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 …

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...

{**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."

"There has been a trend toward the use of microorganisms as the biomaterial for removing dyes and metals from wastewater. However, native microorganism cells have low mechanical stability, which limit their further application in industries. In this study, chlorine dioxide (ClO2), a high-efficiency, low-toxicity, and environmentally benign disinfectant, was used for microorganism surface modification to enhance the mechanical stability and metal ion adsorption of the cell. ClO2 can either modify cell walls to improve their metal adsorption capacity or modify cell membranes to improve their mechanical stability... ClO2 treatment could deter cell membranes from forming vesicles in sodium hydroxide (NaOH) aqueous solution, and ... ClO2 treatment could alter the erythrocyte membrane proteins which might also contribute to improving the cell stability. The experimental results on Bacillus sp., Pseudomonas aeruginosa, and Mucor rouxii show that ClO2 treatment may increase, or at least not reduce, the ability of microbial cells to adsorb heavy metals, but it can significantly improve the resistance of these cells to NaOH cleavage. It seems ClO2 is a promising auxiliary for biosorption of heavy-metal ions."

"The data showed that the residual of chlorine dioxide could stood more active than residual of chlorine in the aqueous environment significantly."

***!!!!*** {Includes table of pathogen effectiveness levels} "Chlorite is the major inorganic by-product of the reaction of chlorine dioxide in water. Usually, the amount of chlorite formed will be 40-60% of the amount of chlorine dioxide which has reacted. " "Chlorine dioxide systems: acid chlorite and electrochemical generators "Typical chlorite yield for an acid-chlorite generator varies between 65-68%. Overall conversion efficiency is much lower than this as much of the acid remains unreacted." "Chlorine Dioxide ClO2 will inactivate pathogenic micro-organisms at the same rate between pH 5 and 9. This makes it ideal for disinfection of potable water and process water where the pH is up around 8.0." "ClO2 is approximately 5 times more soluble than chlorine and 50 times more soluble than ozone." "Chlorine Dioxide Reaction with Inorganic Compounds--Ammonia Nitrogen... Iron... Manganese..." "Sulfur Compounds... Cyanide..." "Oil and Gas... frac water"

"The corrosion scale will cause much more significant ClO2 loss in corroded iron pipes of the distribution system than the total organic carbon t... The application of ClO2 in the water distribution system using cast-iron pipes is not recommended unless measures to prevent corrosion are fully implemented . Although ClO2 loss caused by corrosion scale was much slower in the copper pipe ..., it may still be necessary to prevent the corrosion and unnecessary loss of disinfectant"

****{Summary of specific characteristics***a 35 mg/L chlorine dioxide solution stored in a high-density Polyethylene Terephthalate (PETE) container for 45 days resulted in a 3% loss.. In contrast, the same study stored chlorine dioxide in a clear glass container for 31 days which resulted in a 12% gain, possibly due to continuing formation of chlorine dioxide from chlorite. Another study showed a 6.2% overall gain in chlorine dioxide concentration after 252 days of storage in a PETE container... Chlorite and chlorate show no disinfection capabilities and may cause adverse health effects in children... CTs required for a 2-log virus inactivation were 13 – 20 times higher at a pH of approximately 6 compared to a pH of 9 and 10... two to three-fold increase in inactivation rates per 10° C water temperature increase... bentonite appeared to offer protection or shield the viruses from chlorine dioxide... disinfection capability decreases in more turbid waters since microorganisms are protected by solid particles in water, protected by aggregation or clumping, and protected by loss of chlorine dioxide residual from oxidation of organic matter... Chlorine dioxide should easily achieve a 6-log *bacteria* inactivation at low temperatures and low pHs if chlorine dioxide is used for disinfection of more resistant viruses and cysts." "Colder water temperatures require higher CT values. Use a two-fold increase in CT for every 10° C decrease. Use longer contact time instead of higher dosages to achieve higher CT values. "

