【摘要】 为了解东平湖菹草-上覆水-沉积物系统中重金属汞（Hg）和砷（As）的含量特征及相互关系,于2015年5月菹草生长的旺盛期在东平湖沿湖采集了33个点位的菹草、上覆水和表层沉积物样品,测定了Hg和As的总量,并采用生物富集系数法评价了菹草对上覆水和表层沉积物中Hg和As的富集能力.结果表明,东平湖上覆水中Hg和As浓度的均值分别为0.769μg·L^-1和7.86μg·L^-1,以地表水环境质量Ⅲ类水标准（GB 3838—2002）为参比,As全部达标;Hg超标率为73.3%,其均值是Ⅲ类水标准值的7.7倍.表层沉积物中Hg和As的含量均值分别为0.072 mg·kg^-1和17.09 mg·kg^-1,分别为山东省土壤背景值的3.6倍和1.8倍.菹草中Hg和As的含量均值分别为0.169（干重）和2.11 mg·kg^-1（干重）.菹草对上覆水、表层沉积物中Hg、As的富集系数空间差异性较大,且对上覆水中Hg和As的富集系数（16.2—2581.9）远高于对表层沉积物中的富集系数（0.07—26.2）.表层沉积物中Hg、As与有机质之间均呈显著正相关性,但Hg、As在菹草-上覆水-沉积物系统中相关性不显著,说明了该系统中Hg、As迁移的复杂性.更多还原

【Abstract】 In order to understand the concentrations and correlations of mercury（Hg） and arsenic（As）in the Potamogeton crispus（P. crispus）-overlying water-sediment system of Dongping Lake, P. crispus, overlying water and surface sediment samples were collected in 33 sampling sites during the vigorous growing period of P. crispus in May, 2015. The total concentrations of Hg and As in the samples were analyzed, and the bioconcentration factors（BCFs）were calculated to assess the enrichment of Hg and As in overlying water and surface sediments by P. crispus. The results showed that the average concentrations of Hg and As were 0.769 and 7.86 μg·L^-1 in the overlying water, respectively. The As concentrations in the overlying water samples were all lower than the class Ⅲ standard value of National Environmental Quality for Surface Water（GB 3838—2002）, while the mercury concentrations in 73.3% samples exceeded the standard value and the average concentration of Hg was about 7.7 times of the standard value. The average concentrations of Hg and As in the surface sediments were 0.072 and 17.09 mg·kg^-1 respectively, which were about 3.6 and 1.8 times of the soil background values of Shandong Province. The average concentrations of Hg and As in P. crispus were 0.169 mg·kg^-1 and 2.11 mg·kg^-1 based on the dry weight. The BCFs of P. crispus for Hg and As in the overlying water and surface sediments showed great spatial difference, and the BCFs（16.2—2581.9） of P. crispus for Hg and As in the overlying water were far higher than those（0.07—26.2） in the surface sediments, indicating that P. crispus had higher enrichment capacities for Hg and As in the overlying water than in the surface sediments. The concentrations of mercury, arsenic and organic matter in the surface sediments were significantly positively correlated with each other, neither of Hg and As had significant correlations within the P. crispus-overlying water-sediment system, which indicated the complexity of the transportation of Hg and As in the system.更多还原