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Han J, Li W, Zhang X. An effective and rapidly degradable disinfectant from disinfection byproducts. Nat Commun 2024; 15:4888. [PMID: 38849332 PMCID: PMC11161644 DOI: 10.1038/s41467-024-48752-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 05/08/2024] [Indexed: 06/09/2024] Open
Abstract
Chloroxylenol is a worldwide commonly used disinfectant. The massive consumption and relatively high chemical stability of chloroxylenol have caused eco-toxicological threats in receiving waters. We noticed that chloroxylenol has a chemical structure similar to numerous halo-phenolic disinfection byproducts. Solar detoxification of some halo-phenolic disinfection byproducts intrigued us to select a rapidly degradable chloroxylenol alternative from them. In investigating antimicrobial activities of disinfection byproducts, we found that 2,6-dichlorobenzoquinone was 9.0-22 times more efficient than chloroxylenol in inactivating the tested bacteria, fungi and viruses. Also, the developmental toxicity of 2,6-dichlorobenzoquinone to marine polychaete embryos decreased rapidly due to its rapid degradation via hydrolysis in receiving seawater, even without sunlight. Our work shows that 2,6-dichlorobenzoquinone is a promising disinfectant that well addresses human biosecurity and environmental sustainability. More importantly, our work may enlighten scientists to exploit the slightly alkaline nature of seawater and develop other industrial products that can degrade rapidly via hydrolysis in seawater.
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Affiliation(s)
- Jiarui Han
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Wanxin Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China.
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2
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Hogard S, Pearce R, Gonzalez R, Yetka K, Bott C. Optimizing Ozone Disinfection in Water Reuse: Controlling Bromate Formation and Enhancing Trace Organic Contaminant Oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18499-18508. [PMID: 37467303 PMCID: PMC10690711 DOI: 10.1021/acs.est.3c00802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/21/2023]
Abstract
The use of ozone/biofiltration advanced treatment has become more prevalent in recent years, with many utilities seeking an alternative to membrane/RO based treatment for water reuse. Ensuring efficient pathogen reduction while controlling disinfection byproducts and maximizing oxidation of trace organic contaminants remains a major barrier to implementing ozone in reuse applications. Navigating these challenges is imperative in order to allow for the more widespread application of ozonation. Here, we demonstrate the effectiveness of ozone for virus, coliform bacteria, and spore forming bacteria inactivation in unfiltered secondary effluent, all the while controlling the disinfection byproduct bromate. A greater than 6-log reduction of both male specific and somatic coliphages was seen at specific ozone doses as low as 0.75 O3:TOC. This study compared monochloramine and hydrogen peroxide as chemical bromate control measures in high bromide water (Br- = 0.35 ± 0.07 mg/L). On average, monochloramine and hydrogen peroxide resulted in an 80% and 36% decrease of bromate formation, respectively. Neither bromate control method had any appreciable impact on virus or coliform bacteria disinfection by ozone; however, the use of hydrogen peroxide would require a non-Ct disinfection framework. Maintaining ozone residual was shown to be critical for achieving disinfection of more resilient microorganisms, such as spore forming bacteria. While extremely effective at controlling bromate, monochloramine was shown to inhibit TrOC oxidation, whereas hydrogen peroxide enhanced TrOC oxidation.
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Affiliation(s)
- Samantha Hogard
- Civil
and Environmental Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, United States
- Hampton
Roads Sanitation District, P.O. Box 5911, Virginia Beach, Virginia 23471, United States
| | - Robert Pearce
- Civil
and Environmental Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, United States
- Hampton
Roads Sanitation District, P.O. Box 5911, Virginia Beach, Virginia 23471, United States
| | - Raul Gonzalez
- Hampton
Roads Sanitation District, P.O. Box 5911, Virginia Beach, Virginia 23471, United States
| | - Kathleen Yetka
- Hampton
Roads Sanitation District, P.O. Box 5911, Virginia Beach, Virginia 23471, United States
| | - Charles Bott
- Hampton
Roads Sanitation District, P.O. Box 5911, Virginia Beach, Virginia 23471, United States
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Lee W, Choi S, Kim H, Lee W, Lee M, Son H, Lee C, Cho M, Lee Y. Efficiency of ozonation and O 3/H 2O 2 as enhanced wastewater treatment processes for micropollutant abatement and disinfection with minimized byproduct formation. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131436. [PMID: 37146328 DOI: 10.1016/j.jhazmat.2023.131436] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/21/2023] [Accepted: 04/15/2023] [Indexed: 05/07/2023]
Abstract
Ozonation, a viable option for improving wastewater effluent quality, requires process optimization to ensure the organic micropollutants (OMPs) elimination and disinfection under minimized byproduct formation. This study assessed and compared the efficiencies of ozonation (O3) and ozone with hydrogen peroxide (O3/H2O2) for 70 OMPs elimination, inactivation of three bacteria and three viruses, and formation of bromate and biodegradable organics during the bench-scale O3 and O3/H2O2 treatment of municipal wastewater effluent. 39 OMPs were fully eliminated, and 22 OMPs were considerably eliminated (54 ± 14%) at an ozone dosage of 0.5 gO3/gDOC for their high reactivity to ozone or •OH. The chemical kinetics approach accurately predicted the OMP elimination levels based on the rate constants and exposures of ozone and •OH, where the quantum chemical calculation and group contribution method successfully predicted the ozone and •OH rate constants, respectively. Microbial inactivation levels increased with increasing ozone dosage up to ∼3.1 (bacteria) and ∼2.6 (virus) log10 reductions at 0.7 gO3/gDOC. O3/H2O2 minimized bromate formation but significantly decreased bacteria/virus inactivation, whereas its impact on OMP elimination was insignificant. Ozonation produced biodegradable organics that were removed by a post-biodegradation treatment, achieving up to 24% DOM mineralization. These results can be useful for optimizing O3 and O3/H2O2 processes for enhanced wastewater treatment.
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Affiliation(s)
- Woongbae Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Sangki Choi
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Hyunjin Kim
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Woorim Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea; Busan Water Quality Institute, Gimhae, Gyeongsangnam 621-813, Republic of Korea
| | - Minju Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Heejong Son
- Busan Water Quality Institute, Gimhae, Gyeongsangnam 621-813, Republic of Korea
| | - Changha Lee
- School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Seoul National University, Seoul 08826, Republic of Korea
| | - Min Cho
- SELS Center, Division of Biotechnology, College of Environmental & Bioresource Sciences, Chonbuk National University, Iksan 54596, Republic of Korea.
| | - Yunho Lee
- School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
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Morrison CM, Hogard S, Pearce R, Gerrity D, von Gunten U, Wert EC. Ozone disinfection of waterborne pathogens and their surrogates: A critical review. WATER RESEARCH 2022; 214:118206. [PMID: 35276607 DOI: 10.1016/j.watres.2022.118206] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 05/21/2023]
Abstract
Viruses, Giardia cysts, and Cryptosporidium parvum oocysts are all major causes of waterborne diseases that can be uniquely challenging in terms of inactivation/removal during water and wastewater treatment and water reuse. Ozone is a strong disinfectant that has been both studied and utilized in water treatment for more than a century. Despite the wealth of data examining ozone disinfection, direct comparison of results from different studies is challenging due to the complexity of aqueous ozone chemistry and the variety of the applied approaches. In this systematic review, an analysis of the available ozone disinfection data for viruses, Giardia cysts, and C. parvum oocysts, along with their corresponding surrogates, was performed. It was based on studies implementing procedures which produce reliable and comparable datasets. Datasets were compiled and compared with the current USEPA Ct models for ozone. Additionally, the use of non-pathogenic surrogate organisms for prediction of pathogen inactivation during ozone disinfection was evaluated. Based on second-order inactivation rate constants, it was determined that the inactivation efficiency of ozone decreases in the following order: Viruses >> Giardia cysts > C. parvum oocysts. The USEPA Ct models were found to be accurate to conservative in predicting inactivation of C. parvum oocysts and viruses, respectively, however they overestimate inactivation of Giardia cysts at ozone Ct values greater than ∼1 mg min L-1. Common surrogates of these pathogens, such as MS2 bacteriophage and Bacillus subtilis spores, were found to exhibit different inactivation kinetics to mammalian viruses and C. parvum oocysts, respectively. The compilation of data highlights the need for further studies on disinfection kinetics and inactivation mechanisms by ozone to better fit inactivation models as well as for proper selection of surrogate organisms.
