零价铁材料还原水中硝酸盐的研究进展

硝酸盐（NO3-）是水体中常见的污染物，进入人体后会造成多种损害。零价铁(ZVI)作为一种活性金属，因其高效、无毒、价廉和来源丰富而被广泛用于NO3-的还原。尽管ZVI对硝酸盐有较高的去除效率，但传统ZVI法还原NO3-的主要产物是NH4+，这会对水体造成二次污染。并且由于反应过程中形成的铁氧化物会抑制电子传递，ZVI难以长时间维持高反应活性，对pH有较高的依赖。通过开发或改善现有ZVI复合材料、以及耦合微生物工艺等手段，可降低pH对反应的限制以及还原产物中NH4+的比例，同时将其脱氮性能进一步优化提升，这是目前乃至今后的重点研究方向。该文重点总结了ZVI对NO3-的作用效能和去除机制，阐述了理化特性、pH、温度、溶解氧等因素对ZVI化学反硝化效能的影响，涵盖了ZVI还原硝酸盐的各项性能强化措施。最后归纳了ZVI材料在实际脱氮中需要注意的问题，对其未来发展前景作出了探讨和展望。

Research progress on the reduction of nitrates in water by zero-valent iron materials

Nitrate (NO3-) is a common pollutant in water bodies, which can cause various damages when entering the human body. Zero-valent iron (ZVI), as an active metal, has been widely used for the reduction of NO3- due to its high efficiency, non-toxicity, low cost and abundant sources. Although ZVI has high removal efficiency for nitrate, the main product of NO3- reduction by traditional ZVI method is NH4+, which will cause secondary pollution to water bodies. And because the iron oxide formed during the reaction will inhibit electron transfer, ZVI is difficult to maintain high reactivity for a long time, and has a high dependence on pH. By developing or improving existing ZVI composite materials, and coupled with microbial processes, etc., the pH limit on the reaction and the ratio of NH4+ in the reduction product can be reduced, and its denitrification performance can be further optimized and improved. This is the current and future key research direction. This paper focuses on summarizing the effect and removal mechanism of ZVI on NO3-, expounds the effects of physical and chemical properties, pH, temperature, dissolved oxygen and other factors on the chemical denitrification efficiency of ZVI, and covers various performance enhancement measures for the reduction of nitrate by ZVI . Finally, the problems that need to be paid attention to in the actual denitrification of ZVI materials are summarized, and the future development prospects of ZVI materials are discussed and prospected.