再悬浮底泥污染物在水体中的分层释放特征  

Stratified release characteristics of sediments contaminants during re-suspension in water column

作　　者：王道增[1] 周旭[1] 朱红伟[1,2] 程鹏达[1] 钟宝昌[1] 

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072 [2]中交疏浚技术装备国家工程研究中心有限公司,上海201208

出　　处：《水动力学研究与进展（A辑）》2014年第5期592-598,共7页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金重点项目(11032007);上海市科技攻关项目(11231200300)~~

摘　　要：通过环形水槽实验,该文研究了水流条件和含沙量对悬浮泥沙污染物在水体中动态释放的影响。结果表明,悬浮泥沙污染物的分布和流速及泥沙浓度有着"亦步亦趋"的紧密关系,流速变化和泥沙浓度变化能明显地改变水体中污染物的释放特征。水流流速是改变水体污染物浓度分布的主要动力因素,水槽中清水和挟沙水流在流速的垂向分布上有着显著的不同,挟沙水流靠近水表面的流速比平均流速更大,近底流速更接近于平均流速。在一定的水力条件和含沙量条件下,悬浮黏性泥沙在水体中存在明显的分层结构,浓度突变点在水深的三分之一处,并随深度向水面及水底变小。污染物的垂向分布形成略滞后于泥沙浓度分层和水流流速分层,且污染物的垂向浓度分布更加均匀。水流的流速越大,泥沙污染物的分布随着深度的变化差异也越大;水体的含沙量越大,泥沙污染物的垂向分布越趋向于均匀。The effects of flow conditions and sediment concentration on the dynamic release of pollutants were studied through an annular flume. The results showed that distribution of contaminants had picked up the pace of flow velocity and suspended sediment concentration. The changes of flow velocity and sediment concentration distribution could significantly alter pollutants release characteristics. The current velocity was an important dynamic factor on variation of pollutants distribution. The vertical distribution between the water and sediment-laden flow velocity had a significantly different, surface flowing velocity of sediment-laden water was greater than the average flow velocity while flow rate near the bottom was closer to the average velocity. Under certain hydraulic conditions and sediment concentration, cohesive sediment presented obvious stratified structure, the concentration of point mutations was at a depth of one-third, and became smaller with the depth of the water to surface and underwater. The vertical distribution of contaminants lagged slightly behind sediment one, and its vertical distribution was more uniform. The faster the flow velocity was, the bigger the difference variation of distribution of sediment contaminants with depth was. On the condition of higher sediment concentration, sediment contaminant distribution tended to be more uniform.

关 键 词：环形水槽 挟沙水流 泥沙浓度 污染物 垂向分布 

分 类 号：X501[环境科学与工程—环境工程] TV131.2[水利工程—水力学及河流动力学]