Study On Characters Of Cu Adsorption/Desorption Of The Principal Type Soils In Yangtze River Delta

After heavy metal entering into the soil, the first and inevitable course is "adsorption and desorption", which is one of the most important physical and chemical courses to control heavy metal activity of soil. It has instructional significance to study adsorption character and adsorption influence factor of heavy metal to forecast environmental effect of heavy metal. It will also provide theoretic basis for establishing environment standard and confirming environmental capacity.This paper classifies the typical soils of Yangtze River Delta and studies adsorption and desorption of Cu to confirm the Cu's adsorption and desorption rules in different type of soils. The rationalization characters of different soils are obviously different, which make the Cu's adsorption and desorption different. Soil's adsorption of Cu will increase as the pH heightens. The result is as following:1. The study shows that if the soil growth in the same mother material but different places, there will be the same soils as well as different ones. As to the same soil produced by the same mother materials, when pH indicator is the same, the adsorption order is depended on the organic matter content of soil itself. The adsorption of Cu of the soil, which is in the same mother material but different soil type, is depended on the pH indicator but not organic matter content. Cu's desorption is not very high in the area where adsorption capacity is low. When the adsorption capacity reaches to a certain level, the desorption capacity and rate will increase obviously, which is related to the nature character of soil-specific adsorption is mainly used in the low adsorption area, while electric adsorption is used in mainly used in the high adsorption area.2. The study shows that Cu's adsorption of cyanotic mud, the same soils produced by the different mother material, is depended on organic matter content of the soil, while the pH indicator will not effect the Cu's adsorption of this type of soil. The adsorption rule of this type of soil is the same. It will increase according to the increase of adsorption capacity. It shows electric adsorption is mainly used in this typeof soil and the maximum desorption capacity is close.3. As to the paddy mud, which is produced by the different mother materials and different soils, the study shows as following: when pH indicator of this type of soil is over 7.5, the adsorption order of soil is not related to the organic matter content of the soil, but directly related to the soil's pH indicator. Cu's desorption of soil has big relationship with soil mother material. The desorption capacity is related to the pH indicator of soil. The desorption will be difficult as the pH indicator increases.