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Chen H, Lin T, Wang P, Zhang X, Jiang F, Liu W. Treatment of bromate in UV/sulfite autoxidation process enhances formation of dibromoacetonitrile during chlorination. WATER RESEARCH 2022; 225:119207. [PMID: 36215832 DOI: 10.1016/j.watres.2022.119207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
The integration of UV/sulfite autoxidation process (USAP, i.e., UV activation of sulfite in the presence of 5 ∼ 10 mg/L O2) into conventional water to degrade micropollutants rises extensive attention, but its impact on water quality, and especially the formation of disinfection byproducts is still unclear. Herein, the formation of dibromoacetonitrile (DBAN) from bromate (BrO3-) upon treatment with USAP followed by chlorination was evaluated, in the presence of amino acids (AAs) selected as representative organic matter in drinking water. Results revealed that hydrated electrons (eaq-) produced during USAP contribute to the reduction of BrO3- to Br-, which is then converted into HBrO/BrO- during post-chlorination. At the same time, sulfate radicals (SO4•-) and hydroxyl radicals (•OH) generated in USAP mediated AAs' conversion via α-hydrogen abstraction and NH2-hydrogen abstraction reactions to produce HN=C(CH3)‒COOH, CH3‒CH=NH, and CH3‒CN, which are released into the post-chlorination stage and therefore, enhance the bromine utilization factor (BUF) value and DBAN formation. The effects of the USAP treatment time, BrO3- concentration, AA concentration, pH, and real waters were also evaluated. Although 63.5% of BrO3- was eliminated by USAP followed by chlorination, the toxicity index (TI) was increased by 1.5-fold due to the formation of the all brominated CX3R-type nitrogenous disinfection byproducts (N-DBPs), demonstrating the potential risk of applying USAP as a treatment process in BrO3- containing waters.
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Affiliation(s)
- Han Chen
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
| | - Tao Lin
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Peifang Wang
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Xue Zhang
- Suzhou Water Supply Company Limited, Suzhou 215002, PR China
| | - Fuchun Jiang
- Suzhou Water Supply Company Limited, Suzhou 215002, PR China
| | - Wei Liu
- Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Hohai University, Nanjing 210098, PR China; College of Environment, Hohai University, Nanjing 210098, PR China
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Retrieval of Microbial Inactivation Kinetic Parameters in Chemical Preservation and Disinfection by the Endpoints Method. FOOD ENGINEERING REVIEWS 2022. [DOI: 10.1007/s12393-022-09310-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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3
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Effective E. coli inactivation of core-shell ZnO@ZIF-8 photocatalysis under visible light synergize with peroxymonosulfate: Efficiency and mechanism. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.06.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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4
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Zhang Y, Koehler AV, Wang T, Gasser RB. Enterocytozoon bieneusi of animals-With an 'Australian twist'. ADVANCES IN PARASITOLOGY 2021; 111:1-73. [PMID: 33482973 DOI: 10.1016/bs.apar.2020.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Enterocytozoon bieneusi is a microsporidian microorganism that causes intestinal disease in animals including humans. E. bieneusi is an obligate intracellular pathogen, typically causing severe or chronic diarrhoea, malabsorption and/or wasting. Currently, E. bieneusi is recognised as a fungus, although its exact classification remains contentious. The transmission of E. bieneusi can occur from person to person and/or animals to people. Transmission is usually via the faecal-oral route through E. bieneusi spore-contaminated water, environment or food, or direct contact with infected individuals. Enterocytozoon bieneusi genotypes are usually identified and classified by PCR-based sequencing of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA. To date, ~600 distinct genotypes of E. bieneusi have been recorded in ~170 species of animals, including various orders of mammals and reptiles as well as insects in >40 countries. Moreover, E. bieneusi has also been found in recreational water, irrigation water, and treated raw- and waste-waters. Although many studies have been conducted on the epidemiology of E. bieneusi, prevalence surveys of animals and humans are scant in some countries, such as Australia, and transmission routes of individual genotypes and related risk factors are poorly understood. This article/chapter reviews aspects of the taxonomy, biology and epidemiology of E. bieneusi; the diagnosis, treatment and prevention of microsporidiosis; critically appraises the naming system for E. bieneusi genotypes as well as the phylogenetic relationships of these genotypes; provides new insights into the prevalence and genetic composition of E. bieneusi populations in animals in parts of Australia using molecular epidemiological tools; and proposes some areas for future research in the E. bieneusi/microsporidiosis field.
