疏浚水流扰动作用下的河道底泥污染物释放效应  

Effects of Pollutants Release from River Sediment under Hydro-Dredging Disturbance Conditions

作　　者：朱红伟[1,2] 尚晓 张坤[3] 江帅[1] 

机构地区：[1]中交疏浚技术装备国家工程研究中心有限公司航道疏浚技术交通行业重点实验室,上海200120 [2]中交上海航道勘察设计研究院有限公司,上海200120 [3]城市水资源开发利用(南方)国家工程研究中心,上海200082

出　　处：《净水技术》2014年第2期81-85,共5页Water Purification Technology

基　　金：国家自然科学基金资助项目(10972134;11032007);上海市科技攻关项目(11231200300)

摘　　要：河流湖泊疏浚时,由机械扰动水流造成的底泥再悬浮污染物释放作用十分明显。通过循环长直水槽试验,研究了水动力学条件对底泥污染物内源释放效应的影响。分别在上覆水体静止和流动情况下,分析了水体CODCr的变化规律。结果表明水体的自净作用在动水条件下显著增强。动态水流通过减小底泥-水界面浓度边界层厚度和破坏底泥-水界面底泥表面结构,增大底泥污染物释放速率和通量。底泥CODCr释放量随着流速的增加而增大,随着水深的增加而减小。但是在水深较浅时,波浪会破坏底泥表层结构,引起底泥污染物的再悬浮释放。单位时间单位面积底泥污染物释放量随着时间的增加而迂回减小,底泥内部污染物向泥-水界面的扩散维持了底泥内源释放效应。The effects of hydrodynamic conditions on the pollutant release of sediment were studied. The variation of CODcrunder static and flowing state of the overlying water were analyzed. Experimental results show that CODcr in the overlying water gets a striking increment under the conditions as follow： reducing the thickness of concentration boundary layer near sediment-water interface and destructing the structure of surface sediment, increasing release contaminants rates and the release flux in unit time. The release rates of CODcr increase with flow velocity and decrease with water depth. But at a shallow water depth, the wave will destroy surface sediment structure, and cause sediment resuspension release. The intensity of pollutant release increases with time in a rather circuitous course. The diffusion of pollutant from internal sediment to the sediment-water interface will maintain the endogenous contaminant release effect from sediment.

关 键 词：疏浚扰动 水动力 底泥再悬浮 化学需氧量 水污染 

分 类 号：X143[环境科学与工程—环境科学]