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Affiliation(s)
- Christina M Morrison
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, USA.
| | - Samantha Hogard
- Civil and Environmental Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; Hampton Roads Sanitation District, P.O. Box 5911, Virginia Beach, VA 23471-0911
| | - Robert Pearce
- Civil and Environmental Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; Hampton Roads Sanitation District, P.O. Box 5911, Virginia Beach, VA 23471-0911
| | - Daniel Gerrity
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, USA
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Dubendorf, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Eric C Wert
- Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, USA
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Wu Z, Tang Y, Li W, Qiang Z, Dong H. Formation control of bromate and trihalomethanes during ozonation of bromide-containing water with chemical addition: Hydrogen peroxide or ammonia? J Environ Sci (China) 2021; 110:111-118. [PMID: 34593181 DOI: 10.1016/j.jes.2021.03.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 06/13/2023]
Abstract
To ensure the safety of drinking water, ozone (O3) has been extensively applied in drinking water treatment plants to further remove natural organic matter (NOM). However, the surface water and groundwater near the coastal areas often contain high concentrations of bromide ion (Br-). Considering the risk of bromate (BrO3-) formation in ozonation of the sand-filtered water, the inhibitory efficiencies of hydrogen peroxide (H2O2) and ammonia (NH3) on BrO3- formation during ozonation process were compared. The addition of H2O2 effectively inhibited BrO3- formation at an initial Br- concentration amended to 350 µg/L. The inhibition efficiencies reached 59.6 and 100% when the mass ratio of H2O2/O3 was 0.25 and > 0.5, respectively. The UV254 and total organic carbon (TOC) also decreased after adding H2O2, while the formation potential of trihalomethanes (THMsFP) increased especially in subsequent chlorination process at a low dose of H2O2. To control the formation of both BrO3- and THMs, a relatively large dose of O3 and a high ratio of H2O2/O3were generally needed. NH3 addition inhibited BrO3- formation when the background ammonia nitrogen (NH3N) concentration was low. There was no significant correlation between BrO3- inhibition efficiency and NH3 dose, and a small amount of NH3N (0.2 mg/L) could obviously inhibit BrO3- formation. The oxidation of NOM seemed unaffected by NH3 addition, and the structure of NOM reflected by synchronous fluorescence (SF) scanning remained almost unchanged before and after adding NH3. Considering the formation of BrO3- and THMs, the optimal dose of NH3 was suggested to be 0.5 mg/L.
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Affiliation(s)
- Zhengdi Wu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Yubin Tang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China.
| | - Weiwei Li
- Engineering Design Institute, The Sixth Engineering Bure Crec, Beijing 100036, China
| | - Zhimin Qiang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huiyu Dong
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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6
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Zhang Y, Ji H, Liu W, Wang Z, Song Z, Wang Y, Liu C, Xu B, Qi F. Synchronous degradation of aqueous benzotriazole and bromate reduction in catalytic ozonation: Effect of matrix factor, degradation mechanism and application strategy in water treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 727:138696. [PMID: 32344259 DOI: 10.1016/j.scitotenv.2020.138696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/12/2020] [Accepted: 04/12/2020] [Indexed: 06/11/2023]
Abstract
Ozone-based technologies are used for micro-pollutants removal in wastewater treatment. However, the generation of the toxic by-product bromate (BrO3-) is of a great concern. LaCoO3 (LCO) catalytic ozonation has been used to overcome this significant drawback in the sole ozonation, achieving better BrO3- elimination efficiency. However, a key challenge is how to enhance micro-pollutant (benzotriazole, BZA) degradation efficiency and to eliminate formed BrO3- synchronously under various water qualities in drinking water or wastewater treatment. Therefore, the objective of this study is to propose a practical strategy of BZA removal and BrO3- reduction synchronously in water or wastewater treatment. In this study, important factors influencing BZA removal and BrO3- reduction were investigated, including [catalyst], [BZA], initial pH solution, [NH4+-N] and [(bi)carbonate alkalinity]. Based on the performance and mechanism of these effects, a practical strategy for BZA degradation and BrO3- elimination with and without Br- in the influent was developed. Additionally, the density functional theory (DFT) calculation successfully predicted the attack site on BZA by molecular ozone and formed hydroxyl radical (HO·) during LCO catalytic ozonation. Fukui indexes of f+ and f0 were calculated to forecast direct ozone molecule and HO· attack, respectively. Combination of DFT calculation with intermediates that identified through liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS), BZA degradation pathway was established more accurately. Additionally, four new intermediates were identified in this study. Overall, this study proposes a useful strategy for synchronous micro-pollutants degradation and BrO3- elimination, while also suggesting the feasibility of LCO catalytic ozonation for water or wastewater purification.
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Affiliation(s)
- Yuting Zhang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Haodong Ji
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Wen Liu
- The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Zhenbei Wang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Zilong Song
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Yiping Wang
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Chao Liu
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Bingbing Xu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Fei Qi
- Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China.
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Ekowati Y, Ferrero G, Farré MJ, Kennedy MD, Buttiglieri G. Application of UVOX Redox ® for swimming pool water treatment: Microbial inactivation, disinfection byproduct formation and micropollutant removal. CHEMOSPHERE 2019; 220:176-184. [PMID: 30583210 DOI: 10.1016/j.chemosphere.2018.12.126] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
Alternative disinfection technologies may overcome some of the limitations of conventional treatment applied in swimming pools: chlorine-resistant pathogens (e.g. Cryptosporidium oocysts and Giardia cysts) and the formation of chlorinated disinfection byproducts. In this paper, results of full scale validation of an alternative disinfection technology UVOX Redox® (hereinafter referred to as UVOX) that combines ozonation and UV irradiation are presented. The performance was assessed in terms of microbial inactivation, disinfection byproduct formation and micropollutant removal. UVOX was able to achieve 1.4-2.7 log inactivation of Bacillus subtilis spores at water flows between 20 and 76 m³/h. Lower formation of trichloromethane and dichloroacetic acid was observed with UVOX followed by chlorination when compared to chlorination alone. However, due to the use of ozone and the presence of bromide in the pool water, the formation of trihalomethanes and haloacetic acids shifted to more brominated byproducts. Chlorine alone was able to remove the target micropollutants: acetaminophen, atenolol, caffeine, carbamazepine, estrone, estradiol, and venlafaxine (>97% removal) after 24 h, with the exception of ibuprofen (60% removal). The application of UVOX in chlorinated water enhanced the removal of ibuprofen. The application of UVOX could lower the usage of chlorine to the level that provides an adequate residual disinfection effect.
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Affiliation(s)
- Yuli Ekowati
- IHE Delft Institute for Water Education, Westvest 7, 2611 AX, Delft, the Netherlands.
| | - Giuliana Ferrero
- IHE Delft Institute for Water Education, Westvest 7, 2611 AX, Delft, the Netherlands
| | - Maria José Farré
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H2O Building, c/ Emili Grahit 101, E17003, Girona, Spain
| | - Maria D Kennedy
- IHE Delft Institute for Water Education, Westvest 7, 2611 AX, Delft, the Netherlands; Delft University of Technology, Stevinweg 1, 2628 CN, Delft, the Netherlands
| | - Gianluigi Buttiglieri
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, H2O Building, c/ Emili Grahit 101, E17003, Girona, Spain
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Abstract
The search for alternative water sources is pushing to the reuse of treated water coming from municipal wastewater treatment plants. However, this requires that tightened standards be fulfilled. Among them is the microbiological safety of reused water. Although chlorination is the mostly applied disinfection system, it presents several disadvantages, such as the high doses required and the possibility of formation of dangerous by-products. Moreover, the threat of antibiotic resistance genes (ARGs) spread throughout poorly treated water is requiring the implementation of more efficient disinfection systems. Ozone and photo assisted disinfection technologies are being given special attention to reach treated water with higher quality. Still, much must be done to optimize the processes so that cost-effective systems may be obtained. This review paper gives a critical overview on the application of ozone and photo-based disinfection systems, bearing in mind their advantages and disadvantages when applied to water and municipal wastewater. Also, the possibility of integrated disinfection systems is considered.
