水动力条件对水体自净作用的影响  

The effect of hydrodynamic conditions on the self-purification of water body

作　　者：朱红伟 陈江海 王勇[2] ZHU Hongwei;CHEN Jianghai;WANG Yong(Shanghai Investigation,Design&Research Institute Co.,Ltd,Shanghai 200434,China;Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]上海勘测设计研究院有限公司,上海200434 [2]南京水利科学研究院,南京210029

出　　处：《南水北调与水利科技》2018年第6期97-102,共6页South-to-North Water Transfers and Water Science & Technology

基　　金：国家重点研发计划(2016YFC0401504);国家自然科学基金(11032007;11502138);中国博士后科学基金(2015M581580)~~

摘　　要：通过水槽实验和理论分析,研究了水动力条件对水体自净作用的影响,发现水流流速是影响水体自净作用的主要因素之一,不同断面及水深条件下水体自净作用的差别不是特别明显。分别采用生化需氧量-溶解氧耦合模型和化学一级反应拟合并预测了水质随时间的变化关系。水流流速的增加在一定程度上提高了水体复氧能力,增强了水体的自净作用。当流速超过一个临界值使得底泥再悬浮发生时,水体自净作用在短时间内急剧降低。在引水工程中,合理控制和设计水力参数(流速流量、取水周期及间隔、增加消能水工建筑物)是控制水体水质的有效措施。The effect of hydrodynamic conditions on the self-purification of water body was studied through the water flume experiments and theoretical analysis.It was found that flow velocity was one of the main factors affecting the self-purification of water body,while different section and water depth conditions did not make much difference on the self-purification of water body.We adopted the biochemical oxygen demand-dissolved oxygen coupling model and chemical first-order reaction to predict the variation of water quality with time.To some extent,the increase of water flow velocity improved the reaeration ability of water body and enhanced the self-purification effect of water body.However,when the flow velocity exceeded a certain value causing sediment resuspension,the self-purification effect of the water body decreased sharply in a short time.In a water diversion project,reasonable control and design of hydraulic parameters such as flow velocity and discharge,water intake period and interval,and increase of energy dissipation hydraulic structures are effective measures to control water quality.

关 键 词：水动力 自净作用 流速 底泥再悬浮 引水工程 

分 类 号：TV131.2[水利工程—水力学及河流动力学] X522[环境科学与工程—环境工程]