Disinfection chlorine dioxide

In many patent orHterature descriptions, a stabilized chlorine dioxide solution or component is used or described. These stabilized chlorine dioxide solutions are in actuaHty a near neutral pH solution of sodium chlorite that may contain buffer salts or additives to obtain chlorite stabiHty in the pH 6—10 range. The uv spectra of these solutions is identical to that of sodium chlorite. These pH adjusted chlorite solutions can produce the active chlorine dioxide disinfectant from a number of possible organic or inorganic chemical and microbiological reactions that react, acidify, or catalyze the chlorite ion. 

B. W. Lykins and M. Giiese, Chlorine Dioxide Disinfection and Granular Activated Carbon Absorption, EPA Project Summaiy, EPA-600/S2-82-051, Washington, D.C., May 1983. 

Lactide/glycolide polymers have been investigated for delivery of agents in applications outside the pharmaceutical field. For example, the microbiocidal properties of chlorine dioxide disinfectants have been improved by formulating a long-acting chlorine dioxide system based on lactide/glycolide copolymers. Blends of microspheres based on 50 50 and 87 13 copolymers were developed to afford the release of chlorine dioxide over several months (114). 

Hoehn RC, Long BW, Gates DJ. 2000. Status of chlorine dioxide disinfection technologies. J Am Water Works Assoc 1888-1906. 

Lykins BW, Goodrich JA, Hoff JC. 1990. Concerns with using chlorine-dioxide disinfection in the USA. Aqua39(6) 376-386. 

Moore GS, Calabrese EJ, Forti A. 1984. The lack of nephrotoxicity in the rat by sodium chlorite, a possible byproduct of chlorine dioxide disinfection in drinking water. J Environ Sci Health Part A 19(6) 643-661. 

Richardson SD, Thruston AD, Collette TW, et al. 1994. Multispectral identification of chlorine dioxide disinfection byproducts in drinking water. Environ Sci Technol 28(4) 592-599. 

Complete Treatment Line. The Wilcoxon test was applied to compare mutagenic activity before RSF and after complete treatment lines. Treatment line 4 with chlorine dioxide disinfection significantly decreased the mutagenic activity of the DCM extract. No other statistically significant differences were observed for any other treatment lines from data on DCM or MeOH extracts (Table VI). 

Halogenation and Disinfection chapter introduces various disinfection processes, such as chlorination, chlorine dioxide disinfection, bromination, and iodination which all involve the use of halogens (1). 

Chlorine dioxide Disinfection 6 mmol/m corresponding to 0.4 mg/1 of chlorine dioxide 3 mmol/m corresponding to 0.2 mg/1, in exceptional cases 6 mmol/m corresponding to 0.4 mg/1 of chlorine dioxide Maximum value for chlorite as reaction end product 3 mmol/m corresponding to 0.2 mg/1 in treated drinking water ... 

Chlorine dioxide Disinfection agent SC NAD, 0.4mgr 0.8 mg 1 as CIO2 (MRDL) Amperometric titration, DPD methods... 

Chlorite By-product of chlorine dioxide disinfectant SC 200ng - P 1 mgl 1C... 

Wang and Yuan [13] applied leucomethylene blue reagent for the determination of chlorine dioxide disinfectant residues in drinking water and wastewater samples. In their method, the sample is mixed with 3 cm reagent solution (20 mg/dm ), filled up to 20 cm, and extracted with 1,2-dichloroethane at pH 1.3. After a reaction time of 10 min the absorbance is measured at 658 nm. The interfering chlorine and h5q30chlorite ions can be masked by adding oxalic acid. 

Flow injection analysis apparatus was successfully used by Watanabe et al. [14] for measuring chlorine dioxide disinfectant residues in water samples. They used 4-aminoantipyrine and phenol reagent (mixture of 0.8 mM 4-aminoantipyrine and 2.0 mM phenol in pH = 9.0 Tris-HCl buffer). 

