Disinfection in drinking water

Trihalomethanes. Wherever chlorine is used as a disinfectant in drinking-water treatment, trihalomethanes (THMs) generaUy are present in the finished water. The THMs usuaUy formed are trichloromethane (chloroform), bromodichloromethane, dibromochloromethane, and tribromomethane (bromoform). There are four main techniques for the analysis of THMs headspace, Hquid— Hquid extraction (Ue), adsorption—elution (purge—trap), and direct aqueous injection. The final step in each technique involves separation by gas—Hquid chromatography with a 2 mm ID coUed glass column containing 10 wt % squalene on chromosorb-W-AW (149—177 p.m (80—100 mesh)) with detection generaUy by electron capture. 

Uses. Synthesis of organic chemicals photographic film as a disinfectant in drinking water... 

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. 

The practical use of solar disinfection in drinking water was first studied by Acra et al., who filled polyethylene bags with water before exposing them to full sunlight. Recently, a review of solar disinfection used as a water treatment method has been published (Reed 2004). 

Ozone is a strong oxidising agent and it has been used for many years as a disinfectant in drinking water production. Bott [1990] has compared chlorine and ozone in cooling water treatment. Edwards [1983] compares the oxidising power of some common water treatment chemicals and he concludes that ozone is the most powerful. Table 14.12 gives the comparison. Bott and Kaur [1994] have reviewed the use of ozone in water treatment. 

Maximum Residual Disinfectant Level (MRDL) - The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants. 

Disinfectants Disinfection Byproducts MCLG (mg/L) MCL or TT (mg/L) Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water... 

Of major concern are the health and environmental impacts of the abundant chlorinated and brominated hydrocarbons (ref. 2). These materials have numerous industrial applications as pesticides, solvents, propellants, refrigerants, plastics, fire retardants and extinguishers, disinfectants for drinking water, pharmaceuticals and electronic chemicals. Many chemical manufacturers utilize chlorinated and brominated organics as intermediates. It is estimated, for instance, that almost 85 % of the pharmaceuticals produced in the world require chlorine at some stage of synthesis. 

Xie YF (2004) Disinfection by-products in drinking water. Formation, analysis and control. Lewis, Boca Raton, FL... 

Richardson SD et al. (1999) Identification of new ozone disinfection byproducts in drinking water. Environ Sci Technol 33 3368-3377. 

Richardson SD, AD Thurston, C Rav-Acha, L Groisman, 1 Popilevsky, O Juraev, V Glezer, AB McKague, Ml Plewa, ED Wagner (2003) Tribromopyrrole, brominated acids, and other disinfection byproducts produced by disinfection of drinking water rich in bromide. Environ Sci Technol 37 3782-3793. 

Chlorine is still a time-tested effective disinfectant. In many parts of the world, it is indispensable in drinking water. 

Treatment of municipal water with chlorine and ammonia results in the formation of chloramines, a long-lasting disinfectant. Too much ammonia, however, enhances nitrification by bacteria in the water, which, in turn, increases the nitrate and nitrite levels. High nitrate and nitrite levels in drinking water is a health hazard, particularly for infants. 

SingerPC. 1994. Control of disinfection by-products in drinking water. J Environ Eng 120(4) 727-744. 

Determination of Inorganic Oxyhalide Disinfection By-products in Drinking Water using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis... 

Determination of Chlorinated Disinfection Byproducts and Chlorinated Solvents in Drinking Water by LLE and GC... 

Richardson SD, Plewa Ml, Wagner ED, Schoeny R, DeMarini DM (2007) Occurrence, genotoxicity, and carcinogenicity of regulated and emerging disinfection by-products in drinking water a review and roadmap for research. Mutat Res/Rev Mutat Res 636 178-242... 

The disinfection of drinking water has been rightly hailed as a public health triumph of the twentieth century. Before its widespread use, millions of people died from waterborne diseases. Now, people in developed nations receive quality drinking water every day from their public water systems. However, chemical disinfection has also produced an unintended health hazard the potential for cancer and reproductive and developmental effects (including early-term miscarriages and birth defects) that are associated with chemical disinfection by-products (DBFs) [1-6]. Research is being conducted worldwide to solve these important human health issues. 

Richardson SD (2011) Disinfection by-products formation and occurrence in drinking water. In Nriagu JO (ed) Encyclopedia of environmental health, vol 2. Elsevier, Burlington, M. A., pp 110-136... 

Weinberg HS, Krasner SW, Richardson SD, Thruston AD Jr (2002) The occurrence of disinfection by-products (DBPs) of health concern in drinking water results of a nationwide DBP occurrence study. EPA/600/R02/068. Available at www.epa.gov/athens/publications/ reports/EP A 600 R02 068.pdf... 

Plewa MJ, Wagner ED, Muellner MG, Hsu KM, Richardson SD (2008) Comparative mammalian cell toxicity of N-DBPs and C-DBPs. In Karanfil T, Krasner SW, Westerhoff P, Xie Y (eds) Occurrence, formation, health effects and control of disinfection by-products in drinking water, vol 995. American Chemical Society, Washington DC, pp 36-50... 

Richardson SD, Fasano F, Ellington JJ, Crumley FG, Buettner KM, Evans JJ, Blount BC, Silva LK, Waite TJ, Luther GW, McKague AB, Miltner RJ, Wagner ED, Plewa MJ (2008) Occurrence and mammalian cell toxicity of iodinated disinfection byproducts in drinking water. Environ Sci Technol 42 8330-8338... 

Kundu B, Richardson SD, Swartz PD, Matthews PP, Richard AM, DeMarini DM (2004) Mutagenicity in Salmonella of halonitromethanes a recently recognized class of disinfection by-products in drinking water. Mutat Res 562(l-2) 39-65... 

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