泥沙吸附重金属污染物的数值模拟研究  

Numerical Simulation of Sediment Absorption of Heavy Metal Contaminants

作　　者：胡新启 程凯 周晓泉[1] HU Xinqi;CHENG Kai;ZHOU Xiaoquan(State Key Lab of Hydraulics and Mountain River Eng.,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065

出　　处：《人民黄河》2020年第5期97-102,107,共7页Yellow River

基　　金：国家自然科学基金资助项目(51539007);国家重点研发计划项目(2016YFC0402302)。

摘　　要：为研究分相模型中泥沙颗粒吸附重金属的过程,以Langmuir等温式为基础,将泥沙相和重金属相看作两相,通过步进法和UDS方法两种计算方法对泥沙颗粒的吸附过程进行了数值模拟。首先利用Fluent软件将组分输运模型与UDS法相结合,模拟了7种湍流模型下的泥沙吸附过程,所得结果与Langmuir模型对比,验证了该方法的可行性,并选出了吻合度最高的模型。其次,应用选出的模型对不同含沙量、不同粒径泥沙颗粒吸附量和镉离子水相浓度变化趋势进行了模拟。结果表明:含沙量直接影响水体的吸附作用,含沙量越小,吸附作用越弱,吸附速率越慢,浓度小于一定限度时水体吸附作用可忽略不计;不同粒径泥沙在水体中的吸附作用差异明显,但并不能决定泥沙吸附量;UDS方法和步进方法在考虑粒径的影响时计算的吸附量不同,从吸附量的角度来看UDS法更加贴切,从到达动态平衡的角度来看步进法更加吻合。In order to study the heavy metal pollutant adsorption of sediment under the phase-separation model, based on the Langmuir isothermal equation, the sediment and heavy metal phases were regarded as two phases and the adsorption process was numerically simulated through two calculation methods: time-step method and UDS method. Firstly, the sediment adsorption process under seven turbulence models was simulated by combining component transport model with UDF using commercial software fluent. The results were compared with the Langmuir model, the feasibility of the method was verified and the model with the highest consistency was selected. Secondly, the adsorption capacity of sediment particles under different sediment concentration and particle size were obtained by using the selected model. And the change trend of cadmium ion concentration in aqueous phase was simulated. The results show that the sediment concentration directly affects the adsorption of water, the smaller the concentration, the weaker the adsorption, the slower the adsorption rate is, the less the concentration is and the less the adsorption can be. The adsorption effect of sediment particle size in water is obvious, but it cannot determine the amount of sediment adsorption. Both UDS and time-step methods have advantages and disadvantages in calculating the adsorption amount under the influence of particle size. The results of the dynamic time obtained by the stepwise method are more appropriate and the numerical results of the adsorption amount obtained by the time-step method are in better agreement with each other.

关 键 词：泥沙颗粒 吸附 重金属 湍流模型 FLUENT UDS 步进法 

分 类 号：TV142[水利工程—水力学及河流动力学]