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Affiliation(s)
- Yan Zhang
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Anson V Koehler
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.
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Peleg M. Modeling the dynamic kinetics of microbial disinfection with dissipating chemical agents-a theoretical investigation. Appl Microbiol Biotechnol 2021; 105:539-549. [PMID: 33394150 PMCID: PMC7780086 DOI: 10.1007/s00253-020-11042-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/22/2022]
Abstract
The most notable microbial survival models of disinfection kinetics are the original and modified versions of the static Chick-Watson-Hom's (CWH) initially developed for water chlorination. They can all be viewed as special cases of the Weibull survival model, where the observed static curve is the cumulative form (CDF) of the times at which the individual targeted microbes succumb to the treatment. The CWH model time's exponent is the distribution's shape factor, and its concentration-dependent rate parameter represents the distribution's scale factor's reciprocal. Theoretically, the concentration- dependence of the Weibull model's rate parameter need not to be always in a form of a power-law relationship as the CWH model requires, and two possible alternatives are presented. Apart from being chemically reactive, most chemical disinfectants are also volatile, and their effective concentration rarely remains constant. However, the published dynamic versions of the original CWH model are mathematically incongruent with their static versions. The issue is nonexistent in the dynamic version of the Weibull or other distribution-based models, provided that the momentary inactivation rate is expressed as the static rate at the momentary concentration, at the time that corresponds to the momentary survival ratio. The resulting model is an ordinary differential equation (ODE) whose numerical solution can describe survival curves under realistic regular and irregular disinfectant dissipation patterns, as well as during the disinfectant dispersion and/or its replenishment. KEY POINTS: • The Chick-Watson-Home models are treated as special cases of the Weibull distribution. • Dynamic microbial survival curve described as ordinary differential equation solution. • Survival rate models of disinfectant dissipation and replenishment patterns presented.
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Affiliation(s)
- Micha Peleg
- Department of Food Science, University of Massachusetts, Amherst, MA, 01003, USA.
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6
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Weber R. Intestinal Coccidia and Microsporidia. Infect Dis (Lond) 2017. [DOI: 10.1016/b978-0-7020-6285-8.00192-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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7
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Park KY, Choi SY, Lee SH, Kweon JH, Song JH. Comparison of formation of disinfection by-products by chlorination and ozonation of wastewater effluents and their toxicity to Daphnia magna. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 215:314-321. [PMID: 27213572 DOI: 10.1016/j.envpol.2016.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/27/2016] [Accepted: 04/01/2016] [Indexed: 06/05/2023]
Abstract
This study compared the two most frequently used disinfectants (i.e., chlorine and ozone) to understand their efficiency in wastewater effluents and the ecotoxicity of disinfection by-products created during chlorination and ozonation. Four trihalomethanes (THMs) and nine haloacetic acids (HAAs) were measured from a chlorine-disinfected sample and two aldehydes (i.e., formaldehydes and acetaldehydes) were analyzed after ozonation. Chlorination was effective for total coliform removal with Ct value in the range of 30-60 mg-min/L. Over 1.6 mg/L of ozone dose and 0.5 min of the contact time presented sufficient disinfection efficiency. The concentration of THMs increased with longer contact time (24 h), but that of HAAs showed little change with contact time. The measured concentration of formaldehyde at the ozone dose of 1.6 mg/L and the contact time of 9 min showed the greatest value in this study, approximately 330 μg L(-1), from which the corresponding ecotoxicity was determined using an indicator species, Daphnia magna. The ecotoxicity results were consistent with the toxicological features judged by occurrence, genotoxicity, and carcinogenicity. Both the disinfection efficiency as well as the DBP formation potential should therefore be considered to avoid harmful impacts on aquatic environments when a disinfection method is used for wastewater effluents.
