The Effect of Humic Acid and Fulvic Acid on Adsorption-Desorption Behavior of Copper and Zinc in the Yellow Soil

The adsorption-desorption behavior of copper(Cu) and zinc(Zn) and the influencing factors are very important for the evaluation of migration behavior of Cu(II) and Zn(II) in the soil environment. The study is aimed to research the effect of humic acid (HA) and fulvic acid (FA) on adsorption-desorption behavior of Cu (II) and Zn (II) in the yellow soil. The results showed that the effect of HA and FA on adsorption-desorption behavior of Cu (II) and Zn (II) varies with different concentrations of Cu (II) and Zn (II). In the presence of HA, there is less adsorption amount of Cu (II) in soil. In addition, HA is not conducive to soil Zn-adsorbing at initial low concentration of Zn (II). However, HA is benefit to increase the adsorption amount of Zn (II) in the soil at high concentration. FA has similar effect on adsorption behavior of the Cu (II) and Zn (II). FA is not conducive to the soil adsorption of Cu (II) and Zn (II) at low concentrations. However, FA is benefit to the soil adsorption of Cu (II) and Zn (II) at high concentrations. Besides, Zn (II) adsorbed is harder to be desorbed by the neutral salt solution. Therefore, comparing with Cu (II) adsorbed, the adsorption amount of Zn (II) moves harder in the acidic yellow soil.