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Wu J, Cheng S, Cai MH, Wu YP, Li Y, Wu JC, Li AM, Li WT. Applying UV absorbance and fluorescence indices to estimate inactivation of bacteria and formation of bromate during ozonation of water and wastewater effluent. WATER RESEARCH 2018; 145:354-364. [PMID: 30172218 DOI: 10.1016/j.watres.2018.08.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/11/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
Ozone is an effective oxidant and disinfectant commonly used for elimination of micropollutants and inactivation of resistant microbes. However, undesirable oxidation/disinfection byproducts such as bromate might form during ozonation. In this study, the UV absorbance and fluorescence indices were applied as surrogate indicators for predicting the inactivation of bacteria and formation of bromate during ozonation of water and wastewater effluents. The inactivation efficiencies of lab-cultured Escherichia coli (E. coli) and autochthonous bacteria were measured by plating (for E. coli only) and flow cytometry with fluorescence staining. During ozonation of E. coli spiked into wastewater effluents (∼106 cell/mL), the priority of inactivation efficiency determined by different cell viability methods were in the order of CFU > membrane damage > DNA damage. Approximately, 99% membrane damage and/or 90% DNA damage are conservatively supposed as an indicator for sufficient bacterial inactivation as well as degradation of antibiotic resistance genes. The related required O3 dosing thresholds for sufficient inactivation of E. coli and autochthonous bacteria refer to ∼0.6 O3/DOC (g/g), ∼50% decrease of UVA254, ∼60% decrease of UVA280, or ∼80% decrease of humic-like fluorescence. Within the range of 106-108 cell/mL, the bacterial concentration did not have significant effects on the required thresholds of the specific O3 doses or spectroscopic indicators required for bacterial inactivation. The addition of 50 mM tert-BuOH as ·OH scavenger increased the required specific ozone doses but decreased the losses of spectroscopic indicators necessary for sufficient bacterial inactivation, and also suggested that the membrane/DNA damages for bacterial inactivation were mainly attributed to the direct O3 attacks. The bromate concentration was determined using ion chromatography with MS/MS detection. The results showed that when O3 was dosed at the required thresholds for sufficient bacterial inactivation, bromate formation could usually be suppressed below 10 μg/L. The present work supports that it is possible to reach a balance between bacterial inactivation and bromate formation.
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Affiliation(s)
- Ji Wu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Shi Cheng
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Min-Hui Cai
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Ya-Ping Wu
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Yan Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Ji-Chun Wu
- Key Laboratory of Surficial Geochemistry Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing, 210023, China
| | - Ai-Min Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Wen-Tao Li
- State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; Key Laboratory of Surficial Geochemistry Ministry of Education, School of Earth Sciences and Engineering, Hydrosciences Department, Nanjing University, Nanjing, 210023, China.
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10
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Ruiz-Aguirre A, Polo-López MI, Fernández-Ibáñez P, Zaragoza G. Integration of Membrane Distillation with solar photo-Fenton for purification of water contaminated with Bacillus sp. and Clostridium sp. spores. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 595:110-118. [PMID: 28384567 DOI: 10.1016/j.scitotenv.2017.03.238] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/25/2017] [Accepted: 03/26/2017] [Indexed: 06/07/2023]
Abstract
Although Membrane Distillation (MD) has been extensively studied for desalination, it has other applications like removing all kinds of solutes from water and concentrating non-volatile substances. MD offers the possibility of producing a clean stream while concentrating valuable compounds from waste streams towards their recovery, or emerging contaminants and pathogens present in wastewater in order to facilitate their chemical elimination. This paper analyses the elimination of bacterial spores from contaminated water with MD and the role of MD in the subsequent treatment of the concentrate with photo-Fenton process. The experiments were performed at Plataforma Solar de Almería (PSA) using a plate and frame bench module with a Permeate Gap Membrane Distillation (PGMD) configuration. Tests were done for two different kinds of spores in two different water matrixes: distilled water with 3.5wt% of sea salts contaminated with spores of Bacillus subtilis (B. subtilis) and wastewater after a secondary treatment and still contaminated with Clostridium sp. spores. An analysis of the permeate was performed in all cases to determine its purity, as well as the concentrated stream and its further treatment in order to assess the benefits of using MD. Results showed a permeate free of spores in all the cases, demonstrating the viability of MD to treat biological contaminated wastewater for further use in agriculture. Moreover, the results obtained after treating the concentrate with photo-Fenton showed a shorter treatment time for the reduction of the spore concentration in the water than that when only photo-Fenton was used.
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Affiliation(s)
- A Ruiz-Aguirre
- Universidad de Almería - CIESOL, Ctra. Sacramento, s/n, La Cañada de San Urbano, Almería 04120, Spain
| | - M I Polo-López
- CIEMAT-Plataforma Solar de Almería, Ctra. de Senés s/n, Tabernas, Almería 04200, Spain
| | - P Fernández-Ibáñez
- Nanotechnology and Integrated BioEngineering Centre, School of Engineering, University of Ulster, Newtownabbey, Northern Ireland BT37 0QB, United Kingdom
| | - G Zaragoza
- CIEMAT-Plataforma Solar de Almería, Ctra. de Senés s/n, Tabernas, Almería 04200, Spain.
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Antoniou MG, Sichel C, Andre K, Andersen HR. Novel pre-treatments to control bromate formation during ozonation. JOURNAL OF HAZARDOUS MATERIALS 2017; 323:452-459. [PMID: 27036096 DOI: 10.1016/j.jhazmat.2016.03.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/11/2016] [Accepted: 03/16/2016] [Indexed: 06/05/2023]
Abstract
Worldwide water shortage increase and water quality depletion from microbial and chemical compounds, pose significant challenges for today's water treatment industry. Both the development of new advanced oxidation technologies, but also the enhancement of existing conventional technologies is of high interest. This study tested improvements to conventional ozonation that reduce the formation of the oxidation-by-product bromate, while maintaining the effectiveness for removal emerging contaminants (atrazine). MnO4-, ClO2-, ClO2, ClO-, CH3COOO-, HSO5- or S2O8-2 with NH4+ were tested as pre-treatments to ozonation of ground water. Each oxidant and NH4+ were added in a single stage or separately prior to ozonation. To the best of our knowledge, this is the first study that has tested all the above-mentioned oxidants for the same water matrix. Based on our results, the most promising pre-treatments were MnO4--NH4+, ClO2--NH4+ and ClO2-NH4+. MnO4--NH4+ was the only pre-treatment that did not inhibit atrazine removal. When compared with the previously proposed Cl2/NH4+ pre-treatment, MnO4-+NH4+ was found as effective for preventing BrO3- formation, while atrazine removal was higher. In addition, MnO4-+NH4+ can be added in a single stage (compared to the 2 stage addition of Cl2/NH4+) without causing the formation of potentially harmful chlorination-by-products.
