Effect of dissolved oxygen on the photodecomposition of monochloramine and dichloramine in aqueous solution by UV irradiation at 253.7 nm

Laat, J. De; Boudiaf, Nicolas; Dossier-Berne, Florence

doi:10.1016/j.watres.2010.03.009

Cited by 81 publications

(73 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Pseudo first-order rate constants for NDMA photolysis showed no significant dependence on the initial concentration (5 and 25 mM). The measured NH 2 Cl quantum yields (0.38 AE 0.1 mol E À1 ) were in agreement with previously reported values (0.26e0.62 mol E À1 ) (Cooper et al, 2007;Watts and Linden, 2007;Li and Blatchley, 2009;De Laat et al, 2010;Williams et al, 2011). Li and Blatchley (2009) explained the variation in measured quantum yield by the varying excess of ammonia in the NH 2 Cl production.…”

Section: 5supporting

confidence: 92%

“…The breakage of the NeCl bond is assumed to be the initial step in NH 2 Cl photolysis (Li and Blatchley, 2009;De Laat et al, 2010). The similar nature of the NeCl bond in CDMA and the similar absorption spectrum of CDMA suggest an analogous behaviour.…”

Section: Uv-induced Ndma Formation Pathway In Chloraminated Watermentioning

confidence: 99%

“…DMA and nitrite) is not problematic since the NDMA yield from these substances is very low (0.2% after 24 h in the presence of free chlorine) (Sharpless and Linden, 2003;Xu et al, 2009a). Nevertheless, photolysis of chloramines leads to a number of reactive nitrogen species such as aminyl radicals, nitric oxide, peroxynitrite, and nitrite (Scheme 2) which may lead to N-nitrosamines in combination with secondary amines (Lobachev and Rudakov, 2006;Li and Blatchley, 2009;De Laat et al, 2010). Nitric oxide can react to peroxynitrite in the presence of superoxide ( O 2 À ) (Scheme 2, Eq.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhanced N-nitrosamine formation in pool water by UV irradiation of chlorinated secondary amines in the presence of monochloramine

et al. 2013

View full text Add to dashboard Cite

Section: 5supporting

confidence: 92%

Section: Uv-induced Ndma Formation Pathway In Chloraminated Watermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enhanced N-nitrosamine formation in pool water by UV irradiation of chlorinated secondary amines in the presence of monochloramine

et al. 2013

View full text Add to dashboard Cite

“…In order to confirm the MNZ degradation by the radical oxidation mechanism, tert-butanol was added to the COP [34][35][36][37], which resulted in the efficiency. This illustrates that MNZ degradation followed the radical oxidation mechanism.…”

Section: Effect Of Initial Phmentioning

confidence: 99%

Heterogeneous catalytic ozonation by Nano-MgO is better than sole ozonation for metronidazole degradation, toxicity reduction, and biodegradability improvement

Kermani

Asl

Farzadkia

et al. 2016

Desalination and Water Treatment

View full text Add to dashboard Cite

2015): Heterogeneous catalytic ozonation by Nano-MgO is better than sole ozonation for metronidazole degradation, toxicity reduction, and biodegradability improvement, Desalination and Water Treatment, In the current paper, the removal efficiency of metronidazole (MNZ) using a catalytic ozonation process (COP) in the presence of magnesium oxide nanocrystals, as a catalyst, was investigated in deionized water and compared with a sole ozonation process (SOP). The influence of several operational factors on both removal processes was evaluated: solution pH, MgO dosage, initial MNZ concentration, and reaction time. Biodegradability improvement, mineralization rate, oxidation intermediates, and toxicity were also studied for the COP. The results showed that MgO nanocrystals accelerated MNZ removal compared to the SOP. The optimum pH for both SOP and COP was obtained at 10 and optimum MgO dosage for the COP was determined 0.25 g/L. Under optimum conditions, after 20 min and 35 min, the complete removal of 40 mg/L MNZ solution occurred in COP and SOP, respectively. The COP significantly increased the biological oxygen demand/chemical oxygen demand ratio (from 0.09 to 0.43), caused 93.5% MNZ mineralization, and reduced the toxicity of the MNZ.

show abstract

“…The subsequent reaction of HO • with monochloramine occurs quickly, k = 5.2 × 10 9 M −1 s −1 , (Poskrebyshev et al, 2003), and this radical scavenging pathway could significantly impact the efficiency of the AOP in removing residual chemical contaminants. Photolytic decomposition (Cooper et al, 2007; Watts and Linden, 2007; De Latt et al, 2010; Li and Blatchley, 2009) of these chloramines would also impact the overall AOP efficiency.…”

Section: Introductionmentioning

confidence: 99%

Kinetic study of the reactions between chloramine disinfectants and hydrogen peroxide: Temperature dependence and reaction mechanism

McKay¹,

Sjelin²,

Chagnon³

et al. 2013

Chemosphere

View full text Add to dashboard Cite

The temperature-dependent kinetics for the reaction between hydrogen peroxide and chloramine water disinfectants (NH2Cl, NHCl2, and NCl3) have been determined using stopped flow-UV/Vis spectrophotometry. Rate constants for the mono- and dichloramine–peroxide reaction were on the order of 10−2 M−1 s−1 and 10−5 M−1 s−1, respectively. The reaction of trichloramine with peroxide was negligibly slow compared to its thermal and photolytically-induced decomposition. Arrhenius expressions of ln(kH2O2–NH2Cl) = (17.3 ± 1.5)–(51500 ± 3700)/RT and ln(kH2O2–NHCl2) = (18.2 ± 1.9)–(75800 ± 5100)/RT were obtained for the mono- and dichloramine peroxide reaction over the temperature ranges 11.4–37.9 and 35.0–55.0 °C, respectively. Both monochloramine and hydrogen peroxide were first-order in the rate-limiting kinetic step and concomitant measurements made using a chloride ion selective electrode showed that the chloride was produced quantitatively. These data will aid water utilities in predicting chloramine concentrations (and thus disinfection potential) throughout the water distribution system.

show abstract

Effect of dissolved oxygen on the photodecomposition of monochloramine and dichloramine in aqueous solution by UV irradiation at 253.7 nm

Cited by 81 publications

References 31 publications

Enhanced N-nitrosamine formation in pool water by UV irradiation of chlorinated secondary amines in the presence of monochloramine

Enhanced N-nitrosamine formation in pool water by UV irradiation of chlorinated secondary amines in the presence of monochloramine

Heterogeneous catalytic ozonation by Nano-MgO is better than sole ozonation for metronidazole degradation, toxicity reduction, and biodegradability improvement

Kinetic study of the reactions between chloramine disinfectants and hydrogen peroxide: Temperature dependence and reaction mechanism

Contact Info

Product

Resources

About