河海大学学报(自然科学版)
河海大學學報(自然科學版)
하해대학학보(자연과학판)
Journal of Hohai University (Natural Sciences)
2015年
5期
480-488
,共9页
肖洋%成浩科%唐洪武%李志伟
肖洋%成浩科%唐洪武%李誌偉
초양%성호과%당홍무%리지위
水动力作用%水流紊动强度%流速%泥沙运动%污染物迁移转化
水動力作用%水流紊動彊度%流速%泥沙運動%汙染物遷移轉化
수동력작용%수류문동강도%류속%니사운동%오염물천이전화
hydrodynamic action%water turbulent intensity%velocity%sediment movement%transport and transformation of pollutant
通过总结近年来有关水动力作用对河流中泥沙吸附/释放重金属、磷等污染物影响研究成果,分析了水流紊动强度和流速对污染物在河流水沙两相中分配的影响规律。当水流紊动强度较低时,泥沙主要以床沙形式存在,泥沙对污染物的吸附/释放速率和强度较低;随着紊动强度增大,水沙界面切应力随之增大并促使泥沙悬浮,污染物与悬浮泥沙颗粒接触面积增大,使得泥沙对污染物的吸附/释放速率和强度显著增加。流速对污染物在水沙两相间分配的影响较为复杂。泥沙静止时,流速的增大会减小边界层厚度,增大水体溶解氧含量、氧化还原电位等参数,并使污染物在水体里的扩散由分子扩散转变为以紊动扩散为主,增强污染物在水沙界面的交换通量,对污染物在水沙两相间的分配产生影响;随着流速进一步增大,床沙逐渐起动、悬浮,此时除上述因素外,泥沙运动状态、悬浮颗粒间碰撞强度、悬浮物的絮凝等均会对泥沙吸附/释放污染物产生影响,由于影响因素较多,作用机制复杂,目前关于泥沙运动对污染物在水沙两相间分配的影响所得结论仍存在分歧。相应的机理研究及数学模型的建立均做了较大简化。综观当前的研究成果,水沙运动及其化学生物过程等对污染物在河流水沙两相中的分配作用机理和耗氧有机物、有毒有机物等污染物与泥沙的作用机理是这一领域的未来研究重点。
通過總結近年來有關水動力作用對河流中泥沙吸附/釋放重金屬、燐等汙染物影響研究成果,分析瞭水流紊動彊度和流速對汙染物在河流水沙兩相中分配的影響規律。噹水流紊動彊度較低時,泥沙主要以床沙形式存在,泥沙對汙染物的吸附/釋放速率和彊度較低;隨著紊動彊度增大,水沙界麵切應力隨之增大併促使泥沙懸浮,汙染物與懸浮泥沙顆粒接觸麵積增大,使得泥沙對汙染物的吸附/釋放速率和彊度顯著增加。流速對汙染物在水沙兩相間分配的影響較為複雜。泥沙靜止時,流速的增大會減小邊界層厚度,增大水體溶解氧含量、氧化還原電位等參數,併使汙染物在水體裏的擴散由分子擴散轉變為以紊動擴散為主,增彊汙染物在水沙界麵的交換通量,對汙染物在水沙兩相間的分配產生影響;隨著流速進一步增大,床沙逐漸起動、懸浮,此時除上述因素外,泥沙運動狀態、懸浮顆粒間踫撞彊度、懸浮物的絮凝等均會對泥沙吸附/釋放汙染物產生影響,由于影響因素較多,作用機製複雜,目前關于泥沙運動對汙染物在水沙兩相間分配的影響所得結論仍存在分歧。相應的機理研究及數學模型的建立均做瞭較大簡化。綜觀噹前的研究成果,水沙運動及其化學生物過程等對汙染物在河流水沙兩相中的分配作用機理和耗氧有機物、有毒有機物等汙染物與泥沙的作用機理是這一領域的未來研究重點。
통과총결근년래유관수동력작용대하류중니사흡부/석방중금속、린등오염물영향연구성과,분석료수류문동강도화류속대오염물재하류수사량상중분배적영향규률。당수류문동강도교저시,니사주요이상사형식존재,니사대오염물적흡부/석방속솔화강도교저;수착문동강도증대,수사계면절응력수지증대병촉사니사현부,오염물여현부니사과립접촉면적증대,사득니사대오염물적흡부/석방속솔화강도현저증가。류속대오염물재수사량상간분배적영향교위복잡。니사정지시,류속적증대회감소변계층후도,증대수체용해양함량、양화환원전위등삼수,병사오염물재수체리적확산유분자확산전변위이문동확산위주,증강오염물재수사계면적교환통량,대오염물재수사량상간적분배산생영향;수착류속진일보증대,상사축점기동、현부,차시제상술인소외,니사운동상태、현부과립간팽당강도、현부물적서응등균회대니사흡부/석방오염물산생영향,유우영향인소교다,작용궤제복잡,목전관우니사운동대오염물재수사량상간분배적영향소득결론잉존재분기。상응적궤리연구급수학모형적건립균주료교대간화。종관당전적연구성과,수사운동급기화학생물과정등대오염물재하류수사량상중적분배작용궤리화모양유궤물、유독유궤물등오염물여니사적작용궤리시저일영역적미래연구중점。
Through a review of recent investigations into the effects of hydrodynamic action on the adsorption/release of pollutants ( heavy metals, phosphorus, etc.) by sediments, the influence of water turbulence intensity and velocity on the distribution of pollutants in water and sediment in rivers was analyzed. The results show that, when the turbulence intensity is low, sediments occur in a form close to bed sediment, and the rate and extent of adsorption/release of pollutants by sediments are low. As the turbulence intensity increases, the shear stress at the water?sediment interface increases, sediment suspension is promoted, and the contact area between pollutants and suspended sediment particles increases, leading to a significant increase in the rate and extent of adsorption/release of pollutants by sediments. The effect of the water velocity on the distribution of pollutants in water and sediment is complex. When the sediment is stationary, with the increase of the velocity, the boundary layer thickness decreases, the dissolved oxygen content in water and redox potential increase, the diffusion of pollutants in the water body changes from molecular diffusion to turbulent diffusion, and the pollutant exchange flux at the water?sediment interface increases. With further increase of the velocity, the bed sediment gradually moves and is suspended. At this moment, the state of sediment movement, intensity of collision between suspended matters, and flocculation of sediments also have effects on the adsorption/release of pollutants by sediments. Because of the extensive factors and the complexity of the functional mechanism, there is a disagreement between results regarding the influence of sediment movement on the adsorption/release of pollutants by sediments reported by different researchers, and simplification is carried out through mechanism studies and establishment of mathematical models. It is pointed out that future studies should focus on the mechanism of the influence of the water and sediment movement as well as chemical and biological processes on the distribution of pollutants in water and sediment in rivers and the interaction of oxygen consumption organics and nocuous organics with sediments.