Abstract:

In order to understand the migration and transformation of heavy metal pollutants in the soil covered by different road area vegetation in the Changchun area, the thermodynamics and kinetics of the adsorption of Cu²⁺ and Pb²⁺ in these soils were studied with the batch equilibration method. The results show that the adsorption isotherms of the two heavy metals in different soil both fit the Langmuir equation and Freundlich equation, but both  better fit  the Langmuir equation, which shows that the adsorption process was closer to the monolayer adsorption model. For the  soil covered with the bush vegetation, the saturation adsorption capacities of the Cu²⁺ and Pb²⁺ were the largest, respectively reached 3 429,5 311 mg/kg. Elovich equation can describe the adsorption kinetics processes of the Cu²⁺ and Pb²⁺ in these different soil better, the adsorption rate of the heavy metals into the soil covered with  bush vegetation  was the largest. The adsorption of these metals into the different soil was related to high pH value, CEC, organic matter content, clay content and other physical and chemical
 properties. The results show that  Pb²⁺ was easier to be absorbed by the soil than Cu^2+, which was related to the physical and chemical properties of the heavy metals.

Key words: road area soil, copper, lead, adsorption characteristics