纳米Fe-C内电解与氢自养反硝化耦合体系修复地下水硝酸盐污染研究

针对我国地下水硝酸盐污染日益严峻的形势和传统修复技术存在的不足，开展纳米铁碳内电解与氢自养微生物反硝化联合修复地下水硝酸盐污染的耦合行为与脱氮机制研究，对防治地下水污染和保障饮用水安全有十分重要的意义。本项目拟在已有工作基础上，融合纳米铁反应活性高的优点和微生物反硝化脱氮彻底的特性，通过制备新型纳米铁碳复合材料，以Fe-C在水中发生原电池反应所释放的活性氢作为电子供体供给氢自养反硝化微生物，将Fe-C内电解体系与氢自养反硝化体系耦合。采用批实验和柱模拟实验相结合的方法，系统考察在地下水黑暗、低温、贫氧条件下纳米Fe-C内电解与氢自养反硝化耦合体系对硝酸盐氮的脱除效能，并在脱氮机理及反应动力学等方面做出有益探索。耦合修复体系有望同时解决纳米零价铁易钝化团聚缺陷、还原反应脱氮不彻底和地下水中氢自养微生物反硝化缺少电子供体三个关键问题，以期为地下水硝酸盐污染高效修复提供一定的科学依据和理论支持。

Nitrate contamination in groundwater is becoming increasingly severe in China and the conventional techniques are faced with many limits due to the dark, low-temperature and oxygen-lean environment. Incorporating the nano-iron-carbon internal electrolysis system with autotrophic denitrification process as a novel coupling technique can get over these difficulties and further enhance the nitrate removal in groundwater. Study on this process may provide a solution to groundwater contamination and the drinking water safety issues. Based on previous achievements and pre-experiments, on account of the high reactivity of nano iron and the thorough degradation of bio-denitrification process, the coupling system is tested to in-situ remove nitrate in groundwater. Firstly, dispersive nano-iron-carbon composites is prepared. Then autotrophic denitrifying microorganism is cultivated, optimized and domesticated. Furthermore, the nano-iron-carbon internal eletrolysis system and autotrophic denitrification process will be coupled. Batch and column experiments will be conducted to systematically investigate the removal efficiency of nitrate as well as the mechanism and reaction kinetic of denitrification process. The coupled system is expected to solve the problems of nano iron’s passivation, high ammonia residual in denitration product and the lack of electron donor in the autotrophic denitrification process. This study will provide a novel and efficient remediation technology for nitrate removal in groundwater.