Chemical & Biological Dynamics

"applications in which soil residues are frequent." "One sanitizer was an acidified solution of dilute sodium chlorite at pH 2.7; the other sanitizer was dilute chlorine dioxide (about 15 ppm) in tap water. Stainless steel types 304 and 316 corroded rapidly when exposed to the acidified chlorite solution. Chlorine dioxide near neutral pH 7.2 was noncorrosive to both type 304 and 316 stainless steels at a concentration of 100 ppm during 10 d of continuous exposure. This concentration is well above the typical use Concentration of 15 ppm; typical use time span is 15 min."

"It is produced by reaction between chlorine dioxide and excess ozone:"

Heme b containing chlorite dismutase (Cld) catalyses the conversion of chlorite to chloride and dioxygen which includes an unusual OO bond formation. …

Chlorite dismutase (Cld) is a heme-dependent enzyme that catalyzes the decomposition of toxic chlorite (ClO2(-)) into innocuous chloride and O2. In this paper, using the hybrid B3LYP density functional theory (DFT) method including dispersion interactions, the Cld reaction mechanism has been studied with a chemical model constructed on the X-ray crystal structure. The calculations indicate that the reaction proceeds along a stepwise pathway in the doublet state, i.e. a homolytic O-Cl bond cleavage of the substrate leading to an O-Fe(heme) species and a ClO˙ radical, followed by a rebinding O-O bond formation between them. The O-Fe(heme) species is demonstrated to be a low-spin triplet-state Fe(IV)=O diradicaloid. A low-spin singlet-state Fe(IV)=O is much less stable than the former, with an energy difference of 9.2 kcal mol(-1). The O-Cl bond cleavage is rate-limiting with a barrier of 10.6 kcal mol(-1), in good agreement with the experimental reaction rate of 2.0 × 10(5) s(-1). Furthermore, a heterolytic O-Cl bond dissociation in the initial step is shown to be unreachable, which ensures the high efficiency of the Cld enzyme by avoiding the generation of chlorate byproduct observed in the reactions of synthetic Fe porphyrins. Also, the pathways in the quartet and sextet states are unfavorable for the Cld reaction. The present results reveal a detailed mechanism III (defined in the text) including an interesting di-radical intermediate composed of a low-spin triplet-state Fe(IV)=O and a ClO˙ radical. Compared to a competitive heterolytic Cl-O cleavage in synthetic Fe porphyrins, the revelation of the domination of homolysis in Cld indicates not only the high efficiency of enzyme, but also the sensitivity of a heme and the significance of the enzymatic active-site surroundings (the His170 and Arg183 residues in the present case), which gives more insights into heme chemistry.

1985

"safe and effective fixative, chlorine dioxide (ClO2), instead of traditional hazardous fixatives for the cross-linking of cellular proteins to improve immunofluorescence staining of bacteria. The concentration of ClO2 needed for 100% fixation is 50 μg ml−1, which is much lower than that of traditional fixatives"

"ClO2-gelatin microspheres can stable release low concentration ClO2 gas over an extended period, up to 10 days. The delayed-release ClO2-gelatin microspheres made it stable, effective and long-lasting role and used in various fields, especially small-scale industrial water supply, wastewater and cooling water to kill bacteria, odor removal and indoor formaldehyde, toilet odor disinfection and other occasions. In this paper, the use of food-grade gelatin purpose is to prepare for further expansion into the sterilization of food and drinking water."

"An exposure of the gelatin materials in ClO2 vapor for 12 h generated a cross-linking extent sufficient to preserve their morphology in 37 °C warm water for above 5 days. The cross-linking also led to improved thermostability and enhancement in mechanical properties. Energy dispersion X-ray analysis indicated that no halogen substitution reaction happened in the cross linking reaction, and the residual Cl could be removed thoroughly by pretreatment. Cytotoxicity was evaluated based on a cell proliferation study. It was found cell expansion took place and linearly increased during the course of whole period of the cell culture. Thus the cross-linked material showed no toxicity to the cells."

Chlorine dioxide (ClO2) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and h…

1982

****!!!!****!!!**"Unlike chlorine, ClO2 will react to form mainly inorganic disinfection by products, the predominant species being chlorite. Chlorite will subsequently reduce to form harmless chloride. The speed of this reaction depends upon a number of factors, however within saltwater conditions this can be as low as 5 minutes." "Poorly designed or tuned chlorine dioxide generation equipment can lead to the production of chlorate" "Modern generation systems such as those produced by Scotmas are able to monitor the downstream residual DBP and adjust the dose rate to ensure that environmental limits are not breached. In special cases, downstream reactions can be used to remove excess chlorite residual from the water stream." "It is important to note that the disinfection by products of chlorine dioxide are easily managed with the correct experience and advice, and do not present nearly the same scale of problem as found with other biocides with a higher oxidation potential. Unlike ozone (O3), chlorine dioxide does not oxidise bromide (Br-) ions into bromate ions (BrO3-) which have been identified as carcinogenic. Additionally, chlorine dioxide does not produce large amounts of aldehydes, ketones, or other disinfection by products that originate from the ozonisation of organic substances."

