Organic acids in drinking water

Chaveerach, P., Keuzenkamp, D.A., Lipman, L.J., and Van, K.F. 2004. Effect of organic acids in drinking water for young broilers on Campylobacter infection, volatile fatty acid production, gut microflora and histological cell changes. Poultry Science 83 330-334. 

EPA. 1982f Test method - Base/neutrals and acids. Method-625. In Method for determination of organic compounds in drinking water. Cincinnati, OH U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory. EPA/600/7-82/039. 

T HE PRESENCE OF ORGANIC CONSTITUENTS IN DRINKING WATER has been known for many years because these substances were found to influence the taste, color, and odor of drinking waters (J). The organic constituents consist of compounds of both natural and industrial origin. The natural ones compose the major portion and include mainly undefined fulvic and humic acids (2). For the industrial ones, most attention has been paid so far to the volatile nonpolar compounds. In part, this situation is due to analytical (technical) restrictions and to the growing awareness (3, 4) that volatile halogenated hydrocarbons are introduced as a result of a chlorine treatment. 

Four species of antimony have been identified in natural waters Sb(III), Sb(V), monomethylstibonic acid, and dimethylstibinic acid (the latter two are due to microbial activity)(De La Calle-Guntinas et al. 1995). In view of the high toxicity of antimony, a very low maximal admissible level of Sb in drinking water is imposed (the EC maximum admissible level of Sb in drinking and surface water is 10 xg/L). As Sb(III) is more toxic than Sb(V) and inorganic species are more toxic than organic ones, a distinction between the different species becomes mandatory. 

Some people object to the chlorination of water, and prefer to drink bottled spring water. There is controversy over the level of risk associated with chlorination, and over the possible benefits of spring water. For example, hypochlorous acid reacts with traces of organic materials in the water supply. These reactions can produce toxic substances, such as chloroform. Supporters of chlorination believe that these substances are present at very low, safe levels, but opponents of chlorination disagree. Complete the following practice problems to help you decide on your own opinion of chlorination. 

However, the chief source of chloroform is probably chlorination of naturally formed humic acids, especially in the tropics and subtropics. The World Health Organization has set a limit of 30 fig L-1 as the acceptable chloroform concentration in drinking water. Overzealous use of chlorine to sterilize sewage-plant effluent has also led to major fish kills in rivers. 

Volatile organic compounds (VOCs), especially trihalomethanes, are frequently found in drinking water due to the chlorination of humic acids. When UV irradiation is applied to the pre-ozonation of humic acids, the decomposition of VOC precursors increases (Hayashi et al., 1993). The ozonation rates of compounds such as trichloroethylene, tetrachloroethylene, 1,1,1-trichloroethane, 1,2-dichloroethane, and 1,2-dichloropropane were found to be dependent on UV intensity and ozone concentration in the aqueous phase by Kusakabe et al. (1991), who reported a linear relationship between the logarithmic value of [C]/[C0] and [03]f for 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene. The other two organochlorines followed the same first-order kinetics with and without UV irradiation (Kusakabe et al., 1991). Thus, the decomposition rate can be expressed as ... 

The acute toxicity of phenoxy-acid herbicides to humans and aquatic organisms is relatively low [87]. The USEPA maximum residue level for 2,4-D in drinking water is 70 000 ng/L, and the National Academy of Sciences has recommended a maximum concentration in water for protection of aquatic life of 3000 ng/L [78]. No Canadian guidelines for the protection of aquatic life and drinking water were exceeded (Table 8). 

The World Health Organization recommends that the total concentration of PAHs in drinking water should not exceed 10ngL 1. The ozonation of the above two PAHs, plus benzo[ ]pyrene, in water solution was examined experimentally as a function of pH and concentration of radical scavenger (tert-butanol). Acidic pH values accelerate the disappearance of the PAHs. At pH 2, the direct ozonolysis rates were approximately 33000M-1 s-1 for benzopyrene, 11 000 M-1 s 1 for chrysene, and 45 M 1 s 1 for fluorene <2004MI453>. 

It should be noted that the human body does possess natural barrier systems to prevent aluminum intake. There are various physiological ligands, such as transferrin, citrate, and silicilic acid, which are efficient buffers in preventing the intake of aluminum under natural conditions [28]. Yet the formation of TFA requires only trace amounts of aluminum, and the bioavailability of aluminum to living organisms is increasing. Fluorine, of course, is readily available in drinking water. 

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