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US5389384A - Sterilizing or disinfecting composition - Google Patents
US5389384A - Sterilizing or disinfecting composition - Google Patents
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.
·patents.google.com·
US5389384A - Sterilizing or disinfecting composition - Google Patents
Chlorine Dioxide - Greenhouse and Nursery Water Treatment Information System, University of Guelph
Chlorine Dioxide - Greenhouse and Nursery Water Treatment Information System, University of Guelph
{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"
·ces.uoguelph.ca·
Chlorine Dioxide - Greenhouse and Nursery Water Treatment Information System, University of Guelph
Oxidizing Arsenic III to Arsenic V for Better Removal | Roads & Bridges
Oxidizing Arsenic III to Arsenic V for Better Removal | Roads & Bridges
"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."
·roadsbridges.com·
Oxidizing Arsenic III to Arsenic V for Better Removal | Roads & Bridges
Why is CIO2 Different to Chlorine? | Chlorine Dioxide | Scotmas
Why is CIO2 Different to Chlorine? | Chlorine Dioxide | Scotmas
**** {Includes helpful illustration} "Chlorine dioxide's behaviour as an oxidising agent is quite dissimilar. Like ozone, the predominant oxidation reaction mechanism for chlorine dioxide proceeds through a process known as free radical electrophilic (i.e. electron-attracting) abstraction rather than by oxidative substitution or addition (as in chlorinating agents such as chlorine or hypochlorite). This means that chlorinated organic compounds such as THMs and HAAs are not produced as a result of disinfection using chlorine dioxide"
·scotmas.com·
Why is CIO2 Different to Chlorine? | Chlorine Dioxide | Scotmas
Comparison of the impact of ozone, chlorine dioxide, ferrate and permanganate pre-oxidation on organic disinfection byproduct formation during post-chlorination - Environmental Science: Water Research & Technology (RSC Publishing)
Comparison of the impact of ozone, chlorine dioxide, ferrate and permanganate pre-oxidation on organic disinfection byproduct formation during post-chlorination - Environmental Science: Water Research & Technology (RSC Publishing)
Pre-oxidation is commonly used to mitigate the formation of byproducts during post-disinfection. A comparative study of the impact of four pre-oxidants, ozone (O3), chlorine dioxide (ClO2), permanganate (Mn(vii)) and ferrate (Fe(vi)), on the formation of trihalomethanes (THMs), haloacetonitriles (HANs) and a
·pubs.rsc.org·
Comparison of the impact of ozone, chlorine dioxide, ferrate and permanganate pre-oxidation on organic disinfection byproduct formation during post-chlorination - Environmental Science: Water Research & Technology (RSC Publishing)
Chlorine Dioxide Degradation Issues on Metal and Plastic Water Pipes Tested in Parallel in a Semi-Closed System
Chlorine Dioxide Degradation Issues on Metal and Plastic Water Pipes Tested in Parallel in a Semi-Closed System
**** {Tested at 1 ppm and ph of 7 for 8 wks} "four different kinds of water pipes, two based on plastics, namely random polypropylene (PPR) and polyethylene of raised temperature (PERT/aluminum multilayer), and two made of metals, i.e., copper and galvanized steel, were put in a semi-closed system where ClO2 was dosed continuously. The semi-closed system allowed for the simulation of real ClO2 concentrations in common water distribution systems and to simulate the presence of pipes made with different materials from the source of water to the tap. Results show that ClO2 has a deep effect on all the materials tested (plastics and metals) and that severe damage occurs due to its strong oxidizing power in terms of surface chemical modification of metals and progressive cracking of plastics. These phenomena could in turn become an issue for the health and safety of drinking water due to progressive leakage of degraded products in the water."
