Nanomaterials have great application potential for the remediation of heavy metal contaminated sediments, but their environmental impacts are still limited. Herein, graphene oxide-supported nanoscale zero-valent iron (GNZVI) was synthesized to explore its role in mediating the immobilization of cadmium (Cd) from contaminated river sediments, with the consideration of the potential impacts on sediment enzyme activities and bacterial community. Compared to NZVI and GO, GNZVI could more effectively promote the transformation of mobile Cd into stable speciation with a maximum residual percentage increasing by 64.82% after 56 days of treatment. The activities of urease, catalase and sucrase were gradually increased and stabilized with the prolongation of treatment time, indicating that the metabolic function of sediments was recovered. 16 S rRNA gene sequencing results confirmed that the application of GNZVI increased the abundance of some Fe(III)-reducing bacteria, further stimulating the bioavailability of organic matter. Additionally, the properties of GO were gradually changed via microbial reduction and finally showed similar properties to rGO. The critical role of rGO as an electrical conductor was to promote the electron transfer process of microbial Fe(III) mineral reduction, which redistributes part of the Fe(III) mineral-associated Cd to more stable secondary iron minerals, thereby further improving the stabilization efficiency of r-GNZVI for Cd.

纳米材料在修复重金属污染沉积物方面具有巨大的应用潜力，但其对环境的影响仍然有限。在此，考虑到对沉积物酶活性和细菌群落的潜在影响，合成了氧化石墨烯负载的纳米级零价铁 (GNZVI)，以探索其在介导受污染河流沉积物中镉 (Cd) 固定化中的作用。与NZVI和GO相比，GNZVI可以更有效地促进移动Cd向稳定形态的转化，处理56天后最大残留百分比增加了64.82%。尿素酶、过氧化氢酶和蔗糖酶的活性随着处理时间的延长逐渐升高并趋于稳定，表明沉积物的代谢功能得到恢复。16 S rRNA基因测序结果证实，GNZVI的应用增加了一些Fe(III)还原菌的丰度，进一步刺激了有机物的生物利用度。此外，GO 的特性通过微生物还原逐渐改变，最终表现出与 rGO 相似的特性。rGO 作为电导体的关键作用是促进微生物 Fe(III) 矿物还原的电子转移过程，将部分 Fe(III) 矿物伴生的 Cd 重新分配到更稳定的次生铁矿物，从而进一步提高稳定性r-GNZVI 对 Cd 的效率。GO 的特性通过微生物还原逐渐改变，最终表现出与 rGO 相似的特性。rGO 作为电导体的关键作用是促进微生物 Fe(III) 矿物还原的电子转移过程，将部分 Fe(III) 矿物伴生的 Cd 重新分配到更稳定的次生铁矿物，从而进一步提高稳定性r-GNZVI 对 Cd 的效率。GO 的特性通过微生物还原逐渐改变，最终表现出与 rGO 相似的特性。rGO 作为电导体的关键作用是促进微生物 Fe(III) 矿物还原的电子转移过程，将部分 Fe(III) 矿物伴生的 Cd 重新分配到更稳定的次生铁矿物，从而进一步提高稳定性r-GNZVI 对 Cd 的效率。