O(2), UV/S(2)O(8)(2-) and UV/O(3) were applied to the treatment of model wastewater containing non-biodegradable organic pollutant, azo dye Acid Orange 7 (AO7). Dye degradation was monitored using UV/VIS and total organic carbon (TOC) analysis, determining decolorization, the degradation/formation of naphthalene and benzene structured AO7 by-products, and the mineralization of model wastewater. The water quality during the treatment was evaluated on the bases of ecological parameters: chemical (COD) and biochemical (BOD(5)) oxygen demand and toxicity on Vibrio fischeri determining the EC(50) value. The main goals of the study were to develop an appropriate mathematic model (MM) predicting the behavior of the systems under investigation, and to evaluate the toxicity and biodegradability of the model wastewater during treatments. MM developed showed a high accuracy in predicting the degradation of AO7 when considering the following observed parameters: decolorization, formation/degradation of by-products and mineralization. Good agreement of the data predicted and the empirically obtained was confirmed by calculated standard deviations. The biodegradability of model wastewater was significantly improved by three processes after mineralizing a half of the initially present organic content. The toxicity AO7 model wastewater was decreased as well. The differences in monitored ecological parameters during the treatment indicated the formation of different by-products of dye degradation regarding the oxidant type applied.
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Affiliation(s)
- Hrvoje Kusic
- Faculty of Chemical Engineering and Technology, University of Zagreb, Marulicev trg 19, Zagreb 10000, Croatia.
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Suryaman D, Hasegawa K. Biological and photocatalytic treatment integrated with separation and reuse of titanium dioxide on the removal of chlorophenols in tap water. JOURNAL OF HAZARDOUS MATERIALS 2010; 183:490-496. [PMID: 20692763 DOI: 10.1016/j.jhazmat.2010.07.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 07/13/2010] [Accepted: 07/13/2010] [Indexed: 05/29/2023]
Abstract
We investigated biological, photocatalytic, and combination of biological and photocatalytic treatments in order to remove a mixture of 2-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol, and pentachlorophenol in tap water (total: 100 mg L(-1), each: 25 mg L(-1)). The removal of chlorinated phenols was conducted with a flow biological treatment and a circulative flow photocatalytic treatment under black light and sunlight irradiations integrated with titanium dioxide separation and reuse. The combined biological-photocatalytic treatment significantly shortened the degradation and mineralization time of both the biological treatment and the photocatalytic treatment. The removed chlorophenols per hour by the combined biological-photocatalytic treatment was 25.8 mg h(-1), whereas by the combined photocatalytic-biological treatment was 10.5 mg h(-1). After a large portion of biodegradable 2-chlorophenol and 2,4-dichlorophenol, and around half amount of slightly biodegradable 2,4,5-trichlorophenol were removed by the biological treatment, the remained three chlorophenols, biorecalcitrant pentachlorophenol, and biodegradation products were completely removed by the subsequent photocatalytic treatment. Since titanium dioxide particles in tap water spontaneously sedimented on standing after the photocatalytic treatment, the combined treatment can be operated by integrating with the titanium dioxide separation and reuse. The TiO(2) particles were recovered and reused at least three times without significantly decreasing the removal efficiency.
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Affiliation(s)
- Dhanus Suryaman
- Agency for the Assessment and Application of Technology, M.H. Thamrin No. 8, Jakarta 10340, Indonesia.