·mdpi.com·
Chlorine Dioxide Degradation Issues on Metal and Plastic Water Pipes Tested in Parallel in a Semi-Closed System
Water Handbook - Chlorine & Chlorine Alternatives | SUEZ Water Technologies
Water Handbook - Chlorine & Chlorine Alternatives | SUEZ Water Technologies
****** "The most common method of generating ClO2 is through the reaction of chlorine gas with a solution of sodium chlorite. Theoretically, 1 lb of chlorine gas is required for each 2.6 lb of sodium chlorite. However, an excess of chlorine is often used to lower the pH to the required minimum of 3.5 and to drive the reaction to completion. Sodium hypochlorite can be used in place of the gaseous chlorine to generate chlorine dioxide. This process requires the addition of sulfuric or hydrochloric acid for pH control. Other methods used for chlorine dioxide generation include:..." "Complex organic molecules and ammonia are traditional chlorine-demand materials that do not react with chlorine dioxide. " "The chemical behavior and oxidation characteristics of aqueous chlorine dioxide are not well understood because of the difficulty in differentiating aqueous chlorine-containing species." "Chlorine dioxide consumed in water treatment reactions reverts to chlorite ions (ClO2-), chlorate ions (ClO3- ), and chloride ions (Cl -)." "As a gas, chlorine dioxide is more irritating and toxic than chlorine. Chlorine dioxide in air is detectable by odor at 14-17 ppm, irritating at 45 ppm, fatal in 44 min at 150 ppm, and rapidly fatal at 350 ppm. Concentrations greater than 14% in air can sustain a decomposition wave set off by an electric spark. The most common precursor for on-site generation of chlorine dioxide is also a hazardous material: liquid sodium chlorite. If allowed to dry, this powerful oxidizing agent forms a powdered residue that can ignite or explode if contacted by oxidizable materials. The hazardous nature of chlorine dioxide vapor and its precursor, and the volatility of aqueous solutions of chlorine dioxide, require caution in the design and operation of solution and feeding equipment."
·suezwatertechnologies.com·
Water Handbook - Chlorine & Chlorine Alternatives | SUEZ Water Technologies
Impact of Chlorine Dioxide on Transmission, Treatment, and Distribution System Performance
Impact of Chlorine Dioxide on Transmission, Treatment, and Distribution System Performance
"This book reports on the research done to determine whether East Bay Municipal Utility District, CA, can replace Cl2 with ClO2 for biofouling suppression in the aqueduct and in open-air treatment basins, with the aim of reducing THM and HAA concentrations without sacrificing treatment performance associated with the use of Cl2. "
·books.google.com·
Impact of Chlorine Dioxide on Transmission, Treatment, and Distribution System Performance
Oxidation of the Cyanobacterial Hepatotoxin Microcystin-LR by Chlorine Dioxide: Influence of Natural Organic Matter
Oxidation of the Cyanobacterial Hepatotoxin Microcystin-LR by Chlorine Dioxide: Influence of Natural Organic Matter
"Cyanobacteria (blue-green algae) are known producers of cytotoxic, hepatotoxic, and neurotoxic compounds with severe acute and chronic effects on vertebrates. Successful removal of these toxins in drinking water treatment is therefore of importance for public health. "
·pubs.acs.org·
Oxidation of the Cyanobacterial Hepatotoxin Microcystin-LR by Chlorine Dioxide: Influence of Natural Organic Matter
Minimizing Chlorite Ion and Chlorate Ion in Water Treated With Chlorine Dioxide on JSTOR
Minimizing Chlorite Ion and Chlorate Ion in Water Treated With Chlorine Dioxide on JSTOR
"Minimizing the inorganic by-products chlorite ion and chlorate ion in drinking water treated with chlorine dioxide is important if ClO₂ is to remain a viable alternative in potable water treatment. The use of sulfur dioxide-sulfite ion chemistry to quantitatively remove chlorite ion to below the 0.1-mg/L level is described, along with the use of free chlorine to remove the sulfur dioxide-sulfite ion. The stoichiometry and the rate law are described for pH values of 5.5 to 8.5 so that the chemistry can be applied directly in existing drinking water treatment facilities."