*****"[Note: Some statements about corrosion, reaction with phenols, Cl also released during some specific reactions, etc may have some inaccuracies] Like ozone and chlorine, chlorine dioxide is an oxidizing biocide and not a metabolic toxin. This means that chlorine dioxide kills microorganisms by disruption of the transport of nutrients across the cell wall, not by disruption of a metabolic process." "Unlike chlorine, Chlorine dioxide is effective at pH between 4 and 10. No dumping and filling with fresh water required;" "Chlorine dioxide can be used as a spray. All parts therefore, can easily be reached;" In scrubbers: "In scrubbers, Usually, a very low chlorine dioxide residual, around 0.2-ppm, is sufficient to ensure odour control." {includes effects on specific foods when rinsed}

" it is normal practice to supply water with a chlorine dioxide residual of a few tenths of a milligram per litre to act as a preservative during distribution" "The taste and odour threshold for this compound is 0.4 mg/l."

*****!!!**** {Includes graphs of bactericidal effects at different temperatures and pH} "Chlorine dioxide reacts primarily by oxidation; however, chlorine reacts by both oxidation and electrophilic substitution to yield volatile and nonvolatile chlorinated organic substances (THMs)." "1.34 lb of pure sodium chlorite will react with 0.5 lb of chlorine to produce 1.0 lb of chlorine dioxide. However, since dry technical sodium chlorite is 80% active, the reaction takes 1.68 lb of technical sodium chlorite. Usually a slight excess of chlorine should be used to insure that the reaction solution has a pH value between 2-4. This will produce chlorine dioxide more efficiently" "chlorine dioxidecan also be prepared by mixing sodium hypochlorite bleaching solution with sodium chlorite and an acid... The reaction with sulfuric acid as shown... produces the highest purity chlorine dioxide. Other inorganic and organic acids may be used and hydrochloric acid reportedly produces the most efficient generation of chlorine dioxide." "Sodium chlorite may cause anemia by oral exposure and has low toxicity by dermal exposure. Dry sodium chlorite has an oral LD50 (rat) of 165 mg/kg and sodium chlorite solutions have an oral LD50 (rat) of 350 mg/kg. Sodium chlorite dry and solution products have a dermal LD50 (rabbit) of greater than 2 g/kg." "Sodium chlorite, dry, is a fire or explosion hazard when contaminated with combustible material... Sodium chlorite, solution, also becomes a fire or explosion hazard if allowed to dry and can ignite... Continue to keep damp."

The emergence of waterborne viruses with resistance to disinfection has been demonstrated in the laboratory and in the environment. Yet, the implications of such resistance for virus control remain obscure. In this study we investigate if viruses with resistance to a given disinfection method exhibit cross-resistance to other disinfectants. Chlorine dioxide (ClO2)- or UV-resistant populations of echovirus 11 were exposed to five inactivating treatments (free chlorine, ClO2, UV radiation, sunlight, and heat), and the extent of cross-resistance was determined. The ClO2-resistant population exhibited cross-resistance to free chlorine, but to none of the other inactivating treatments tested. ...Overall, our results indicate that viruses with resistance to multiple disinfectants exist, but that they can be controlled by inactivating methods that operate by a distinctly different mechanism.

" this study investigated the reactions of ClO2 with 30 model compounds, 10 humic substances and 2 surface waters. ClO2- yields were found to be dependent on the distribution of functional groups. ClO2 oxidation of amines, di- and tri-hydroxybenzenes at pH 7.0 had ClO2- yields 50%, while oxidation of olefins, thiols and benzoquinones had ClO2- yields..."

ClO2 is frequently used as a pre-oxidant in water treatment plants. However, the effects of ClO2 pre-oxidation on disinfection by-product (DBP) formation, especially the highly toxic nitrogenous DBPs, during subsequent chlor(am)ination have not been studied thoroughly... Results imply that ClO2 is probably more suitable for use in combination with chloramination disinfection, rather than chlorination, in the integrated control of CX3R-type DBPs from source waters abundant in AAs.

Chlorine dioxide water treatment has advantages over chlorine, ozone, UV and other methods. Learn about benefits, disadvantages, dosing, and compliance.

**Includes pathogens resistant to Chlorine. Chlorine bleach: It's convenient to purchase. It's cheap. It's a well-known household cleaner and disinfectant. But is it best to use as a water sanitizer in the poultry house?