中国农业大学学报2017，Vol.22Issue(7)：78-89,12.DOI:10.11841/j.issn.1007-4333.2017.07.10
城市河道不同深度沉积物对氨氮的吸附-解吸特征
Study on the adsorption/desorption characteristics of different depth sediments for ammonia nitrogen in urban river
摘要
Abstract
In view of the problem that it is difficult to determine whether or not need dredge to govern urban polluted river,indoor research of batch equilibrium static and the Langmuir,Freundlich and Henry model simulation were conducted.And the research materials were sediments from different depths of three typical sections in North Canal,Tongzhou District,Beijing,including Tugou,Yulin Village and Hehe Station were taken as study materials.Thermodynamic behaviors of adsorption and desorption for ammonia nitrogen were studied under eight ammonia nitrogen solution concentration gradients of 20,40,80,160,200,320,400 and 600 mg/L.The results show that:1) Adsorption and desorption processes fitted well with the Langmuir,Freundlich and Henry model with correlation coefficient R2 ＞ 0.85;2) The sediments' maximum adsorption capacities for ammonia nitrogen of typical sections,whose depth were respectively 0-20,20-40 and 40-60 cm,were 1 184.60-26 168.00,343.46-648.00 and 228.10-462.05 mg/kg.Therefore,0-20 cm sediments' adsorption potential was the biggest.And their maximum desorption capacities were 178.11-367.52,98.45-329.62 and 78.58-148.51 mg/kg,respectively.Thus,the 0-60 cm sediments' desorption potential had little difference;3) The adsorption constants of Langmuir model at different depths in ascending order was kL(0-20 cm),kL(20-40 cmn) and kL(40-60 cmn).The sort of n,which was adsorption constant of Freundlich model in ascending order was n(0-20 cm),n(20-40 cm)and n(40-60cm).Above results reflected that the greater the depth of sediment was,the better the adsorption performance was;The desorption ratio of three different depth sediments in ascending order was n(0-20 cmn),n(20-40 cm) and n(40-60 cme）,which reflected that the greater the depth of sediment was,the bigger the degree of desorption for ammonia nitrogen was;4) About magnitude relation of the ammonia nitrogen mass concentration between sediments' adsorption/desorption critical state and overlying water body,Tugou section's at 0-40 cm depth was greater;Yulin Village and Hehe Station sections' at 0-60 cm depth were less than overlying water body.Dynamic balance for ammonia nitrogen existed in the sediments' adsorption/desorption processes.This study provided theoretical guidance for dredging river management.关键词
城市河道/沉积物/氨氮/吸附/解吸/沉积物深度Key words
urban river/sediment/ammonia nitrogen/adsorption/desorption/depth of sediment分类
资源环境引用本文复制引用
胡洁蕴,李淑芹,李云开,郎琪,丁璨..城市河道不同深度沉积物对氨氮的吸附-解吸特征[J].中国农业大学学报,2017,22(7):78-89,12.基金项目
水利公益性行业科研专项(201401054) （201401054）
