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Zhao J, Shang C, Yin R. A High-Radical-Yield Advanced Oxidation Process Coupling Far-UVC Radiation with Chlorinated Cyanurates for Micropollutant Degradation in Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18867-18876. [PMID: 37158565 DOI: 10.1021/acs.est.3c00255] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Increasing the radical yield and reducing energy consumption would enhance the sustainability and competitiveness of advanced oxidation processes (AOPs) for micropollutant degradation in water. We herein report a novel AOP coupling far-UVC radiation at 222 nm with chlorinated cyanurates (termed the UV222/Cl-cyanurates AOP) for radical generation and micropollutant abatement in water. We experimentally determined the concentrations of HO•, Cl•, and ClO• in the UV222/Cl-cyanurates AOP in deionized water and swimming pool water. The radical concentrations are 10-27 times and 4-13 times, respectively, higher than those in the UV254/Cl-cyanurates AOP and the well-documented UV254/chlorine AOP under comparable conditions (e.g., same UV fluence and oxidant dosing). We determined the molar absorption coefficients and innate quantum yields of two chlorine species and two Cl-cyanurates at 222 nm and incorporated these parameters into a kinetic model. The model enables accurate prediction of oxidant photodecay rates as well as the pH impact on radical generation in the UV222/Cl-cyanurates AOP. We predicted the pseudo-first-order degradation rate constants of 25 micropollutants in the UV222/Cl-cyanurates AOP and demonstrated that many micropollutants can be degraded by >80% with a low UV fluence of 25 mJ cm-2. This work advances the fundamental photochemistry of chlorine and Cl-cyanurates at 222 nm and offers a highly effective engineering tool in combating micropollutants in water where Cl-cyanurates are suitable to use.
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Affiliation(s)
- Jing Zhao
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
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2
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Zhao J, Payne EM, Liu B, Shang C, Blatchley ER, Mitch WA, Yin R. Making waves: Opportunities and challenges of applying far-UVC radiation in controlling micropollutants in water. WATER RESEARCH 2023; 241:120169. [PMID: 37290191 DOI: 10.1016/j.watres.2023.120169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 05/27/2023] [Accepted: 06/02/2023] [Indexed: 06/10/2023]
Abstract
Concerns over human health risks associated with chemical contaminants (micropollutants) in drinking waters are rising due to the increased use of reclaimed water or water supplies impacted by upstream wastewater discharges. Ultraviolet (UV)-driven advanced oxidation processes (UV-AOPs) using radiation sources that emit at 254 nm have been developed as advanced treatments to degrade contaminants, while those UV-AOPs can be improved towards higher radical yields and lower byproduct formation. Several previous studies have suggested that Far-UVC radiation (200-230 nm) is a promising radiance source to drive UV-AOPs because the direct photolysis of micropollutants and production of reactive species from oxidant precursors can both be improved. In this study, we summarize from the literature the photodecay rate constants of five micropollutants by direct UV photolysis, which are higher at 222 than 254 nm. We experimentally determine the molar absorption coefficients at 222 and 254 nm of eight oxidants commonly used in water treatment and present the quantum yields of the oxidant photodecay. Our experimental results also show that the concentrations of HO·, Cl·, and ClO· generated in the UV/chlorine AOP can be increased by 5.15-, 15.76-, and 2.86-fold, respectively, by switching the UV wavelength from 254 to 222 nm. We also point out the challenges of applying Far-UVC for micropollutant abatement in water treatment, including the strong light screening effect of matrix components (e.g., carbonate, nitrate, bromide, and dissolved organic matter), the formation of byproducts via new reaction pathways, and the needs to improve the energy efficiency of the Far-UVC radiation sources.
