The Experts below are selected from a list of 3147 Experts worldwide ranked by ideXlab platform
Wolfgang Uhl - One of the best experts on this subject based on the ideXlab platform.
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N2 yields from Monochloramine conversion by granular activated carbons are decisive for effective swimming pool water treatment.
Water Research, 2019Co-Authors: Bertram Skibinski, Eckhard Worch, Wolfgang UhlAbstract:Abstract Inorganic chloramines (mono-, di- and trichloramine) are formed in swimming pool water from the unintended reaction of free chlorine with ammonia that is introduced by bathers. Monochloramine is of particular interest as it is known to react further in pool water forming harmful DBPs, such carcinogenic N-nitrosodimethylamine (NDMA). During pool water treatment with granular activated carbon (GAC) filters, Monochloramine is transformed by chemical reactions on the carbon surface to N2 and ammonia. As ammonia is led back into the pool where it is chlorinated again under the renewed formation of inorganic chloramines, it is recommended to use GACs with a high N2 yield for Monochloramine transformation in pool water treatment. In this study, yields of N2 and ammonia from Monochloramine conversion by commercially available GACs were determined using a fixed-bed reactor system under conditions that are typical for swimming pool water treatment. The N2 yields remained constant with on-going exposure of the GAC to Monochloramine and ranged from 0.5% to 21.3%, depending on the type of GAC used. Correlation analyses were conducted to identify carbon properties that can determine the N2 yield for Monochloramine conversion, such as the amount of oxygen groups, the elemental composition and the trace metal content. It was found that the N2 yield significantly correlates with the copper content of the tested carbons. Model calculations combining pool hydraulics with formation/abatement of inorganic chloramines and NDMA as well as chloramine transformations in GAC filters showed that the concentration of inorganic chloramines and carcinogenic NDMA can be decreased by a factor of ∼2, if the tested GACs could be modified to convert up to ∼50% of the Monochloramine to N2.
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pore diffusion limits removal of Monochloramine in treatment of swimming pool water using granular activated carbon
Water Research, 2017Co-Authors: Bertram Skibinski, Christoph Gotze, Eckhard Worch, Wolfgang UhlAbstract:Overall apparent reaction rates for the removal of Monochloramine (MCA) in granular activated carbon (GAC) beds were determined using a fixed-bed reactor system and under conditions typical for swimming pool water treatment. Reaction rates dropped and quasi-stationary conditions were reached quickly. Diffusional mass transport in the pores was shown to be limiting the overall reaction rate. This was reflected consistently in the Thiele modulus, in the effect of temperature, pore size distribution and of grain size on the reaction rates. Pores <2.5 times the diameter of the Monochloramine molecule were shown to be barely accessible for the Monochloramine conversion reaction. GACs with a significant proportion of large mesopores were found to have the highest overall reactivity for Monochloramine removal.
Benito J. Mariñas - One of the best experts on this subject based on the ideXlab platform.
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Inactivation Kinetics and Replication Cycle Inhibition of Adenovirus by Monochloramine
Environmental Science & Technology Letters, 2016Co-Authors: Aimee M. Gall, Joanna L. Shisler, Benito J. MariñasAbstract:Monochloramine is commonly used as a secondary disinfectant to maintain a residual in drinking water distribution systems in the United States. The mechanism by which waterborne viruses become inactivated by Monochloramine remains widely unknown. A more fundamental understanding of how viruses become inactivated is necessary for better detection and control of viruses in drinking water. Human adenovirus (HAdV) is known to be the waterborne virus most resistant to Monochloramine disinfection, and this study presents inactivation kinetics over a range of environmental conditions. Several steps in the HAdV replication cycle were investigated to determine which steps become inhibited by Monochloramine disinfection. Interestingly, Monochloramine-inactivated HAdV could bind to host cells, but genome replication and early and late mRNA transcription were inhibited. We conclude that Monochloramine exposure inhibited a replication cycle event after binding but prior to early viral protein synthesis.
