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Hu XR, Wang YC, Tong Z, Wang C, Duan EH, Han MF, Hsi HC, Deng JG. Degradation of trichloroethylene by double dielectric barrier discharge (DDBD) plasma technology: Performance, product analysis and acute biotoxicity assessment. CHEMOSPHERE 2023; 329:138651. [PMID: 37059204 DOI: 10.1016/j.chemosphere.2023.138651] [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: 01/23/2023] [Revised: 04/07/2023] [Accepted: 04/07/2023] [Indexed: 05/03/2023]
Abstract
Trichloroethylene is carcinogenic and poorly degraded by microorganisms in the environment. Advanced Oxidation Technology is considered to be an effective treatment technology for TCE degradation. In this study, a double dielectric barrier discharge (DDBD) reactor was established to decompose TCE. The influence of different condition parameters on DDBD treatment of TCE was investigated to determine the appropriate working conditions. The chemical composition and biotoxicity of TCE degradation products were also investigated. Results showed that when SIE was 300 J L-1, the removal efficiency could reach more than 90%. The energy yield could reach 72.99 g kWh-1 at low SIE and gradually decreased with the increase of SIE. The k of the Non-thermal plasma (NTP) treatment of TCE was about 0.01 L J-1. DDBD degradation products were mainly polychlorinated organic compounds and produced more than 373 mg m-3 ozone. Moreover, a plausible TCE degradation mechanism in the DDBD reactors was proposed. Lastly, the ecological safety and biotoxicity were evaluated, indicating that the generation of chlorinated organic products was the main cause of elevated acute biotoxicity.
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Affiliation(s)
- Xu-Rui Hu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300072, China
| | - Yong-Chao Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300072, China
| | - Zhen Tong
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300072, China
| | - Can Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Tianjin Key Lab of Indoor Air Environmental Quality Control, Tianjin, 300072, China.
| | - Er-Hong Duan
- School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei, 050018, China
| | - Meng-Fei Han
- School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang, Hebei, 050018, China
| | - Hsing-Cheng Hsi
- Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 106, Taipei, Taiwan
| | - Ji-Guang Deng
- College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
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2
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Tang L, Zhang X, Li J, Shen Z, Lyu J. Optimization of photothermal conversion and catalytic sites for photo-assisted-catalytic degradation of volatile organic compounds. CHEMOSPHERE 2023; 310:136696. [PMID: 36223826 DOI: 10.1016/j.chemosphere.2022.136696] [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: 08/25/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Solar energy conversion is a promising strategy to enhance the elimination of volatile organic compounds (VOCs) and minimize power consumption. Herein, non-noble metal WC@WO3 as cocatalyst was composited with CeO2 to optimize photochemical and photothermal conversion for the catalytic ozonation of toluene and acetone. The photothermal conversion efficiencies of visible and infrared lights on 20%WC@WO3-CeO2 were 2.2 and 10.4 times higher than those on CeO2, respectively, which indicates that the equilibrium temperature of the catalyst remarkably increased under full-spectrum light irradiation. Moreover, WC@WO3 transferred electrons to CeO2 in 20%WC@WO3-CeO2 and thus remarkably improved the activity of catalytic sites. The synergy factor of light and O3 on 20%WC@WO3-CeO2 was 5.8, and the reaction rate of toluene and acetone reached 9274.5 and 35779.0 mg/(m3∙min), respectively. This work provides a low-cost and high-efficient catalyst for the utilization of solar energy for VOC control.
