Omirbekov Sagyn, Colombano Stéfan, Alamooti Amir, Batikh Ali, Cochennec Maxime, Amanbek Yerlan, Ahmadi-Senichault Azita, Davarzani Hossein
BRGM (French Geological Survey), 3 Avenue Claude Guillemin, Orléans 45100, France; Institut de Mécanique et Ingénierie de Bordeaux (I2M), Arts et Métiers Institute of Technology, CNRS, Talence 33405, France; Nazarbayev University, 53 Kabanbay Batyr Avenue, Astana, 010000, Kazakhstan.
BRGM (French Geological Survey), 3 Avenue Claude Guillemin, Orléans 45100, France.
J Contam Hydrol. 2023 Jan;252:104120. doi: 10.1016/j.jconhyd.2022.104120. Epub 2022 Nov 28.
The remediation of DNAPL-contaminated soil with lower-density fluids is ineffective due to the over-riding of displacing fluid. The densification of biopolymers is experimentally studied to develop a solution with the same density as a pollutant. Polymer solutions and contaminants are characterized through rheometer. A 1D column filled with monodisperse glass beads was used to measure their apparent viscosity in porous media. The displacement of pollutants by biopolymers (such as xanthan gum, guar gum, and carboxymethyl cellulose) and densified solutions based on barite are investigated in the 1D porous column. In addition, the polymer solution flow is studied using an upscaling method based on the shear viscosity measured with rheometer. The upscaling results are compared with the 1D column experimental outcomes. We found that carboxymethyl cellulose is the best for densifying polymer and showed the highest remediation yield for DNAPL remediation. The polymers' rheology was represented well through the Carreau rheological model. The discrepancy of apparent viscosity in porous media from polymers' shear viscosity measured with rheometer is explained by the adsorption of polymers on pore surfaces and deposition of barite particles in a porous medium, which led to a decrease in permeability. The upscaling results are in good agreement with experimental outcomes at low-pressure gradients. The impact of porous media geometry on polymer flow in porous media is described.
由于驱替流体的超覆作用，用低密度流体修复受重质非水相液体（DNAPL）污染的土壤是无效的。对生物聚合物的致密化进行了实验研究，以开发一种与污染物密度相同的溶液。通过流变仪对聚合物溶液和污染物进行了表征。使用填充有单分散玻璃珠的一维柱来测量它们在多孔介质中的表观粘度。在一维多孔柱中研究了生物聚合物（如黄原胶、瓜尔胶和羧甲基纤维素）以及基于重晶石的致密化溶液对污染物的驱替作用。此外，基于流变仪测量的剪切粘度，采用一种尺度放大方法研究了聚合物溶液的流动。将尺度放大结果与一维柱实验结果进行了比较。我们发现羧甲基纤维素在聚合物致密化方面表现最佳，并且在DNAPL修复中显示出最高的修复率。通过Carreau流变模型很好地描述了聚合物的流变学特性。聚合物在多孔介质中的表观粘度与流变仪测量的聚合物剪切粘度之间的差异，是由聚合物在孔隙表面的吸附以及重晶石颗粒在多孔介质中的沉积导致渗透率降低所解释的。在低压梯度下，尺度放大结果与实验结果吻合良好。描述了多孔介质几何形状对聚合物在多孔介质中流动的影响。
