Chemical Research in Chinese Universities ›› 2013, Vol. 29 ›› Issue (1): 42-47.doi: 10.1007/s40242-013-2200-1

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Thermodynamic Characteristics and Mechanisms of Heavy Metals Adsorbed onto Urban Soil

LI Yue-ming, KANG Chun-li, CHEN Wei-wei, MING Lian, ZHANG Sai, GUO Ping   

  1. Key Lab of Groundwater Resources and Environment, Ministry of Education, College of Environment and Resources, Jilin University, Changchun 130012, P. R. China
  • Received:2012-05-21 Revised:2012-08-22 Online:2013-02-01 Published:2013-01-23
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.40971248).

Abstract:

The thermodynamic characteristics of heavy metals adsorbed onto urban soil and the relative adsorption mechanisms were studied by the batch experiment. The results show that there existed dynamic adsorption-desorption equilibrium processes of cationic and anionic ions of heavy metals onto urban soil, which may have an impact on the pH of the adsorption system. The amounts of heavy metals adsorbed onto urban soil increased with the increase of the equilibrium concentration, but their adsorption amounts were not the maximum adsorption amounts. The higher the pH was, the greater the adsorption capacity of the urban soil at the same equilibrium concentration was, and the adsorption amounts of heavy metals onto urban soil followed the order of Pb>Cu>Cd>Zn>Ni. There were coordination reaction, hydrolysis reaction, exchange reaction in the adsorption processes of heavy metals onto urban soil. With the increase of pH, the influencing degree of pH on the different reactions of heavy metals in the soil increased, meanwhile the effects of other physicochemical properties of soil on the adsorption of heavy metals were weakened.

Key words: Urban soil, Heavy metal, Adsorption, pH