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Affiliation(s)
- Lingling Tang
- School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Xian Zhang
- School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Ji Li
- School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, 214122, China; Jiangsu College of Water Treatment Technology and Material Collaborative Innovation Center, Suzhou, Jiangsu, 215009, China
| | - Zhizhang Shen
- School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jinze Lyu
- School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu, 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
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3
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Dutschke M, Schnabel T, Schütz F, Springer C. Degradation of chlorinated volatile organic compounds from contaminated ground water using a carrier-bound TiO 2/UV/O 3-system. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 304:114236. [PMID: 34920281 DOI: 10.1016/j.jenvman.2021.114236] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/02/2021] [Accepted: 12/02/2021] [Indexed: 06/14/2023]
Abstract
In the present work, a suitable experimental setup was developed to successfully apply advanced oxidation processes (AOP) to real groundwater matrices. This setup combines an O3-bubble column reactor with a carrier-bound TiO2/UV-system. The degradation of various chlorinated ethene and methane derivatives commonly found of chlorinated volatile organic compound polluted regional groundwater samples was investigated. Because of known issues within water remediation using AOP such as toxification by transformation products, this study aimed at complete mineralization of the contained organic micropollutants. Moreover, the influences of variable process parameters such as flow rate, ozone concentration, and radiation dose on process performance were statistically evaluated and discussed. Parameter optimization using a Box-Behnken experimental design resulted in very promising degradation rates. It was thus possible to achieve a degradation rate of at least 98% for cis-dichloroethene, trichloroethene and tetrachloroethene and 85% for trichloromethane without formation of transformation products. The results of this work open up the possibility of developing innovative technologies based on AOP, which can be universally applied even to challenging matrices such as groundwater.
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Affiliation(s)
- Manuel Dutschke
- MFPA Weimar, Materials Research and Testing Institute Weimar, Germany.
| | - Tobias Schnabel
- MFPA Weimar, Materials Research and Testing Institute Weimar, Germany.
| | - Frank Schütz
- MFPA Weimar, Materials Research and Testing Institute Weimar, Germany.
| | - Christian Springer
- Erfurt University of Applied Sciences, Department of Civil Engineering, Urban Water Management and Environmental Technology, Germany.
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da Costa Filho BM, Silva GV, Boaventura RAR, Dias MM, Lopes JCB, Vilar VJP. Ozonation and ozone-enhanced photocatalysis for VOC removal from air streams: Process optimization, synergy and mechanism assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 687:1357-1368. [PMID: 31412469 DOI: 10.1016/j.scitotenv.2019.05.365] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/04/2019] [Accepted: 05/24/2019] [Indexed: 06/10/2023]
Abstract
The present work evaluates ozone driven processes (O3, O3/UVC, O3/TiO2/UVA) in the NETmix mili-photoreactor, as a cost-effective alternative for the removal of volatile organic compounds (VOCs) from air streams, using n-decane as a model pollutant. The network of channels and chambers of the mili-photoreactor was coated with a TiO2-P25 thin film, resulting in a catalyst coated surface per reactor volume of 990 m2 m-3. Ozone and n-decane streams were fed to alternate chambers of the mili-photoreactor, promoting a good contact between O3/n-decane/catalyst. Initially, direct reaction between n-decane and ozone (ozonation) was assessed for different O3/n-decane (O3/dec) feed molar ratios and total feed flow rates. Under the best conditions, ozonation process achieved total n-decane conversion (below the limit of detection), yielding a reaction rate (rdec) of 6.8 μmol min-1 or 6.7 mmol m-3reactor s-1. However, the low reactivity of ozone with the degradation by-products resulted in a quite poor mineralization (~10%). For the O3/UVC system, an increase on relative humidity from 7 to 40% slight improved the n-decane oxidation rate, mainly associated with the generation of HO from the reaction of active oxygen radicals (O) and water molecules. A strong synergistic effect was observed when coupling TiO2/UVA photocatalysis with ozonation (O3/TiO2/UVA), enhancing substantially the mineralization of n-decane molecules up to 100% under O3/dec feed molar ratio of 15, photonic flux of 2.67 ± 0.03 J s-1 and a residence time of 2.0 s. Different reaction intermediates were detected for O3, TiO2/UVA and O3/TiO2/UVA oxidative systems, indicating the participation of different oxidant species (O3, HO, O, etc.).