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Khataee AR, Fathinia M, Aber S. Kinetic Modeling of Liquid Phase Photocatalysis on Supported TiO2 Nanoparticles in a Rectangular Flat-Plate Photoreactor. Ind Eng Chem Res 2010. [DOI: 10.1021/ie101997u] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. R. Khataee
- Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
| | - M. Fathinia
- Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
| | - S. Aber
- Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
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Neti NR, Misra R, Bera PK, Dhodapkar R, Bakardjieva S, Bastl Z. Synthesis of C-Doped TiO2 Nanoparticles by Novel Sol-Gel Polycondensation of Resorcinol with Formaldehyde for Visible-Light Photocatalysis. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/15533174.2010.486820] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Nageswara Rao Neti
- a National Environmental Engineering Research Institute, Council of Scientific and Industrial Research (CSIR, New Delhi) , Nagpur, India
| | - Rohit Misra
- a National Environmental Engineering Research Institute, Council of Scientific and Industrial Research (CSIR, New Delhi) , Nagpur, India
| | - Prabir Kumar Bera
- a National Environmental Engineering Research Institute, Council of Scientific and Industrial Research (CSIR, New Delhi) , Nagpur, India
| | - Rita Dhodapkar
- a National Environmental Engineering Research Institute, Council of Scientific and Industrial Research (CSIR, New Delhi) , Nagpur, India
| | | | - Zdenek Bastl
- c Department of Chemical Physics , J. Herovsky Institute of Physical Chemistry , Dolejškova, Prague, Czech Republic
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Zanjanchi MA, Ebrahimian A, Arvand M. Sulphonated cobalt phthalocyanine-MCM-41: an active photocatalyst for degradation of 2,4-dichlorophenol. JOURNAL OF HAZARDOUS MATERIALS 2010; 175:992-1000. [PMID: 19939562 DOI: 10.1016/j.jhazmat.2009.10.108] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 10/24/2009] [Accepted: 10/28/2009] [Indexed: 05/16/2023]
Abstract
The photocatalytic activity of sulphonated cobalt phthalocyanine immobilized onto MCM-41 was investigated for decomposition of 2,4-dichlorophenol (2,4-DCP) in aqueous solutions. Immobilization of anion sulpho-cobalt phthalocyanine to the walls of MCM-41 was performed by pre-anchorage of 3-(aminopropyl)-triethoxysilane (APTES) onto MCM-41 via post-synthesis method. X-ray diffraction, nitrogen physisorption, diffuse reflectance spectroscopy, energy-dispersive X-ray and FT-IR methods were used to characterize the product. Photocatalytic efficiency of the prepared catalyst for degradation of 2,4-DCP was tested under illumination of UV-A and visible light. The results obtained reveal that the photocatalyst is very active in degradation of 2,4-DCP. The photodegradation process is completed within 3h using a dose of 0.6g/L of the catalyst under UV irradiation. The reactions follow a pseudo-first-order kinetics and the observed rate constant values change with 2,4-DCP concentrations. The reproducibility of the catalyst was tested. The reaction intermediates were identified by gas chromatoghraphy-mass spectrometry (GC-MS) technique.
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Affiliation(s)
- M A Zanjanchi
- Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Namjoo St., Rasht 41335, Iran.
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Huang HH, Tseng DH, Juang LC. Heterogeneous photocatalytic degradation of monochlorobenzene in water. JOURNAL OF HAZARDOUS MATERIALS 2008; 156:186-193. [PMID: 18215461 DOI: 10.1016/j.jhazmat.2007.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/06/2007] [Accepted: 12/06/2007] [Indexed: 05/25/2023]
Abstract
This investigation evaluated the photocatalytic degradation of monochlorobenzene (MCB) in an aqueous TiO(2) suspension. In accordance with the experimental results, the degradation of MCB was a function of the initial substrate concentration, incident light intensity, and TiO(2) dosage. However, the solution pH had insignificant effect on the degradation efficiency. The heterogeneous photocatalytic degradation of MCB followed the Langmuir-Hinshelwood kinetics. The adsorption coefficient of MCB (K) and the observed degradation rate constant (k) were calculated as 13.4 mM(-1) and 0.0054 mM min(-1), respectively. In addition, a 0.255 dependency of the initial degradation rate on the light intensity revealed the considerable adverse effect of e(-)-h(+) pair recombination. Both mineralization and dechlorination occurred during the photocatalytic degradation of MCB. Under the operating condition of initial MCB concentration of 0.1mM, light intensity of 5.68 microEinsteins(-1), TiO(2) dosage of 1.0 g L(-1), and solution pH of 7, about 93.7% of MCB was mineralized after 240 min of irradiation. Nevertheless, 64.3% of the stoichiometric amount of Cl(-) ions was released into the bulk solution. The simulation results derived from the X-ray photoelectron spectroscopy (XPS) analysis was suggested that the interaction between Cl(-) ions and TiO(2) surface tended to lower the released amount of Cl(-) ions.
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Affiliation(s)
- Hsin-Hsu Huang
- Graduate Institute of Environmental Engineering, National Central University, Jhongli, Taiwan.
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Poulopoulos SG, Nikolaki M, Karampetsos D, Philippopoulos CJ. Photochemical treatment of 2-chlorophenol aqueous solutions using ultraviolet radiation, hydrogen peroxide and photo-Fenton reaction. JOURNAL OF HAZARDOUS MATERIALS 2008; 153:582-587. [PMID: 17931771 DOI: 10.1016/j.jhazmat.2007.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 03/07/2007] [Accepted: 09/01/2007] [Indexed: 05/25/2023]
Abstract
In the present work, the photochemical oxidation of 2-chlorophenol aqueous solutions in a batch recycle photochemical reactor using ultraviolet irradiation and hydrogen peroxide was studied. Specifically, the effect of hydrogen peroxide initial concentration (0-10316 mg L(-1)) and 2-chlorophenol initial concentration (150-3000 mg L(-1)) was examined. The process was attended via total organic carbon (TOC), 2-chlorophenol, chloride ion, acetic acid, formic acid and pH measurements. The conversion of 2-chlorophenol observed was always much higher than the corresponding total organic carbon removal, whereas the increase in hydrogen peroxide amount in the solution led to higher values of 2-chlorophenol conversion and total organic carbon removal. Finally, the photo-Fenton reaction was applied to the oxidation of 2-chlorophenol, leading to a higher degree of mineralization of the parent compound.
