| Heavy metals in lake sediments is an important pollutant. It is important to master the content, regularities of distribution and release mechanism of heavy metals in sediments characteristics of surface sediments are analyzed and assessed with these methods of field investigation, monitoring system and laboratory chemical analysis etc. The main results were given as follows:1. On the whole, there were distinct differences about the concentration of heavy metals in sediments in different period. Compared with winter, four heavy metals concentration in sediment in summer increased in different degree especially the concentration of Cu. In 12 simpling sites collected in two times, the concentration Cu of sediment in summer was more than that in winter. The concentration Zn of site 5,6,11,12 in winter was more than that in summer. For Pb, the concentration in site 7,8 in winter was more than that in summer. For Cd, the concentration in site 4,11 in winter was more than that in summer. The reasons of this phenomena was given as follows: in winter, the Dongping Lake accepted water from the Dawen River but also sluiced to Yellow River; the fluidity of water body increased. The release degree of heavy metals from sediments to overlying water strengthen which made the heavy metals concentration in sediments was low. The reasons for heavy metals concentration in winter more than in summer were these sites were almost in the two sides of Dongping Lake, which influenced less by water body fluidity.2. According to the analysis of interstitial water of surface sediment, the results were given as followed. pH values and concentration s of heavy metals had distinct difference in horizontal direction. pH interstitial water of in summer and winter was neutral and slightly alkaline. pH values in summer was higher than in winter. The average of in summer was 7.35 and the variation range was 6.55~8.45. pH values in winter was 6.87, the variation...
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