On the basis of gas chromatography(GC) coupled with a short capillary column and an electron capture detector ( ECD), a simple and rapid method for the determination of five haloaceric acids ( HAAs ) in drinking...On the basis of gas chromatography(GC) coupled with a short capillary column and an electron capture detector ( ECD), a simple and rapid method for the determination of five haloaceric acids ( HAAs ) in drinking water was developed by the optimization of derivation conditions and the modification of gas chromatographic program. HAAs formarion potential(HAAFP) of the reaction of humic acid with chlorine was determined via this method. The major advantages of the method are the simplicity of chromatographic temperature program and the short run time of GC. Dichloroaceric acid(DCAA) and Trichloroacetic acid(TCAA), which were detected in the determination of HAAFP, were rapidly formed in the first 72 h of the reaction of humic acid with chlorine. HAAFP of the reaction of humic acid with chlorine increased with the increase in the concentrations of humic acid and chlorine. The average HAAFP of the reaction of humic acid with chlorine was 39.9μg/mg TOC under the experimental conditions. When the concentration of humic acid was 4 mg/L, the concentration of HAAs, which were produced in the reaction of humic acid with choline, may exceed MCL of 60μg/L HAAs as the water quality standards for urban water supply of China and the first stage of US EPA disinfecrion/disinfection by-products(D/DBP) rule; when the concentration of humic acid was 2 mg/L, the concentration of HAAs may exceed MCL of 30 μg/L HAAs for the second stage of US EPA D/DBP rule. When humic acid was reacted with chlorine dioxide, only DCAA was detected with a maximum concentration of 3.3 μg/L at a humic acid content of 5 mg/L. It was demonstrated that the substitution of chlorine dioxide for chorine may entirely or partly control the formation of HAAs and effectively reduce the health risk associated with disinfected drinking water.展开更多
The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution syst...The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg.m), showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 μg/L.展开更多
基金Supported by the Key Project of Shanghai Municipal Committee of Science and Technology(No05JC14059) the Key Pro-ject of Small Town Development of Ministry of Science and Technology of China(No2003BA808A17)
文摘On the basis of gas chromatography(GC) coupled with a short capillary column and an electron capture detector ( ECD), a simple and rapid method for the determination of five haloaceric acids ( HAAs ) in drinking water was developed by the optimization of derivation conditions and the modification of gas chromatographic program. HAAs formarion potential(HAAFP) of the reaction of humic acid with chlorine was determined via this method. The major advantages of the method are the simplicity of chromatographic temperature program and the short run time of GC. Dichloroaceric acid(DCAA) and Trichloroacetic acid(TCAA), which were detected in the determination of HAAFP, were rapidly formed in the first 72 h of the reaction of humic acid with chlorine. HAAFP of the reaction of humic acid with chlorine increased with the increase in the concentrations of humic acid and chlorine. The average HAAFP of the reaction of humic acid with chlorine was 39.9μg/mg TOC under the experimental conditions. When the concentration of humic acid was 4 mg/L, the concentration of HAAs, which were produced in the reaction of humic acid with choline, may exceed MCL of 60μg/L HAAs as the water quality standards for urban water supply of China and the first stage of US EPA disinfecrion/disinfection by-products(D/DBP) rule; when the concentration of humic acid was 2 mg/L, the concentration of HAAs may exceed MCL of 30 μg/L HAAs for the second stage of US EPA D/DBP rule. When humic acid was reacted with chlorine dioxide, only DCAA was detected with a maximum concentration of 3.3 μg/L at a humic acid content of 5 mg/L. It was demonstrated that the substitution of chlorine dioxide for chorine may entirely or partly control the formation of HAAs and effectively reduce the health risk associated with disinfected drinking water.
基金supported by the High-Tech Research and Development Program (863) of China(No.2007AA06A414)the National Basic Research Development Program (973) of China(No. 2006CB403306)the Chinese Academy of Sciences Major Projects of Knowledge Innovation Program(No. KZCX1-YW-06)
文摘The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg.m), showed that the organic compounds in different source waters exhibited different reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 μg/L and the THMFP ranged from 29 to 259 μg/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 μg/L.