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Affiliation(s)
- S G Poulopoulos
- Chemical Process Engineering Laboratory, School of Chemical Engineering, National Technical University of Athens, Heroon Politechniou 9, Zografou Campus, Athens, Greece
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41
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Hong SH, Kwon BH, Lee JK, Kim IK. Degradation of 2-chlorophenol by Fenton and photo-Fenton processes. KOREAN J CHEM ENG 2008. [DOI: 10.1007/s11814-008-0008-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Nikolaki MD, Philippopoulos CJ. Photochemical degradation of 1,3-dichloro-2-propanol aqueous solutions. JOURNAL OF HAZARDOUS MATERIALS 2007; 146:674-9. [PMID: 17524555 DOI: 10.1016/j.jhazmat.2007.04.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The photochemical oxidation of 1,3-dichloro-2-propanol (1,3-DCP) was studied by following the target compound degradation, the total carbon removal rate by a total organic carbon (TOC) analyzer and by identifying the oxidation products by gas chromatography-mass spectrometry (GC-MS). The reaction was performed in a batch recycle reactor, at room temperature, using UV radiation provided by a low pressure 12W Hg lamp and H(2)O(2) as oxidant. Chloride ions, formic, acetic and chloroacetic acid were measured by ion chromatography. Apart from the chloride ions and the organic acids, the presence of 1,3-dichloro-2-propanone and chloroacetyl chloride was also detected and a possible pathway is proposed for the degradation of the parent compound. Complete degradation of 1,3-dichloro-2-propanol was achieved and the TOC removal reached as much as 80% at the end of the reaction time. The effect of the initial concentration of hydrogen peroxide was investigated and it was established that higher concentrations of H(2)O(2) slow down the reaction rate. Finally, the effect of the initial concentration of 1,3-DCP was investigated.
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Affiliation(s)
- M D Nikolaki
- Chemical Process Engineering Laboratory, Department of Chemical Engineering, National Technical University, 9 Heroon Polytechniou Str., Zografou Campus, 157 80 Athens, Greece
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Palmisano G, Addamo M, Augugliaro V, Caronna T, Di Paola A, López EG, Loddo V, Marcì G, Palmisano L, Schiavello M. Selectivity of hydroxyl radical in the partial oxidation of aromatic compounds in heterogeneous photocatalysis. Catal Today 2007. [DOI: 10.1016/j.cattod.2007.01.026] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Suryaman D, Hasegawa K, Kagaya S. Combined biological and photocatalytic treatment for the mineralization of phenol in water. CHEMOSPHERE 2006; 65:2502-6. [PMID: 16989890 DOI: 10.1016/j.chemosphere.2006.07.059] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Revised: 07/19/2006] [Accepted: 07/22/2006] [Indexed: 05/11/2023]
Abstract
Phenol is degraded by biological treatment, however mineralization requires long time. To decrease the time and operational cost necessary for the mineralization of phenol, an optimum operation condition of the combined biological-photocatalytical treatment was investigated. The mineralization of phenol (50 mg l(-1)) was conducted in a flow-type biomembrane tank combined with a batch-type TiO2-suspended photocatalytic reactor. Phenol was degraded biologically to the concentration of 6.8 mg l(-1), an effective concentration for further photocatalytic treatment. After the biological treatment, the biotreated phenol was treated photocatalytically to complete the mineralization of phenol. The combined treatment shortened the mineralization time compared to the biological treatment and electric cost compared to the photocatalytic treatment only. The combined treatment may be suitable for a short-time mineralization of phenol in wastewater.
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Affiliation(s)
- Dhanus Suryaman
- Department of Chemical and Biochemical Engineering, Faculty of Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555, Japan
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Palmisano G, Addamo M, Augugliaro V, Caronna T, García-López E, Loddo V, Palmisano L. Influence of the substituent on selective photocatalytic oxidation of aromatic compounds in aqueous TiO2 suspensions. Chem Commun (Camb) 2006:1012-4. [PMID: 16491193 DOI: 10.1039/b515853b] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.
