Reaction scheme for the chlorination of ammoniacal water

Jafvert, Chad T.; Valentine, Richard L.

doi:10.1021/es00027a022

Cited by 386 publications

(341 citation statements)

References 14 publications

(30 reference statements)

Supporting

Mentioning

323

Contrasting

Order By: Relevance

“…Under our experimental conditions (pH 8.0, 25°C, 4:1 Cl 2 :N mass ratio, 10 mM phosphate concentration, and 5, 10, and 20 mg Cl 2 /liter total chlorine), monochloramine was the dominant species. This was confirmed by experimental measurements and further supported by implementation of a monochloramine autodecomposition model (20,51) in the computer program AQUASIM (EAWAG, Dübendorf, Switzerland) (39). Under the modeled experimental conditions, monochloramine comprised Ͼ99% of the total chlorine present.…”

Section: Methodssupporting

confidence: 60%

Monochloramine Disinfection Kinetics of Nitrosomonas europaea by Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

Wahman

Wulfeck-Kleier

Pressman

2009

Appl Environ Microbiol

View full text Add to dashboard Cite

Monochloramine disinfection kinetics were determined for the pure-culture ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) by two culture-independent methods, namely, Live/Dead BacLight (LD) and propidium monoazide quantitative PCR (PMA-qPCR). Both methods were first verified with mixtures of heat-killed (nonviable) and non-heat-killed (viable) cells before a series of batch disinfection experiments with stationary-phase cultures (batch grown for 7 days) at pH 8.0, 25°C, and 5, 10, and 20 mg Cl 2 /liter monochloramine. Two data sets were generated based on the viability method used, either (i) LD or (ii) PMA-qPCR. These two data sets were used to estimate kinetic parameters for the delayed Chick-Watson disinfection model through a Bayesian analysis implemented in WinBUGS. This analysis provided parameter estimates of 490 mg Cl 2 -min/liter for the lag coefficient (b) and 1.6 ؋ 10 ؊3 to 4.0 ؋ 10 ؊3 liter/mg Cl 2 -min for the Chick-Watson disinfection rate constant (k). While estimates of b were similar for both data sets, the LD data set resulted in a greater k estimate than that obtained with the PMA-qPCR data set, implying that the PMA-qPCR viability measure was more conservative than LD. For N. europaea, the lag phase was not previously reported for culture-independent methods and may have implications for nitrification in drinking water distribution systems. This is the first published application of a PMA-qPCR method for disinfection kinetic model parameter estimation as well as its application to N. europaea or monochloramine. Ultimately, this PMA-qPCR method will allow evaluation of monochloramine disinfection kinetics for mixed-culture bacteria in drinking water distribution systems.As a result of stage 1 and stage 2 disinfectant and disinfection by-product rules, chloramination for secondary disinfection in the United States is predicted to increase to 57% of all surface and 7% of all groundwater treatment systems (49). A recent survey reported that 30% of the respondents currently chloraminate to maintain distribution system residual, and other recent surveys suggest that between 8 and 12% of drinking water utilities are contemplating a future switch to chloramination (3, 43).Although chloramines are considered weaker disinfectants than chlorine for suspended bacteria, chloramines are perceived as more effective disinfectants for a biofilm (25, 53). As a result of their lower reactivity, chloramines are believed to penetrate a biofilm further and thereby to more effectively disinfect biofilm bacteria with depth than chlorine (53).Chloramination comes with the risk of distribution system nitrification (2, 21, 22). Based on utility surveys, 30 to 63% of utilities practicing chloramination for secondary disinfection experience nitrification episodes (3,21,43,54). Nitrification in drinking water distribution systems is undesirable and may result in water quality degradation (e.g., disinfectant depletion, coliform occurrences, or nitrite/nitrate formation) and subsequent noncompliance with exis...

show abstract

Section: Methodssupporting

confidence: 60%

Monochloramine Disinfection Kinetics of Nitrosomonas europaea by Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

Wahman

Wulfeck-Kleier

Pressman

2009

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…S2, SI). The 220 decay of monochloramine was always caused by its autodecomposition since no significant 221 variations were observed between all the experiments, and the experimental values fitted well with 222 the autodecomposition model reported by Jafvert and Valentine (1992). 223…”