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Affiliation(s)
- Maria G Antoniou
- Technical University of Denmark (DTU), Department of Environmental Engineering, Miljoevej, Building 113, 2800 Kgs. Lyngby, Denmark; Cyprus University of Technology Department of Environmental Science and Technology, Corner of Athinon and Anexartisias 57, PO Box: 50329, 3603 Lemesos, Cyprus.
| | - Cosima Sichel
- Siemens AG, Industry Sector, Industry Automation Division,Water Technologies, Auf der Weide 10, 89312 Günzburg, Germany; Siemens AG, Industry Sector, Industry Automation Division, Sensors and Communication, I IA SC S PI IBD-E, Oestliche Rheinbrueckenstr. 50, 76187 Karlsruhe, Germany
| | - Klaus Andre
- Siemens AG, Industry Sector, Industry Automation Division,Water Technologies, Auf der Weide 10, 89312 Günzburg, Germany
| | - Henrik R Andersen
- Technical University of Denmark (DTU), Department of Environmental Engineering, Miljoevej, Building 113, 2800 Kgs. Lyngby, Denmark
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Czekalski N, Imminger S, Salhi E, Veljkovic M, Kleffel K, Drissner D, Hammes F, Bürgmann H, von Gunten U. Inactivation of Antibiotic Resistant Bacteria and Resistance Genes by Ozone: From Laboratory Experiments to Full-Scale Wastewater Treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:11862-11871. [PMID: 27775322 DOI: 10.1021/acs.est.6b02640] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ozone, a strong oxidant and disinfectant, seems ideal to cope with future challenges of water treatment, such as micropollutants, multiresistant bacteria (MRB) and even intracellular antibiotic resistance genes (ARG), but information on the latter is scarce. In ozonation experiments we simultaneously determined kinetics and dose-dependent inactivation of Escherichia coli and its plasmid-encoded sulfonamide resistance gene sul1 in different water matrixes. Effects in E. coli were compared to an autochthonous wastewater community. Furthermore, resistance elimination by ozonation and post-treatment were studied in full-scale at a wastewater treatment plant (WWTP). Bacterial inactivation (cultivability, membrane damage) and degradation of sul1 were investigated using plate counts, flow cytometry and quantitative real-time PCR. In experiments with E. coli and the more ozone tolerant wastewater community disruption of intracellular genes was observed at specific ozone doses feasible for full-scale application, but flocs seemed to interfere with this effect. At the WWTP, regrowth during postozonation treatment partly compensated inactivation of MRB, and intracellular sul1 seemed unaffected by ozonation. Our findings indicate that ozone doses relevant for micropollutant abatement from wastewater do not eliminate intracellular ARG.
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Affiliation(s)
- Nadine Czekalski
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Stefanie Imminger
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Elisabeth Salhi
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Marjan Veljkovic
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Karolin Kleffel
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - David Drissner
- Agroscope, Institute for Food Sciences , CH-8820 Wädenswil, Switzerland
| | - Frederik Hammes
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Helmut Bürgmann
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , Ueberlandstrasse 133, CH-8600 Duebendorf or Seestrasse 79, CH-6047 Kastanienbaum, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich , CH-8092 Zurich, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015, Lausanne, Switzerland
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Lee Y, Imminger S, Czekalski N, von Gunten U, Hammes F. Inactivation efficiency of Escherichia coli and autochthonous bacteria during ozonation of municipal wastewater effluents quantified with flow cytometry and adenosine tri-phosphate analyses. WATER RESEARCH 2016; 101:617-627. [PMID: 27322566 DOI: 10.1016/j.watres.2016.05.089] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/27/2016] [Accepted: 05/28/2016] [Indexed: 06/06/2023]
Abstract
Inactivation kinetics of autochthonous bacteria during ozonation of wastewater effluents were investigated using cultivation-independent flow cytometry (FCM) with total cell count (TCC) and intact cell count (ICC) and intracellular adenosine triphosphate (ATP) analysis. The principles of the methods including ozone inactivation kinetics were demonstrated with laboratory-cultured Escherichia coli spiked into filtered and sterilized wastewater effluent. Both intracellular ATP and ICC decreased with increasing ozone doses, with ICC being the more conservative parameter. The log-inactivation levels (-log(N/N0) of E. coli reached the method detection limits for FCM (∼3) and ATP (∼1.7) at specific ozone doses of ≥0.5 gO3/gDOC. During ozonation of four real wastewater effluents, the log-inactivation of autochthonous bacteria with FCM ICC was 0.3-1.0 for 0.25 gO3/gDOC and increased to 1.1-2.1 for 0.5 gO3/gDOC, but remained at a similar level of 1.5-2.8 for a further increase of the specific ozone doses to 1.0 and 1.5 gO3/gDOC. The FCM data also showed that autochthonous bacteria were composed of communities with high and low ozone reactivity. The inactivation levels measured with intracellular ATP were reasonably correlated to ICC (r(2) = 0.8). Overall, FCM and ATP measurements were demonstrated to be useful tools to monitor the inactivation of autochthonous bacteria during ozonation of municipal wastewater effluents.
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Affiliation(s)
- Yunho Lee
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland; School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea.
| | - Stefanie Imminger
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
| | - Nadine Czekalski
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, CH-8092 Zurich, Switzerland; School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Frederik Hammes
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf, Switzerland.
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Effects of bacterial concentrations and centrifugations on susceptibility of Bacillus subtilis vegetative cells and Escherichia coli O157:H7 to various electrolyzed oxidizing water treatments. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.08.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Yong EL, Lin YP. Effects of pH value and temperature on the initiation, promotion, inhibition and direct reaction rate constants of natural organic matter in ozonation. RSC Adv 2016. [DOI: 10.1039/c5ra19359a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
pH and temperature affect the kinetics of specific reactions of NOM and influence organic contaminants removal in the ozonation process.
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Affiliation(s)
- Ee Ling Yong
- Centre for Environmental Sustainability and Water Security
- Faculty of Civil Engineering
- Universiti Teknologi Malaysia
- 81310 Skudai
- Malaysia
| | - Yi-Pin Lin
- Graduate Institute of Environmental Engineering
- National Taiwan University
- Taipei 10617
- Taiwan
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16
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Zhang Y, Zhang Y, Zhou L, Tan C. Factors affecting UV/H2O2 inactivation of Bacillus atrophaeus spores in drinking water. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 134:9-15. [DOI: 10.1016/j.jphotobiol.2014.03.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 02/26/2014] [Accepted: 03/26/2014] [Indexed: 11/26/2022]
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17
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Zhang Y, Zhou L, Zhang Y, Tan C. Inactivation ofBacillus subtilisSpores Using Various Combinations of Ultraviolet Treatment with Addition of Hydrogen Peroxide. Photochem Photobiol 2014; 90:609-14. [DOI: 10.1111/php.12210] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 11/04/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Yiqing Zhang
- Key Laboratory of Yangtze River Water Environment; Ministry of Education (Tongji University); Shanghai China
| | - Lingling Zhou
- State Key Laboratory of Pollution Control and Resources Reuse; College of Environmental Science & Engineering; Tongji University; Shanghai China
| | - Yongji Zhang
- Key Laboratory of Yangtze River Water Environment; Ministry of Education (Tongji University); Shanghai China
| | - Chaoqun Tan
- Key Laboratory of Yangtze River Water Environment; Ministry of Education (Tongji University); Shanghai China
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18
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Forsyth JE, Zhou P, Mao Q, Asato SS, Meschke JS, Dodd MC. Enhanced inactivation of Bacillus subtilis spores during solar photolysis of free available chlorine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:12976-12984. [PMID: 24191705 DOI: 10.1021/es401906x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Aqueous free available chlorine (FAC) can be photolyzed by sunlight and/or artificial UV light to generate various reactive oxygen species, including HO(•) and O((3)P). The influence of this chemistry on inactivation of chlorine-resistant microorganisms was investigated using Bacillus subtilis endospores as model microbial agents and simulated and natural solar radiation as light sources. Irradiation of FAC solutions markedly enhanced inactivation of B. subtilis spores in 10 mM phosphate buffer; increasing inactivation rate constants by as much as 600%, shortening inactivation curve lag phase by up to 73% and lowering CTs required for 2 log10 inactivation by as much as 71% at pH 8.0 and 10 °C. Similar results were observed at pH 7.4 and 10 °C in two drinking water samples with respective DOC concentrations and alkalinities of 0.6 and 1.2 mg C/L and 81.8 and 17.1 mg/L as CaCO3. Solar radiation alone did not inactivate B. subtilis spores under the conditions investigated. A variety of experimental data indicate that the observed enhancements in spore inactivation can be attributed to the concomitant attack of spores by HO(•) and O3, the latter of which was found to accumulate to micromolar concentrations during simulated solar irradiation of 10 mM phosphate buffer (pH 8, 10 °C) containing [FAC]0 = 8 mg/L as Cl2.
