外文翻译原文 吕卓峰.docVIP

Investigation and assessment of volatile organic compounds in water sources in China Abstract 456 water samples collected from 152 water sources in 2006 were analyzed for 21 volatile organic compounds (VOCs). Concentrations of 21 VOCs ranged from below method detection limits of the laboratory to 7.65 μg/L (toluene), but seldom exceeded the concentration limits set in the National Drinking Water Quality Standards (GB5749-2006) or the National Environmental Quality Standards for Surface Water (GB3838-2002) of China. Of the 21 individual VOCs analyzed, 11 VOCs were detected in at least one sample at or above 1.0 μg/L; 6.6% of the water samples had a detection of at least one VOC at or above 1.0 μg/L, and 2.6% had a detection of at least two VOCs at or above 1.0 μg/L. Based on the statistical data of detection frequencies above the method detection limits,75% of the samples detected at least one VOC, and 65% of the samples detected at least two VOCs. Chloroform, toluene, and 1,2-dichloroethene were the three most frequently detected VOCs, with detec. Keywords:Volatile organic compounds Water sources Surface water Groundwater China Introduction Volatile organic compounds (VOCs) are carboncontaining organic chemicals that have low water solubility and high enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. Due to their volatility at low temperatures, VOCs are much more mobile,therefore, much more likely to be released to the environment. Volatile organic compounds are used extensively in urban areas and occur in numerous products including fuels, solvents, paints, adhesives, deodorants, refrigerants, and combustion exhausts (Ehrenfeld 1986; Howard 1991a, b; Golfinopoulos et al. 1998; Lopes and Bender 1998). Volatile organic compounds are released into the environment during their production, distribution, storage, handling, and use and can enter both surface water and groundwater from many point and nonpoint sources (L