流速对胶体在植被过滤带中迁移的影响  

Effects of Flow Velocity on Migration of Colloidal Particulate Matter in Vegetative Filter Strips

作　　者：熊雄 庾从蓉[1,2] 段佩怡 XIONG Xiong;YU Congrong;DUAN Peiyi(College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China;State Key Labaratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源学院,江苏南京210098 [2]水文水资源与水利工程科学国家重点实验室,江苏南京210098

出　　处：《水文》2023年第3期9-15,共7页Journal of China Hydrology

基　　金：国家自然科学基金青年科学基金项目(51509069);国家自然科学基金联合基金项目(U2040209);“一带一路”水与可持续发展科技基金资助项目(202041711)。

摘　　要：为探讨流速导致的流态变化对胶体在植被过滤带中迁移产生的影响,结合地表水水槽室内试验和COMSOL数值模型,观测和模拟不同流速下胶体在植被过滤带中的迁移过程。实验发现胶体在流速0.017~0.029m/s内,随着流速的增加,胶体的去除效率先增大,后减小。这与胶体过滤理论不一致。通过COMOSOL模拟胶体在稳态和瞬态的水流流态发现,卡门涡街的存在会增大胶体在植被过滤带中的去除效率,并且随着流速的增加,去除效率与实验结果一致,先增加后降低,说明流速的增加导致流态的变化,是影响胶体迁移的主导因素。研究还发现在2m长的植被过滤带中,单位植被长度去除效率随迁移距离的增加而减小。研究结果可以为设计植被过滤带去除胶体的工程设计提供理论依据。In order to explore the effect of flow regime changes caused by flow velocity on the migration of colloids in vegetation systems,this paper combined the surface water tank laboratory test and COMSOL numerical model to observe and simulate the migration process of colloids in vegetation at different flow rates.The experiment has found that the colloid removal efficiency increase at first and then decrease with the increase of the flow velocity within the flow velocity of 0.017~0.029 m/s.This is inconsistent with colloidal filtration theory.Through COMOSOL simulation of colloids in steady-state and transient water flow,it is found that the existence of Karman vortex street will increase the removal efficiency of colloids in vegetation,and with the increase of flow rate,the removal efficiency is consistent with the experimental results,first increases and then decreases,indicating that the increase of the flow rate leads to the change of the flow state,which is the dominant factor affecting the colloid migration.The study also has found that in the 2 m long vegetation system,the removal efficiency per unit vegetation length decrease with the increase of migration distance.The research results can provide a theoretical basis for the engineering design of colloid removal in vegetation systems.

关 键 词：胶体 植被过滤带 数值模型 流速 

分 类 号：X143[环境科学与工程—环境科学] TV11[水利工程—水文学及水资源] P339[天文地球—水文科学]