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Affiliation(s)
- Jing Zhao
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Emma M Payne
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, 4001 Discovery Drive, Boulder, CO 80303, United States
| | - Bryan Liu
- Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, 4001 Discovery Drive, Boulder, CO 80303, United States
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
| | - Ernest R Blatchley
- Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907, United States; Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN 47907, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, CA 94305, United States
| | - Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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Kodamatani H, Kubo S, Takeuchi A, Kanzaki R, Tomiyasu T. Sensitive Detection of Nitrite and Nitrate in Seawater by 222 nm UV-Irradiated Photochemical Conversion to Peroxynitrite and Ion Chromatography-Luminol Chemiluminescence System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5924-5933. [PMID: 36973229 DOI: 10.1021/acs.est.3c00273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Sensitive detection methods for nitrite (NO2-) and nitrate (NO3-) ions are essential to understand the nitrogen cycle and for environmental protection and public health. Herein, we report a detection method that combines ion-chromatographic separation of NO2- and NO3-, on-line photochemical conversion of these ions to peroxynitrite (ONOO-) by irradiation with a 222 nm excimer lamp, and chemiluminescence from the reaction between luminol and ONOO-. The detection limits for NO2- and NO3- were 0.01 and 0.03 μM, respectively, with linear ranges of 0.010-2.0 and 0.10-3.0 μM, respectively, at an injection volume of 1 μL. The results obtained by the proposed method for seawater analysis corresponded with those of a reference method (AutoAnalyzer based on the Griess reaction). As luminol chemiluminescence can measure ONOO- at picomolar concentrations, our method is expected to be able to detect NO2- and NO3- at picomolar concentrations owing to the high conversion ratio to ONOO- (>60%), assuming that contamination and background chemiluminescence issues can be resolved. This method has the potential to emerge as an innovative technology for NO2- and NO3- detection in various samples.
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Affiliation(s)
- Hitoshi Kodamatani
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
| | - Shotaro Kubo
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
| | - Akinori Takeuchi
- Health and Environmental Risk Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Ryo Kanzaki
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
| | - Takashi Tomiyasu
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan
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Fan J, Deng C, Rao Y. Photodegradation of N-nitrosodimethylamine under 365 nm Light Emitting Diode Irradiation. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2022; 94:e10787. [PMID: 36082624 DOI: 10.1002/wer.10787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/12/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
The photodegradation of NDMA has been extensively investigated under the irradiation of low-pressure or medium-pressure Hg lamps and xenon lamp. However, NDMA photolysis remains unknown under 365 nm ultraviolet light-emitting diode (UV-LED) irradiation. This study conducted a comprehensive investigation on NDMA photodegradation by 365 nm UV-LED illumination. The quantum yield of NDMA photolysis under 365 nm UV-LED irradiation was determined to be 0.0312 ± 0.0047. The influence of pH on NDMA photodegradation was found to be wavelength dependent. Compared with distilled and deionized water (DDW), tap water inhibited NDMA photodegradation, but secondary wastewater effluent did not. Based on the quantification of NDMA photolysis products and pH influence, the photooxidation of the excited NDMA in the nonprotonated form was proposed to be a major pathway for NDMA photodegradation under the irradiation of UV-LED lamp at 365 nm. This study further enhances our knowledge on NDMA photodegradation. PRACTITIONER POINTS: Quantum yield of NDMA photolysis at 365 nm was determined to be 0.0312 ± 0.0047. The influence of pH on NDMA photodegradation was wavelength dependent. NDMA photodegradation was inhibited in tap water compared with that in DDW. NDMA photodegradation in SWE was similar to that in DDW. Excited nonprotonated NDMA photooxidation is a major degradation pathway.
