|Statement||Joseph G. Jacangelo, Vincent P. Olivieri, Kazuyoshi Kawata.|
|Series||Research report / AWWA Research Foundation, Research report (AWWA Research Foundation)|
|Contributions||Olivieri, Vincent P., Kawata, Kazuyoshi.|
|LC Classifications||QR48 .J33 1987|
|The Physical Object|
|Pagination||xvii, 122 p. :|
|Number of Pages||122|
|LC Control Number||87404587|
Mechanism of Inactivation of Microorganisms by Combined Chlorine (Research report / AWWA Research Foundation) Jun 1, by Joseph G. Jacangelo, Vincent P. . " Mechanism of Inactivation of Microor-ganisms by Combined Chlorine" (catalog no. ), is available from the A WW A Research Foundation, W. Quincy Ave., Denver, CO ♦Model XVI, Sargent- Welch, Skokie, 80 RESEARCH AND TECHNOLOGY JOURNAL AWWA. This means that the inactivation of micro- organisms by free chlorine tends to be more sensitive to chlorine concentration than does the inactivation of microorganisms by combined chlorine. With tem- perature, there are no obvious trends in n values for either free or combined chlorine, and a more detailed analysis is not possible since the Cited by: coli to chlorine was Lmg −1 min −1, and the Chick model described best for the inactivation by chlorine disinfection for E. coli. Therefore, the predicted chlorine dose for 3 log inactivation of E. coli was mgmin/L, and the Ct values of M. fortuitum and M. mucogenicum were 67– times of that of E. coli.
Mechanism of disinfection The decrease in oxygen uptake of chlorine treated cell extract may be due to inhibition of enzyme(sl which catalyse the oxidation of substrate. In the present experiments succinate was used as substrate and hence the reduced oxygen uptake is partly due to inhibition of succinic dehydrogenase (Venkobachar er al.. ). Abstract. Inactivation of Microcystis aeruginosa by UV/chlorine process was investigated in this study. Chlorine decay with or without the presence of algal cells was modeled based on a kinetic model, and the second-order rate constant between chlorine and algal cells was determined to be × 10 −4 (mgC/L) −1 s −1. The relative chlorine sensitivities of bacteria isolated from chlorinated and unchlorinated drinking water distribution systems were compared by two independent methods. One method measured the toxic effect of free chlorine on bacteria, whereas the other measured the effect of combined chlorine. Chlorine and derivatives (1, 3, 6, 21, 22) Chlorine is electronegative, and therefore oxidises peptide links and denatures proteins. Hypochlorite and chloramine in water produce hypochloric acid, which then decomposes. Both chlorine and oxygen are involved, and thiol groups are oxidised.
The relationship between cell inactivation and membrane damage was studied in two gram-positive organisms, Listeria monocytogenes and Bacillus subtilis, and two gram-negative organisms, Yersinia enterocolitica and Escherichia coli, exposed to chlorine in the absence and presence of ppm of organic matter (Trypticase soy broth).L. monocytogenes and B. subtilis were more resistant to chlorine. The high oxidative power of chlorine, as well as of other oxidant biocides, causes the inactivation of metabolic enzymes and other cellular components (biocide action), leading to the death of all microorganisms within seconds or minutes from contact (Jolley, ). Similarly, the bacteria size and shape are important parameters, which might influence the inactivation of bacteria, depending on their state of growth (e.g., log phase vs stationary phase). Combination of hurdle technologies involving high-power ultrasound, such as manosonication, could offer further advantage in the use of nonthermal. Wastewater Technology Fact Sheet: Chlorine Disinfection Author: US EPA, OW, OWM, Water Permits Division Subject: Fact sheet on disinfection, one of the primary mechanisms for the inactivation or destruction of pathogenic organisms. Contains information on how to use chlorine as a disinfectant for municipal wastewater.