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Affiliation(s)
- Keun-Young Park
- Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea
| | - Su-Young Choi
- Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea
| | - Seung-Hoon Lee
- Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea; Youngsin Metal Industrial Co., LTD., Electricity Business Division, 593 Manho-ri, Poseung-myun, Pyongtaek-si, Kyunggi-do, South Korea
| | - Ji-Hyang Kweon
- Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea.
| | - Ji-Hyeon Song
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul, 05006, South Korea
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8
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Zhou W, Orr MW, Lee VT, Zachariah MR. Synergistic effects of ultrafast heating and gaseous chlorine on the neutralization of bacterial spores. Chem Eng Sci 2016. [DOI: 10.1016/j.ces.2016.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Azam A, Peerzada MN, Ahmad K. Parasitic diarrheal disease: drug development and targets. Front Microbiol 2015; 6:1183. [PMID: 26617574 PMCID: PMC4621754 DOI: 10.3389/fmicb.2015.01183] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/12/2015] [Indexed: 12/23/2022] Open
Abstract
Diarrhea is the manifestation of gastrointestinal infection and is one of the major causes of mortality and morbidity specifically among the children of less than 5 years age worldwide. Moreover, in recent years there has been a rise in the number of reports of intestinal infections continuously in the industrialized world. These are largely related to waterborne and food borne outbreaks. These occur by the pathogenesis of both prokaryotic and eukaryotic organisms like bacteria and parasites. The parasitic intestinal infection has remained mostly unexplored and under assessed in terms of therapeutic development. The lack of new drugs and the risk of resistance have led us to carry out this review on drug development for parasitic diarrheal diseases. The major focus has been depicted on commercially available drugs, currently synthesized active heterocyclic compounds and unique drug targets, that are vital for the existence and growth of the parasites and can be further exploited for the search of therapeutically active anti-parasitic agents.
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Affiliation(s)
- Amir Azam
- Medicinal Chemistry Laboratory, Department of Chemistry, Jamia Millia IslamiaNew Delhi, India
| | - Mudasir N. Peerzada
- Medicinal Chemistry Laboratory, Department of Chemistry, Jamia Millia IslamiaNew Delhi, India
| | - Kamal Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia IslamiaNew Delhi, India
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10
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Lee OM, Kim HY, Park W, Kim TH, Yu S. A comparative study of disinfection efficiency and regrowth control of microorganism in secondary wastewater effluent using UV, ozone, and ionizing irradiation process. JOURNAL OF HAZARDOUS MATERIALS 2015; 295:201-208. [PMID: 25955959 DOI: 10.1016/j.jhazmat.2015.04.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 04/06/2015] [Accepted: 04/06/2015] [Indexed: 06/04/2023]
Abstract
Ionizing radiation technology was suggested as an alternative method to disinfection processes, such as chlorine, UV, and ozone. Although many studies have demonstrated the effectiveness of irradiation technology for microbial disinfection, there has been a lack of information on comparison studies of disinfection techniques and a regrowth of each treatment. In the present study, an ionizing radiation was investigated to inactivate microorganisms and to determine the critical dose to prevent the regrowth. As a result, it was observed that the disinfection efficiency using ionizing radiation was not affected by the seasonal changes of wastewater characteristics, such as temperature and turbidity. In terms of bacterial regrowth after disinfection, the ionizing radiation showed a significant resistance of regrowth, whereas, on-site UV treatment is influenced by the suspended solid, temperature, or precipitation. The electric power consumption was also compared for the economic feasibility of each technique at a given value of disinfection efficiency of 90% (1-log), showing 0.12, 36.80, and 96.53 Wh/(L/day) for ionizing radiation, ozone, and UV, respectively. The ionizing radiation requires two or three orders of magnitude lower power consumption than UV and ozone. Consequently, ionizing radiation can be applied as an effective and economical alternative technique to other conventional disinfection processes.
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Affiliation(s)
- O-Mi Lee
- Quarantine Technology Center, Animal and Plant Quarantine Agency Plant, 175 Anyangro, Manan-Gu, Anyang-Si, Gyeonggi-Do 480-757, South Korea
| | - Hyun Young Kim
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185, South Korea
| | - Wooshin Park
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185, South Korea
| | - Tae-Hun Kim
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185, South Korea
| | - Seungho Yu
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup, Jeonbuk 580-185, South Korea.
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11
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Van Haute S, López-Gálvez F, Gómez-López VM, Eriksson M, Devlieghere F, Allende A, Sampers I. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid. Int J Food Microbiol 2015; 208:102-13. [PMID: 26065727 DOI: 10.1016/j.ijfoodmicro.2015.05.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 05/19/2015] [Accepted: 05/27/2015] [Indexed: 11/25/2022]
Abstract
A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.