Section: Kinetics Of Dbp Formation 217supporting

confidence: 63%

The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter

2016

View full text Add to dashboard Cite

Please cite this article as: Le Roux, J., Nihemaiti, M., Croué, J.-P., The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter, Water Research (2015), doi: 10.1016/j.watres.2015.10.036. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

show abstract

“…The inclusion of 1 mM PB provided a decreased ionic strength to span that of typical drinking water (i.e., less than 12.5 meq/liter, based on the secondary maximum contaminant level for total dissolved solids of 500 mg/liter and the Langelier correlation [24]) and an additional phosphate concentration. For monochloramine, phosphate concentration may be important because monochloramine disproportionation increases with increasing phosphate concentration through general acid catalysis (13,25). If the disinfection mechanism is general acid catalyzed or related to products from monochloramine disproportionation (e.g., dichloramine), the disinfection rate may also increase with increasing phosphate concentration.…”

mentioning

confidence: 99%

Determination of the Effects of Medium Composition on the Monochloramine Disinfection Kinetics of Nitrosomonas europaea by the Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

Wahman

Schrantz

Pressman

2010

Appl Environ Microbiol

View full text Add to dashboard Cite

Previous research has shown that water quality and ionic environment affect disinfection kinetics (see, e.g., references 1, 2, 6, 7, 8, 9, 10, and 21). As a first step in exploring possible medium effects on disinfection kinetics, as determined using two culture-independent methods, Live/Dead BacLight (LD) and propidium monoazide quantitative PCR (PMA-qPCR), batch disinfection experiments were conducted with three different phosphate buffer media (PB) (1, 10, and 50 mM Na 2 HPO 4 , pH 8.0) to compare our results with previous research that used 10 mM phosphate-buffered saline (PBS) (10 mM Na 2 HPO 4 and 130 mM NaCl, pH 8) (27) and to serve as a baseline for future experiments with finished drinking water. Ten millimolar PB, 50 mM PB, and 10 mM PBS represent media commonly used in disinfection experiments (see, e.g., references 18, 20, and 22). The inclusion of 1 mM PB provided a decreased ionic strength to span that of typical drinking water (i.e., less than 12.5 meq/liter, based on the secondary maximum contaminant level for total dissolved solids of 500 mg/liter and the Langelier correlation [24]) and an additional phosphate concentration. For monochloramine, phosphate concentration may be important because monochloramine disproportionation increases with increasing phosphate concentration through general acid catalysis (13,25). If the disinfection mechanism is general acid catalyzed or related to products from monochloramine disproportionation (e.g., dichloramine), the disinfection rate may also increase with increasing phosphate concentration. The experimental results were interpreted based on medium differences in ionic strength and phosphate concentration.Nitrosomonas europaea (ATCC 19718; ATCC, Manassas, VA) bacteria were batch grown (25 to 28°C) to stationary phase (7 days) and then harvested and washed in the same medium used in the batch disinfection experiments as described previously (27). N. europaea was studied because of its use in previous monochloramine disinfection research (27). Batch disinfection experiments were conducted at least in duplicate at pH 8.0 and 25°C as described previously (27), except that the medium was varied as either 1, 10, or 50 mM PB, and for all experiments, a single 5-mg Cl 2 /liter monochloramine concentration was used. Preformed monochloramine solutions were prepared by the addition of (NH 4 ) 2 SO 4 and NaOCl at a 4:1 (Cl 2 -N) mass ratio. During batch disinfection experiments, viable and nonviable bacteria were quantified with two cultureindependent methods described previously (27): (i) with Live/ Dead BacLight kit L7012 (Invitrogen, Carlsbad, CA) and (ii) by PMA-qPCR, where samples were subjected to PMA treatment according to Nocker et al. (16). Genomic DNA was extracted using the DNeasy blood and tissue kit (Qiagen, Valencia, CA) and quantified by the qPCR method of Regan et al. (19). pH and total ammonia were measured on a model 250 pH/ion-selective electrode (ISE)/conductivity meter with a pH electrode and ammonia ion-selective electrode (Denver Instrument, De...

show abstract

Reaction scheme for the chlorination of ammoniacal water

Cited by 386 publications

References 14 publications

Monochloramine Disinfection Kinetics of Nitrosomonas europaea by Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

Monochloramine Disinfection Kinetics of Nitrosomonas europaea by Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

The role of aromatic precursors in the formation of haloacetamides by chloramination of dissolved organic matter

Determination of the Effects of Medium Composition on the Monochloramine Disinfection Kinetics of Nitrosomonas europaea by the Propidium Monoazide Quantitative PCR and Live/Dead BacLight Methods

Contact Info

Product

Resources

About