In situ immobilization of heavy metals by plant polyphenol in metal-contaminated soils:I. Effect on sorption and dissolution of copper
植物多酚物质原位钝化污染土壤重金属的研究 I.对土壤Cu吸持与溶出的影响

The sorption and dissolution of copper in acidic and calcareous soils by two condensed plant polyphenols L and Y were studied. The results showed that plant polyphenols L and Y could increase markedly the sorption and decrease the dissolution of copper for both soils and the effect was more pronounced for calcareous soil than acidic soil. Within the Cu and polyphenol solution concentration ranges studied ,the increase in Cu sorption caused by Y was consistently greater than that by L. The Cu sorption isotherms could be well described by the Freundlich equation. With the presence of plant polyphenols Cu sorption capacity of both soils was 3-6 times higher than that of control. Increasing the polyphenols solution concentration caused a significant enhancement on the sorption of Cu by both soils, especiaug at the range of 0 00mg(C)/L of polyphenol solution, sorption of Cu was increased by 33 3% and 56 6% with a polyphenol solution increment of 100mg(C)/L for L and Y, respectively,in acidic sandy soil, and 14 1% and 21 4% in calcareous soil. An increase in polyphenol concentration significantly increased the sorption of Cu by both soils. Moreover, the increase of Cu sorption caused by plant polyphenols was more obvious in acidic soil with lower pH (pH2-5). In addition, the dissolution of Cu decreased with an increase of the concentration of plant polyphenols for both soils.