Department of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore City, 639798, Singapore.
Microb Biotechnol. 2019 Mar;12(2):324-333. doi: 10.1111/1751-7915.13315. Epub 2018 Oct 6.
This paper presents a novel approach of using in-situ microbially induced Ca -alginate polymeric sealant for seepage control in porous materials. This process comprises two steps: (i) generation of insoluble calcium carbonate inside the pores of porous materials (such as sand) through a microbially induced carbonate precipitation (MICP) process in-situ and (ii) injection of sodium alginate for in-situ gelation via reaction between alginate and Ca ions. The experimental results showed that the hydraulic conductivity/permeability of sand decreased with the increase in alginate concentration. When 5% alginate was used with a CaCO concentration of 0.18 g g sand, the permeability of the alginate-treated sand reduced from 5.0 × 10 to 2.2 × 10 m s . The scanning electron microscopy images revealed that a film-type coating was formed around sand particles with spherical round crystals embedded. Furthermore, the in-situ formed Ca-alginate polymeric sealant can also be used for the removal of Cu ion and suspended particles from contaminated water by more than 90%. Built on the current research, the envisioned practical application of the proposed method may include clogging fractured rock, reducing seepage and prevent piping through dams, excavation dewatering, and forming barriers for remediating specific contaminants.
本文提出了一种利用原位微生物诱导 Ca-藻酸盐聚合密封剂控制多孔材料渗流的新方法。该过程包括两个步骤：（i）通过原位微生物诱导碳酸盐水沉淀（MICP）过程在多孔材料（如沙子）的孔隙内生成不溶性碳酸钙；（ii）通过藻酸盐和 Ca 离子之间的反应注入藻酸钠以进行原位凝胶化。实验结果表明，沙子的水力传导率/渗透率随藻酸盐浓度的增加而降低。当使用 5%的藻酸盐和 0.18 g g 沙的 CaCO 浓度时，用藻酸盐处理过的沙子的渗透率从 5.0×10 降低到 2.2×10 。扫描电子显微镜图像显示，在沙粒周围形成了一种膜状涂层，其中嵌入了球形圆形晶体。此外，原位形成的 Ca-藻酸盐聚合密封剂也可用于去除受污染水中的 Cu 离子和悬浮颗粒，去除率超过 90%。基于当前的研究，预计该方法的实际应用可能包括堵塞断裂岩石、减少渗流并防止通过水坝管涌、挖掘脱水以及形成修复特定污染物的屏障。