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Affiliation(s)
- Giovanni Palmisano
- Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
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Mohanty S, Rao NN, Khare P, Kaul SN. A coupled photocatalytic-biological process for degradation of 1-amino-8-naphthol-3, 6-disulfonic acid (H-acid). WATER RESEARCH 2005; 39:5064-70. [PMID: 16310240 DOI: 10.1016/j.watres.2005.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 05/07/2005] [Accepted: 05/10/2005] [Indexed: 05/05/2023]
Abstract
There has been growing emphasis on the development of coupled treatment systems (e.g., advanced oxidation-biological) for treating poorly biodegradable wastewater. An attempt has been made in the present study to couple photocatalytic (TiO2/UV) pretreatment with conventional activated sludge process to achieve improvement in the biodegradation of H-acid. The combination of titanium dioxide and UV light has been known to generate strong oxidants that degrade several organic pollutants into carbon dioxide via the formation of some intermediates. The intermediates formed may undergo biodegradation readily. Accordingly, photodegradation experiments were carried out initially at an optimized TiO2 dose and the minimum pretreatment time required for transforming H-acid was identified. For this purpose, UV-vis spectrophotometry and high-performance liquid chromatography (HPLC) were extensively used. Subsequently, it was attempted to biodegrade untreated and pretreated H-acid using activated sludge from the textile industry acclimatized to H-acid. It was found that photocatalytic pretreatment of H-acid for 30 min, during which period approximately 8-10% chemical oxygen demand (COD) removal occurred, can be coupled to second-stage biological treatment for achieving enhanced biodegradation of H-acid.
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Affiliation(s)
- Sagarika Mohanty
- National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, India
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Zainal Z, Lee CY, Hussein MZ, Kassim A, Yusof NA. Electrochemical-assisted photodegradation of dye on TiO2 thin films: investigation on the effect of operational parameters. JOURNAL OF HAZARDOUS MATERIALS 2005; 118:197-203. [PMID: 15721544 DOI: 10.1016/j.jhazmat.2004.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Revised: 09/12/2004] [Accepted: 11/02/2004] [Indexed: 05/24/2023]
Abstract
Electrochemical-assisted photodegradation of methyl orange has been investigated using TiO2 thin films. The films were prepared by sol-gel dip-coating method. Several operational parameters to achieve optimum efficiency of this electrochemical-assisted photodegradation system have been tested. Photoelectrochemical degradation was studied using different light sources and light intensity. The light sources chosen ranged from ultraviolet to visible light. The effect of agitation of the solution at different speeds has also been studied. Slight improvement of photodegradation rate was observed by applying higher agitation speed. Investigation on the electrode after repeated usages show the electrode can be reused up to 20 times with percentage of deficiency less than 15%. The study on the effect of solution temperature indicated that the activation energy of the methyl orange degradation is 18.63 kJ mol(-1).
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Affiliation(s)
- Zulkarnain Zainal
- Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia.
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Vorontsov AV, Chen YC, Smirniotis PG. Photocatalytic oxidation of VX simulant 2-(butylamino)ethanethiol. JOURNAL OF HAZARDOUS MATERIALS 2004; 113:89-95. [PMID: 15363518 DOI: 10.1016/j.jhazmat.2004.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Revised: 05/04/2004] [Accepted: 05/19/2004] [Indexed: 05/24/2023]
Abstract
Photocatalytic oxidation of 2-(butylamino)ethanethiol (BAET) was undertaken in aqueous suspension of TiO2 Hombikat UV 100 and Degussa P25 under different initial reaction conditions in order to determine the best parameters for the fastest mineralization of the substrate. BAET is considered to be a simulant for the VX chemical warfare agent. The application of ultrasound had only a small positive effect on the BAET photocatalytic degradation. The highest mineralization rate of 0.433 mg/(l min) was found in unbuffered TiO2 Degussa P25 suspension with initial pH value of about 9.4, TiO2 concentration 500 mg/l and the initial BAET concentration 1000 mg/l. Decreasing of the initial solution pH to 6.1 or below stops the mineralization of BAET while increasing of pH to about 11 drastically changed the degradation profile. At this initial pH, the first 100 min of reaction led to only oxidation of sulfur moiety and organic intermediates accumulated in the solution. Thereafter, mineralization of the products started. The main detected volatile product was butyl aldehyde and the main polar one was 2-(butylamino) acetic acid. In the case of TiO2 Hombikat UV 100, conversion of TOC at initial pH 11 exceeded that at initial pH 9.1. For Degussa P25, the starting pH 9.4 was the best for TOC conversion. The results can be used for treatment of water from pollutants with aliphatic nitrogen and sulfur atoms.
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