浙江某农场土壤和沟渠沉积物对氨氮的吸附研究  

Property of Ammonium Adsorption on Sediments in Ditches and Adjacent Soils

作　　者：翟丽华[1] 刘鸿亮[2] 徐红灯[3] 席北斗[2] 

机构地区：[1]清华大学环境科学与工程系,北京100084 [2]中国环境科学研究院,北京100012 [3]北京化工大学环境工程系,北京100029

出　　处：《环境科学》2007年第8期1770-1773,共4页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2002CB410800-07;2002CB412302;2005CB724203)

摘　　要：通过静态吸附实验，研究农田土壤及沟渠沉积物对氨氮的吸附作用．实验表明，水相氨氮浓度为5—100mg／L时，风干农田土壤、风干沟渠沉积物及新鲜沟渠沉积物3种吸附剂的吸附等温线均呈良好线性关系，并符合Freundlich吸附模式；农田土壤与沟渠沉积物的氨氮背景含量分别为12mg·kg^-1和92mg·kg^-1，并且农田土壤对氨氮的吸附系数为8．21，而风干沟渠沉积物与新鲜沟渠沉积物吸附系数分别为5．42与6．84，因此，土壤的吸附能力要大于沟渠沉积物，后两者的吸附能力相近．对3种吸附剂吸附机制的讨论表明，吸附特性与界面性质相关，实验氨氮浓度范围内吸附作用主要为离子交换．相同实验条件下，当初始氨氮浓度较大时，随温度升高，3种吸附剂对氨氮的平衡吸附量减小，对氨氮的吸附为弱放热过程．Static adsorption experiments were performed to investigate the adsorption characteristics of ammonium on soils and ditch sediments. Air-dry soil, ditch sediment and wet ditch sediment were used as three kinds of sorbents. The experiments showed that the adsorption isotherms on three sorbents agreed well with linear relation and conformed to Freundlich isotherm ; the adsorption ability of soil was stronger than that of ditch sediment, and for the blank ammonium concentrations of soil were higher than that of sediments. The adsorption mechanisms were related to the characteristics of interface, and ion exchange was the main adsorption function under certain concentration range. Effects of temperature on the adsorption of sorbents were observed. The results showed that the quantity of absorbed ammonium slightly decreased with the increasing of temperature under higher concentrations of ammonium.

关 键 词：沟渠沉积物 氨氮 吸附 温度 

分 类 号：X522[环境科学与工程—环境工程]