Wang Xinwen, Zhang Shixu, Chen Ke
School of Intelligent Construction and Civil Engineering, Luoyang Institute of Science and Technology Luoyang 471023 China
School of Civil Engineering, Xi'an University of Architecture and Technology Xi'an 710055 China
RSC Adv. 2025 Aug 18;15(35):29063-29076. doi: 10.1039/d5ra04818d. eCollection 2025 Aug 11.
This study explores the synergistic effects of microbially induced carbonate precipitation (MICP) combined with graphene-based adsorptive materials, namely graphene (GR) and graphene oxide (GO), for the remediation of lead-contaminated loess. A series of systematic experiments were conducted, including unconfined compressive strength (UCS) testing, toxicity characteristic leaching procedure analysis, zeta potential measurements, scanning electron microscopy (SEM) observation, X-ray fluorescence (XRF) analysis, and microstructural modeling. The results revealed that MICP effectively improved soil strength and immobilized Pb through carbonate precipitation and microbial surface adsorption, reducing lead leaching concentrations by up to 39.56%. The addition of GR and GO significantly enhanced the remediation performance by further lowering Pb mobility and improving soil mechanical properties. Optimal results were achieved with 1.0% GO content, where UCS increased by approximately 11.7% compared to MICP alone, and lead leaching concentration was reduced by 61.63% relative to untreated soil. Microstructural analysis indicated that the combined remediation process promoted denser soil packing, enhanced calcium carbonate distribution, and facilitated multi-pathway Pb immobilization, including precipitation, chemical adsorption, and physical encapsulation. GO exhibited superior performance due to its higher negative surface charge, larger specific surface area, and abundant oxygen-containing functional groups. These findings highlight the potential of integrating MICP with graphene-based materials for the simultaneous stabilization and strengthening of heavy metal-contaminated loess, providing valuable insights for the development of advanced soil remediation technologies.
本研究探讨了微生物诱导碳酸钙沉淀（MICP）与基于石墨烯的吸附材料（即石墨烯（GR）和氧化石墨烯（GO））相结合对铅污染黄土进行修复的协同效应。进行了一系列系统实验，包括无侧限抗压强度（UCS）测试、毒性特性浸出程序分析、zeta电位测量、扫描电子显微镜（SEM）观察、X射线荧光（XRF）分析和微观结构建模。结果表明，MICP通过碳酸盐沉淀和微生物表面吸附有效地提高了土壤强度并固定了铅，使铅浸出浓度降低了39.56%。GR和GO的添加通过进一步降低铅的迁移率和改善土壤力学性能，显著提高了修复性能。当GO含量为1.0%时取得了最佳效果，此时UCS比单独使用MICP时提高了约11.7%，铅浸出浓度相对于未处理土壤降低了61.63%。微观结构分析表明，联合修复过程促进了土壤更紧密的堆积，增强了碳酸钙分布，并促进了多途径的铅固定，包括沉淀、化学吸附和物理包裹。GO由于其更高的负表面电荷、更大的比表面积和丰富的含氧官能团而表现出优异的性能。这些发现突出了将MICP与基于石墨烯的材料相结合用于同时稳定和强化重金属污染黄土的潜力，为先进土壤修复技术的发展提供了有价值的见解。
