京杭运河镇江—无锡段沉积物不同粒径颗粒物镉的分布、吸附及影响因素  

Distribution,Adsorption and Related Factors of Cadmium on Particles with Size Distribution in the Sediments in Zhenjiang—Wuxi Section of Beijing-Hangzhou Canal

作　　者：万可可 易齐涛[1,2] 王聪慧 卜阳时娇 WAN Ke-ke;YI Qi-tao;WANG Cong-hui;BUYANG Shi-jiao(School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China)

机构地区：[1]安徽理工大学地球与环境学院,淮南232001 [2]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《科学技术与工程》2020年第12期5005-5011,共7页Science Technology and Engineering

基　　金：流域水循环模拟与控制国家重点实验室开放基金(IWHR-SKL-KF201805)。

摘　　要：城市运河受水动力扰动强烈,沉积物再悬浮频繁并易于导致颗粒物发生粒径分选,从而影响各类污染物质的迁移转化过程。研究在京杭运河的镇江-无锡段设置3个采样点J1、J2和J3,对表层沉积物镉(Cd)的含量进行分析。以J2采样点为代表,采用湿沉降法对沉积物进行粒级分选,分离出50~150、30~50、10~30、5~10、<5μm 5组不同粒径颗粒物,以此为基础对各粒径组颗粒物Cd的含量及相关理化指标有机质(OM)、铁(Fe)、铝(Al)进行了测定,并对Cd的吸附动力学、等温吸附特征进行了研究,分析了理化性质对吸附特征参数的影响。结果表明:镇江-无锡段沉积物Cd的含量为0.61~0.95 mg/kg,为太湖背景值的2~3倍;J2采样点沉积物Cd含量随颗粒物粒径的减少有增加的趋势,其中<5μm粒径颗粒物Cd的含量为1.67 mg/kg;Cd的吸附容量和吸附能力随着颗粒物粒径的减小而增加,OM、铁氧化物和铝氧化物在不同粒径颗粒物上的分异可能是导致其Cd吸附性能差异的重要原因所在。Sediment resuspension frequently occurs in canals between cities,which are usually sieved into different grain size groups influencing the migration of pollutants.The Cadmium(Cd)content in the surface sediments of three sampling sites(J1,J2 and J3)of the Zhenjiang-Wuxi section of Beijing-Hangzhou Canal was analyzed.One sediment sample(J2)was sieved into five different particle size groups of particles,including groups of 50~150,30~50,10~30,5~10,<5μm,through the wet sedimentation method.The adsorption of Cd and related chemical properties of oxidizable matter(OM),aluminum(Al)and ferrum(Fe)were analyzed within the five groups of particles.The results show that the content of Cd in the river ranged from 0.61 to 0.95 mg/kg,around 2~3 times of the background content in Taihu Lake.Cd content increases as the particle size decreases at sites J2,with highest content of 1.67 mg/kg occurred within<5μm particles.Both adsorption capacity and ability of Cd by fine particles are higher than that by coarse particles,probably due to enrichment of OM and non-crystal Fe/Al oxides by fine particles.

关 键 词：沉积物再悬浮 粒径分布 镉 吸附动力学 等温吸附 

分 类 号：X703[环境科学与工程—环境工程]