****!!!!****!!!!*** "In alkaline media the permeability of living cell walls to gaseous chlorine dioxide radicals seems to be increased allowing an easier access to vital molecules. The reaction of chlorine dioxide with vital amino acids is one of the dominant processes of its action on bacteria and viruses. Compounds within the cells and on the surface of cell membranes that contain oxidisable material react with chlorine dioxide, causing cell metabolism to be disrupted. Chlorine dioxide also reacts directly with disulphide bonds in the amino acids and the RNA in the cell. Unlike non-oxidizing disinfectants, chlorine dioxide kills microorganisms even when they are inactive. The oxidative load placed on the cells by the action of chlorine dioxide mean that most microorganisms are unable to build up resistance to chlorine dioxide." In practical terms however, few bacteria live alone, and they are most often found in water and on surfaces in the form of a "biofilm" which is a close association of many millions of bacteria. Many biocides have particular problems in penetrating this biofilm, due to the polysaccharide "glue" that is secreted by bacteria such as Pseudomonas to hold the biofilm together. Unlike most biocides, chlorine dioxide can effectively penetrate the polysaccharide layer of biofilm without being used up in reacting with the inert sugars. This allows the ClO2 to act on the bacteria themselves, destroying the biofilm."

****!!!!**** "Chlorine dioxide chemistry works by selective oxidation, targeting the biocide where it is needed most." "Generally Chlorine Dioxide (ClO2) rapidly oxidises phenol type compounds, secondary and tertiary amines, organic sulphides and certain hydrocarbon polycyclic aromatics such as benzopyrene, anthracene and benzoathracene. In general, Chlorine Dioxide will not react on double carbon bonds, aromatic cores, quinionic and carboxylic structures as well as primary amines and urea. Commercial applications have shown that Chlorine Dioxide can effectively oxidise many compounds considered to be waste and water pollutants. The table below lists a selection of pollutants found in various industries from our files, and demonstrates the wide range of possible applications for Chlorine Dioxide... Aldehydes... Amines and Mercaptans" "Chlorine Dioxide, however reacts with THM precursors primarily by oxidation to make them non-reactive or unavailable for THM production."

"Chlorine and oxygen can bond in many ways..."

Methods, kits, cartridges and compounds related to generating chlorine dioxide by exposing ClO 2 − to at least one of a manganese porphyrin catalyst or a manganese porphyrazine catalyst are described.

****!!!!**** "Microbial analysis indicated that ASC reduced E. coli O157:H7 population by 2.2 log cycles over that of water wash, while the reduction from other sanitizers was about 1 log cycle. " " An increase in the ASC concentration enhanced the efficacy of the combined treatment of ASC and ultrasonication, especially at ASC concentrations of < 300 mg/L. Increasing the ultrasound treatment time from 0 to 4 min and AED from 0 to 500 W/L were both effective in increasing the effectiveness of the ASC and ultrasound combined treatments."

The synergistic effect of sodium chlorite and bromochloroacetic acid on BrO3−-induced renal cell death | Xiaoling Zhang; Richard J. Bull; Jeffery Fisher; Joseph A. Cotruvo; Brian S. Cummings | download | BookSC. Download books for free. Find books

The dismutation of chlorite into chloride and O[2] represents a central step in the reductive pathway of perchlorate that is common to all dissimilatory perchlorate-reducing bacteria and is mediated by a single enzyme, chlorite dismutase. The chlorite ...

The chlorite-based drug solution WF10 has been successfully applied to dampen strong inflammatory disease states and to improve wound healing processes. However, the molecular mechanisms of this drug are not well understood. This study is directed to investigate how WF10 and its components affect the expression of surface markers and sulphated proteoglycans and glycosaminoglycans in proinflammatory-stimulated monocytes and macrophages.

Chlorite dismutase (EC 1.13.11.49), an enzyme capable of reducing chlorite to chloride while producing molecular oxygen, has been characterized using EPR and optical spectroscopy. The EPR spectrum of GR-1 chlorite dismutase shows two different high-spin ferric heme species, which we have designated …

Several chlorooxygen compounds, hydrogen peroxide and reducing molecules in the presence of chelated iron (Fenton systems) are oxidants of biological relevance. These compounds are either produced in living tissues or are in use as disinfectants or drugs. Tetrachlorodecaoxide as the active principle in the drug OXOFERIN can be differentiated from the above mentioned oxidants by means of simple biochemical test systems where different activators and detector molecules are used."

{Solumium}

{Also specifically refers to Sanova sanitizing product for food uses} "Sodium chlorite solution is made with sodium chloride crystals or flakes and water, and available at various concentrations, such as SANOVA® Base (25%) and Sanova® Antimicrobial Food Additive Base (25%) containing 20-50% by weight of sodium chlorite (NaClO2). While the chlorite ion (ClO2 –) is stable in aqueous solution, under acidic conditions— the acidifier can be any one of food-grade acids, chlorite forms chlorous acid (HClO2). Chlorous acid is unstable and dissociates back to chlorite ion. Other compounds like chlorine dioxide (ClO2) and chlorate also generated. Ultimately, chlorous acid degrades to chloride (Cl–). "

1977

Abstract Chlorine dioxide is one of the most interesting oxidants because it combines a strong capacity of o | Mayra Kerolly Sales Monteiro, Mayara Maria Sales M | Current Opinion in Electrochemistry |