Cao Gang, Qiao Jiachang, Ai Juehao, Ning Shuaiqi, Sun Huimin, Chen Menghua, Zhao Lin, Zhang Guilong, Lian Fei
College of Natural Resources and Environment, Northwest A&F University, Xianyang 712100, China.
Key Laboratory of Plant Nutrition and the Agri-Environment in Northwest China, Ministry of Agriculture, Xianyang 712100, China.
Nanomaterials (Basel). 2022 Mar 17;12(6):988. doi: 10.3390/nano12060988.
Ball-milled biochar (BMBC) is a typical engineering material that has promising application prospects in remediating contaminated soil and water. It is fundamental to rate the transport behaviors of BMBC in the underground environment before extensive use. In this study, the effects of the ubiquitous cations (Na, Mg, and Al) and model organic matter (humic acid) on the transport of BMBC were investigated using laboratory column experiments. The results demonstrated the facilitated effect of HA on the transport of BMBC due to the negatively charged surface and steric effect under neutral conditions. HA and ionic strength manifested an antagonistic effect on the transport of BMBC, where the presence of one could weaken the effect from the other. We also found the charge reversal of the BMBC surface in the presence of Mg, thus enhancing the deposition of BMBC onto the medium surface. On the other hand, the charge reversal from Al-coupled acid conditions led to the restabilization and transport of BMBC in porous media. Therefore, the rational usage of BMBC is indispensable and more attention should be paid to the composition and change in underground water that might facilitate the transport of BMBC and thus lead to negative environmental implications.
球磨生物炭（BMBC）是一种典型的工程材料，在修复污染土壤和水体方面具有广阔的应用前景。在广泛应用之前，对BMBC在地下环境中的迁移行为进行评估至关重要。在本研究中，通过实验室柱实验研究了常见阳离子（Na、Mg和Al）和模型有机物（腐殖酸）对BMBC迁移的影响。结果表明，在中性条件下，由于表面带负电荷和空间位阻效应，腐殖酸对BMBC的迁移具有促进作用。腐殖酸和离子强度对BMBC的迁移表现出拮抗作用，其中一种物质的存在会削弱另一种物质的作用。我们还发现，在Mg存在的情况下，BMBC表面发生电荷反转，从而增强了BMBC在介质表面的沉积。另一方面，在Al耦合酸性条件下的电荷反转导致BMBC在多孔介质中重新稳定并迁移。因此，合理使用BMBC是必不可少的，并且应该更加关注可能促进BMBC迁移从而导致负面环境影响的地下水成分和变化。
