Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China.
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China.
Sci Total Environ. 2021 Nov 10;794:148699. doi: 10.1016/j.scitotenv.2021.148699. Epub 2021 Jun 25.
Nitrate (NO) pollution in water and wastewater has become a serious global issue. Biological denitrification, which reduces NO to N (nitrogen gas) by denitrifying microorganisms, is an efficient and economical process for the removal of NO from water and wastewater. During the denitrification process, electron donor is required to provide electrons for reduction of NO. A variety of electron donors, including organic and inorganic compounds, can be used for denitrification. This paper reviews the state of the art of various electron donors used for biological denitrification. Depending on the types of electron donors, denitrification can be classified into heterotrophic and autotrophic denitrification. Heterotrophic denitrification utilizes organic compounds as electron donors, including low-molecular-weight organics (e.g. acetate, methanol, glucose, benzene, methane, etc.) and high-molecular-weight organics (e.g. cellulose, polylactic acid, polycaprolactone, etc.); while autotrophic denitrification utilizes inorganic compounds as electron donors, including hydrogen (H), reduced sulfur compounds (e.g. sulfide, element sulfur and thiosulfate), ferrous iron (Fe), iron sulfides (e.g. FeS, FeS and FeS), arsenite (As(Ш)) and manganese (Mn(II)). The biological denitrification processes and the representative denitrifying microorganisms are summarized based on different electron donors, and their denitrification performance, operating costs and environmental impacts are compared and discussed. The pilot- or full-scale applications were summarized. The concluding remarks and future prospects were provided. The biodegradable polymers mediated heterotrophic denitrification, as well as H and sulfur mediated autotrophic denitrification are promising denitrification processes for NO removal from various types of water and wastewater.
硝酸盐（NO）污染是一个全球性的严重问题。生物反硝化作用通过反硝化微生物将 NO 还原为 N（氮气），是一种从水中去除 NO 的高效、经济的方法。在反硝化过程中，需要电子供体为 NO 的还原提供电子。多种电子供体，包括有机和无机化合物，可用于反硝化。本文综述了用于生物反硝化的各种电子供体的最新研究进展。根据电子供体的类型，反硝化可分为异养反硝化和自养反硝化。异养反硝化利用有机化合物作为电子供体，包括低分子量有机物（如乙酸盐、甲醇、葡萄糖、苯、甲烷等）和高分子量有机物（如纤维素、聚乳酸、聚己内酯等）；而自养反硝化则利用无机化合物作为电子供体，包括氢气（H）、还原硫化合物（如硫化物、元素硫和硫代硫酸盐）、亚铁（Fe）、铁硫化物（如 FeS、FeS 和 FeS）、亚砷酸盐（As(Ш))和锰（Mn(II))。根据不同的电子供体，总结了生物反硝化过程和代表性的反硝化微生物，并对它们的反硝化性能、运行成本和环境影响进行了比较和讨论。总结了中试或全规模应用情况。提供了结论和展望。可生物降解聚合物介导的异养反硝化以及 H 和硫介导的自养反硝化是从各种类型的水和废水中去除 NO 的有前途的反硝化方法。