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Affiliation(s)
- Batuira M da Costa Filho
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; CNPq - National Council of Technological and Scientific Development, Brazil
| | - Gabriela V Silva
- INEGI - Institute of Science and Innovation in Mechanical Engineering and Industrial Management, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - Rui A R Boaventura
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Madalena M Dias
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - José C B Lopes
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - Vítor J P Vilar
- Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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Marchiori LA, Doubek ÚLR, Ribeiro BMB, Fujimoto TM, Tomaz E. Photodegradation of cyclohexane and toluene using TiO 2/UV/O 3 in gas phase. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:4234-4241. [PMID: 29948690 DOI: 10.1007/s11356-018-2484-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Volatile organic compounds (VOC) are air pollutants usually found in urban and industrial areas. Heterogeneous photocatalysis is an interesting technique used to degrade these compounds. Several approaches may enhance this process; some studies have shown higher VOC conversions by adding ozone to the experimental system, once ozone increases the number of reactive radicals in the reaction. In this context, this work studied the conversion of cyclohexane and toluene by heterogeneous photocatalysis in gas phase, in the presence of titanium dioxide (TiO2), UV light, and different concentrations of ozone. For fixed space times from 13.1 to 48.8 s, an average increase of 9% was reached in cyclohexane conversion when comparing the system with maximum concentration of ozone (0.8%) and the system without it. In addition, difference of less than 2% in the conversion of cyclohexane with different moisture fractions was observed. Toluene photodegradation was also analyzed in the presence of ozone and although the conversion was only about 40% for the space time of 25 s, this result was maintained during 4 h of experiment, with no catalyst deactivation as usually reported in the literature for aromatic compounds. Based on the results, ozone addition is an advantageous technique to improve the photodegradation of VOC.
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Affiliation(s)
- Luís Antonio Marchiori
- School of Chemical Engineering, UNICAMP - University of Campinas, Av. Albert Einstein 500, Cidade Universitária, Campinas, Brazil.
| | - Úrsula Luana Rochetto Doubek
- School of Chemical Engineering, UNICAMP - University of Campinas, Av. Albert Einstein 500, Cidade Universitária, Campinas, Brazil
| | - Bárbara Maria Borges Ribeiro
- School of Chemical Engineering, UNICAMP - University of Campinas, Av. Albert Einstein 500, Cidade Universitária, Campinas, Brazil
| | - Tânia Miyoko Fujimoto
- School of Chemical Engineering, UNICAMP - University of Campinas, Av. Albert Einstein 500, Cidade Universitária, Campinas, Brazil
| | - Edson Tomaz
- School of Chemical Engineering, UNICAMP - University of Campinas, Av. Albert Einstein 500, Cidade Universitária, Campinas, Brazil.
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Jeon JW, Lee DH, Won YS, Lee MG. Characteristics of photocatalytic decomposition of individual and binary mixture vapors of some VOCs by a cylindrical UV reactor with helically installed TiO2-coated perforated planes. KOREAN J CHEM ENG 2018. [DOI: 10.1007/s11814-017-0320-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Ye ZL, Han QY, Jiang YF, Zhang SD, Shu L, Zhang RX. Synergetic Effect Between Plasma and UV for Toluene Conversion in Integrated Combined Plasma Photolysis Reactor with KrCl/KrBr/XeCl/Xe2Excilamp. CAN J CHEM ENG 2015. [DOI: 10.1002/cjce.22209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zhao-Lian Ye
- College of Chemistry and Environmental Engineering; Jiangsu University of Technology; Changzhou, 213001 P. R. China
| | - Qiu-Yi Han
- Institute for Electric Light Sources; Fudan University; Shanghai, 200433 P. R. China
| | - Yi-Fei Jiang
- College of Chemistry and Environmental Engineering; Jiangsu University of Technology; Changzhou, 213001 P. R. China
| | - Shan-Duan Zhang
- Institute for Electric Light Sources; Fudan University; Shanghai, 200433 P. R. China
| | - Li Shu
- College of Chemistry and Environmental Engineering; Jiangsu University of Technology; Changzhou, 213001 P. R. China
| | - Ren-Xi Zhang
