长江武汉段水体邻苯二甲酸酯分布特征研究

分别采集了丰水期和枯水期时长江武汉段30个点位上的河水和沉积物样品,用气相色谱法对样品中的邻苯二甲酸酯类(PAEs)含量进行测定,分析其在长江武汉段水体中的分布特征.结果表明,1]丰水期时支流和湖泊水中PAEs浓度范围为0.114～1.259 μg/L,枯水期时为0.25～132.12 μg/L.丰、枯水期干流水相中PAEs的浓度范围分别为0.034～0.456 μg/L和35.73～91.22 μg/L,均有沿程升高的趋势.2]枯水期支流和湖泊沉积相中PAEs浓度范围为6.3～478.9 μg/g,邻苯二甲酸二丁酯(DBP)、邻苯二甲酸双(2-乙基己基)酯(DEHP)有由水中向沉积物中迁移的较强趋.丰、枯水期干流沉积相中PAEs浓度范围分别为151.7～450.0 μg/g和76.3～275.9 μg/g;丰水期时DBP由沉积相向水相迁移,枯水期时DEHP在沉积物中未达到吸附最大.3]5种被研究的邻苯二甲酸酯类化合物中, DBP和DEHP是主要污染物,国家地表水环境质量标准规定这2种物质的标准限值分别为0.001、0.004 mg/L,丰水期时所有的干支流均符合此标准,枯水期时干支流超标率为82.4%.4]长江武汉段PAEs污染水平与意大利Velino河以及黄河中下游水体相近,但丰水期时水相PAEs含量远低于国内外一般水平.

Distribution Characteristics of Phthalic Acid Esters in the Wuhan Section of the Yangtze River

Samples of water and sediment were collected at 30 sites in Wuhan section of the Yangtze River in high and low water period. Phthalic acid esters (PAEs) concentrations in each sample were determined by Gas Chromatography. The results were shown as follows: (1) PAEs concentrations in water phase of lakes and tributaries ranged from 0.114-1.259 microg/L in high water period and 0.25-132.12 microg/L in low water period, while slight increasing trends could be discovered in the main stream (0.034-0.456 microg/L and 35.73-91.22 microg/L in high and low water period, respectively). (2) PAEs concentrations in sediment phase of tributaries and lakes in low water period were from 6.3 to 478.9 microg/g. Di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) both had strong trends from water to sediment phase, and the PAEs concentration ranges of the sediment phase in the main stream were 151.7-450.0 microg/g in high water period and 76.3-275.9 microg/g in low water period; DBP could transfer from sediment to water in high water period, while DEHP still had a potential for adsorption in low water period. (3) Among five studied PAEs compounds, DBP and DEHP were the main pollutants. According to the Surface Water Quality Criteria of China (GB 3838-2002), the limit values of DBP and DEHP for drinking water sources were 0.001 and 0.004 mg/L. All water samples in high water period were up to standard while the standard-exceeding sections accounted for 82.4% in low water period. (4) The PAEs pollution of the Wuhan section was similar to the Velino lake in Italy or the middle and lower stream of the Yellow River in China. However, PAEs concentrations in water phase of the Wuhan section in high water period were lower than most water bodies at home and abroad.