Heavy Metal Adsorption Characteristics of Purple Soil in Water-Level-Fluctuating Zone of the Three-Gorge Reservoir Region

In order to understand heavy metal(including Pb²⁺,Cu²⁺,Zn²⁺,Cd²⁺) adsorption characteristics of purple soil in the water-level-fluctuating zone of the Three-Gorge reservoir region,an experiment was carried out to study heavy metal adsorption behavior of acidic,neutral and calcareous purplish soils under different conditions with the batch sorption method.Results show that(1)with a certain pH,a soil adsorbed heavy metals with strength varying in the order of Pb²⁺>Cu²⁺>Cd²⁺≈Zn²⁺;(2)with a certain pH,the three soils absorbed the same heavy metal with strength in the order of calcareous purplish soils>neutral>acidic,which is in line with the order in surface charge density;(3)Pb²⁺and Cu²⁺ adsorption on the surface of the three soils existed in both static and specific patterns.The specific pattern accounted for 56%,67% and 50% respectively,in the case of Pb²⁺.Static pattern was in dominancy in the case of Zn²⁺and Cd²⁺.