耐镉脱氮微生物胁迫响应机制及废水处理应用研究进展

Advances in stress response mechanisms and wastewater treatment application of cadmium-tolerant denitrifying microbes

摘要:

在电池生产、金属冶炼和电镀等工业生产过程中产生的废水同时含有高浓度镉和氮，会形成镉-氮复合污染。针对该类废水中同步去除镉、氮的难题，传统物理化学处理方法存在工艺复杂、能耗高、易产生二次污染等局限。相比之下，利用耐镉脱氮微生物，通过吸附、生物矿化等途径实现镉-氮协同去除，表现出低能耗与高效性的优势。本文综述了耐镉脱氮微生物的分类与脱氮特性，重点分析了以假单胞菌属为代表的该类微生物的耐镉机制及脱氮性能；系统分析了镉对脱氮过程的抑制效应及其分子机制；归纳了微生物在镉胁迫下的响应机制和除镉途径；并概述了功能菌株在不同反应工艺中实现镉-氮协同去除的研究进展，总结了生物膜与固定化床反应器通过生物矿化及复合载体构建在提升污染物去除效率与系统稳定性方面取得的成果。最后，基于研究现状分析了存在的问题与局限性，并对未来的研究方向进行了展望，为镉-氮复合污染废水的生物治理提供了理论与实践参考。

Abstract:

Industrial wastewater from battery manufacturing, metal smelting, and electroplating often contains high concentrations of cadmium and nitrogen, resulting in cadmium-nitrogen combined pollution. Conventional physicochemical methods for simultaneous removal of cadmium and nitrogen face limitations such as complex processes, high energy consumption, and risks of secondary pollution. In contrast, using cadmium-tolerant denitrifying microbes, which achieve synergistic removal of cadmium and nitrogen through adsorption, biomineralization, and other pathways, offers advantages of low energy consumption and high efficiency. In this review, we summarize the classification and denitrification characteristics of cadmium-tolerant denitrifying microbes, with a focus on the cadmium tolerance mechanisms and nitrogen removal performance of Pseudomonas as a representative microbial group. We analyze the inhibitory effects of cadmium on denitrification, explore the underlying molecular mechanisms, and summarize microbial response mechanisms and cadmium removal pathways under cadmium stress. In addition, we review the advances in the application of functional bacterial strains in various reactor systems for synergistic cadmium and nitrogen removal, and reviews the achievements in enhancing removal efficiency and system stability through biomineralization and carrier optimization. Finally, we discuss current challenges and limitations and makes an outlook on the future research directions, aiming to provide theoretical and practical insights for the bioremediation of wastewater co-contaminated with cadmium and nitrogen.