Civil Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland; Ryan Institute, National University of Ireland, Galway, Ireland.
Institute of Environmental Engineering and Management, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
Water Res. 2020 Jul 15;179:115914. doi: 10.1016/j.watres.2020.115914. Epub 2020 May 6.
Iron sulphides, mainly in the form of mackinawite (FeS), pyrrhotite (FeS, x = 0-0.125) and pyrite (FeS), are the most abundant sulphide minerals and can be oxidized under anoxic and circumneutral pH conditions by chemoautotrophic denitrifying bacteria to reduce nitrate to N. Iron sulphides mediated autotrophic denitrification (ISAD) represents an important natural attenuation process of nitrate pollution and plays a pivotal role in linking nitrogen, sulphur and iron cycles in a variety of anoxic environments. Recently, it has emerged as a promising bioprocess for nutrient removal from various organic-deficient water and wastewater, due to its specific advantages including high denitrification capacity, simultaneous nitrogen and phosphorus removal, self-buffering properties, and fewer by-products generation (sulphate, waste sludge, NO, NH, etc.). This paper provides a critical overview of fundamental and engineering aspects of ISAD, including the theoretical knowledge (biochemistry, and microbial diversity), its natural occurrence and engineering applications. Its potential and limitations are elucidated by summarizing the key influencing factors including availability of iron sulphides, low denitrification rates, sulphate emission and leaching heavy metals. This review also put forward two key questions in the mechanism of anoxic iron sulphides oxidation, i.e. dissolution of iron sulphides and direct substrates for denitrifiers. Finally, its prospects for future sustainable wastewater treatment are highlighted. An iron sulphides-based biotechnology towards next-generation wastewater treatment (NEO-GREEN) is proposed, which can potentially harness bioenergy in wastewater, incorporate resources (P and Fe) recovery, achieve simultaneous nutrient and emerging contaminants removal, and minimize waste sludge production.
铁硫化物主要以磁黄铁矿（FeS）、磁黄铁矿（FeS，x=0-0.125）和黄铁矿（FeS）的形式存在，是最丰富的硫化物矿物，在缺氧和近中性 pH 条件下可被化能自养反硝化细菌氧化，将硝酸盐还原为 N。铁硫化物介导的自养反硝化（ISAD）是硝酸盐污染的一种重要自然衰减过程，在各种缺氧环境中连接氮、硫和铁循环中起着关键作用。最近，由于其具有高反硝化能力、同时去除氮和磷、自缓冲特性以及生成较少副产物（硫酸盐、废污泥、NO、NH 等）等特定优势，它已成为从各种有机贫水和废水去除营养物的有前途的生物过程。本文批判性地综述了 ISAD 的基础和工程方面，包括理论知识（生物化学和微生物多样性）、自然发生和工程应用。通过总结关键影响因素，包括铁硫化物的可用性、低反硝化速率、硫酸盐排放和浸出重金属，阐明了其潜力和局限性。本文还提出了缺氧铁硫化物氧化机制中的两个关键问题，即铁硫化物的溶解和反硝化菌的直接底物。最后，强调了其在未来可持续废水处理方面的前景。提出了一种基于铁硫化物的生物技术，即下一代废水处理（NEO-GREEN），该技术可以利用废水中的生物能源，结合资源（磷和铁）回收，实现同时去除营养物和新兴污染物，并减少废污泥的产生。