·jstor.org·
Minimizing Chlorite Ion and Chlorate Ion in Water Treated With Chlorine Dioxide on JSTOR
Formation of chlorite and chlorate from chlorine dioxide with Han river water
Formation of chlorite and chlorate from chlorine dioxide with Han river water
****!!!!****** {Includes equations for predicting impact of variables in determining quantity of byproducts} "At 20oC, pH 7, 70-80% of chlorine dioxideinjected was converted to chlorite and 0-10% of that was transformed into chlorate within 120 min with 2.91 mg/Lof DOC. The amount of chlorite formed also increased when pH and temperature increased. As DOC content increased,the residual chlorine dioxide decreased but the amount of chlorite and chlorate were increased. These experimentsrevealed that chlorate was a dominant by-product under UV irradiation."
·cheric.org·
Formation of chlorite and chlorate from chlorine dioxide with Han river water
US EPA, Pesticide Product Label, SELECTROCIDE 5G ~EPA
US EPA, Pesticide Product Label, SELECTROCIDE 5G ~EPA
****!!!!****!!!! {Materials suitable for Chlorine Dioxide containers} "Construction should be of dark or opaque/UV-blocking (preferred) oxidation-resistant plastic or glass. Some materials recommended include: -High Density Polyethylene (HDPE)- Polypropylene (PP)- Polyethylene Terephthalate (PET) (PETE)- Polyvinyl Chloride (PVC)- Polycarbonate (PC)- Glass (UV-blocking preferred)- Gasket materials; silicone, viton or EPDM" "DECORATIVE AND ORNAMENTAL FOUNTAINS 5 ppm residual chlorine dioxide level. Circulate water in normal operation of the system.... Repeat daily until desired results are achieved." "Selective Micro® Chlorine Dioxide Test Strips"
·www3.epa.gov·
US EPA, Pesticide Product Label, SELECTROCIDE 5G ~EPA
Oxine Versus Tech‐Grade Sodium Chlorite Products ~Neeraj Khanna, Bio-cide Int'l (in Best Vet Solutions Poultry Talk)
Oxine Versus Tech‐Grade Sodium Chlorite Products ~Neeraj Khanna, Bio-cide Int'l (in Best Vet Solutions Poultry Talk)
****!!!!!****!!!!**** pg 31. "Using a proprietary technique, Oxine® solution is buffered at a pH between 8.0 – 8.5. Most other chlorite products are buffered at a pH of 11‐12. Therefore, the higher pKa acids perform poorly with tech‐grade products" "The intermediates (such as HClO2) generated in this reaction, act as a reservoir for replenishing ClO2 as it gets used up in the system" "Oxine® is much more potent than tech-grade sodium chlorite when tested on pseudomonas aeruginosa, staphylococcus aureus and saccharomyces cerevisiae, which serve as indicator organisms for an array of bacteria and fungi." "test strips are not the best way to measure free ClO2 in this range. Iodometric drop-titration or spectrophotometric methods are the best ways to measure free ClO2 concentrations." "dozens of regulations were submitted by BCI to FDA, EPA, USDA, FSIS, NSF and OMRI, to expand the use of this chemistry in direct-food and other applications. Millions of dollars were spent on toxicology and efficacy studies to ensure that the Oxine product delivers all its label claims." "Whereas solids may seem convenient for use, there are disadvantages...1. Solid sodium chlorite...is mixed with stabilizers to minimize its fire hazard. Stabilizers that are at least 20% (by total weight) of the chlorite salt consist of various salts, such as calcium carbonate, that can shield bacteria from antimicrobial activity. Liquid solutions of chlorite, on the other hand, do not contain substantial amounts of stabilizers. 2. Homogeneous dissolution of tablets or flakes require extra care; otherwise the concentration gradients are formed, causing inconsistent activation of product. 3. The biggest disadvantage with these products is the cost factor... [One specific solid product is} at least 500% more expensive than Oxine."
