Evaluating bacterial aerobic spores as a surrogate for Giardia and Cryptosporidium inactivation by ozone

Facile, Nathalie; Barbeau, Benoît; Prévost, Michèle; Koudjonou, Boniface

doi:10.1016/s0043-1354(00)00086-5

Cited by 89 publications

(41 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One other advantage of hypochlorite is that while it may compare well with the efficiency of ozone and chlorine dioxide it does not produce bromate like ozone. However, it may be less effective against Cryptosporidium parvum and Giardia lamblia (Facile et al, 2000). Several studies have reported varying efficiency of hypochlorite against bacteria, viruses and fungi (Barbeau et al, 2006) and others have been conducted to evaluate the impact of water quality on chlorine chemistry and disinfection efficacy (Barbeau et al, 2004) but none has reported acquired microbial resistance to it.…”

mentioning

confidence: 99%

Evaluation of <i>Escherichia coli</i> as indicator of point-of-use chlorination efficiency of drinking water

Adebisi¹,

Ifeyinwa²,

Akinsolu³

et al. 2017

Journal of Applied Sciences and Environmental Management

View full text Add to dashboard Cite

ABSTRACT:In this study, the relevance of the presence of Escherichia coli in drinking water as an indicator of point-of-use chlorination efficiency is examined. The survival of clinical isolates of human enteric pathogenic bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae, Staphylococcus aureus, Streptococcus faecalis and Vibrio cholerae) as well as E. coli was monitored as a function of effective germicidal concentration and contact time. The inactivation kinetics indicated that the minimum effective dose for three-log units (99.9%) inactivation of E. coli (C·T99.9% = 10 mgl -1 -min) can sufficiently eliminate the other pathogens (C·T99.9% ranged from 5.6-10.5 mgl -1 -min); the exception being K. pneumoniae, which required more than 1.4-times higher dose. In general, the results implied that the branded hypochlorite solution should effectively inactivate almost all vegetative bacteria in household drinking water at the manufacturer's recommended dosage of 0.5 mgl -1 after at least 30 minutes contact time. The application of point-of-use chemical disinfectants to drinking water in households will significantly reduce the incidence of water-borne infections particularly in rural communities where central treatment of water is mostly unavailable. © JASEM http://dx.doi.org/10.4314/jasem.v20i4.7

show abstract

mentioning

confidence: 99%

Evaluation of <i>Escherichia coli</i> as indicator of point-of-use chlorination efficiency of drinking water

Adebisi¹,

Ifeyinwa²,

Akinsolu³

et al. 2017

Journal of Applied Sciences and Environmental Management

View full text Add to dashboard Cite

show abstract

“…Many studies on ozone disinfection have focused on the effects of ozone on various microorganisms and the factors affecting the inactivation of these microorganisms such as pH, temperature, contact time, ozone dose, and ozone demand (1,6,9,19). Among the factors, the role of pH in inactivating microorganisms is not well understood and is somewhat controversial (2,5,12,19,25). No pH requirement for inactivation of microroganisms or fast inactivation by low pH has been reported without much discussion of the exact duration of exposure to ozone or the coexistence of hydroxyl radicals.…”

mentioning

confidence: 99%

Disinfection of Water Containing Natural Organic Matter by Using Ozone-Initiated Radical Reactions