- Institute of Environmental Science; Fudan University; Shanghai, 200433 P. R. China
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8
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Sun J, Yan X, Lv K, Sun S, Deng K, Du D. Photocatalytic degradation pathway for azo dye in TiO2/UV/O3 system: Hydroxyl radical versus hole. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2012.10.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Degradation of cypermethrin, malathion and dichlorovos in water and on tea leaves with O3/UV/TiO2 treatment. Food Control 2012. [DOI: 10.1016/j.foodcont.2012.05.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Novel Bioreactors for Waste Gas Treatment. ENVIRONMENTAL CHEMISTRY FOR A SUSTAINABLE WORLD 2012. [DOI: 10.1007/978-94-007-2439-6_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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Rene ER, Veiga MC, Kennes C. Combined biological and physicochemical waste-gas cleaning techniques. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2012; 47:920-939. [PMID: 22486662 DOI: 10.1080/10934529.2012.667289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This review presents a general overview of physical, chemical and biological waste-gas treatment techniques such as adsorption, absorption, oxidation and biodegradation, focusing more extensively on combined processes. It is widely recognized that biological waste-gas treatment devices such as biofilters and biotrickling filters can show high performance, often reaching removal efficiencies above 90 % for pollutant concentrations below 5 g/m(3). However, for concentrations exceeding this limit and under transient shock-load conditions that are frequently encountered in industrial situations, a physicochemical gas cleaning process can sometimes be advantageously combined with a biological one. Besides improving the overall treatment efficiency, the non-biological, first-stage process could also serve as a load equalization system by reducing the pollutant load during periodic shock-loads, to levels that can easily be handled in the second-stage bioreactor. This article reviews the operational advantages of integrating different non-biological and biological processes, i.e., adsorption pre-treatment+bioreactor, bioreactor+adsorption post-treatment, absorption pre-treatment+bioreactor, UV pre-treatment+bioreactor, and bioreactor/bioreactor combinations, for waste-gas treatment, where different gas-phase pollutants have been tested.
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Affiliation(s)
- Eldon R Rene
- Chemical Engineering Laboratory, Faculty of Sciences, University of La Coruña, La Coruña, Spain
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12
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13
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Jung JT, Choi JY, Chung J, Lee YW, Kim JO. UV/TiO2 and UV/TiO2/chemical oxidant processes for the removal of humic acid, Cr and Cu in aqueous TiO2 suspensions. ENVIRONMENTAL TECHNOLOGY 2009; 30:225-232. [PMID: 19438054 DOI: 10.1080/09593330802503750] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The objective of this study was to investigate the treatment efficiency of UV/TiO2 and UV/TiO2/chemical oxidant processes for the removal of humic acid and hazardous heavy metals in aqueous TiO2 suspensions. The reaction rate (k) of humic acid and hazardous heavy metals by UV/TiO2 was higher than that of UV illumination alone or TiO2 alone. The removal efficiency for humic acid and Cr(VI) at acid or neutral pH values was higher than that at basic pH values. However, the removal efficiency for Cu(II) at acid pH values was smaller compared with that at neutral or basic pH values. The reaction rate (k) of humic acid and hazardous heavy metals in the TiO2 concentration range of 0.1-0.3 g l(-1) increased with increasing TiO2 dosage. However, amounts higher than a TiO2 dosage of 0.3 g l(-1) reduced the removal efficiency for humic acid and hazardous heavy metals because of the shielding effect on the UV light penetration in the aqueous solution caused by the presence of excessive amounts of TiO2. The addition of oxidants to the UV/TiO2 system showed an increase in degradation efficiency for the treatment of humic acid and hazardous heavy metals. The optimal concentration of oxidants was: H2O2 50 mg l(-1), O3 20 g m(-3) and K2S2O8 50 mg l(-1), respectively. The degradation efficiency of UV/TiO2/oxidant systems for the removal of humic acid and hazardous heavy metals was much greater when H2O2 was used as the oxidant.