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Affiliation(s)
- S Van Haute
- Laboratory of Food Microbiology and Biotechnology, Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium
| | - F López-Gálvez
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, P.O. Box 164, 30100 Espinardo, Murcia, Spain; Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - V M Gómez-López
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, P.O. Box 164, 30100 Espinardo, Murcia, Spain; Catedra Alimentos para la Salud, Departamento de Tecnologia de la Alimentación y Nutrición, Facultad de Ciencias de la Salud, UCAM Universidad Catolica San Antonio de Murcia, Murcia, Spain
| | - Markus Eriksson
- Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - F Devlieghere
- Laboratory of Food Microbiology and Food Preservation, Department of Food Safety and Food Quality, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium
| | - Ana Allende
- Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, P.O. Box 164, 30100 Espinardo, Murcia, Spain
| | - I Sampers
- Laboratory of Food Microbiology and Biotechnology, Department of Industrial Biological Sciences, Faculty of Bioscience Engineering, Ghent University Campus Kortrijk, Graaf Karel de Goedelaan 5, 8500 Kortrijk, Belgium.
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Jin X, Jin P, Wang X. A study on the effects of ozone dosage on dissolved-ozone flotation (DOF) process performance. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2015; 71:1423-1428. [PMID: 25945861 DOI: 10.2166/wst.2015.115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dissolved-ozone flotation (DOF) is a tertiary wastewater treatment process, which combines ozonation and flotation. In this paper, a pilot-scale DOF system fed by secondary effluent from a wastewater treatment plant (WWTP) in China was used to study the effect of ozone dosage on the DOF process performance. The results show that an ozone dosage could affect the DOF performance to a large extent in terms of color and organic matter removal as well as disinfection performance. The optimal color and organic matter removal was achieved at an ozone dosage of 0.8 mg/l. For disinfection, significant improvement in performance could be achieved only when the organic matter removal was optimal. The optimal ozone dosage of at least 1.6 mg/l was put forward, in this case, in order to achieve the optimal color, turbidity, organic matter and disinfection performance.
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Affiliation(s)
- Xin Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 710055 Xi'an, China E-mail:
| | - Pengkang Jin
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 710055 Xi'an, China E-mail:
| | - Xiaochang Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 710055 Xi'an, China E-mail:
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Al-Gabr HM, Zheng T, Yu X. Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 463-464:525-529. [PMID: 23831798 DOI: 10.1016/j.scitotenv.2013.06.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/16/2013] [Accepted: 06/16/2013] [Indexed: 06/02/2023]
Abstract
The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations.
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Affiliation(s)
- Hamid Mohammad Al-Gabr
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; State Key Laboratory of Environmental Sciences, and Key Laboratory of Ministry of Education for Coast and Wetland Ecosystems, School of Life Sciences, Xiamen University, Xiamen 361005, China
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Poma HR, Cacciabue DG, Garcé B, Gonzo EE, Rajal VB. Towards a rational strategy for monitoring of microbiological quality of ambient waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 433:98-109. [PMID: 22771467 PMCID: PMC4492939 DOI: 10.1016/j.scitotenv.2012.06.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 05/26/2023]
Abstract
Water is one of the main sources of human exposure to microbiological hazards. Although legislation establishes regulatory standards in terms of fecal indicator bacteria to assess the microbiological quality of water, these do not necessarily predict the presence of pathogens such as parasites and viruses. Better surveillance and management strategies are needed to assess the risk of pathogens' waterborne transmission. We established a baseline dataset to characterize river water quality, identify changes over time, and design a rational monitoring strategy. Data from a year-long monthly monitoring campaign of the polluted Arenales River (Argentina), were analyzed to statistically correlate physicochemical and microbiological variables, the seasonal and longitudinal variations of the water quality and determine the similarity between study sites. The measured variables (sixteen) reflected the deterioration in the river quality through the city. Different viruses and parasites found did not correlate with the concentration of total and thermotolerant coliforms. There was significant seasonal variation for temperature, turbidity, conductivity, dissolved oxygen, enterococci, and norovirus. Strong correlations between some variables were found; we selected eight variables (dissolved oxygen, conductivity, turbidity, total and thermotolerant coliforms, Enterococcus, and adenovirus and Microsporidium as viral and parasitological indicators, respectively) for future monitoring. There was similarity between the monitoring locations, which were grouped into four clusters validated by cophenetic correlation and supported by discriminant analysis. This allowed us to reduce the number of sites, from eleven down to five. Sixty seven percent of the total variance and the correlation structure between variables were explained using five principal components. All these analyses led to a new long-term systematic monitoring scheme. A rational monitoring strategy based on the selection of the most suitable monitoring points and of the most significant variables to measure, will result in optimal use of the limited resources available to adequately protect the public and environmental health.
