Chemical & Biological Dynamics

Aims: To model survival curves of Dothiorella gregaria Sacc. and Fusarium tricinctum (Corda) Sacc. spores inoculated on fresh chestnut kernel exposed to aqueous chlorine dioxide (ClO2). Methods and ...

"This paper proposes that chlorine dioxide (ClO2) should be considered as an alternative to common antibiotics. ClO2 disinfects via oxidation and is highly selective due to its one‐electron transfer mechanisms." "...indicates that ClO2 is as effective as phenol in inhibiting bacterial growth." "In part two, ClO2 was found to be less effective than peniciliin against the three opportunistic pathogens. These results may be erroneous, however..."

****!!!! "The inactivation efficiencies vary greatly among different virus species. The inactivation rates for different serotypes within a family of viruses can differ by over 284%. Generally, to achieve a 4-log removal, the exposure doses, also being referred to as Ct values (mutiplying the concentration of ClO2 and contact time) vary in the range of 0.06–10 mg L−1 min. Inactivation kinetics of viruses show two phases: an initial rapid inactivation phase followed by a tailing phase. Inactivation rates of viruses increase as pH or temperature increases, but show different trends with increasing concentrations of dissolved organic matter (DOM). Both damages in viral proteins and in the 5′ noncoding region within the genome contribute to virus inactivation upon ClO2 disinfection."

****!!!!**** 1967 {This is 1 of at least 3 papers that derived differing theories on dynamics of E. coli after chlorine dioxide treatment} "Survival data are presented for a fecal strain of Escherichia coli exposed to three concentrations of chlorine dioxide at four temperatures... Initial experiments support the thesis that the mechanism of chlorine dioxide kill occurs via disruption of protein synthesis."

1965 "We found chlorine dioxide to be a more effective disinfectant than chlorine in sewage effluent at pH 8.5. Chlorine dioxide was also found to be a more stable bactericide in relation to pH in the range studied."

The present invention provides for a stabilized solution containing a halogen containing compound which is effective as a sterilizing or disinfecting agent, and a stabilizing agent which suppresses the chemical dissociation of the halogen compound such that the sterilizing capability of the solution is maintained for extended periods of time relative to the solution without the stabilizing agent. The halogen containing compound is selected from the group consisting of chlorine dioxide, bromine oxide, bromine chloride, monochloroamine, bromic acid, iodine monochloride, iodine trichloride and iodine monobromide. The stabilizing agent is a compound having at least one accessible sulphur containing group selected from the group consisting of cyclamic acid, dimethyl sulphoxide, glyoxyl sodium bisulphite, potassium sorbate, sodium cyclamate, sodium metabisulphite, sodium oxalate, sodium sulphite, sodium thiosulphate and thioacetamide. Processes and kits for sterilizing or disinfecting water and objects utilizing the stabilized solutions are also provided by the present invention.

There is disclosed, in one aspect, chlorous acid generating compositions useful for disinfecting substrates

****!!!!**** "activated with material provided by BCI Inc., which included phosphoric acid and a surfactant." "12-14 ppm free chlorine dioxide" [Note: Oxine also contains other active oxychlorine species] "Viable cell counts were reduced by more than 99.99% after 60 seconds" "These are significant reductions, especially since the viable counts are primarily from fungal spores rather than vegetative cells."

"Spores of Mucor piriformis were killed after a 4-min exposureat 1 mg ClO2 ml-1 or 30 sec exposure at 3 mg ClO2 ml-1,"

{Significant info on Chlorine Dioxide use, particularly against anthrax} "1994 study by Roberts and Reymond wherein vitro tests on Mucor piriformis, Botrytis cinerea, Penicillium expansum, and Cryptosporiopsis perennans were conducted. Conidial suspensions of each pathogen were pipetted into test tubes containing ClO2 at concentrations of 1, 3, and 5 mg/l. Samples were drawn at 30 second intervals and the number of viable colony forming units/ml (CFU) was determined. The resultsof the tests are presented in Table 3.2-7."

