A (Simplified) Biogeochemical Numerical Model to Predict Saturation, Porosity and Permeability During Microbially Induced Desaturation and Precipitation
A (Simplified) Biogeochemical Numerical Model to Predict Saturation, Porosity and Permeability During Microbially Induced Desaturation and Precipitation
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DOI：
10.1029/2022wr032907
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发表时间：
2023-01
影响因子：
5.4
通讯作者：
Liya Wang;L. V. van Paassen;V. Pham;Nariman Mahabadi;Jibo He;Yunqi Gao
中科院分区：
文献类型：
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作者：
Liya Wang;L. V. van Paassen;V. Pham;Nariman Mahabadi;Jibo He;Yunqi Gao
通过反硝化作用的微生物诱导的去饱和和沉淀（MIDP）是一种新兴的土壤改良方法，其中内源硝酸盐还原菌被刺激以在土壤基质中引入沼气、生物矿物和生物量。在这项研究中，一个数值模型的开发，以评估沼气，生物矿物和生物量对土壤的水力性质与MIDP处理的效果。该模型将生化转化与孔隙度和含水饱和度的变化相耦合，并通过两个独立的幂律方程预测渗透率的变化。文献中的实验研究被用来校准模型。将结果与多孔介质中的生物堵塞或生物矿化的其他研究进行比较，揭示了生物气、生物质和生物矿物的组合生产导致有效堵塞，在这个意义上，只有少量的产品导致渗透率大幅降低。基于这种比较，作者假设生物成因的气泡优选在较大的孔隙体内形成。在较大孔隙体中生物气的存在迫使碳酸钙矿物和生物质主要在孔喉处形成。不同相之间的相互作用导致比仅关注单一产品的其他研究中观察到的更有效的堵塞。
Microbially Induced Desaturation and Precipitation (MIDP) through denitrification is an emerging ground improvement method in which indigenous nitrate reducing bacteria are stimulated to introduce biogas, biominerals and biomass in the soil matrix. In this study, a numerical model is developed to evaluate the effect of biogas, biominerals and biomass on the hydraulic properties of soils treated with MIDP. The proposed model couples the biochemical conversions to changes of porosity and water saturation and predicts changes in permeability through two separate power law equations. Experimental studies from the literature are used to calibrate the model. Comparing the results with other studies on bioclogging or biomineralization in porous media reveals that the combined production of biogas, biomass, and biominerals results in efficient clogging, in the sense that only a small amount of products leads to a substantial permeability reduction. Based on this comparison, the authors postulate that biogenic gas bubbles preferably form within the larger pore bodies. The presence of biogenic gas in the larger pore bodies forces calcium carbonate minerals and biomass to be formed mainly at the pore throats. The interaction between the different phases results in more efficient clogging than observed in other studies which focus on a single product only.