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Affiliation(s)
- Hugo Ramiro Poma
- INIQUI-CONICET, Universidad Nacional de Salta, Av. Bolivia 5150, Salta, 4400, Argentina
| | | | - Beatriz Garcé
- INIQUI-CONICET, Universidad Nacional de Salta, Av. Bolivia 5150, Salta, 4400, Argentina
| | - Elio Emilio Gonzo
- INIQUI-CONICET, Universidad Nacional de Salta, Av. Bolivia 5150, Salta, 4400, Argentina
| | - Verónica Beatriz Rajal
- INIQUI-CONICET, Universidad Nacional de Salta, Av. Bolivia 5150, Salta, 4400, Argentina
- Fogarty International Center, CCRBM, 6519 GBSF, University of California, Davis, CA 95616, USA
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15
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Evaluation of some physical and chemical treatments for inactivating microsporidian spores isolated from fish. Int J Food Microbiol 2012; 156:152-60. [DOI: 10.1016/j.ijfoodmicro.2012.03.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 02/29/2012] [Accepted: 03/09/2012] [Indexed: 11/22/2022]
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16
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Sarkar P, Gerba CP. Inactivation ofNaegleria Fowleriby chlorine and ultraviolet light. ACTA ACUST UNITED AC 2012. [DOI: 10.5942/jawwa.2012.104.0041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Calik S, Karaman U, Colak C. Prevalence of microsporidium and other intestinal parasites in children from malatya, Turkey. Indian J Microbiol 2011; 51:345-9. [PMID: 22754014 DOI: 10.1007/s12088-011-0107-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 11/23/2009] [Indexed: 10/18/2022] Open
Abstract
Parasite infections are common during the critical developmental period in children. The occurrences of intestinal parasites are also common in orphanage, nurseries and schools in Turkey. The study was carried out to determine the percentage of microsporidium and intestinal parasites in children from Malatya, Turkey. This study was carried out at the Department of Parasitology of Inonu University, Turgut Ozal Medical Center, during January-December 2006. Totally, 1,181 stool samples were examined using the native-Lugol, sedimentation-techniques, modified trichrome (MTS), acid-fast-trichrome stain and calcofluor staining methods. In addition, perianal region material was taken from the children to examine with cellophane tape method. Power analyses were performed for statistical analyses used. Microsporidia were found in 92 (7.8%) of the samples, and also intestinal parasites were detected in 329 (27.8%). The numbers of infections according to the species were as follows: 69 (5.8%) Entamoeba coli, 7 (0.6%) Blastocystis hominis, 114 (9.7%) Giardia intestinalis, 15 (1.3%) Iodomoeba butchlii, 8 (0.7%) Dientamoeba fragilis, 7 (0.6%) Taenia spp. 70 (5.9%) Enterobius vermicularis, 11 (0.9%) Hymenolepis nana, 25 (2.1%) Trichomonas intestinalis, 1 (0.1%) Ascaris lumbricoides and 2 (0.2%) Chilomastix mesnilii. Also, greater than 90% power values were achieved for statistical analyses. Whereas the detection rates of microsporidium and intestinal parasites were found to be low, it was concluded that in addition to intestinal parasites, microsporidium should be also searched for in children with complaints of intestinal system.