****!!!!*** "ule type that potentially had low sensitivity to ClO2. The information generated from this research indicates whether a narrow or wide range in rate of ClO2 is needed for efficacy against different fungal propagules as a result of the interactions of water properties (e.g., pH and water hardness) that vary with the source (e.g., ponds, wells, municipal water, and recirculating systems), in combination with the presence of nutrient leachates that collect in catchment ponds and ebb-and-flow systems" " a high reduction in viable propagules resulted when conidia or sporangiospores of Botrytis cinerea, Penicillium expansum, Mucor piriformis, and Cryptosporiopsis perennans... These papers demonstrated that concentration of ClO2 varies with time, with an equal mortality of propagules obtained at lower concentrations of ClO2 by lengthening the duration of exposure. " "A higher concentration of ClO2 was required at pH 8 than at pH 5 to achieve a lethal dose resulting in 50% mortality of spores (LD50). The addition of the divalent metal ion solution required an increase in ClO2 concentration to maintain a LD50. When combined with the nitrogen and hard water solution, the divalent metal ion solution placed a higher demand on ClO2 at pH 5 and a lower demand on ClO2 at pH 8,"

2005. The efficacy of chlorine dioxide (ClO2) in detoxifying two potential bioterrorism agents, the trichothecene mycotoxins verrucarin A and roridin A, was evaluated...

2003. Appendix B: "CT VALUES* FOR 4-LOG INACTIVATION OF VIRUSES BY CHLORINE DIOXIDE pH 6-9" "CT VALUES* FOR 3-LOG INACTIVATION OF GIARDIA CYSTS BY CHLORINE DIOXIDE"

Appendix B: "T VALUES* FOR 4-LOG INACTIVATION OF VIRUSES BY CHLORINE DIOXIDE pH 6-9"

"Table D-8. CT Values for Inactivation of GimYi” Cysts by Chlorine Dioxide...Table D-9. CT Values for Inactivation of Viruses by Chlorine Dioxide pH 6-9"

{Good FAQ info} "It delivers broad spectrum performance against bacteria, fungi, algae, viruses, and parasitic microorganisms. ClO2 kills vegetative microorganisms and effectively deactivates sporulated species."

The University of Oklahoma Libraries has used chlorine dioxide as a treatment for mold on books since 1991. This research project compared the pH leve…

A collection of chlorine dioxide-based mold removal chemicals have entered the report stronger, faster, and safer remediation.

{Effectiveness against mucor pathogens "Information obtained from CSI beta-lactam inactivation at Pharmaceutical facility. " and "Study performed by the University of Tennessee at Knoxville."}

(2001) "The efficacy of chlorine dioxide as a water disinfectant is sufficiently well characterized that EPA has developed a set of tables predicting the degree of inactivation of microorganisms as a function of the concentration of disinfectant, the time of contact, temperature, and acidity of the water to be treated [Note: EPA document says that data sources used were quite limited, however.]"

{Examples of using concentrations in ppm from product labels} "How do I adjust my use of a sanitizer for disinfection?"

{Includes chart of critical levels for pathogens in water} "Shock treatment is recommended twice a year and usually requires a concentration of 20-50ppm chlorine dioxide be maintained for 12 hours, and then the irrigation system thoroughly rinsed before irrigation begins again, due to risk of phytotoxic effects with high concentrations. After shock treatment, a continuous treatment of 0.25ppm residual chlorine dioxide is usually sufficient to prevent regrowth of biofilm. " "The optimum chlorine dioxide range to treat biofilms and common plant pathogens is 0.25 to 3.3 ppm"

*****!!!!*** {Very useful info on chemistry. List of susceptible pathogens} "Chlorine dioxide exists in the water as ClO2 (little or no dissociation) and thus is able to permeate through bacterial cell membranes and destroy bacterial cells (Junli et. Al, 1977b). its action on viruses involves adsorbing onto and penetrating the protein coat of the viral capsid and reacting with the viral RNA... As a result, the genetic capability of the virus is damaged (Junli et. Al, 1977a). In comparison to chlorine, chlorine dioxide can be more effective as a disinfectant due to the fact that chlorine exists in the water as HOCL or OCL-. As a result, bacterial cell walls are negatively charged and repel these compounds, leading to less penetration and absorption of the disinfectant into the membranes. " "ClO2 DOES NOT REACT WITH: hippuric acid, cinnamic acid, betaine, creatine, alanine, phenylalanine, valine, leucine, asparaginic acid, asparagine, glutaminic acid...."

****!!!!*** 2020 label {Chart of some effective concentrations against pathogens}

This invention relates to biocidal blends comprising quaternary ammonium compounds and chlorine dioxide. It also relates to a process of inhibiting the growth of bacteria in aqueous system which comprises adding the biocidal blend to an aqueous system containing bacteria. The use of the biocidal blend results in an unexpected synergism.

"Surprisingly, chlorine dioxide was not effective for As III oxidation. A three-fold stoichiometric dose of chlorine dioxide produced only 20 to 30 percent oxidation in 21 seconds and none thereafter. Even a 100-times stoichiometric dose produced only 76 percent oxidation in five minutes."