| 处理采矿废水湿地沉积物中厌氧氨氧化过程 |
| 摘要点击 1981 全文点击 804 投稿时间：2018-01-17 修订日期：2018-03-01 |
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| 中文关键词 氨氮 厌氧氨氧化(ANAMMOX) Feammox 水铁矿 采矿废水 |
| 英文关键词 ammonia anaerobic ammonia oxidation(ANAMMOX) Feammox ferrihydrite mining wastewater |
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| 中文摘要 |
| 氮元素在人工湿地生物地球化学循环中起到了重要作用，因此本文以处理采矿废水人工湿地为研究对象，分析了富硫、富铁沉积物中氨氮的厌氧转化过程及其主要途径.本实验以湿地沉积物为样品，通过添加氨氮和利用乙炔抑制剂的技术手段，探究了水铁矿对减少湿地氮流失的效果.结果发现了湿地中存在厌氧氨氧化（anaerobic ammonium oxidation，ANAMMOX）以及厌氧氨氧化作用与铁还原耦合的作用过程（anaerobic ammonium oxidation coupled to iron reduction，Feammox）.Feammox可以利用Fe（Ⅲ）氧化氨氮产生氮气，中间产物包括硝酸盐、亚硝酸盐、及温室气体N2O等.水铁矿的加入对Feammox过程有促进作用，使得Feammox过程主导的氨氮流失速率从1.69 mg·（kg·d）-1增强到2.72 mg·（kg·d）-1，进而使得Feammox过程对氨氮流失的贡献率从28%增加到42%.但同时，水铁矿的加入使得ANAMMOX作用显著地降低，从而使得湿地系统总体氮流失可以减少约25%.研究结果表明水铁矿矿化形成针铁矿而抑制ANAMMOX过程、以及促进Feammox争夺硫酸盐型厌氧氨氧化过程（sulfate-reducing anaerobic ammonium oxidation，S-ANAMMOX）电子供体而抑制S-ANAMMOX过程，达到了减少湿地系统总氮流失的目的.另外，对于进一步认识湿地中铁的氧化还原循环过程同氮循环之间的交互作用具有一定的意义. |
| 英文摘要 |
| Nitrogen elements play an important role in the biogeochemical cycle of artificial wetlands. In this study, we investigated the anaerobic transformation of ammonia nitrogen and its main pathways in sediment in an artificial wetland. Results showed that the anaerobic ammonia oxidation (ANAMMOX) process and iron reduction occurred in wetland sediment, coupled with anaerobic ammonia oxidation (Feammox). Feammox used Fe(Ⅲ) to oxidize ammonia nitrogen to produce nitrogen; intermediate products were nitrate, nitrite, and N2O. Addition of ferrihydrite promoted the Feammox process and ammonia nitrogen loss caused by Feammox was enhanced from 1.69 to 2.72 mg·(kg·d)-1. When ferrihydrite was added, a loss of 28% of total nitrogen (TN) in the wetland occurred, associated with Feammox, increasing to 42%. Anaerobic ammonia oxidation was significantly inhibited with addition of ferrihydrite and TN loss in the system decreased by about 25%. Results showed that the formation of goethite by mineralization of ferrihydrite inhibited the ANAMMOX process, promoting Feammox to lead to competing electronic donors for the S-ANAMMOX process, causing inhibition of the S-ANAMMOX process. This achieves the purpose of reducing TN loss in the wetland system. In addition, this may have some significance for further understanding the interaction between iron reduction and the nitrogen cycle in the wetland. |
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