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Swimming pool water treatment in general includes flocculation, sand filtration and subsequent disinfection. Chlorite, chlorate and bromate are disinfection by-products of swimming pool water treated by chlorine species or ozone. They are responsible for adverse effects on human health and their analyses in swimming pool water are necessary. The simply and fast suppressed ion chromatography simultaneous separation and conductivity determination of chlorite, chlorate, bromate, fluoride, chloride, nitrate, bromide, phosphate and sulfate in disinfected swimming pool water has been described. The separation was performed on an anion-exchange column with 1.0 mM Na₂CO₃ + 3.2 mM NaHCO₃ as eluent, and determination by suppressed conductivity detection. Chlorite has been found in 5 analyzed samples, chlorate in all of them, and bromate in the 2 samples originated from ozonated swimming pool water. Ions were analyzed in the wide concentrations range from 0.05 mg L⁻¹ (bromate) up to 300 mg L⁻¹ (chloride, sulfate). Linearity of disinfection by-products was checked up to 2.0 mg/L (chlorite), 30 mg L⁻¹ (chlorate) and 0.5 mg L⁻¹ (bromate) with a 50 μL injection loop (r²= 0.9966 – 0.9985), respectively. Fluoride, chloride, nitrate, bromide, phosphate, and sulfate did not interfere with target anions. The detection limits of ClO₂⁻, ClO₃⁻ and BrO₃⁻ were on the levels: 0.19 mg L⁻¹, 0.69 mg L⁻¹ and 0.006 mg L⁻¹, respectively. The mean recoveries of target anions for spiked samples were 85% – 110% and coefficient of variation of analyzed anions do not exceed 4.72%. The concentrations of inorganic disinfection by-products differ from 0.31 mg L⁻¹ up to 31.92 mg L⁻¹.
One possible method of drinking water treatment is chlorine dioxide disinfection. This technology, however, requires reliable control of its byproducts, including chlorite ions., which pose a threat to human health. In this paper an original procedure for flow indirect determination of chlorite in drinking water was described. This method relies on oxidization of chlorite ions by iron(III) in acid environment measurement of the spectrophotometric signal for the phenanthroline/iron(II) complex. The determinations were carried out by flow analysis with the use of a dedicated set of flow instruments. The method was used for analysis of natural samples collected from various water intakes in Kraków. The new analytic approach was compared with the routinely applied ion chromatography method.
Many drinking water utilities are changing their primary disinfectant from chlorine to alternative disinfectants such as ozone, chlorine dioxide and chloramines, which reduce regulated trihalomethanes and some organochlorine compounds levels, but often increase levels of others potentially toxicologically important compounds. The hazardous inorganic oxyhalide by-products are bromate, chlorite and chlorate, some of which have been classified as probable human carcinogens. The most important of these is bromate, formed when source waters containing bromide are ozonated. Chlorite is formed when chlorine dioxide is used, whereas chlorate is formed when chlorine, chlorine dioxide, hypochlorite acid or chloramine is used to disinfect drinking water. This paper is a review of ion chromatographic separations of these inorganic oxyhalide disinfection byproducts in drinking water and their detection using conductivity, UV/Vis or mass spectrometry detection. The critical comparison of ISO, US EPA and other methods including limits of detection, availability and costs of analyses is given. Furthermore, a review of papers concerning ion chromatography determination of inorganic oxyhalides in drinking water published during the last 20 years is presented.
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