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Affiliation(s)
- Jenna E Forsyth
- Department of Civil and Environmental Engineering, University of Washington , 201 More Hall, Box 352700, Seattle, Washington 98195, United States
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19
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Jakubek D, Guillaume C, Binet M, Leblon G, DuBow M, Le Brun M. Susceptibility of Legionella strains to the chlorinated biocide, monochloramine. Microbes Environ 2013; 28:336-45. [PMID: 24005820 PMCID: PMC4070956 DOI: 10.1264/jsme2.me12205] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Members of the Legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. To limit the proliferation of Legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. Although the treatment is highly effective, i.e. it reduces Legionella numbers by over 99%, Legionella bacteria can still be detected at low concentrations and rapid re-colonisation of circuits can occur after the treatment has ceased. The aim of this study was to develop an in vitro methodology for determining the intrinsic susceptibility of L. pneumophila strains, collected from various nuclear power plant cooling circuits subjected to different treatment conditions. The methodology was developed by using an original approach based on response surface methodology (RSM) combined with a multifactorial experimental design. The susceptibility was evaluated by the Ct factor. The susceptibility of environmental strains varies widely and is, for some strains, greater than that of known tolerant species; however, strain susceptibility was not related to treatment conditions. Selection pressure induced by monochloramine use did not result in the selection of more tolerant Legionella strains and did not explain the detection of Legionella during treatment or the rapid re-colonisation of cooling circuits after disinfection has ceased.
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20
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Nie Y, Hu C, Yang L, Hu J. Inhibition mechanism of BrO3- formation over MnOx/Al2O3 during the catalytic ozonation of 2,4-dichlorophenoxyacetic acid in water. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2013.03.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Gerrity D, Gamage S, Jones D, Korshin GV, Lee Y, Pisarenko A, Trenholm RA, von Gunten U, Wert EC, Snyder SA. Development of surrogate correlation models to predict trace organic contaminant oxidation and microbial inactivation during ozonation. WATER RESEARCH 2012; 46:6257-6272. [PMID: 23062789 DOI: 10.1016/j.watres.2012.08.037] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/21/2012] [Accepted: 08/24/2012] [Indexed: 06/01/2023]
Abstract
The performance of ozonation in wastewater depends on water quality and the ability to form hydroxyl radicals (·OH) to meet disinfection or contaminant transformation objectives. Since there are no on-line methods to assess ozone and ·OH exposure in wastewater, many agencies are now embracing indicator frameworks and surrogate monitoring for regulatory compliance. Two of the most promising surrogate parameters for ozone-based treatment of secondary and tertiary wastewater effluents are differential UV(254) absorbance (ΔUV(254)) and total fluorescence (ΔTF). In the current study, empirical correlations for ΔUV(254) and ΔTF were developed for the oxidation of 18 trace organic contaminants (TOrCs), including 1,4-dioxane, atenolol, atrazine, bisphenol A, carbamazepine, diclofenac, gemfibrozil, ibuprofen, meprobamate, naproxen, N,N-diethyl-meta-toluamide (DEET), para-chlorobenzoic acid (pCBA), phenytoin, primidone, sulfamethoxazole, triclosan, trimethoprim, and tris-(2-chloroethyl)-phosphate (TCEP) (R(2) = 0.50-0.83) and the inactivation of three microbial surrogates, including Escherichia coli, MS2, and Bacillus subtilis spores (R(2) = 0.46-0.78). Nine wastewaters were tested in laboratory systems, and eight wastewaters were evaluated at pilot- and full-scale. A predictive model for OH exposure based on ΔUV(254) or ΔTF was also proposed.
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Affiliation(s)
- Daniel Gerrity
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, Las Vegas, NV 89154-4015, United States.
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Talbot P, Martinelli L, Talvy S, Chauveheid E, Haut B. Ozone inactivation of resistant microorganisms: Laboratory analysis and evaluation of the efficiency of plants. WATER RESEARCH 2012; 46:5893-5903. [PMID: 22959560 DOI: 10.1016/j.watres.2012.07.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/21/2012] [Accepted: 07/29/2012] [Indexed: 06/01/2023]
Abstract
In this work, the ozone inactivation of resistant microorganisms is studied and a method to assess the efficiency of a drinking water plant to inactivate resistant microorganisms using ozone is proposed. This method aims at computing the fraction of resistant microorganisms that are not inactivated at the exit of an ozonation step by evaluating the duration of the lag phase of the ozone inactivation of these microorganisms and the contact time distribution of these microorganisms with the ozone in the step. To evaluate the duration of the lag phase of the ozone inactivation of resistant pathogenic microorganisms, an experimental procedure is proposed and applied to Bacillus subtilis spores. The procedure aims at characterizing the ozone inactivation kinetics of B. subtilis spores for different temperature and ozone concentration conditions. From experimental data, a model of the ozone inactivation of B. subtilis spores is built. One of the parameters of this model is called the lag time and it measures the duration of the lag phase of the ozone inactivation of B. subtilis spores. This lag time is identified for different temperature and ozone concentration conditions in order to establish a correlation between this lag time and the temperature and ozone concentration conditions. To evaluate the contact time distribution between microorganisms and the ozone in a disinfection step of a drinking water plant, a computational fluid dynamics tool is used. The proposed method is applied to the ozonation channel of an existing drinking water plant located in Belgium and operated by Vivaqua. Results show that lag times and contact times are both in the same order of magnitude of a few minutes. For a large range of temperatures and ozone concentrations in the Tailfer ozonation channel and for the highest hydraulic flow rate applied, a significant fraction of resistant microorganisms similar to B. subtilis spores is not inactivated.
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Affiliation(s)
- Pauline Talbot
- Transfers, Interfaces and Processes - Chemical Engineering Unit, Université Libre de Bruxelles, Av. F.D. Roosevelt 50, CP 165/67, 1050 Brussels, Belgium.
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Rosenblum J, Ge C, Bohrerova Z, Yousef A, Lee J. Ozonation as a clean technology for fresh produce industry and environment: sanitizer efficiency and wastewater quality. J Appl Microbiol 2012; 113:837-45. [PMID: 22788957 DOI: 10.1111/j.1365-2672.2012.05393.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 06/15/2012] [Accepted: 07/06/2012] [Indexed: 12/16/2023]
Abstract
AIMS Inactivating microbial contaminants in fresh produce commonly uses chlorine washing. The effectiveness of ozone was explored as an alternative to chlorine in produce washing for ensuring microbial safety while maximizing water reusability. METHODS AND RESULTS An ozone washing system was designed to permit continuous addition of contaminated produce and the reuse of washing water. The effectiveness of ozonation (<2 mg l(-1) ) was determined using Bacillus subtilis spores as a stricter measure of efficiency with processing time of 10 min. As a comparison, chlorine (c. 100 mg l(-1) ) was tested in parallel. Water quality characteristics, including chemical oxygen demand, total suspended solids, disinfectants concentration and microbial reduction were measured. Ozonation showed an average of 1·56 log reduction of B. subtilis spores on lettuce, while chlorination achieved a 1·30 log reduction. The effluents after ozonation demonstrated improved water quality, both in physicochemical quality and microbial quality compared to chlorination. CONCLUSION Aqueous ozone treatment is effective against microbial contaminants on fresh produce and enables extended use of washing water. SIGNIFICANCE AND IMPACT OF THE STUDY The results provide significant data about ozone disinfection efficacy and its impact on the water reusability, which can facilitate the ozone utilization in the fresh produce production as an environmental friendly alternative.
