J4 ›› 2012, Vol. 50 ›› Issue (03): 593-.

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Effect of FreezeThaw on the Adsorption of Heavy Metals by Soil

GUO Ping, LI Yang, ZHANG Ying xin, MING Lian, ZHANG Sai, LI Yueming   

  1. Key Laboratory of Groundwater Resourses and Environment of the Ministry of Education,College of Environment and Resources, Jilin University, Changchun 130012, China
  • Received:2012-01-12 Online:2012-05-26 Published:2012-05-28
  • Contact: GUO Ping E-mail:hjxjx@jlu.edu.cn

Abstract:

We used Pb2+ and Cd2+ as target pollutants to  study the effect of freezethawing cycles on the adsorption of heavy metals by soil, decuced the effect mechanisms, and analyzed the effect of  temperature on heavy metal adsorption on freezethaw soils. The results show that the freezethawing cycles reduced the Pb2+ and Cd2+ adsorption  on soil, and changed the slope of Pb2+ and Cd2+ adsorption isotherms. Freezthawing cycles changed the adsorption mechanism of soil from specific adsorption to nonspecific adsorption, and it promotes soil to desorbe and release Pb2+ and Cd2+ to the environment. Freezethaw did not change the therm odynamic property of Pb2+, Cd2+ adsorption on soil, with the rise of temperature, Pb2+ adsorptions on freezethaw soil and untreated soil were increased, which belong to endothermic reaction; but the adsorption of Cd2+ reduced with temperature rise, which belongs to the exothermic reaction. Under the same pH conditions,  the adsorption quantities of Pb2+ and  Cd2+ on freezethaw soil were lower than those on untreated soil.

Key words: heavy metal adsorption; Pb2+; Cd2+; freezethaw

CLC Number: 

  • X142