铁/锰矿基人工湿地脱氮除磷性能及机理

铁氧化物和锰氧化物均可在缺氧条件下介导氨氮(NH₄⁺-N)的氧化去除，这2项技术被称为铁氨氧化(Feammox)和锰氨氧化(Mnammox)。此外，金属氧化物对总磷(TP)也有去除能力，因此，在人工湿地中具有良好的应用前景。为比较铁矿基和锰矿基人工湿地的脱氮除磷效果，本研究建立了铁矿基人工湿地(CW-Fe)、锰矿基人工湿地(CW-Mn)和砾石对照组人工湿地(CW-C)3组人工湿地。结果表明，CW-Fe和CW-Mn的脱氮除磷性能均优于CW-C。尽管锰矿对NH₄⁺-N的吸附作用最强，但CW-Fe却表现出了更优越的NH₄⁺-N长期去除性能。在基质对NH₄⁺-N的吸附饱和后，CW-Fe对NH₄⁺-N的去除率仍有39.93%~62.4%，而CW-Mn只有29.15%~35.4%。由于铁矿和锰矿溶出的金属离子能与磷酸盐结合形成稳定的沉淀，从而有效去除TP，CW-Fe和CW-Mn均有优异的TP去除性能。CW-Mn的TP去除率最高，为95.26%，其次是CW-Fe，为79.97%。在微生物方面，具有还原铁氧化物和氧化NH₄⁺-N潜力的Bacillus和Exiguobacterium在CW-Fe中均得到了显著富集。结合水质数据及脱氮相关功能菌的分析，推测出Feammox中可能更倾向于将NH₄⁺-N直接氧化为N₂，而Mnammox则是更倾向于先将NH₄⁺-N氧化为NO_x⁻-N。本研究可为探索同步脱氮除磷的低能耗污水处理工艺及人工湿地中基质的选择提供案例参考。

Performance and mechanism of nitrogen and phosphorus removal in iron/manganese ore-based constructed wetlands for

Both Fe(III) and Mn(IV) oxides can oxidize and remove ammonia nitrogen (NH4+-N) under anoxic conditions, and these two technologies are known as Feammox and Mnammox. Additionally, metal oxides also have the ability to remove total phosphorus (TP), making them a promising option for use in constructed wetlands (CWs). In order to compare the nitrogen and phosphorus removal efficiency of iron ore-based and manganese ore-based CWs, three groups of CWs were established for this study: iron ore (CW-Fe), manganese ore (CW-Mn), and a control group with gravel (CW-C). The experimental results showed that both CW-Fe and CW-Mn had better nitrogen and phosphorus removal performance than CW-C. Although manganese ore had the strongest adsorption effect on NH4+-N, CW-Fe exhibited a superior performance on long-term removal for NH4+-N. Even after saturated adsorption to NH4+-N by the substrates, the removal efficiency of NH4+-N by CW-Fe remained at 39.93% to 62.4%, while that of CW-Mn only remained 29.15% to 35.4%. Because metal ions dissolved from iron ore and manganese ore can combine with phosphates to form stable precipitates, effectively removing TP, both CW-Fe and CW-Mn showed the excellent TP removal performance. The TP removal efficiency of CW-Mn was the highest, at 95.26%, followed by CW-Fe at 79.97%. In terms of microorganisms, Bacillus and Exiguobacterium, which have the potential to reduce iron oxides and oxidize NH4+-N, were significantly enriched in CW-Fe. Based on the water quality data and analysis of nitrogen-related functional bacteria, it was speculated that Feammox may be more likely to directly oxidize NH4+-N to N2, while Mnammox is more likely to first oxidize NH4+-N to NOx−-N. This study provides a reference for exploring low-energy wastewater treatment processes that achieve simultaneous nitrogen and phosphorus removal, as well as selecting substrates used in constructed wetlands.