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Affiliation(s)
- J Rosenblum
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH 43210, USA
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24
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Jung JA, Kwak DH, Oh DW, Park DM, Yang OB. Disinfection of E.coli in Drinking Water by TiO2Photocatalytic System. KOREAN CHEMICAL ENGINEERING RESEARCH 2012. [DOI: 10.9713/kcer.2012.50.1.011] [Citation(s) in RCA: 2] [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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25
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Sobhani R, McVicker R, Spangenberg C, Rosso D. Process analysis and economics of drinking water production from coastal aquifers containing chromophoric dissolved organic matter and bromide using nanofiltration and ozonation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2012; 93:209-217. [PMID: 22054587 DOI: 10.1016/j.jenvman.2011.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 08/27/2011] [Accepted: 09/15/2011] [Indexed: 05/31/2023]
Abstract
In regions characterized by water scarcity, such as coastal Southern California, groundwater containing chromophoric dissolved organic matter is a viable source of water supply. In the coastal aquifer of Orange County in California, seawater intrusion driven by coastal groundwater pumping increased the concentration of bromide in extracted groundwater from 0.4 mg l⁻¹ in 2000 to over 0.8 mg l⁻¹ in 2004. Bromide, a precursor to bromate formation is regulated by USEPA and the California Department of Health as a potential carcinogen and therefore must be reduced to a level below 10 μg l⁻¹. This paper compares two processes for treatment of highly coloured groundwater: nanofiltration and ozone injection coupled with biologically activated carbon. The requirement for bromate removal decreased the water production in the ozonation process to compensate for increased maintenance requirements, and required the adoption of catalytic carbon with associated increase in capital and operating costs per unit volume. However, due to the absence of oxidant addition in nanofiltration processes, this process is not affected by bromide. We performed a process analysis and a comparative economic analysis of capital and operating costs for both technologies. Our results show that for the case studied in coastal Southern California, nanofiltration has higher throughput and lower specific capital and operating cost, when compared to ozone injection with biologically activate carbon. Ozone injection with biologically activated carbon, compared to nanofiltration, has 14% higher capital cost and 12% higher operating costs per unit water produced while operating at the initial throughput. Due to reduced ozone concentration required to accommodate for bromate reduction, the ozonation process throughput is reduced and the actual cost increase (per unit water produced) is 68% higher for capital cost and 30% higher for operations.
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Affiliation(s)
- R Sobhani
- Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, USA
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L. Asfahl K, C. Savin M. Destruction of <i>Escherichia coli</i> and Broad-Host-Range Plasmid DNA in Treated Wastewater by Dissolved Ozone Disinfection under Laboratory and Field Conditions. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/aim.2012.21001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Makky EA, Park GS, Choi IW, Cho SI, Kim H. Comparison of Fe(VI) (FeO4(2-)) and ozone in inactivating Bacillus subtilis spores. CHEMOSPHERE 2011; 83:1228-1233. [PMID: 21489600 DOI: 10.1016/j.chemosphere.2011.03.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 05/30/2023]
Abstract
The protozoan parasites such as Cryptosporidiumparvum and Giardialamblia have been recognized as a frequent cause of recent waterborne disease outbreaks because of their strong resistance against chlorine disinfection. In this study, ozone and Fe(VI) (i.e., FeO(4)(2-)) were compared in terms of inactivation efficiency for Bacillus subtilis spores which are commonly utilized as an indicator of protozoan pathogens. Both oxidants highly depended on water pH and temperature in the spore inactivation. Since redox potential of Fe(VI) is almost the same as that of ozone, spore inactivation efficiency of Fe(VI) was expected to be similar with that of ozone. However, it was found that ozone was definitely superior over Fe(VI): at pH 7 and 20°C, ozone with the product of concentration×contact time (C¯T) of 10mgL(-1)min inactivate the spores more than 99.9% within 10min, while Fe(VI) with C¯T of 30mgL(-1) min could inactivate 90% spores. The large difference between ozone and Fe(VI) in spore inactivation was attributed mainly to Fe(III) produced from Fe(VI) decomposition at the spore coat layer which might coagulate spores and make it difficult for free Fe(VI) to attack live spores.
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Affiliation(s)
- Essam A Makky
- Faculty of Industrial Sciences and Technology, University Malaysia Pahang, 26300 Kuantan, Gambang, Pahang, Malaysia
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Rowan NJ. Defining established and emerging microbial risks in the aquatic environment: current knowledge, implications, and outlooks. Int J Microbiol 2010; 2011:462832. [PMID: 20976256 PMCID: PMC2952898 DOI: 10.1155/2011/462832] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 07/27/2010] [Indexed: 01/31/2023] Open
Abstract
This timely review primarily addresses important but presently undefined microbial risks to public health and to the natural environment. It specifically focuses on current knowledge, future outlooks and offers some potential alleviation strategies that may reduce or eliminate the risk of problematic microbes in their viable but nonculturable (VBNC) state and Cryptosporidium oocysts in the aquatic environment. As emphasis is placed on water quality, particularly surrounding efficacy of decontamination at the wastewater treatment plant level, this review also touches upon other related emerging issues, namely, the fate and potential ecotoxicological impact of untreated antibiotics and other pharmaceutically active compounds in water. Deciphering best published data has elucidated gaps between science and policy that will help stakeholders work towards the European Union's Water Framework Directive (2000/60/EC), which provides an ambitious legislative framework for water quality improvements within its region and seeks to restore all water bodies to "good ecological status" by 2015. Future effective risk-based assessment and management, post definition of the plethora of dynamic inter-related factors governing the occurrence, persistence and/or control of these presently undefined hazards in water will also demand exploiting and harnessing tangential advances in allied disciplines such as mathematical and computer modeling that will permit efficient data generation and transparent reporting to be undertaken by well-balanced consortia of stakeholders.
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Affiliation(s)
- Neil J Rowan
- Department of Nursing and Health Science, School of Science, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath, Ireland
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Wright DA, Gensemer RW, Mitchelmore CL, Stubblefield WA, van Genderen E, Dawson R, Orano-Dawson CE, Bearr JS, Mueller RA, Cooper WJ. Shipboard trials of an ozone-based ballast water treatment system. MARINE POLLUTION BULLETIN 2010; 60:1571-1583. [PMID: 20483433 DOI: 10.1016/j.marpolbul.2010.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 04/19/2010] [Accepted: 04/23/2010] [Indexed: 05/29/2023]
Abstract
Legislation introduced by the United Nations International Maritime Organization (IMO) has focused primarily on standards defining successful treatments designed to remove invasive species entrained in ballast water. An earlier shipboard study found that ozone introduced into salt water ballast resulted in the formation of bromine compounds, measured as total residual oxidants (TRO) that were toxic to both bacteria and plankton. However, the diffuser system employed to deliver ozone to the ballast water tanks resulted in patchiness in TRO distribution and toxicity to entrained organisms. In this follow-up study, the shipboard diffuser system was replaced by a single Venturi-type injection system designed to deliver a more homogeneous biocide distribution. Within-tank variability in TRO levels and associated toxicity to zooplankton, phytoplankton and marine bacteria was measured via a matrix of tubes deployed to sample different locations in treated and untreated (control) tanks. Three trials were conducted aboard the oil tanker S/T Prince William Sound in the Strait of Juan de Fuca off Port Angeles, Washington State, USA, between June and December 2007. Mortalities of plankton and bacteria and oxidant concentrations were recorded for treated and untreated ballast water up to 3days following treatment, and residual toxicity beyond this period was measured by bioassay of standard test organisms. Results indicated uniform compliance with current IMO standards, but only partial compliance with other existing and pending ballast water legislation.
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Affiliation(s)
- David A Wright
- University of Maryland, Center for Environmental Science (UMCES), Chesapeake Biological Laboratory, Solomons, MD 20688, USA.
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Watanabe M, Masaki H, Mori T, Tsuchiya T, Konuma H, Hara-Kudo Y, Takatori K. Inactivation effects of UV irradiation and ozone treatment on the yeast and the mold in mineral water. J Food Prot 2010; 73:1537-42. [PMID: 20819369 DOI: 10.4315/0362-028x-73.8.1537] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In recent years, bottled mineral water has undergone inactivation by methods other than the traditional heat treatment during the production process; there are fewer reports of the effectiveness of these inactivation methods on yeasts and molds in mineral water than on bacteria and protozoan oocysts. In this study, we evaluated the effects of UV irradiation and ozone treatment compared with heat treatment at 85 degrees C on yeast cells and mold spores inoculated into mineral water. A 5-log reduction occurred at a UV radiation dose of 31,433 microJ/cm2 for Saccharomyces cerevisiae and at 588,285 microJ/cm2 for Penicillium pinophilum. The treatment time for 5-log reduction estimated for UV irradiation was about 0.6 min for S. cerevisiae and about 10.7 min for P. pinophilum; at an ozone concentration of 0.1 ppm, it was 1.75 min for S. cerevisiae and 2.70 min for P. pinophilum, and at a concentration of 0.6 ppm, it was 0.32 min for S. cerevisiae and 0.57 min for P. pinophilum. Comparison of the inactivation effects among the three methods showed that UV irradiation and ozone treatment were less effective than heat treatment at 85 degrees C. Thus, when UV irradiation and ozone treatment are used for inactivation of mineral water, it seems that they need to be combined with heat treatment to achieve a definite effect. Yeast cells are more sensitive to all three inactivation methods than are mold spores, and the sensitivity of yeast cells and mold spores to these inactivation methods may vary among genera.