·bestvetsolutions.com·
Oxine Versus Tech‐Grade Sodium Chlorite Products ~Neeraj Khanna, Bio-cide Int'l (in Best Vet Solutions Poultry Talk)
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - ScienceDirect
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - ScienceDirect
***** 2020 "Chlorine dioxide (ClO2) has emerged as a promising alternative to free chlorine for water disinfection and/or pre-oxidation due to its reduced yields of chlorinated disinfection byproducts...""ClO2− serves as a radical generator, a light competitor and a radical/ozone scavenger. ClO2− reduces the concentrations of radicals and ozone in the UV/chlorine process. UV photolysis of ClO2− only generates HO• under drinking water relevant conditions. ClO3− is mainly generated from oxidation of ClO2− by HO• in the UV/chlorine process."
·sciencedirect.com·
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - ScienceDirect
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - PubMed
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - PubMed
***** 2020 "Chlorine dioxide (ClO2) has emerged as a promising alternative to free chlorine for water disinfection and/or pre-oxidation due to its reduced yields of chlorinated disinfection byproducts. ClO2 decomposes to form chlorite (ClO2-), which influences the following advanced oxidation processes (AOPs) for micropollutant abatement in drinking water. This study aims at investigating the effects of ClO2- on the concentrations of reactive species (e.g., radicals and ozone) and on the formation of chlorate in the UV/chlorine AOP. Results showed that the concentration of ClO· in the UV/chlorine process remarkably decreased by 98.20-100.00% in the presence of ClO2- at concentration of 0.1-1.0 mg·L-1 as NaClO2. The concentrations of HO· and ozone decreased by 42.71-65.42% and by 22.02-64.31%, respectively, while the concentration of Cl· was less affected (i.e., 31.00-36.21% reduction). The overall concentrations of the reactive species were differentially impacted by ClO2-'s multiple roles in the process. UV photolysis of ClO2- generated HO· but not Cl·, ClO· or ozone under the drinking water relevant conditions. ClO2- also competed with chlorine for UV photons but this effect was minor (< 1.0%). The radicals/ozone scavenging by ClO2- outcompeted the above two to lead to the overall decreasing concentrations of the reactive species, in consistency with the kinetic model predicted trends. ClO2- reacted with radicals and ozone to form chlorate (ClO3-) but not perchlorate (ClO4-). HO· played a dominant role in ClO3- formation."
·pubmed.ncbi.nlm.nih.gov·
The multiple roles of chlorite on the concentrations of radicals and ozone and formation of chlorate during UV photolysis of free chlorine - PubMed
Experimental observation on the disinfection effect and toxicity of three kinds of chlorine dioxide on drinking water, 2004
Experimental observation on the disinfection effect and toxicity of three kinds of chlorine dioxide on drinking water, 2004
"...The microporous membrane suction filtration method and animal test method were used to observe the sterilization effect and toxicology. As a result, the chlorine dioxide produced by the Juyuan brand chlorine dioxide generator containing 0.5mg/L of chlorine dioxide, the Sadi brand stable chlorine dioxide and the Siriman disinfectant were used for 1min, 5min and 10min, respectively. The killing rate of Escherichia coli in water reached 100%. The pH value of water above 7.0 has a slight influence on the sterilization effect of the three kinds of chlorine dioxide; organic matter affects the sterilization effect of chlorine dioxide. The oral toxicity test of the three disinfectants is LD50 500 mg/kg (body weight); the accumulation coefficient K 5 is weak accumulative toxicity; the mouse bone marrow polychromatic erythrocyte micronucleus test is negative. The results show that the three chlorine dioxide disinfectants have a strong killing effect on E. coli in the water, and the toxicity is low "
·zwf4si7npfrj5lihspusodnepm--www-cnki-com-cn.translate.goog·
Experimental observation on the disinfection effect and toxicity of three kinds of chlorine dioxide on drinking water, 2004
Oxidation of N-Nitrosodimethylamine (NDMA) Precursors with Ozone and Chlorine Dioxide: Kinetics and Effect on NDMA Formation Potential | Environmental Science & Technology
Oxidation of N-Nitrosodimethylamine (NDMA) Precursors with Ozone and Chlorine Dioxide: Kinetics and Effect on NDMA Formation Potential | Environmental Science & Technology
The oxidation of N-nitrosodimethylamine (NDMA) precursors during water treatment was investigated using ozone and chlorine dioxide (ClO2). Second-order rate constants for the reactions of model NDMA precursors (dimethylamine (DMA) and 7 tertiary amines) with ozone (kapp at pH 7 = 2.4 × 10-1 to 2.3 × 109 M-1 s-1), ClO2 (kapp at pH 7 = 6.7 × 10-3 to 3.0 × 107 M-1 s-1), and hydroxyl radical (•OH) (kapp at pH 7 = 6.2 × 107 to 1.4 × 1010 M-1 s-1) were determined, which showed that the selected NDMA precursors, with the exception of dimethylformamide (DMFA) can be completely transformed via their...
