Synergy in sequential inactivation of Cryptosporidium parvum with ozone/free chlorine and ozone/monochloramine

Rennecker, Jason L.; Driedger, A.; Rubin, Sara A.; Mariñas, Benito J.

doi:10.1016/s0043-1354(00)00188-3

Cited by 82 publications

(53 citation statements)

References 10 publications

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“…An interesting strategy proposed relatively recently to improve chemical disinfection is the use of sequential disinfection (Corona-Vasquez et aL 2002). It has been suggested that the application of ozone followed by free chlorine, hypochlorous acid, or chloramines, significantly increases the inactivation rate of Cryptosporidium parvum oocysts (Driedger et al , 2001Rennecker et al 2000). The high efficiency demonstrated by sequential disinfection using the ozone-chlorine pair could be related to the generation of different reactive oxygen species (i.e.…”

Section: Introductionmentioning

confidence: 99%

Inactivation of Ascaris eggs in water using sequential solar driven photo-Fenton and free chlorine

Bandala

Pampillón-González

Sánchez-Salas

et al. 2011

Journal of Water and Health

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Sequential helminth egg inactivation using a solar driven advanced oxidation process (AOP) followed by chlorine was achieved. The photo-assisted Fenton process was tested alone under different H(2)O(2) and/or Fe(II) concentrations to assess its ability to inactivate Ascaris suum eggs. The effect of free chlorine alone was also tested. The lowest egg inactivation results were found using Fe(II) or H(2)O(2) separately (5 and 140 mmol L(-1), respectively) in dark conditions, which showed about 28% inactivation of helminth eggs. By combining Fe(II) and H(2)O(2) at the same concentrations described earlier, 55% of helminth egg inactivation was achieved. By increasing the reagent's concentration two-fold, 83% egg inactivation was achieved after 120 min of reaction time. Process efficiency was enhanced by solar excitation. Using solar disinfection only, the A. suum eggs inactivation reached was the lowest observed (58% egg inactivation after 120 min (120 kJ L(-1))), compared with tests using the photo-Fenton process. The use of the photo-Fenton reaction enhanced the process up to over 99% of egg inactivation after 120 kJ L(-1) when the highest Fe(II) and H(2)O(2) concentration was tested. Practically no effect on the helminth eggs was observed with free chlorine alone after 550 mg min L(-1) was used. Egg inactivation in the range of 25-30% was obtained for sequential processes (AOP then chlorine) using about 150 mg min L(-1).

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Section: Introductionmentioning

confidence: 99%

Inactivation of Ascaris eggs in water using sequential solar driven photo-Fenton and free chlorine

Bandala

Pampillón-González

Sánchez-Salas

et al. 2011

Journal of Water and Health

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“…A combination of O 3 and ClO 2 could successfully control some microorganisms, which could not be removed with the separate use of both disinfectants (Rennecker et al 2000). Therefore, a recent interest is dedicated for the processes that produce a mixture of disinfectants, which further react together to produce the hydroxyl radical.…”

Section: Introductionmentioning

confidence: 99%

Electroanalysis of a Ternary Disinfectant Mixture

2012

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The analysis of a ternary mixture containing ozone (O 3 ), sodium hypochlorite (NaClO), and hydrogen peroxide (H 2 O 2 ), in their coexistence was simultaneously performed using a potentiometric method. In this method, the change in the open circuit potential of a Pt indicator electrode dipped in a potential buffer containing I À /I À 3 upon the addition of the ternary mixture is measured. The analysis was based on the different reaction kinetics of the three oxidants with I À . The kinetics of the reaction of O 3 and I À is about three orders of magnitude faster than that of sodium hypochlorite, and the reaction of hydrogen peroxide and I À is negligible compared with those of O 3 or hypochlorite ion and I À unless a molybdate catalyst is added. Several factors, including the iodide concentration, pH, and the molybdate concentration were investigated to optimize the analysis and achieve a reasonable separation among the reactions of the three oxidants and I À . A theoretical model was developed to compare with the experimental results and a reasonable correlation was obtained.

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“…In recent years, the use of combined or sequential disinfection has been explored (e.g., Pennell et al, 2008;Jung et al, 2008;Dow et al, 2006;Rennecker et al, 2000). The application of disinfectants in combination offers the potential to expand the scope of antimicrobial activity, and may also yield additive or synergistic effects.…”

Section: Introductionmentioning

confidence: 99%

Application of Ozone and UV<SUB>254</SUB> Radiation for Effluent Disinfection at Municipal Wastewater Treatment Facilities

Blatchley¹,

Weng²,

Afifi³

et al. 2011

proc water environ fed

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Chlorination/dechlorination is the most commonly applied form of disinfection for municipal wastewaters; however, important drawbacks to chlorine-based disinfection processes have been identified. The most common alternatives to chlorination/dechlorination are ozonation and UV irradiation.The City of Indianapolis is considering a switch from their existing chlorination/dechlorination operations to ozonation, UV irradiation, or a combination of these processes at their Belmont and Southport Wastewater Treatment Facilities. To examine the feasibility of these disinfection process alternatives, bench-scale experiments were conducted with effluent samples from each facility. The results of these experiments demonstrated that effluents from these facilities have high ozone demand, which promotes efficient transfer of ozone, but diminishes its disinfection efficacy. On the other hand, UV 254 irradiation yielded consistent compliance with effluent discharge permit limitations at UV 254 doses of 15-20 mJ/cm 2 , depending on pre-ozonation dose. No evidence of synergism between O 3 and UV 254 radiation was found in the measured inactivation responses of E. coli among the effluent samples from Belmont and Southport. The antimicrobial effects of these two disinfectants appeared to be additive for the range of disinfectant exposure conditions used in these experiments.The nature of the data sets collected in these studies is such that variability in several fundamental properties of the effluent samples could be defined. These data sets form the foundation of a new design protocol for UV systems, which is based on a stochastic approach, and that incorporates modern tools for prediction and measurement of UV process performance.This new design protocol has the potential to yield UV system designs that are not only reliable, but that also lead to process efficiency and reduced operating costs, relative to designs based on conventional protocols.

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Synergy in sequential inactivation of Cryptosporidium parvum with ozone/free chlorine and ozone/monochloramine

Cited by 82 publications

References 10 publications

Inactivation of Ascaris eggs in water using sequential solar driven photo-Fenton and free chlorine

Inactivation of Ascaris eggs in water using sequential solar driven photo-Fenton and free chlorine

Electroanalysis of a Ternary Disinfectant Mixture

Application of Ozone and UV<SUB>254</SUB> Radiation for Effluent Disinfection at Municipal Wastewater Treatment Facilities

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