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Affiliation(s)
- Jiahui Fan
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Cun Deng
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Yongfang Rao
- Department of Environmental Science and Engineering, Xi'an Jiaotong University, Xi'an, China
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Dong L, Jiang Z, Yang L, Hu F, Zheng W, Xue P, Jiang S, Andersen ME, He G, Crabbe MJC, Qu W. The genotoxic potential of mixed nitrosamines in drinking water involves oxidative stress and Nrf2 activation. JOURNAL OF HAZARDOUS MATERIALS 2022; 426:128010. [PMID: 34929594 DOI: 10.1016/j.jhazmat.2021.128010] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/26/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
Nitrosamine by-products in drinking water are designated as probable human carcinogens by the IARC, but the health effects of simultaneous exposure to multiple nitrosamines in drinking water remain unknown. Genotoxicity assays were used to assess the effects of both individual and mixed nitrosamines in finished drinking water produced by a large water treatment plant in Shanghai, China. Cytotoxicity and genotoxicity were measured at 1, 10-, 100- and 1000-fold actual concentrations by the Ames test, Comet assay, γ-H2AX assay, and the cytokinesis-block micronuclei assay; oxidative stress and the Nrf2 pathway were also assessed. Nitrosamines detected in drinking water included NDMA (36.45 ng/L), NDPA (44.68 ng/L), and NEMA (37.27 ng/L). Treatment with a mixture of the three nitrosamines at 1000-fold actual drinking-water concentration induced a doubling of revertants in Salmonella typhimurium strain TA100, DNA and chromosome damage in HepG2 cells, while 1-1000-fold concentrations of compounds applied singly lacked these effects. Treatment with 100- and 1000-fold concentrations increased ROS, GSH, and MDA and decreased SOD activity. Thus, nitrosamine mixtures showed greater genotoxic potential than that of the individual compounds. N-Acetylcysteine protected against the nitrosamine-induced chromosome damage, and Nrf2 pathway activation suggested that oxidative stress played pivotal roles in the genotoxic property of the nitrosamine mixtures.
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Affiliation(s)
- Lei Dong
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | - Zhiqiang Jiang
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | - Lili Yang
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | - Fen Hu
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | - Weiwei Zheng
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China; Key Laboratory of Health Technology Assessment, Ministry of Health, Fudan University, Shanghai 200032, China
| | - Peng Xue
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | - Songhui Jiang
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China
| | | | - Gengsheng He
- Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China; Key Laboratory of the Public Health Safety, Ministry of Education, Department of Nutrition and Food Hygiene, Fudan University, Shanghai 200032, China
| | - M James C Crabbe
- Wolfson College, Oxford University, Oxford OX2 6UD, United Kingdom; Institute of Biomedical and Environmental Science & Technology, University of Bedfordshire, Luton LU1 3JU, UK
| | - Weidong Qu
- Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, China; Center for Water and Health, School of Public Health, Fudan University, Shanghai 200032, China; Key Laboratory of Health Technology Assessment, Ministry of Health, Fudan University, Shanghai 200032, China.
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Fujioka T, Kodamatani H, Minh Tran HD, Fujioka A, Hino K, Yoshikawa T, Inoue D, Ikehata K. Degradation of N-nitrosamines and 1,4-dioxane using vacuum ultraviolet irradiation (UV 254+185 nm or UV 172 nm). CHEMOSPHERE 2021; 278:130326. [PMID: 33836400 DOI: 10.1016/j.chemosphere.2021.130326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/01/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Advanced oxidation processes (AOPs) play a vital role in attenuating contaminants of emerging concern (CECs) during potable water reuse. AOPs are conventionally performed by irradiating with a 254-nm low-pressure (LP) mercury-vapor (Hg) ultraviolet (UV) lamp along with chemical treatment. Compared with UV-C light treatment (200-280 nm), vacuum-UV (V-UV) light treatment (100-200 nm) is advantageous in terms of hydroxyl radical generation without the requirement for chemical treatment. This study assessed the potential of V-UV (172-nm Xe2 excimer or 185 + 254-nm LP-Hg) lamps on the destruction of two major CECs in potable water reuse, namely N-nitrosodimethylamine (NDMA) and 1,4-dioxane. Direct irradiation using UV254 nm or UV185+254 nm lamps achieved ≥94% removal of N-nitrosamines, including NDMA, at a UV dose of 900 mJ/cm2. In contrast, the Xe2 excimer lamp (UV172 nm) was less effective for N-nitrosamine removal, achieving up to 82% removal of NDMA. The removal of 1,4-dioxane by V-UV lamps at a UV dose of 900 mJ/cm2 reached 51% (UV172 nm) and 28% (UV185+254 nm), both of which results were superior to that obtained using a conventional UV254 nm lamp (10%). The addition of hydrogen peroxide during UV254 nm or UV185+254 nm irradiation was found to enhance the removal of 1,4-dioxane, while UV172 nm irradiation without hydrogen peroxide addition still exhibited greater efficiencies than those UV254 nm lamps-based AOPs. Overall, this study demonstrated that the removal of both NDMA and 1,4-dioxane can be successfully achieved using either a UV254+185 nm lamp with hydrogen peroxide or a UV172 nm Xe2 excimer lamp without hydrogen peroxide.