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Affiliation(s)
- M Watanabe
- Division of Microbiology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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Matos CT, Velizarov S, Reis MAM, Crespo JG. Removal of bromate from drinking water using the ion exchange membrane bioreactor concept. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:7702-7708. [PMID: 18983096 DOI: 10.1021/es801176f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Bromate is a disinfection byproduct with carcinogenic properties that has to be removed from drinking water to concentrations below 10 or 25 microg/L. This work evaluates the applicability of the ion exchange membrane bioreactor (IEMB) concept for the removal of bromate from drinking water, in situations where nitrate is also present in concentrations up to 3 orders of magnitude higher than bromate. The batch results obtained show that the biological reduction of bromate was slow and only occurring after the complete reduction of nitrate. The specific bromate reduction rates varied from 0.027 +/- 0.01 mg BrO3(-)/g(cell dry weight) x h to 0.090 mg BrO3(-)/ g(cell dry weight) x h for the studied concentrations. On the other hand, transport studies, using anion exchange membranes showed that Donnan dialysis could efficiently remove bromate from polluted waters. Therefore, the use of a dense, nonporous membrane in the IEMB system, isolates the water stream from the biological compartment, allowing for the uncoupling of the water production rate from the biological reduction rate. The IEMB system was used for the treatment of a polluted water stream containing 200 microg/L of BrO3(-) and 60 mg/L of NO3(-). The concentrations of both ions in the treated water were reduced below the recommended levels. No bromate accumulation was observed in the biocompartment of the IEMB, suggesting its complete reduction in the biofilm formed on the membrane surface contacting the biocompartment. Therefore, the IEMB has proven to be a technology able to solve specific problems associated with the removal of bromate from water streams, since it efficiently removes bromate from drinking water even in the presence of nitrate, a known competitor of bromate biological reduction, without secondary contamination of the treated water by cells or excess of carbon source.
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Affiliation(s)
- Cristina T Matos
- CQFB/REQUIMTE, Department of Chemistry, FCT, Universidade Nova de Lisboa, P-2829-516 Caparica, Portugal
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Bactericidal effect of solar water disinfection under real sunlight conditions. Appl Environ Microbiol 2008; 74:2997-3001. [PMID: 18359829 DOI: 10.1128/aem.02415-07] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Batch solar disinfection (SODIS) inactivation kinetics are reported for suspensions in water of Campylobacter jejuni, Yersinia enterocolitica, enteropathogenic Escherichia coli, Staphylococcus epidermidis, and endospores of Bacillus subtilis, exposed to strong natural sunlight in Spain and Bolivia. The exposure time required for complete inactivation (at least 4-log-unit reduction and below the limit of detection, 17 CFU/ml) under conditions of strong natural sunlight (maximum global irradiance, approximately 1,050 W m(-2) +/- 10 W m(-2)) was as follows: C. jejuni, 20 min; S. epidermidis, 45 min; enteropathogenic E. coli, 90 min; Y. enterocolitica, 150 min. Following incomplete inactivation of B. subtilis endospores after the first day, reexposure of these samples on the following day found that 4% (standard error, 3%) of the endospores remained viable after a cumulative exposure time of 16 h of strong natural sunlight. SODIS is shown to be effective against the vegetative cells of a number of emerging waterborne pathogens; however, bacterial species which are spore forming may survive this intervention process.
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Jung YJ, Oh BS, Kang JW. Synergistic effect of sequential or combined use of ozone and UV radiation for the disinfection of Bacillus subtilis spores. WATER RESEARCH 2008; 42:1613-1621. [PMID: 18028981 DOI: 10.1016/j.watres.2007.10.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 09/27/2007] [Accepted: 10/06/2007] [Indexed: 05/25/2023]
Abstract
This study was performed to evaluate the inactivation efficiency or synergy of combined ozone and UV processes (combined ozone/UV process) or sequential processes (ozone-UV, UV-ozone) compared with individual unit processes and to investigate the specific roles of ozone, UV and the hydroxyl radical, which is formed as an intermediate in the combined ozone/UV process. The Bacillus subtilis spore, which has often been used as a surrogate microorganism for Cryptosporidium parvum oocysts, was used as a target microorganism. Compared to individual unit processes with ozone or UV, the inactivation of B. subtilis spores by the combined ozone/UV process was enhanced under identical conditions. To investigate the specific roles of ozone and UV in the combined ozone/UV process, sequential ozone-UV and UV-ozone processes were tested for degrees of inactivation. Additionally, the experiment was performed in the presence and absence of tert-butyl alcohol, which acted as a hydroxyl radical scavenger to assess the role of inactivation by the hydroxyl radical in the combined ozone/UV process. Among the five candidate processes, the greatest synergistic effect was observed in the combined ozone/UV process. From the comparison of five candidate processes, the hydroxyl radical and ozone were each determined to significantly enhance the overall inactivation efficiency in the combined ozone/UV process.
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Affiliation(s)
- Yeon Jung Jung
- Department of Environmental Engineering, Yonsei University, Wonju 220-710, Republic of Korea.
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Choi Y, Cho M, Lee Y, Choi J, Yoon J. Inactivation of Bacillus subtilis spores during ozonation in water treatment plant: influence of pre-treatment and consequences for positioning of the ozonation step. CHEMOSPHERE 2007; 69:675-81. [PMID: 17604815 DOI: 10.1016/j.chemosphere.2007.05.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 05/16/2007] [Accepted: 05/17/2007] [Indexed: 05/16/2023]
Abstract
This study reports on quantitative methodology for rational selection of the ozone injection point within unit processes of conventional drinking water treatment plants to improve disinfection efficiencies. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a Delayed Chick-Watson model (C T(lag): 1.03mgl(-1), k: 1.44mg(-1)lmin(-1)). This study demonstrated this phenomenon by performing the inactivation of Bacillus subtilis (B. subtilis) spores with ozone in various types of water collected from a series of unit processes in a water treatment plant. Simple measurements of the ozone decomposition behavior in waters from each unit process of a water treatment plant can allow the quantitative evaluation of the ozone needed to achieve a required level of inactivation. This methodology will be useful for drinking water treatment plants which intend to improve the disinfection efficiencies of their ozonation process.
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Affiliation(s)
- Yuseung Choi
- The Environment Technology Institute Department of Development II, Naewei Bldg., 7F, 6 Euljiro 2-ga, Joong-gu, Seoul 100-844, Republic of Korea
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Cho M, Kim JH, Yoon J. Investigating synergism during sequential inactivation of Bacillus subtilis spores with several disinfectants. WATER RESEARCH 2006; 40:2911-20. [PMID: 16884760 DOI: 10.1016/j.watres.2006.05.042] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2005] [Revised: 05/01/2006] [Accepted: 05/30/2006] [Indexed: 05/11/2023]
Abstract
The sequential application of ozone, chlorine dioxide, or UV followed by free chlorine was performed to investigate the synergistic inactivation of Bacillus subtilis spores. The greatest synergism was observed when chlorine dioxide was used as a primary disinfectant followed by secondary disinfection with free chlorine. A lesser synergistic effect was observed when ozone was used as the primary disinfectant, but no synergism was observed when UV was used as the primary disinfectant. When free chlorine was used as the primary disinfectant (i.e., sequential application in the reverse order), the synergistic effect was shown only when chlorine dioxide was applied as the secondary disinfectant. The synergistic effect observed could be related to damage to the spore coat during primary disinfection, suggested by the loss of proteins from spores during disinfectant treatment. The greatest synergism observed by the chlorine dioxide/free chlorine pair suggested that common reaction sites might exist for these disinfectants. The concept of percent synergistic effect was introduced to quantitatively compare the extent of synergistic effects in the sequential disinfection processes.
