水动力扰动作用对太湖水体胶体相痕量金属浓度影响的模拟

在水槽中模拟研究了太湖中动力扰动作用引发底泥再悬浮对水体Cd、Cu、Pb、Fe、Mn、Zn等痕量金属的胶体相浓度的影响.结果表明,上覆水各元素的胶体相浓度在模拟扰动22h后均达最高值,其中,胶体相Cd、Fe、Cu、Mn浓度均与水动力扰动强度显著正相关(r=0.799、0.709、0.820、0.788,P=0.001、0.007、0.001、0.001),胶体Pb、Zn浓度均与水动力扰动作用不相关(r=0.542、0.523,P=0.056、0.067);水动力作用主要通过改变上覆水各痕量金属总量和胶体有机碳(COC)浓度而影响胶体相痕量金属的浓度,而且,其影响存在一定的滞后效应;由于上覆水中COC浓度低于太湖水体,使得其对胶体相痕量金属浓度的影响比在太湖中显著.

Effects of hydrodynamics on colloidal trace-metal concentrations in Taihu Lake,China

The effects of hydrodynamics on the concentrations of the colloidal trace metals Cd,Cu,Pb,Fe,Mn and Zn in Taihu Lake were studied by hydrodynamic disturbance simulation. It was found that concentration of each colloidal trace metal in the overlying water reached a peak after 22-hours of continuous disturbance. Concentrations of colloidal Cd,Fe,Cu and Mn were significantly correlated with disturbance intensity (r=0.799,0.709,0.820,0.788; p=0.001,0.007,0.001,0.001),while the concentrations of colloidal Pb,Zn were not so significantly affected (r=0.542,0.523; p=0.056,0.067). Hydrodynamics affected colloidal trace-metal concentrations mainly by changing the total trace-metal contents and colloidal organic carbon (COC) contents,which lagged a short period behind the hydrodynamics. Effects of COC on colloidal trace-metal contents in the simulation were stronger than in the real situation at Taihu Lake,since the COC content in the lake water is higher than that in the experiment.