分段非均质多孔介质中双分子反应性溶质运移实验与模拟研究  

Experimental and simulation study on bimolecular reactive solute transport in segmented heterogeneous porous media

作　　者：钱家忠[1] 王永媛 刘雅静 刘咏 邓亚平 QIAN Jiazhong;WANG Yongyuan;LIU Yajing;LIU Yong;DENG Yaping(School of Resource and Environmental Engineering,Hefei University of Technology,Hefei 230009;School of Food and Biological Engineering,Hefei University of Technology,Hefei 230601)

机构地区：[1]合肥工业大学资源与环境工程学院,合肥230009 [2]合肥工业大学食品与生物工程学院,合肥230601

出　　处：《环境科学学报》2023年第10期123-132,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.41831289,U2267218,42102283)。

摘　　要：地下水中反应性溶质运移量化对地下水污染的防治具有重要作用,然而对于反应性溶质运移的研究,以往大多集中在均质多孔介质中,非均质多孔介质中反应性运移机理尚不明确.为了探究非均质多孔介质中的反应性溶质运移规律,本研究采用分段非均质多孔介质模型,以CuSO_(4)和Na_(2)EDTA^(2-)的双分子反应为例,开展了不同流量、不同相邻介质粒径比条件下的反应性溶质运移实验,采用考虑不完全混合的反应性对流弥散模型(IM-ADRE)对溶质运移进行数值模拟,并进行了参数分析.结果表明:双分子反应性溶质在分段非均质多孔介质中运移时,其扩散受到介质的阻滞导致迁移速度变慢,与均质介质相比,生成物在分段非均质多孔介质中的峰值浓度更高;IM-ADRE模型对双分子反应性溶质运移过程的生成物峰值浓度拟合度高,其实验值与模拟值的误差小于1.35%;随着相邻介质粒径之比R的增大,生成物“拖尾”现象更加显著;在不同的R值条件下,弥散系数D、参数β_(0)及m与流量呈线性关系;IM-ADRE模型的灵敏度分析表明,生成物峰值浓度对m的变化最敏感.Quantification of reactive solute transport in groundwater plays an important role in the prevention and control of groundwater pollution.However,previous studies on reactive solute transport have mostly focused on homogeneous porous media,and the mechanism of reactive transport in heterogeneous porous media is still unclear.In order to explore the rules of reactive solute transport in heterogeneous porous media,a segmented heterogeneous porous media model was used in this study.Taking the bimolecular reaction of CuSO_(4) and Na_(2)EDTA^(2-)as an example,the reactive solute transport experiments were carried out under different flow rates and particle size ratios of adjacent media.A reactive convective dispersion model considering incomplete mixing(IM-ADRE)was used to simulate solute transport,and parameters were analyzed.The results showed that when the bimolecular reactive solutes transported in segmented heterogeneous porous medium,the diffusion was retarded by the medium,resulting in slower migration rate.The peak concentration of the product in the segmented heterogeneous porous medium was higher than that in the homogeneous medium.The IM-ADRE model has a good fit degree for the peak concentration of the products during the bimolecular reactive solute transport,and the error between the experimental and simulated values is less than 1.35%.With the increase of the ratio R of the particle size of the adjacent medium,the"tailing"phenomenon of the product becomes more significant.Under different R-values,parameters D,β_(0) and m have a linear relationship with flow rate.The sensitivity analysis of the IM-ADRE model showed that the peak concentration of products is most sensitive to the change of m.

关 键 词：双分子反应 溶质运移 分段非均质多孔介质 IM-ADRE模型 

分 类 号：X523[环境科学与工程—环境工程]