长江三角洲地区海相沉积物母质土壤对Cu的吸附解吸特性

分别以长江三角洲地区海相沉积物母质土壤的表层土和心层土为例，考察了其对重金属Cu的吸附、解吸及固定特性，目的是了解其在不同土壤结构的存在形态和迁移特性。研究表明：不同表层土和心层土的铜吸附容量可用Langmuir,Freundlich和Temkin吸附等温方程拟合，其中以Langmuir方程吻合度最高，回归计算出的最大吸附容量与实验结果基本一致;而其解吸动力学大部分符合指数方式。研究发现，大多数土壤的心层土的最大吸附容量大于表层土，解吸量小于表层土；表层土中对Cu的固定吸附量最大的是滩涂泥，最小的是滩砂泥；心层土中对Cu的固定吸附量最大的是滩潮土，最小的是滩砂泥。不同土壤对Cu的固定吸附量存在差异性，这与土壤自身的pH、OM等多种因素有关, 一般pH值大、OM值高的土壤对Cu的固定吸附量越大.

CHARACTERISTICS OF Cu ADSORPTION AND DESORPTION IN MARINE-FACE SEDIMENT MATRIX SOILS IN YANGTZE RIVER DELTA REGIONS

The objective of this study was to investigate the form and spacial distribution of Cu,by analyzing its characteristics in terms of adsorption,desorption and fixation in different marine-face sediment matrix soils in the delta region of the Yangtze River.It was shown that for different kinds of surface and subsurface soils,Cu adsorption was well regressed with the Langmuir,Freundlich and Temkin equations,especially the Langmuir equation,through which the maximum adsorption capacities were in harmony with the experimental results.Meanwhile,the Cu desorption data could be regressed by exponential equation.For most soils,the maximum adsorption capacities of Cu by subsurface soils were larger than those of surface soils,yet their desorption capacities of Cu were less than the latter.The fixed adsorption of Cu for different soils were analyzed: for surface soils,Tantu mud was the maximum of fixed Cu,and the minimum was Tansha mud;for subsurface soils,the maximum was Tanchao mud,and the minimum was Tansha mud.OM,pH and other factors might have an influence on the maximum of fixed Cu of soils.In general,if the soil had higher pH and OM values,its fixed adsorption of Cu was mostly larger than other soils correspondingly.