Simulation on release of heavy metals Cd and Pb in sediments
(1. School of Energy Science and Engineering, Central South University, Changsha 410083, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. Changsha Environmental Protection College, Changsha 410004, China)
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. Changsha Environmental Protection College, Changsha 410004, China)
Abstract: The re-release process and the release rate of heavy metals, cadmium and plumbum, which are rich in sediments of a certain water area, were investigated using a combined experimental and numerical method. Results show that the release law of Cd and Pb in sediments is divided into two stages: rapid release and dynamic equilibrium, which is in great agreement with the pseudo second-order kinetic equation with a correlation coefficient R2 above 0.99. As the flow velocity accelerates, the release rate of heavy metals increases. The analysis results indicate that the water quality in the area can exceed the surface water Class V standard less than 3 h, and all but one of the relative deviations between the simulation value and the field survey result are within ±10%.
Key words: sediment; heavy metal pollution; re-release rate; numerical simulation