中国地质大学（北京）何宝南ET&I： “BDOM-NEVO”复合修复剂强化地下水六价铬高效自然衰减

Chao1指数表明碳源添加后物种丰富度下降，说明 微生物对碳源具有选择性 。BDOM的引入不仅增强了 协同效应 ，还促进了 优势菌的富集 ，使BDOM-NEVO在Cr(VI)降解中表现更优。基因功能分析显示，BDOM-NEVO显著上调 铬还原、脂质代谢、膜运输和碳水化合物代谢相关通路 ，增强了微生物活性与代谢能力（图4a）。此外，关键铬还原基因（ChrA、azoR、ChrR、pta、adh）与优势菌属（ Achromobacter 、 Pseudomonas ）呈正相关，进一步表明BDOM-NEVO可 促进抗铬基因表达和菌群生长 ，从而提升Cr(VI)去除效率（图4b）。

The Chao1 index showed a decrease in species richness after carbon addition, indicating microbial selectivity. BDOM enhanced synergistic effects and promoted the enrichment of dominant strains, contributing to the superior Cr(VI) removal by BDOM-NEVO. Functional gene analysis revealed significant upregulation of pathways related to chromium reduction, lipid metabolism, membrane transport, and carbohydrate metabolism (Fig. 4a). Key Cr-reducing genes (ChrA, azoR, ChrR, pta, adh) were positively correlated with dominant genera ( Achromobacter and Pseudomonas ), suggesting that BDOM-NEVO promotes gene expression and microbial growth, thereby enhancing Cr(VI) removal efficiency (Fig. 4b).

图4 微生物功能和基因分析图

（a）不同碳源条件下的反应途径和功能基因；（b）不同环境因素、基因、微生物属之间的相关性热图分析

Fig. 4 Microbial functional and gene analysis

(a) Reaction pathways and functional genes under different carbon source conditions;(b) Correlation heatmap analysis among different environmental factors, genes, and microbial genera.

本研究探讨了不同碳源（NEVO、BDOM 和 BDOM-NEVO ）对地下水中低浓度 Cr(VI) 自然衰减的增强效果及其机制。相比单一碳源，BDOM-NEVO显著提高了去除效率，反应速率加快，半衰期缩短。微生物生理与功能基因分析表明，BDOM-NEVO通过促进微生物生长、增强酶和电子传递活性、优化群落结构及代谢功能，有效提升了Cr(VI)的降解能力。本研究为 低浓度 Cr(VI) 地下水污染 的生物修复提供了重要参考。

This study investigated the effects and mechanisms of different carbon sources (NEVO, BDOM, and BDOM-NEVO) on the natural attenuation of low-concentration Cr(VI) in groundwater. Compared to single carbon sources, BDOM-NEVO significantly enhanced removal efficiency, increased reaction rates, and shortened half-lives. Microbial physiological and gene analyses revealed that BDOM-NEVO promoted microbial growth, enhanced enzyme and electron transfer activity, and optimized community structure and metabolism, thereby improving Cr(VI) degradation. These findings provide valuable insights for the bioremediation of low-level Cr(VI) contamination in groundwater.