【摘要】 依据表层沉积物样品测定结果,着重分析了东平湖表层沉积物有机质浓度的空间分布特征及其影响因素,并结合历史数据对20世纪90年代以来东平湖沉积物有机质浓度变化状况进行了研究。同时,对东平湖沉积物有机质地球化学行为的环境意义进行了探讨。研究结果表明:东平湖表层沉积物中有机质浓度为0. 74%～2. 83%,平均值为1. 56%。在空间上具有湖区东南向西北方向舌状递减趋势。大汶河来水所携带的外源有机质输入是控制东平湖有机质分布特征的主要因素,养殖业与旅游业的发展以及区域性污废水排放等因素也有一定影响。受外源污染物入湖量显著降低等因素的影响,21世纪以来东平湖有机质浓度较20世纪90年代明显下降。此外,有机质矿化过程中释放的营养盐增加了东平湖水质恶化及水体富营养化的风险,但沉积物中有机质对重金属的吸附、络合作用则有效降低了东平湖重金属污染危害。更多还原

【Abstract】 This paper aimed to understand the distribution of orgainic matter( OM) and its influencing factors in Dongping Lake,a shallow eutrophic lake located in the lower reaches of the Yellow River. The environmental significance of geochemical behavior of OM was also discussed. Thirty-three surface sediment samples( 0 ～ 2 cm) from the lake and five documentary records were collected. The results showed that OM in the surface sediments represented a strong spatial variability( 0. 74% ～2. 83%). The highest OM concentration was observed in the south-eastern and north-eastern region of the lake and decreased gradually away from the mouth area of Dawen River,suggesting that the input of exogenous OM carried by the Dawen River was a critical limiting factor for the lake’s OM distribution. Compared with the OM concentration survey results of Dongping Lake in the 1990 s,the OM content in the sedments of Dongping Lake decreased significantly since the commence of the 21 st century,which may be affected by factors such as the meaning decrease of point source pollution. In addition,nutrients such as nitrogen and phosphorus was released from the sediments along with mineralization of OM,which increased the risk of eutrophication. However,the presence of OM was helpful to the improvement of water environment. Some heavy metals can be absorbed or sequestered by OM,thereby reducing the risk of heavy metal pollution.更多还原