Experimental study on the migration and transformation patterns of arsenic and mercury in water level fluctuation zone

Abstract

[Objective] Understanding the migration and transformation patterns of contaminants in the groundwater level fluctuation zone is crucial for uncovering the root causes of groundwater pollution. [Methods] Based on the theory of groundwater solute transport, soil column simulation experiments were conducted to investigate the migration and transformation patterns of arsenic and mercury under different water level fluctuation amplitudes(ΔH=0 cm, 10 cm, 20 cm) in the water level fluctuation zone. [Results] The results showed that the variation amplitude of total arsenic and As(V) concentrations in soil solution at sampling points followed the same trend as the water level fluctuation amplitudes, with an overall performance of column 3(ΔH=20 cm)> column 2(ΔH=10 cm). However, the concentration of mercury in the soil solution was not affected by the water level fluctuation and showed an overall increasing trend. [Conclusion] The result indicate that the periodic fluctuation of the water level mainly affects the characteristics of key environmental factors in the medium of the fluctuation zone, which in turn impacts the migration and transformation patterns of arsenic in this zone. The amplitude of water level fluctuation is positively correlated with the degree of this effect. Therefore, in groundwater arsenic pollution risk assessments, the impact of groundwater level fluctuation on arsenic migration should not be overlooked.

Keywords

water level fluctuation / fluctuation amplitude / water environment / arsenic / mercury / migration and transformation