Xuzhou And Suzhou Soil, Lead, Copper And Zinc Cadmium Adsorption And Desorption Characteristics

With the development of industry and agriculture, heavy metals population is more serious in soils. Pb, Cu ,Zn and Cd are more popular metal contaminations in soil. Xuzhou city is an important coal industry base of south China. Suzhou, which is an important industry concentrated area and famous tourist and culture city in the world. So it is very important study the four heavy metals adsorption and desorption characteristics in the soil of the two areas. The experiments results is important for preventing, remediation and control of Pb, Cu, Zn and Cd contamination.Eight soil samples were collected from the city of Xuzhou namely Wangzhuang Colliery (WZK, paddy soil), Kuihe river (KH, garden soil), Xuzhou Background-1 (XZBG-1, garden soil), Xuzhou Background -2 (XZBG-2, paddy soil), and the city of Suzhou namely Xushuguan-1 (XSG-1, garden soil), Xushuguan-2 (XSG-2, paddy soil), Suzhou Background-1 (SZBG-1, paddy soil), Suzhou Background-2 (SZBG-2, garden soil) for experiment.The static adsorption-desorption experiments of Pb²⁺, Cu²⁺, Zn²⁺and Cd²⁺ from the eight soil samples were conducted under a series of concentration gradients of Pb²⁺, Cu²⁺, Zn²⁺and Cd²⁺, desorbed by 0.01mol/l NaNO₃ when extruding the adsorption equilibrium solution with a force pump after 96 hours in the hermetical glass pillar. The conclusions are as follows: The adsorption values and desorption values increased with the concentration of Pb²⁺,Cu²⁺,Zn²⁺and Cd²⁺ increasing in the eight soils, Significant or extremely significant positive linear relationship were observed between the equilibrium concentration of Pb²⁺, Cu²⁺ - Zn²⁺and Cd²⁺ in soil solutions and adsorption values, the adsorption values and desorption values, desorption rates. The four heavy metals adsorption values and in the four soils of Xuzhou city behaved as WZK > KH >XZBG-2 >XZBG-1. in the four soils of Xuzhou city behaved as SZBG-2 (garden soil) >SZBG-1 (paddy soil) >XSG-1 (garden soil) >XSG-2 (paddy soil) . the adsorption rates of Pb²⁺, Cu²⁺ , Zn²⁺ and Cd²⁺ in all soils all behaved as Cd²⁺ >Pb²⁺> Cu²⁺> Zn²⁺, the desorption rates of Pb²⁺, Cu²⁺ , Zn²⁺ and Cd²⁺, in the four soils of Xuzhou behaved as Cd²⁺> Cu²⁺>Pb²⁺> Zn²⁺, the four soils of Suzhou behaved as Cd²⁺ > Pb²⁺ > Cu²⁺ >Zn²⁺.At the same time, correlative analyses were done in order to explain the effects of the physiochemical properties of the soils on the heavy metals adsorption and desorption. Resultsindicated that heavy metals content, contentrations of organic matter, pH, cation exchange content and soil's granularity etc, have varied degree effect for Pb,Gu, Zn and Cd adsorption and desorption in soils.