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Ortega YR, Torres MP, Tatum JM. Efficacy of levulinic acid-sodium dodecyl sulfate against Encephalitozoon intestinalis, Escherichia coli O157:H7, and Cryptosporidium parvum. J Food Prot 2011; 74:140-4. [PMID: 21219777 DOI: 10.4315/0362-028x.jfp-10-104] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Foodborne parasites are characterized as being highly resistant to sanitizers used by the food industry. In 2009, a study reported the effectiveness of levulinic acid in combination with sodium dodecyl sulfate (SDS) in killing foodborne bacteria. Because of their innocuous properties, we studied the effects of levulinic acid and SDS at various concentrations appropriate for use in foods, on the viability of Cryptosporidium parvum and Encephalitozoon intestinalis. The viability of Cryptosporidium and E. intestinalis was determined by in vitro cultivation using the HCT-8 and RK-13 cell lines, respectively. Two Escherichia coli O157:H7 isolates were also used in the present study: strain 932 (a human isolate from a 1992 Oregon meat outbreak) and strain E 0018 (isolated from calf feces). Different concentrations and combinations of levulinic acid and SDS were tested for their ability to reduce infectivity of C. parvum oocysts (10(5)), E. intestinalis spores (10(6)), and E. coli O157:H7 (10(7)/ml) when in suspension. Microsporidian spores were treated for 30 and 60 min at 20 ± 2°C. None of the combinations of levulinic acid and SDS were effective at inactivating the spores or oocysts. When Cryptosporidium oocysts were treated with higher concentrations (3% levulinic acid-2% SDS and 2% levulinic acid-1% SDS) for 30, 60, and 120 min, viability was unaffected. E. coli O157:H7, used as a control, was highly sensitive to the various concentrations and exposure times tested. SDS and levulinic acid alone had very limited effect on E. coli O157:H7 viability, but in combination they were highly effective at 30 and 60 min of incubation. In conclusion, Cryptosporidium and microsporidia are not inactivated when treated for various periods of time with 2% levulinic acid-1% SDS or 3% levulinic acid-2% SDS at 20°C, suggesting that this novel sanitizer cannot be used to eliminate parasitic contaminants in foods.
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Affiliation(s)
- Ynes R Ortega
- Center for Food Safety, University of Georgia, Griffin, Georgia 30223, USA.
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Weber R. Protozoa. Infect Dis (Lond) 2010. [DOI: 10.1016/b978-0-323-04579-7.00181-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Ortega YR, Torres MP, Van Exel S, Moss L, Cama V. Efficacy of a sanitizer and disinfectants to inactivate Encephalitozoon intestinalis spores. J Food Prot 2007; 70:681-4. [PMID: 17388059 DOI: 10.4315/0362-028x-70.3.681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The order Microsporidia contains a number of ubiquitous pathogens that can infect various animals, including humans. Enterocytozoon bieneusi and Encephalitozoon intestinalis have been associated with gastrointestinal illness in humans. The effect of four disinfectants--ammonium hydroxide, hydrogen peroxide, and two commercial disinfectants containing peroxyacetic acid (Tsunami) and N-alkyl dimethyl benzyl ammonium chloride (Timsen)--on E. intestinalis spores was examined using exposure times of 1, 5, and 15 min. Spore viability was determined in vitro with RK-13 cells. Hydrogen peroxide was most efficient at inactivating microsporidial spores at all tested concentrations and treatment times, whereas ammonium hydroxide was effective only at the highest concentration at all exposure times. Tsunami (40 microg/ml) and Timsen (200 and 400 ppm) could inactivate spores when incubated for 5 and 15 min.
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Affiliation(s)
- Ynes R Ortega
- Center for Food Safety, Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223, USA.
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Abstract
PURPOSE OF REVIEW Microsporidiosis is an emerging and opportunistic infection associated with a wide range of clinical syndromes in humans. This review highlights the research on microsporidiosis in humans during the previous 2 years. RECENT FINDINGS The reduced and compact microsporidian genome has generated much interest for better understanding the evolution of these parasites, and comparative molecular phylogenetic studies continue to support a relationship between the microsporidia and fungi. Through increased awareness and improved diagnostics, microsporidiosis has been identified in a broader range of human populations that, in addition to persons with HIV infection, includes travelers, children, organ transplant recipients, and the elderly. SUMMARY Effective commercial therapies for Enterocytozoon bieneusi, the most common microsporidian species identified in humans, are still lacking, making the need to develop tissue culture and small animal models increasingly urgent. Environmental transport modeling and disinfection strategies are being addressed for improving water safety. Questions still exist about whether microsporidia infections remain persistent in asymptomatic immune-competent individuals, reactivate during conditions of immune compromise, or may be transmitted to others at risk, such as during pregnancy or through organ donation. Reliable serological diagnostic methods are needed to supplement polymerase chain reaction or histochemistry when spore shedding may be sporadic.
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Affiliation(s)
- Elizabeth S Didier
- Division of Microbiology, Tulane National Primate Research Center, Covington, Louisiana 70433, USA.
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