Chlorine. Chlorine is a weU known disinfectant for water and wastewater treatment, however, it can react with organics to form toxic chlorinated compounds such as the tribalomethanes bromodichloromethane, dibromochloromethane, chloroform [67-66-3] and bromoform [75-25-2]. Chlorine dioxide [10049-04-4] may be used instead since it does not produce the troublesome chlorinated by-products as does chlorine. In addition, by-products formed by chlorine dioxide oxidation tend to be more readHy biodegradable than those of chlorine, however, chlorine dioxide is not suitable for waste streams containing cyanide. 

The uses for chlorine dioxide take advantage of the high oxidising power and broad-spectrum disinfection capabiUty. 

Chlorine dioxide yields of 95% or greater have been demonstrated. The use of chlorine as an oxidant has distinct advantages because it is usually present in municipal water treatment plants for water disinfection. 

More than 80% of all the sodium chlorite produced is used for the generation of chlorine dioxide. Sodium chlorite or the chlorine dioxide generated from it or from sodium chlorate must be registered with the USEPA for each specific appHcation use as a biocide for microbial growth control or disinfection. These regulations are covered under the Eederal Insecticide, Eungicide, and Rodenticide Act (EIERA). 

Chlorine Dioxide. Like ozone, chlorine dioxide [10049-04-4] is a powerflil oxidant. It is usually generated as used. It has been used for disinfecting drinking water and bleaching paper pulp. Its effectiveness in killing microorganisms is well documented (305,306), and it has received recent study as a gas to sterilize medical devices. It requites 50% rh or higher to be effective. Bacterial cells had a D-value of 2.6 min and spores of 24 min (307). 

For inactivation of microorganisms disinfection. Typical disinfectants are chlorine, chlorine dioxide, chloramines, and ozone. 

At present, chlorine dioxide is primarily used as a bleaching chemical in the pulp and paper industry. It is also used in large amounts by the textile industry, as well as for the aching of flour, fats, oils, and waxes. In treating drinking water, chlorine dioxide is used in this country for taste and odor control, decolorization, disinfection, provision of residual disinfectant in water distribution systems, and oxidation of iron, manganese, and organics. The principal use of chlorine dioxide in the United States is for the removal of taste and odor caused by phenolic compounds in raw water supplies. 

Ozone is more effective than chlorine in deactivating poliovirus, Cryptosporidium parvum, Giardia lamblia, and other protozoa. It also improves the color, taste, and odor of water dramatically. However, since no residual amount remains, it is always necessary to add a small amount of a more stable disinfectant as well (sodium hypochlorite, chlorine dioxide, etc.). 

J. Katz (ed.). Ozone and Chlorine Dioxide Technology for Disinfection of Drinking Water, Noyes Data Corp., Park Ridge, New Jersey, 1980, 659 pp. R. G. Rice and M. E. Browning, Ozone Treatment of Industrial Wastewater, Noyes Data Coip., Park Ridge, New Jersey, 1981, 371 pp. 

Chlorine dioxide has been used widely in Europe since the early 1940 s as a drinking water disinfectant. More recently the USA has suggested the use of chlorine dioxide to reduce the formation of chloro-organic compounds particularly chloroform and other trihalomethanes (THM s) which are known carcinogens(7). 

The newly developed ACTIV-OX chlorine dioxide system has effectively delivered continuous low levels of chlorine dioxide which were effective in controlling Legionella in a hot and cold water system without the need for prior disinfection. 

The most widely used and effective disinfectant solutions are based on iodine (iodophor) with concentrations ranging between 0.05% and 0.1%, but sometimes higher concentrations are recommended. Other agents such as chlorhexidine or chlorine dioxide, peroxide, sodium chloride and lactic acid may also be effective (Wilson et al., 1997) but are not common. Recent trials show positive effects of aloe vera-based dipping agents (Leon et al., 2004). One problem of iodine containing products is their low pH value (<4.0), which is necessary for their antimicrobial activity (Hansen and Hamann, 2003). 

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