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effect of exposure to uv c irradiation and Monochloramine on adenovirus serotype 2 early protein expression and dna replication
Applied and Environmental Microbiology, 2008Co-Authors: Kwanrawee Sirikanchana, Joanna L. Shisler, Benito J. MariñasAbstract:The mechanisms of adenovirus serotype 2 inactivation with either UV light (with a narrow emission spectrum centered at 254 nm) or Monochloramine were investigated by assessing the potential inhibition of two key steps of the adenovirus life cycle, namely, E1A protein synthesis and viral genomic replication. E1A early protein synthesis was assayed by using immunoblotting, while the replication of viral DNA was analyzed by using slot blotting. Disinfection experiments were performed in phosphate buffer solutions at pH 8 and room temperature (UV) or 20°C (Monochloramine). Experimental results revealed that normalized E1A levels at 12 h postinfection (p.i.) were statistically the same as the corresponding decrease in survival ratio for both UV and Monochloramine disinfection. Normalized DNA levels at 24 h p.i. were also found to be statistically the same as the corresponding decrease in survival ratio for Monochloramine disinfection. In contrast, for UV disinfection, genomic DNA levels were much lower than E1A or survival ratios, possibly as a result of a delay in DNA replication for UV-treated virions compared to that for controls. Future efforts will determine the pre-E1A synthesis step in the adenovirus life cycle affected by exposure to UV and Monochloramine, with the goal of identifying the viral molecular target of these two disinfectants.
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Inactivation of Bacillus subtilis spores with ozone and Monochloramine
Water Research, 2003Co-Authors: Matthew A. Larson, Benito J. MariñasAbstract: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°C for ozone, 1–20°C for Monochloramine). The corresponding activation energies were 46,820 J/mol for ozone and 79,640 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 Cl2 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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synergy in sequential inactivation of cryptosporidium parvum with ozone free chlorine and ozone Monochloramine
Water Research, 2000Co-Authors: Jason L Rennecker, Amy M Driedger, S A Rubin, Benito J. MariñasAbstract:Abstract The main objective of this study was to investigate the inactivation kinetics of Cryptosporidium parvum oocysts with sequential disinfection schemes involving ozone as a primary disinfectant, and free chlorine or Monochloramine as a secondary disinfectant. Two types of synergistic effects were observed. Ozone pre-treatment resulted in the removal of the relatively more pronounced initial lag phases observed for Monochloramine and hypochlorous acid. An additional and more important synergistic effect was an enhancement in the rate of secondary inactivation with both hypochlorous acid and Monochloramine after complete removal of the lag phase by ozone pre-treatment. A stronger synergy was observed at a lower temperature. The secondary inactivation rate was 1.1–2.8 (hypochlorous acid) and 2.4–9.2 (Monochloramine) times faster than the corresponding post lag-phase primary inactivation rate at respective temperatures of 30–10°C. Consistency between the two viability assessment methods, modified in-vitro excystation and animal infectivity, was demonstrated or shown for both primary inactivation with ozone and secondary inactivation with ozone/Monochloramine.
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Synergy in sequential inactivation of Cryptosporidium parvum with ozone/free chlorine and ozone/Monochloramine
Water Research, 2000Co-Authors: Jason L Rennecker, Amy M Driedger, S A Rubin, Benito J. MariñasAbstract:Abstract The main objective of this study was to investigate the inactivation kinetics of Cryptosporidium parvum oocysts with sequential disinfection schemes involving ozone as a primary disinfectant, and free chlorine or Monochloramine as a secondary disinfectant. Two types of synergistic effects were observed. Ozone pre-treatment resulted in the removal of the relatively more pronounced initial lag phases observed for Monochloramine and hypochlorous acid. An additional and more important synergistic effect was an enhancement in the rate of secondary inactivation with both hypochlorous acid and Monochloramine after complete removal of the lag phase by ozone pre-treatment. A stronger synergy was observed at a lower temperature. The secondary inactivation rate was 1.1–2.8 (hypochlorous acid) and 2.4–9.2 (Monochloramine) times faster than the corresponding post lag-phase primary inactivation rate at respective temperatures of 30–10°C. Consistency between the two viability assessment methods, modified in-vitro excystation and animal infectivity, was demonstrated or shown for both primary inactivation with ozone and secondary inactivation with ozone/Monochloramine.