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Affiliation(s)
- Min Cho
- School of Chemical Engineering, College of Engineering, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, 151-742, Republic of Korea
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36
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Dow SM, Barbeau B, von Gunten U, Chandrakanth M, Amy G, Hernandez M. The impact of selected water quality parameters on the inactivation of Bacillus subtilis spores by monochloramine and ozone. WATER RESEARCH 2006; 40:373-82. [PMID: 16364398 DOI: 10.1016/j.watres.2005.10.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2004] [Revised: 10/04/2005] [Accepted: 10/05/2005] [Indexed: 05/05/2023]
Abstract
Selected water quality parameters-pH, dissolved organic carbon, turbidity (NTU), and temperature-were tested for their potential effects on ozone and monochloramine inactivation of Bacillus subtilis spores. In oxidant demand-free phosphate-buffer, temperature had the strongest influence on inactivation kinetics when using ozone, pH had a smaller but significant impact on B. subtilis spore inactivation with both monochloramine and ozone. Where monochloramine was applied, modeling and experimental measurements confirmed that dichloramine levels were too low to produce significant inactivation effects under these experimental conditions. It was demonstrated that oxidant demand-free phosphate buffer may not be an adequate environmental analogue for inactivation responses in natural waters.
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Affiliation(s)
- S M Dow
- Department of Civil, Environmental, and Architectural Engineering University of Colorado, Campus Box 428, Boulder, CO 80309, USA
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Mazoua S, Chauveheid E. Aerobic spore-forming bacteria for assessing quality of drinking water produced from surface water. WATER RESEARCH 2005; 39:5186-98. [PMID: 16280148 DOI: 10.1016/j.watres.2005.09.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 09/26/2005] [Accepted: 09/28/2005] [Indexed: 05/05/2023]
Abstract
Cryptosporidium and Giardia represent a major microbiological issue for drinking water production from surface water. As their monitoring through a treatment process is rather tedious and as low-concentration goals should be reached for drinking water, aerobic spore-forming bacteria (ASFB) have been studied as an indicator microorganism for a drinking water treatment plant using surface water. The results reveal that monitoring naturally occurring ASFB better highlights daily achievable performances and identifies unusual process events for global disinfection, for both physical and chemical treatment steps in a multi-barrier drinking water treatment plant. Advantages of ASFB over usual process parameters are that these microorganisms are more sensitive to process fluctuations. The use of ASFB also showed that the efficiency of ozone disinfection is not as significantly influenced by the water temperature as reported, despite similar or higher CT values applied during warmer periods. Thus, the disinfection of resistant microorganisms with ozone can also be an efficient process at lower water temperature. ASFB have been shown to be a conservative indicator for Cryptosporidium and Giardia up to a 1st stage filtration and the ASFB Log removals can be used to estimate Log removals for Cryptosporidium and Giardia: compared to ASFB, the Log removals for Cryptosporidium or Giardia are at least equal or 50% higher, respectively. Thus, the monitoring of ASFB along a drinking water treatment process could be a useful tool for performing risk analysis for parasites such as Cryptosporidium and Giardia, and would further allow integration of daily variability into a risk analysis.
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Affiliation(s)
- Stephane Mazoua
- Water Quality Department, Brussels Water Company (C.I.B.E.), Chaussée de Waterloo 764, 1180 Brussels, BE, Belgium
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von Gunten U. Ozonation of drinking water: part II. Disinfection and by-product formation in presence of bromide, iodide or chlorine. WATER RESEARCH 2003; 37:1469-1487. [PMID: 12600375 DOI: 10.1016/s0043-1354(02)00458-x] [Citation(s) in RCA: 649] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ozone is an excellent disinfectant and can even be used to inactivate microorganisms such as protozoa which are very resistant to conventional disinfectants. Proper rate constants for the inactivation of microorganisms are only available for six species (E. coli, Bacillus subtilis spores, Rotavirus, Giardia lamblia cysts, Giardia muris cysts, Cryptosporidium parvum oocysts). The apparent activation energy for the inactivation of bacteria is in the same order as most chemical reactions (35-50 kJ mol(-1)), whereas it is much higher for the inactivation of protozoa (80 kJ mol(-1)). This requires significantly higher ozone exposures at low temperatures to get a similar inactivation for protozoa. Even for the inactivation of resistant microorganisms, OH radicals only play a minor role. Numerous organic and inorganic ozonation disinfection/oxidation by-products have been identified. The by-product of main concern is bromate, which is formed in bromide-containing waters. A low drinking water standard of 10 microg l(-1) has been set for bromate. Therefore, disinfection and oxidation processes have to be evaluated to fulfil these criteria. In certain cases, when bromide concentrations are above about 50 microg l(-1), it may be necessary to use control measures to lower bromate formation (lowering of pH, ammonia addition). Iodate is the main by-product formed during ozonation of iodide-containing waters. The reactions involved are direct ozone oxidations. Iodate is considered non-problematic because it is transformed back to iodide endogenically. Chloride cannot be oxidized during ozonation processes under drinking water conditions. Chlorate is only formed if a preoxidation by chlorine and/or chlorine dioxide has occurred.
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Affiliation(s)
- Urs von Gunten
- Swiss Federal Institute for Environmental Science and Technology, EAWAG, Ueberlandstr 133, CH-8600 Dübendorf, Switzerland.
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Abstract
Disinfection of some microorganisms is characterized by a lag-phase (a minimum required ozone exposure until disinfection occurs). This phenomenon is easy to model in laboratory batch reactors but not in continuous flow mixed reactors. This paper introduces a stochastic disinfection model where individual microorganisms are followed on their paths through full-scale reactors. Combining exponentially distributed transport processes with delayed exponential disinfection kinetics for large populations of microorganisms (up to 10,000 individuals) yields predictions which can be evaluated statistically. It could be shown that deterministic models work well for systems with good disinfection performance (more than 2 log units reduction of active microorganisms), for reactors with poor performance stochastic models have to be applied. It could be demonstrated for real reactors that Bacillus subtilis spores are poor surrogates for Cryptosporidium parvum oocysts. The differences between the two microorganisms are large for reactors that deviate significantly from plug-flow behaviour.
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Affiliation(s)
- Willi Gujer
- Swiss Federal Institute for Environmental Science and Technology (EAWAG) and Swiss Federal Institute of Technology (ETH), Duebendorf, Switzerland.
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Larson MA, Mariñas BJ. Inactivation of Bacillus subtilis spores with ozone and monochloramine. WATER RESEARCH 2003; 37:833-844. [PMID: 12531265 DOI: 10.1016/s0043-1354(02)00381-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The inactivation kinetics of Bacillus subtilis spores with ozone and monochloramine was characterized by a lag phase followed by a pseudo-first-order rate of inactivation. The lag phase decreased and the post-lag phase rate constant increased with increasing temperature within the range investigated (1-30 degrees C for ozone, 1-20 degrees C for monochloramine). The corresponding activation energies were 46820 J/mol for ozone and 79640 J/mol for monochloramine. The CT concept was found to be valid within the concentration range investigated of 0.44-4.8 mg/l for ozone, and 3.8-7.7 mg/l as Cl(2) for monochloramine. The inactivation kinetics of B. subtilis spores with both ozone and monochloramine varied with pH within the range of pH 6-10 investigated. The fastest ozone and monochloramine inactivation rates were observed at pH 10 and 6, respectively. Different stocks of the same strain of B. subtilis spores had different resistance to ozone and monochloramine mainly because of discrepancies in the extent of the lag phase. B. subtilis spores might not be conservative surrogates for C. parvum oocysts for ozone disinfection at relatively low temperature mainly due to the spores having a lower activation energy compared to that for the oocysts. In contrast, the activation energy for monochloramine was comparable for both microorganisms but differences in the extent of the lag phase might result in the spores being overly conservative surrogates for the oocysts at relatively low temperature.
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Affiliation(s)
- Matthew A Larson
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue Urbana, Il 61801, USA
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