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利用再悬浮装置研究不同扰动强度、不同盐度下,再悬浮作用对长江口中、低潮滩沉积物中Hg释放的影响.结果表明,在扰动期间,上覆水环境(pH、Eh、DO、TSS等)剧变.在再悬浮实验中,上覆水中HgD(溶解态汞)和HgP(颗粒态汞)含量分别主要集中在0.152～2.657μg.L-1、0.080～2.722μg.L-1范围内.再悬浮作用使得盐度为4.1‰、8.0‰、10.0‰、13.0‰条件下的中潮滩及盐度为13.0‰条件下的低潮滩都发生了汞释放,释放的汞含量为0.053～0.673μg.g-1,但对盐度为4.1‰、8.0‰、10.0‰条件下的低潮滩汞释放影响并不明显,这反映了上覆水盐度对再悬浮中汞释放具有重要影响.同时,也表明再悬浮作用对长江口中、低潮滩的Hg释放影响也有差异,中潮滩表现出了比低潮滩要明显的汞释放.扰动动力为(210±5)r.min-1时能明显增加汞的解吸,从而对汞释放产生影响.
The effect of resuspension on the release of Hg from sediments in the middle and low tidal flats of the Yangtze Estuary was studied using resuspension devices at different turbulence intensities and salinities. The results showed that during the disturbance period, the overlying water environment (pH, Eh, DO, TSS, etc.) In the resuspension experiment, the content of HgD (dissolved mercury) and HgP (particulate mercury) in the overlying water mainly concentrated in the range of 0.152-2.657μg.L-1.0.080-2.722μg.L-1, respectively. Resuspension results in release of mercury from the tide beach with salinity of 4.1 ‰, 8.0 ‰, 10.0 ‰ and 13.0 ‰, and low tide beach with salinity of 13.0 ‰, and the released mercury content is from 0.053 to 0.673 μg. g-1, but not obvious for low-tide beach mercury release under the salinity of 4.1 ‰, 8.0 ‰ and 10.0 ‰, which indicates that over-water salinity has an important influence on mercury release from resuspended water. The effects of resuspension on Hg release in the middle and low tidal flats of the Yangtze Estuary are also different, and the tide beach shows a significant release of mercury than the low tide flats. The desorption of mercury can be significantly increased when the disturbance power is (210 ± 5) r.min-1 , Thus affecting the release of mercury.