长江中下游浅水湖泊表层沉积物对氨氮的吸附特征  

Ammonium Adsorption Characteristics onto the Sediments from Shallow Lakes in the Middle and Lower Reaches of the Yangtze River

作　　者：王娟[1] 王圣瑞[2] 金相灿[2] 朱书全[1] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]中国环境科学研究院国家环境保护湖泊污染控制重点实验室,北京100012

出　　处：《农业环境科学学报》2007年第4期1224-1229,共6页Journal of Agro-Environment Science

基　　金：国家重点基础研究发展规划(973)项目(2002CB412304)

摘　　要：在室内模拟条件下,研究了长江中下游浅水湖泊13个表层沉积物对氨氮的吸附动力学和热力学特征,并分析了沉积物理化性质对氨氮吸附特性的影响。结果表明:①沉积物对氨氮的吸附主要在前2h内完成,之后逐渐达到吸附平衡;用多个模型对实验结果进行模拟,除一级反应动力学模型外,其他模型拟合的效果都较好;②用Henry方程能很好地模拟低浓度条件下沉积物对氨氮的吸附,沉积物对氨氮的吸附-解吸平衡浓度变化较大,为0.60￣2.77mg·L-1;③用Langmuir模型对吸附热力学的实验结果进行拟合,达到显著水平,沉积物对氨氮的最大吸附量为294.11～1466.67mg·kg-1;④沉积物对氨氮的最大吸附量Q_(max)取决于沉积物对氨氮的总最大吸附量Qd+Qmax,而沉积物对氨氮的吸附-解吸平衡浓度X0则取决于沉积物对氨氮的本底吸附量Qd;⑤Qmax和Qd+Qmax与沉积物的OM和CEC呈正相关关系,与总氮、总磷和小于0.01mm的粒度分布均呈较差的负相关关系;X0和Qd与沉积物OM、CEC、总氮、总磷和小于0.01mm的粒度分布均呈正相关关系。Adsorption kinetics and isotherms of ammonium onto the 13 sediments taken from shallow lakes in the middle and lower reaches of the Yangtze River were determined, and the effect of physical and chemical properties of the sediments on its ammonium adsorption characteristics was also analyzed. The results indicated that： （1）The process of ammonium adsorption onto sediments mainly occurred within 0-2 h, then attended to a dynamic equilibrium; Three kinetic models can describe the experiment data, and the fitting results by the parabolic diffusion model and the simple Elovich model were the best, that of the First Order model was the worst; （2）The Henry model can well describe the results of the ammonium sorption isotherms at low concentrations, and the adsorption-desorption equilibrium concentration（X0） varied from 0.60 to 2.77 mg·L^-1;（3）The data of the ammonium sorption isotherms at different initial concentration ranges can be fitted by the linear form of Langmuir model remarkably, and the maximal ammonium sorption capacity ranged from 294.11 to 1 466.67 mg·kg^1; （4）Qmax, depended on Qd and Qmax, respectively. （5）Qmax, Qd＋Qmax had positive correlation with OM and CEC, and had negative correlation with TN, TP and the content of fine particle less than 0.01 mm, while, X0, Qd had positive correlation with OM, CEC, TN, TP and the content of fine particle less than 0.01 mm.

关 键 词：浅水湖泊 沉积物 氨氦 吸附量 相关关系 

分 类 号：X524[环境科学与工程—环境工程]