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Affiliation(s)
- Takahiro Fujioka
- Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan.
| | - Hitoshi Kodamatani
- Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima, 890-0065, Japan
| | - Hai Duc Minh Tran
- Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan; Faculty of Environmental Engineering, National University of Civil Engineering, 55 Giai Phong Road, 100000, Hanoi, Viet Nam
| | - Atsushi Fujioka
- Toshiba Lighting & Technology Corporation, 5-2-1 Asahimachi, Imabari, 794-0042, Japan
| | - Koki Hino
- Toshiba Lighting & Technology Corporation, 5-2-1 Asahimachi, Imabari, 794-0042, Japan
| | - Takumi Yoshikawa
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan
| | - Daisuke Inoue
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan
| | - Keisuke Ikehata
- Ingram School of Engineering, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
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Kodamatani H, Sugihara K, Tanisue T, Kanzaki R, Tomiyasu T. Contamination, Decomposition, and Formation of N-Nitrosodimethylamine in Water Samples at the ng/L Level of Determination. ANAL SCI 2020; 36:1393-1399. [PMID: 32713901 DOI: 10.2116/analsci.20p162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An ultra-sensitive analytical system that can determine the concentration of N-nitrosamines at the ng/L level without preconcentration was used to investigate the contamination, decomposition, and formation of N-nitrosodimethylamine (NDMA) and other N-nitrosamines in water samples during general analytical procedures. A preliminary experiment was performed to estimate the NDMA concentrations in ambient air. Since the air samples contained NDMA at concentrations in the range of 2.0 - 10.7 ng/m3, ambient air was identified as the source of NDMA contamination in water samples. We directly confirmed that the concentration of aqueous 10-ng/L NDMA samples stored in clear glass bottles decreased upon exposure to sunlight. Thus, to maintain the N-nitrosamine concentration, such samples must always be protected from sunlight during sampling. The existence of N-nitrosamines in experimental reagents, such as ranitidine and sodium hypochlorite solutions, was also confirmed, as was the formation of NDMA on an activated carbon solid-phase extraction cartridge.
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Affiliation(s)
- Hitoshi Kodamatani
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University
| | - Kenta Sugihara
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University
| | - Taketo Tanisue
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University
| | - Ryo Kanzaki
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University
| | - Takashi Tomiyasu
- Division of Earth and Environmental Science, Graduate School of Science and Engineering, Kagoshima University
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Aristizábal A, Perilla G, Lara-Borrero JA, Diez R. KrCl and XeCl excilamps and LP-Hg lamp for UV and UV/H 2O 2 decolourization of dyes in water. ENVIRONMENTAL TECHNOLOGY 2020; 41:238-250. [PMID: 29985103 DOI: 10.1080/09593330.2018.1494755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
In the present study, the decolourization efficiencies of LP-Hg lamp, XeCl and KrCl excilamps at the same power density were compared for the decolourization of dyes in water by UV and UV/H2O2 processes in a batch reactor. Laboratory prototypes of XeCl and KrCl excilamps and a commercial LP-Hg lamp were studied as UV sources. Methylene Blue and Eliamine Blue dyes were used as model pollutants. The effect of the initial concentrations of dye and H2O2 in the TOC removal and kinetic parameters were also studied. The ratio of dye decolourization to the electric power consumption of the KrCl excilamp and LP-Hg lamp for the decolourization of Methylene Blue and Eliamine Blue were evaluated. As a result, the KrCl excilamp showed significantly higher decolourization efficiencies than LP-Hg lamp and XeCl excilamp, but the dye removal rate was significantly slower for Methylene Blue than for Eliamine Blue with this lamp. The KrCl lamp can be an alternative to conventional LP-Hg lamp for the decolourization of dyes by photodegradation, but it depends on the type of dye treated. The addition of H2O2 in a concentration between 0.05 and 0.09%v/v increases significantly the efficiency of the decolourization of Methylene Blue, and further increase does not lead to a higher increase in conversion. The experimental data were fitted to the one phase decay kinetic model with good agreement and the kinetic parameters were reported.
