Simulation of Release of Cr and Pb from Solidified Sediment of River and Lake under Nature Conditions

Soil column tests were used to simulate the release of chromium and lead ions from the solidified/stabilized residual soil in nature conditions. Test conditions involved temperature,rainfall,rainfall pH value and light intensity. The duration of the test was 110 days. Every 10 days,a simulated rainfall test was carried out and the samples were taken. The soil samples and leachate samples were taken at each time,and the contents of heavy metals in the leachate and overflow were measured and analyzed. The results showed that relatively high total content of Cr and Pb in the residual soil. With the passage of the test time,the leaching rate of chromium ion was almost unaffected by natural factors under different test conditions,and the cumulative leaching rate of chromium ion was stable after 30 days of the test; and the leaching rate of lead ion was also in a stable state. Under different experimental conditions,the leaching rate at different stages was unaffected by natural factors,but the cumulative leaching rate of lead ion increased until 90 days. Therefore,chromium ions of sediments of rivers and lakes were leached and dynamic equilibrium preferentially,in same nature conditions.