Sprocati Riccardo, Flyvbjerg John, Tuxen Nina, Rolle Massimo
Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800, Kgs. Lyngby, Denmark.
Centre for Regional Development, Capital Region of Denmark, Kongens Vænge 2, 3400, Hillerød, Denmark.
J Hazard Mater. 2020 Oct 5;397:122787. doi: 10.1016/j.jhazmat.2020.122787. Epub 2020 Apr 21.
This study presents a process-based modeling analysis of electrokinetic-enhanced bioremediation (EK-Bio) to illuminate the complex interactions between physical, electrostatic and biogeochemical processes occurring during the application of this remediation technique. The features of the proposed model include: (i) multidimensional electrokinetic transport in saturated porous media by electromigration and electroosmosis, (ii) charge interactions, (iii) degradation kinetics, (iv) microbial populations dynamics of indigenous and specialized exogenous degraders, (v) mass transfer limitations, and (vi) geochemical reactions. A scenario modeling investigation is presented, which was inspired by an EK-Bio pilot application conducted in a clayey aquitard at the Skuldelev site (Denmark) contaminated by chlorinated ethenes. Lactate and specialized degraders are delivered under conservative and reactive transport conditions. In the considered setup, transport of lactate using electrokinetics results in more than fourfold increase in the distribution efficiency with respect to a diffusion-only scenario. Moreover, EK transport by electromigration and electroosmosis yields fluxes at least two orders of magnitude larger than diffusive fluxes. Quantitative metrics are also defined and used to assess the amendment distribution and the enhanced contaminant biodegradation in the different conservative and reactive transport scenarios.
本研究对电动强化生物修复（EK-Bio）进行了基于过程的建模分析，以阐明该修复技术应用过程中发生的物理、静电和生物地球化学过程之间的复杂相互作用。所提出模型的特点包括：（i）饱和多孔介质中通过电迁移和电渗作用的多维电动传输；（ii）电荷相互作用；（iii）降解动力学；（iv）本地和特定外源降解菌的微生物种群动态；（v）传质限制；以及（vi）地球化学反应。本文给出了一个情景建模研究，其灵感来源于在丹麦斯库勒代勒遗址一个被氯乙烯污染的黏土层滞水层中进行的EK-Bio中试应用。乳酸盐和特定降解菌在保守和反应性传输条件下输送。在所考虑的设置中，与仅扩散的情景相比，利用电动技术输送乳酸盐可使分布效率提高四倍以上。此外，通过电迁移和电渗作用的EK传输产生的通量比扩散通量至少大两个数量级。还定义了定量指标，用于评估不同保守和反应性传输情景下的修正剂分布和强化的污染物生物降解情况。