Frank Sacher - One of the best experts on this subject based on the ideXlab platform.
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selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography tandem mass spectrometry analysis
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.
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Selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography/tandem mass spectrometry analysis.
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.
Aziz Kinani - One of the best experts on this subject based on the ideXlab platform.
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selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography tandem mass spectrometry analysis
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.
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Selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography/tandem mass spectrometry analysis.
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.
Said Kinani - One of the best experts on this subject based on the ideXlab platform.
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Tracking Monochloramine Decomposition in MIMS Analysis.
Sensors, 2019Co-Authors: Adrien Roumiguières, Said Kinani, Stéphane BouchonnetAbstract:Membrane-introduction mass spectrometry (MIMS) has been presented as one of the promising approaches for online and real-time analysis of Monochloramine (NH2Cl) in diverse matrices such as air, human breath, and aqueous matrices. Selective pervaporation of NH2Cl through the introduction membrane overcomes the need for sample preparation steps. However, both the selectivity and sensitivity of MIMS can be affected by isobaric interferences, as reported by several researchers. High-resolution mass spectrometry helps to overcome those interferences. Recent miniaturization of Fourier transform—ion cyclotron resonance—mass spectrometry (FT-ICR MS) technology coupled to the membrane-introduction system provides a potent tool for in field analysis of Monochloramine in environmental matrices. Monochloramine analysis by MIMS based FT-ICR MS system demonstrated decomposition into ammonia. To further clarify the origin of this decomposition, headspace analyses after bypassing the membrane were undertaken and showed that Monochloramine decomposition was not exclusively related to interactions within the membrane. Adsorption inside the MIMS device, followed by surface-catalyzed decomposition, was suggested as a plausible additional mechanism of Monochloramine decomposition to ammonia.
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selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography tandem mass spectrometry analysis
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.
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Selective and trace determination of Monochloramine in river water by chemical derivatization and liquid chromatography/tandem mass spectrometry analysis.
Talanta, 2015Co-Authors: Said Kinani, Stéphane Bouchonnet, Stephany Layousse, Bertille Richard, Aziz Kinani, Astrid Thoma, Frank SacherAbstract:Abstract Monochloramine (MCA) may enter the aquatic environment through three main sources: wastewater treatment plant effluents, industrial effluents and thermal power plant wastes. Up to date, there are no available data about the concentration levels of this chemical in river water due to lack of appropriate analytical methods. Therefore, sensitive and selective analytical methods for Monochloramine analysis in river water are required to evaluate its environmental fate and its effects on aquatic ecosystems. Thus, in this study we describe a highly specific and sensitive method for Monochloramine determination in river water. This method combines chemical derivatization of Monochloramine into indophenol followed by liquid chromatography coupled to electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis. Two precursor-to-product ion transitions were monitored (200→127 and 200→154) in positive ionisation mode, fulfilling the criteria of selectivity, in accordance with the European Legislation requirements (decision 2002/657/EC). Ion structures and fragmentation mechanisms have been proposed to explain the selected transitions. Linearity range, accuracy and precision of the method have been assessed according to the French method validation standard NF T90-210. Detecting the derivatized Monochloramine (indophenol) in Multiple Reaction Monitoring (MRM) mode provided a limit of quantification of 40 ng L −1 equivalent Monochloramine. Applied to Loire river water (France), the developed method occasionally detected Monochloramine at concentrations less than 300 ng L −1 , which could be explained by punctual discharges of water containing active chlorine upstream of the sampling point. Indeed, it is widely reported in the literature that the addition of chlorine to water containing ammonia (e.g., wastewater effluents and river water) may result in the instantaneous formation of Monochloramine. The proposed method is a powerful tool that can be used in environmental research (e.g., assessment of environmental fate and generating of ecotoxicological data) as well as in research studies concerning the evaluation of water disinfection efficiency; but it is not currently appropriate for routine use in industrial applications given the complexity of the procedure, the instability of indophenol and the use of certain toxic reagents.