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Affiliation(s)
- J-T Jung
- Department of Civil Engineering, Kangnung National University, Gangneung-daehangno 120, Gangneung, Gangwon-do, 210-702, Korea
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15
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Kinetic and degradation mechanism study on Sr2CeO4-promoted photo-oxidation of gaseous benzene. Sep Purif Technol 2007. [DOI: 10.1016/j.seppur.2007.01.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Wang S, Ang HM, Tade MO. Volatile organic compounds in indoor environment and photocatalytic oxidation: state of the art. ENVIRONMENT INTERNATIONAL 2007; 33:694-705. [PMID: 17376530 DOI: 10.1016/j.envint.2007.02.011] [Citation(s) in RCA: 238] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2006] [Revised: 02/02/2007] [Accepted: 02/14/2007] [Indexed: 05/14/2023]
Abstract
Volatile organic compounds (VOCs) are the major pollutants in indoor air, which significantly impact indoor air quality and thus influencing human health. A long-term exposure to VOCs will be detrimental to human health causing sick building syndrome (SBS). Photocatalytic oxidation of VOCs is a cost-effective technology for VOCs removal compared with adsorption, biofiltration, or thermal catalysis. In this paper, we review the current exposure level of VOCs in various indoor environment and state of the art technology for photocatalytic oxidation of VOCs from indoor air. The concentrations and emission rates of commonly occurring VOCs in indoor air are presented. The effective catalyst systems, under UV and visible light, are discussed and the kinetics of photocatalytic oxidation is also presented.
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Affiliation(s)
- Shaobin Wang
- Department of Chemical Engineering, Curtin University of Technology, Perth, WA 6845, Australia.
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17
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Yang L, Liu Z, Shi J, Zhang Y, Hu H, Shangguan W. Degradation of indoor gaseous formaldehyde by hybrid VUV and TiO2/UV processes. Sep Purif Technol 2007. [DOI: 10.1016/j.seppur.2006.09.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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He Y, Lv Y, Hu J, Qi L, Hou X. Simple, sensitive and on-line fluorescence monitoring of photodegradation of phenol and 2-naphthol. LUMINESCENCE 2007; 22:309-16. [PMID: 17471454 DOI: 10.1002/bio.964] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A simple molecular fluorescence spectrometer based on a hand-held CCD spectrometer was constructed for on-line monitoring of the photodegradation of pollutants. A high-pressure Hg vapour lamp was used for the UV photodegradation and simultaneously for the fluorescence excitation. Phenol and 2-naphthol were selected as the targets for this preliminary study. Using peak fluorescence, figures of merit for monitoring these two hydroxybenzene were obtained. Degradation efficiencies with different homogeneous photocatalyst systems were investigated, including UV only, UV/H(2)O(2) and UV/Fe(3+) degradation systems. The kinetics modelling showed that their photodegradation fitted the Langmuir-Hinshelwood model. Results showed that the proposed method is potentially applicable to both on-line real-time monitoring and field analysis.
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Affiliation(s)
- Yihua He
- Key Laboratory of Green Chemistry and Technology of MOE, College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China
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Qi H, Sun DZ, Chi GQ. Formaldehyde degradation by UV/TiO2/O3 process using continuous flow mode. J Environ Sci (China) 2007; 19:1136-1140. [PMID: 17966522 DOI: 10.1016/s1001-0742(07)60185-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The degradation of formaldehyde gas was studied using UV/TiO2/O3 process under the condition of continuous flow mode. The effects of humidity, initial formaldehyde concentration, residence time and ozone adding amount on degradation of formaldehyde gas were investigated. The experimental results indicated that the combination of ozonation with photocatalytic oxidation on the degradation of formaldehyde showed a synergetic action, e.g., it could considerably increase decomposing of formaldehyde. The degradation efficiency of formaldehyde was between 73.6% and 79.4% while the initial concentration in the range of 1.84-24 mg/m3 by O3/TiO2/UV process. The optimal humidity was about 50% in UV/TiO2/O3 processs and degradation of formaldehyde increases from 39.0% to 94.1% when the ozone content increased from 0 to 141 mg/m3. Furthermore, the kinetics of formaldehyde degradation reaction could be described by Langmuir-Hinshelwood model. The rate constant k of 46.72 mg/(m3 x min) and Langmuir adsorption coefficient K of 0.0268 m3/mg were obtained.