·pubs.acs.org·
Oxidation of N-Nitrosodimethylamine (NDMA) Precursors with Ozone and Chlorine Dioxide: Kinetics and Effect on NDMA Formation Potential | Environmental Science & Technology
Effect of pipe corrosion scales on chlorine dioxide consumption in drinking water distribution systems - PubMed
Effect of pipe corrosion scales on chlorine dioxide consumption in drinking water distribution systems - PubMed
Previous studies showed that temperature and total organic carbon in drinking water would cause chlorine dioxide (ClO(2)) loss in a water distribution system and affect the efficiency of ClO(2) for Legionella control. However, among the various causes of ClO(2) loss in a drinking water distribution …
·pubmed.ncbi.nlm.nih.gov·
Effect of pipe corrosion scales on chlorine dioxide consumption in drinking water distribution systems - PubMed
Enhanced Chlorine Dioxide Decay in the Presence of Metal Oxides: Relevance to Drinking Water Distribution Systems | Environmental Science & Technology
Enhanced Chlorine Dioxide Decay in the Presence of Metal Oxides: Relevance to Drinking Water Distribution Systems | Environmental Science & Technology
Chlorine dioxide (ClO2) decay in the presence of typical metal oxides occurring in distribution systems was investigated. Metal oxides generally enhanced ClO2 decay in a second-order process via three pathways: (1) catalytic disproportionation with equimolar formation of chlorite and chlorate, (2) reaction to chlorite and oxygen, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly stronger abilities than goethite (α-FeOOH) to catalyze the ClO2 disproportionation (pathway 1), which pr...
·pubs.acs.org·
Enhanced Chlorine Dioxide Decay in the Presence of Metal Oxides: Relevance to Drinking Water Distribution Systems | Environmental Science & Technology
Enhanced chlorine dioxide decay in the presence of metal oxides: relevance to drinking water distribution systems - PubMed
Enhanced chlorine dioxide decay in the presence of metal oxides: relevance to drinking water distribution systems - PubMed
{**Reactions with metal in pipes} "The possible ClO2 loss and the formation of chlorite/chlorate should be carefully considered in drinking water distribution systems containing copper pipes."" Metal oxides generally enhanced ClO2 decay in a second-order process via three pathways: (1) catalytic disproportionation with equimolar formation of chlorite and chlorate, (2) reaction to chlorite and oxygen, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state."
·pubmed.ncbi.nlm.nih.gov·
Enhanced chlorine dioxide decay in the presence of metal oxides: relevance to drinking water distribution systems - PubMed
Chlorine Dioxide and Unusual Odors
Chlorine Dioxide and Unusual Odors
****!!!! When a water tap is opened, small amounts of chlorine dioxide diffuse into the air and combine with existing household odors. All homes have volatile organic compounds (VOCs) in the ambient air produced by scented products (soaps, candles, air fresheners, incense, potpourri), cleaning agents or solvents, paint, carpet, furnishings, fresh flowers or wreaths, and many other common household items. The VOC/chlorine dioxide combination odors have been described as smelling like fuel oil, kerosene, chemicals or cat urine, to name the most common. Studies have not identified any health concerns associated with this combined odor. The strongest odors are associated with installing new carpet, upholstered furniture or draperies andinterior painting. The odor will continue until the level of VOCs decreases (new smell goes away). This can take from a few weeks up to several months to dissipate depending on the situation, type of materials, amount of ventilation, etc.
·bhws.org·
Chlorine Dioxide and Unusual Odors