Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan, 250061, China; Institute of Geothermal Development, Shandong University, Weifang, 261200, China.
Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan, 250061, China; Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266100, China; Institute of Geothermal Development, Shandong University, Weifang, 261200, China.
Chemosphere. 2022 Nov;307(Pt 4):136128. doi: 10.1016/j.chemosphere.2022.136128. Epub 2022 Aug 19.
Most of the commonly used traditional permeable reactive barrier (PRB) fillers have many drawbacks, such as poor retention of hydraulic conductivity, high cost, and a complex preparation process. Porous geopolymers (PGPs) with controllable pore structures could circumvent these drawbacks owing to their high adsorption capacity, cost-effective synthesis, and good chemical stability. In this study, based on our previous research, the "foaming-liquid film" balance control method was proposed and used to fabricate three PGPs with gradient pore connectivity. The influence of pore structure on the Pb removal performance and migration mechanism were investigated by conducting both batch and column experiments. Closed, dead-end, capillary, and interconnected pores exist in the PGPs, and results indicated that interconnected pores effectively promote the migration of solute in the main flow channels to the deeper matrix, thereby enhancing the long-term dynamic removal efficiency. At breakthrough, the Pb uptake of PGP-3 reached 146 mg g. Further, the proposed "foaming-liquid film" balance control method is effective to prepare PGPs with controllable connectivity, and the PGP-PRBs with a high proportion of interconnected pores exhibit excellent performance for the removal of heavy metals, which is advantageous for their future applications in groundwater decontamination.
大多数常用的传统渗透反应屏障（PRB）填充材料都存在许多缺点，例如水力传导率保持性差、成本高和制备工艺复杂。具有可控孔结构的多孔地质聚合物（PGP）由于其高吸附能力、经济高效的合成和良好的化学稳定性，可以避免这些缺点。在本研究中，基于我们之前的研究，提出了“发泡-液膜”平衡控制方法，并用于制备具有梯度连通孔结构的三种 PGPs。通过批处理和柱实验研究了孔结构对 Pb 去除性能和迁移机制的影响。PGP 中存在封闭、死端、毛细和连通孔，结果表明连通孔有效地促进了溶质在主流道向更深基质中的迁移，从而提高了长期动态去除效率。在穿透时，PGP-3 的 Pb 摄取量达到 146mg/g。此外，所提出的“发泡-液膜”平衡控制方法可有效地制备具有可控连通性的 PGPs，并且具有高比例连通孔的 PGP-PRB 对重金属的去除性能优异，有利于其在地下水净化中的未来应用。