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Affiliation(s)
- Hong Qi
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
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The combination of heterogeneous photocatalysis with chemical and physical operations: A tool for improving the photoprocess performance. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2006. [DOI: 10.1016/j.jphotochemrev.2006.12.001] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Den W, Ravindran V, Pirbazari M. Photooxidation and biotrickling filtration for controlling industrial emissions of trichloroethylene and perchloroethylene. Chem Eng Sci 2006. [DOI: 10.1016/j.ces.2006.09.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Yoa SJ, Cho YS, Kim JH. Photocatalytic degradation of toluene with ozone addition. KOREAN J CHEM ENG 2005. [DOI: 10.1007/bf02719412] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Zhang P, Liu J. Photocatalytic degradation of trace hexane in the gas phase with and without ozone addition: kinetic study. J Photochem Photobiol A Chem 2004. [DOI: 10.1016/j.jphotochem.2004.05.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lim TH, Kim SD. Trichloroethylene degradation by photocatalysis in annular flow and annulus fluidized bed photoreactors. CHEMOSPHERE 2004; 54:305-312. [PMID: 14575743 DOI: 10.1016/s0045-6535(03)00753-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effects of trichloroethylene (TCE) gas flow rate, relative humidity, TiO(2) film thickness, and UV light intensity on photodegradation of TCE have been determined in an annular flow type photoreactor. Phosgene and dichloroacetyl chloride formation could be controlled as a function of TCE gas flow rate and photodegradation of TCE decreased with increasing relative humidity. The optimum thickness of TiO(2) film was found to be approximately 5 mum and the photocatalytic reaction rate of TCE increased with square root of UV light intensity. In addition, the effects of the initial TCE concentration, phase holdup ratio of gas and solid phases (epsilon(g)/epsilon(s)), CuO loading on the photodegradation of TCE have been determined in an annulus fluidized bed photoreactor. The TCE photodegradation decreased with increasing the initial TCE concentration. The optimum conditions of the phase holdup ratio (epsilon(g)/epsilon(s)) and CuO wt.% for the maximum photodegradation of TCE was found to be 2.1 and 1.1 wt.%, respectively. Therefore, an annulus fluidized bed photoreactor is an effective tool for TCE degradation over TiO(2)/silica gel with efficient utilization of photon energy.
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Affiliation(s)
- Tak Hyoung Lim
- Department of Chemical and Biomolecular Engineering, Energy and Environment Research Center, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yuson-gu, DaeJeon 305-701, South Korea
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Chang CP, Chen JN, Lu MC. Heterogeneous photocatalytic oxidation of acetone for airpurification by near UV-irradiated titanium dioxide. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2003; 38:1131-1143. [PMID: 12774914 DOI: 10.1081/ese-120019869] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This work presents a photocatalysis-based method to treat and purify air because of its broad applicability to common, oxidizable air contaminants. The effect of oxygen content, temperature, water vapor, and acetone concentration on the photooxidation of acetone on TiO2 surface was investigated. The photocatalytic decomposition reaction of acetone obeyed the first-order equation. The decomposition rate increased with increasing the oxygen content. The rate of acetone oxidation increased when water vapor increased from 18.7 to 417 microM and decreased at higher than 417 microM. The conversion and mineralization of acetone decreased at higher than 138 degrees C. The initial rate of acetone degradation can be well described by the Langmuir-Hinshelwood rate form. The specific reaction rate constant and the equilibrium adsorption are 15.8 microM/min and 0.0671 L/microM, respectively. The difference between observed and estimated half-lives became larger when the initial concentration of acetone was increased. It is assumed that the intermediates competed with parent compound so that delayed the half-life. The detection of CO2 production can support this assumption.
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Affiliation(s)
- Chiu-Ping Chang
- Institute of Environmental Engineering, National Chiao Tung University, Hsinchu, Taiwan, ROC.
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Sekiguchi K, Sanada A, Sakamoto K. Degradation of toluene with an ozone-decomposition catalyst in the presence of ozone, and the combined effect of TiO2 addition. CATAL COMMUN 2003. [DOI: 10.1016/s1566-7367(03)00047-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Pengyi Z, Fuyan L, Gang Y, Qing C, Wanpeng Z. A comparative study on decomposition of gaseous toluene by O3/UV, TiO2/UV and O3/TiO2/UV. J Photochem Photobiol A Chem 2003. [DOI: 10.1016/s1010-6030(02)00432-x] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Salem I. Recent Studies on the Catalytic Activity of Titanium, Zirconium, and Hafnium Oxides. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING 2003. [DOI: 10.1081/cr-120015740] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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