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[摘要]
地下水中微生物等胶体对多环芳烃的运移具有促进作用,为进行多环芳烃污染的精准、高效修复,需要建立准确、可靠的多环芳烃与细菌胶体共运移数值模拟模型。研究基于室内砂柱荧蒽运移系列实验,采用Hydrus中Colloid-Facilitated Solute Transport(C-Ride)模块构建荧蒽与细菌FA1共运移数值模型,并采用马尔科夫链蒙特卡洛方法(Markov Chain Monte Carlo, MCMC)进行模型参数不确定性分析,定量刻画荧蒽在水动力和微生物胶体作用下的运移过程。结果表明:基于Hydrus C-Ride模块和MCMC参数不确定性分析,能够准确地刻画荧蒽和细菌FA1的共运移过程;细菌FA1促进了荧蒽在多孔介质中的迁移速度,且导致荧蒽在多孔介质中运移回收率的增加,即由55.06%提升至76.16%,其中吸附至可移动胶体迁移和随水流迁移贡献的回收率分别为41.46%、34.69%。研究成果对于指导地下水污染微生物修复方案的优化设计具有重要的理论和现实意义。
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[Abstract]
The co-transport of polycyclic aromatic hydrocarbons (PAHs) with bacterial colloids plays a facilitating role in the precise and efficient remediation of PAH pollution. It is crucial to establish an accurate and reliable numerical simulation model for the co-transport of PAHs and bacterial colloids. A numerical model was constructed for the co-transport of fluoranthene (a type of PAH) and bacterium FA1 using the Colloid-Facilitated Solute Transport (C-Ride) module in Hydrus. Uncertainties in the model parameters were analyzed through the Markov Chain Monte Carlo (MCMC) method, allowing for a quantitative depiction of the transport processes of fluoranthene influenced by water dynamics and microbial colloidal interactions.A series of indoor column experiments were conducted to investigate the transport of fluoranthene. The numerical model for the co-transport of fluoranthene and bacterium FA1 was constructed using the Hydrus C-Ride module. The MCMC method was applied to analyze parameter uncertainties, enabling a comprehensive understanding of the transport processes of fluoranthene under the influence of water dynamics and microbial colloidal interactions.The results demonstrated that bacterium FA1 enhanced the migration velocity of fluoranthene in the porous medium and increased the recovery rate of fluoranthene transport within the porous medium. The recovery rate increased from 55.06% to 76.16%. Specifically, the contribution of fluoranthene adsorbed onto mobile colloids and transported with water flow accounted for 41.46% and 34.69% of the recovery rate, respectively.The research findings hold both theoretical and practical significance in guiding the optimization design of microbial remediation strategies for groundwater pollution. The establishment of a numerical model provides a reliable tool for accurately characterizing the co-transport process of fluoranthene and bacterium FA1. These insights shed light on the understanding of PAH transport influenced by microbial colloidal interactions in porous media and contribute to the development of effective and efficient strategies for remediating PAH-contaminated groundwater.
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