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Affiliation(s)
- A Aristizábal
- Process Engineering Department, Universidad EAFIT, Medellín, Colombia
- Environmental Engineering Department, Universidad de Medellín, Medellín, Colombia
- Industrial Engineering Department, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - G Perilla
- Electronics Engineering Department, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - J A Lara-Borrero
- Civil Engineering Department, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - R Diez
- Electronics Engineering Department, Pontificia Universidad Javeriana, Bogotá, Colombia
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Mishra N, Reddy R, Kuila A, Rani A, Nawaz A, Pichiah S. A Review on Advanced Oxidation Processes for Effective Water Treatment. ACTA ACUST UNITED AC 2017. [DOI: 10.12944/cwe.12.3.02] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Advanced oxidation processes (AOPs) such as fenton, ozonation, sonolysis, photocatalysis, UV photolysis, and wet air oxidation are one amongst the most suitable techniques for water and wastewater treatment. These, AOPs have also been chosen for the complete degradation of various categories of emerging pollutants that could not be managed by any conventional technologies. The mineralization is achieved by chemical reactions between the various reacting species generated and the pollutants. The present article provides a vivid view of the mechanistic features of various AOPs and its possible synergisation for process enhancement to achieve better treatment efficiency.
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Affiliation(s)
- Nirmalendu Mishra
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
| | - Rajesh Reddy
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
| | - Aneek Kuila
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
| | - Ankita Rani
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
| | - Ahmad Nawaz
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
| | - Saravanan Pichiah
- Department of Environmental Science and Engineering, Indian Institute of Technology (ISM), Dhanbad, 826004 Jharkhand India
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Li Y, Cao X, Wang L. Elucidating the removal mechanism of N,N-dimethyldithiocarbamate in an anaerobic-anoxic-oxic activated sludge system. J Environ Sci (China) 2014; 26:566-574. [PMID: 25079269 DOI: 10.1016/s1001-0742(13)60448-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 06/28/2013] [Accepted: 07/04/2013] [Indexed: 06/03/2023]
Abstract
N,N-Dimethyldithiocarbamate (DMDTC) is a typical precursor of N-nitrosodimethylamine (NDMA). Based on separate hydrolysis, sorption and biodegradation studies of DMDTC, a laboratory-scale anaerobic-anoxic-oxic (AAO) system was established to investigate the removal mechanism of DMDTC in this nutrient removal biological treatment system. DMDTC hydrolyzed easily in water solution under either acidic conditions or strong alkaline conditions, and dimethylamine (DMA) was the main hydrolysate. Under anaerobic, anoxic or oxic conditions, DMDTC was biodegraded and completely mineralized. Furthermore, DMA was the main intermediate in DMDTC biodegradation. In the AAO system, the optimal conditions for both nutrient and DMDTC removal were hydraulic retention time 8 hr, sludge retention time 20 day, mixed-liquor return ratio 3:1 and sludge return ratio 1:1. Under these conditions, the removal efficiency of DMDTC reached 99.5%; the removal efficiencies of chemical organic demand, ammonium nitrogen, total nitrogen and total phosphorus were 90%, 98%, 81% and 93%, respectively. Biodegradation is the dominant mechanism for DMDTC removal in the AAO system, which was elucidated as consisting of two steps: first, DMDTC is transformed to DMA in the anaerobic and anoxic units, and then DMA is mineralized to CO2 and NH3 in the anoxic and oxic units. The mineralization of DMDTC in the biological treatment system can effectively avoid the formation of NDMA during subsequent disinfection processes.
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Affiliation(s)
- Yongmei Li
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
| | - Xianzhong Cao
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China; Henan Institute of Metallurgy, Henan Academy of Science, Zhengzhou 450053, China
| | - Lin Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
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