Cho

Chung

Yoon

2003

Appl Environ Microbiol

168

View full text Add to dashboard Cite

Ozone is widely used to disinfect drinking water and wastewater due to its strong biocidal oxidizing properties. Recently, it was reported that hydroxyl radicals ( ⅐ OH), resulting from ozone decomposition, play a significant role in microbial inactivation when Bacillus subtilis endospores were used as the test microorganisms in pH controlled distilled water. However, it is not yet known how natural organic matter (NOM), which is ubiquitous in sources of drinking water, affects this process of disinfection by ozone-initiated radical reactions. Two types of water matrix were considered for this study. One is water containing humic acid, which is commercially available. The other is water from the Han River. This study reported that hydroxyl radicals, initiated by the ozone chain reaction, were significantly effective at B. subtilis endospore inactivation in water containing NOM, as well as in pH-controlled distilled water. The type of NOM and the pH have a considerable effect on the percentage of disinfection by hydroxyl radicals, which ranged from 20 to 50%. In addition, the theoretical C T value of hydroxyl radicals for 2-log B. subtilis removal was estimated to be about 2.4 ؋ 10 4 times smaller than that of ozone, assuming that there is no synergistic activity between ozone and hydroxyl radicals.Ozone is widely used to disinfect drinking water and wastewater due to its strong biocidal oxidizing properties. Many studies on ozone disinfection have focused on the effects of ozone on various microorganisms and the factors affecting the inactivation of these microorganisms such as pH, temperature, contact time, ozone dose, and ozone demand (1,6,9,19). Among the factors, the role of pH in inactivating microorganisms is not well understood and is somewhat controversial (2,5,12,19,25). No pH requirement for inactivation of microroganisms or fast inactivation by low pH has been reported without much discussion of the exact duration of exposure to ozone or the coexistence of hydroxyl radicals. This is partly due to the limited approaches used which considered mainly the biocidal activity of molecular ozone (5, 11, 12) rather than the indirect effect of hydroxyl radicals resulting from ozone decomposition. On the other hand, several studies did emphasize the importance of hydroxyl radicals in microorganism inactivation (1, 3). Recently, Cho et al. (2) reported that under certain experimental conditions, the presence of hydroxyl radicals produced by ozone disinfection plays a significant role in the inactivation of Bacillus subtilis endospores in pH-controlled ozone-demand-free distilled water. In their study, the observed C T values for achieving a 2-log inactivation were 40% lower at pH 8.2 than at pH 5.6 when time-dependent ozone decay as a function of the reaction time was considered in relation to the pH difference. However, in the presence of excess hydroxyl radical scavengers (t-butanol), where it is difficult for hydroxyl radical to exist, all the observed C T values achieved parity, within a 10% margin of error, ...

show abstract

“…Ozonation destroys the cell wall of the bacteria as well as semi-permeable membrane. The destruction in the cell wall and membrane leads to the bacterial cell death (Facile et al 2000). Tripathi et al (2011) claimed that 5 min of exposure at a concentration of 10 mg ozone L −1 was suitable for the inactivation of pathogenic bacteria by 95-98%.…”

Section: Ozonationmentioning

confidence: 99%

Removal of pathogenic bacteria from sewage-treated effluent and biosolids for agricultural purposes

et al. 2018

View full text Add to dashboard Cite

The reuse of treated sewage for irrigation is considered as an important alternative water source in the new water management strategy of the countries that face a severe deficiency of water resources such as the Middle East countries. The organic material and fertilizing elements contained in biosolids are essential for maintaining soil fertility. However, both treated sewage and biosolids contain a large diversity of pathogens that would be transmitted to the environment and infect human directly or indirectly. Therefore, those pathogens should be reduced from the treated sewage and biosolids before the reuse in the agriculture. This paper reviews the considerations for reuse of treated sewage and biosolids in agriculture and further treatments used for reduction of pathogenic bacteria. The treatment methods used for the reduction of pathogens in these wastes have reviewed. It appeared that the main concern associated with the reduction of pathogenic bacteria lies in their ability to regrow in the treated sewage and biosolids. Therefore, the effective treatment method is that it has the potential to destruct pathogens cells and remove the nutrients to prevent the regrowth or recontamination from the surrounded environment. The removal of nutrients might be applicable in the sewage but not in the biosolids due to high nutrient contents. However, the reduction of health risk in the biosolids might be carried out by regulating the biosolid utilization and selecting the plant species grown in the fertilized soil with biosolids.

show abstract

Evaluating bacterial aerobic spores as a surrogate for Giardia and Cryptosporidium inactivation by ozone

Cited by 89 publications

References 26 publications

Evaluation of <i>Escherichia coli</i> as indicator of point-of-use chlorination efficiency of drinking water

Evaluation of <i>Escherichia coli</i> as indicator of point-of-use chlorination efficiency of drinking water

Disinfection of Water Containing Natural Organic Matter by Using Ozone-Initiated Radical Reactions

Removal of pathogenic bacteria from sewage-treated effluent and biosolids for agricultural purposes

Contact Info

Product

Resources

About