Research of Effect of Groundwater Table Fluctuation on Migration Law of Cadmium

Abstract

In this paper, we conduct the soil-column experiment on underground soil in a laboratory of Changping, Beijing, to simulate the effect of water table fluctuation on the cadmium migration law after twice pollution. The main job of the experience is to test the adsorption and desorption characteristics of the soil as well as the temporal and spatial distribution of cadmium ions in soil column. The experimental data show that (1) the two kinds of soil used in the test both have a strong adsorption capacity to cadmium ions, and the values could reach to 1026mg/kg and 2804mg/kg. (2) The dominant factor on cadmium ions migration under water table fluctuation is the soil adsorption when a small amount of cadmium ions are poured into soil column. On the other hand, convection plays a significant role in migration when plenty of cadmium ions are injected. (3) When plenty of cadmium nitrate are injected, the concentrations of cadmium ions in fluctuating zone increase with water table rise, and decrease with water table decline. The concentrations of cadmium ions, which exist in the saturated zone decrease when the water table rises and increase with water table decline.

A Critical Review of Groundwater Table Fluctuation: Formation, Effects on Multifields, and Contaminant Behaviors in a Soil and Aquifer System

“…155 Moreover, the concentrations of Cd in the fluctuating zone increase with a rising groundwater table and decrease with a declining groundwater table, while that in the saturated zone decreases with a rising water table. 154 Furthermore, the Cd concentration was also primarily increased when groundwater conditions were oxic and autotrophic nitrate reducing. 155 The rate of oxidation of the top 10 cm soil layer increased with a lower groundwater table, whereas the Cd concentration fluctuated below the Flemish sanitation threshold; when the groundwater table was lowered to only 40 cm, the Cd concentration increased.…”

“…In addition, enhanced groundwater recharge and limited Cd retention capacity by the aquifer matrix were responsible for increased Cd concentrations in groundwater . Moreover, the concentrations of Cd in the fluctuating zone increase with a rising groundwater table and decrease with a declining groundwater table, while that in the saturated zone decreases with a rising water table . Furthermore, the Cd concentration was also primarily increased when groundwater conditions were oxic and autotrophic nitrate reducing .…”

“…The mobilization and migration of heavy metals attached to the surface of mineral particles over time also have not been sufficiently examined. Soil adsorption and convection also play significant roles in the migration of cadmium (Cd) during GTF . In addition, enhanced groundwater recharge and limited Cd retention capacity by the aquifer matrix were responsible for increased Cd concentrations in groundwater .…”

“…Soil adsorption and convection also play significant roles in the migration of cadmium (Cd) during GTF. 154 In addition, enhanced groundwater recharge and limited Cd retention capacity by the aquifer matrix were responsible for increased Cd concentrations in groundwater. 155 Moreover, the concentrations of Cd in the fluctuating zone increase with a rising groundwater table and decrease with a declining groundwater table, while that in the saturated zone decreases with a rising water table.…”