不同溶氧濃度對厭氧氨氧化反應脫氮之影響

Effect of Dissolved Oxygen Concentrations on Nitrogen Removal of ANAMMOX Reactions

本研究以家庭污水處理廠之活性污泥，經合適之條件馴養出本土性厭氧氨氧化菌，並藉由重複之批次試驗探討不同溶氧濃度下對厭氧氨氧化菌脫氮之影響。實驗結果顯示，當僅存氨氮之系統中，控制反應條件 （pH = 7 ± 0.2, Temp =35°C） 及固定NH4+-N = 25 mg/L 濃度時，不同初始溶氧濃度對厭氧安氧化（ANAMMOX） 反應影響差異明顯。較低溶氧濃度 （DO0 = 0.37 mg/L, 1.13 mg/L）系統中，混菌均能利用微量溶氧先進行部分硝化，直至溶氧耗盡，後續則進行厭氧氨氧化反應。進行至氨氮耗盡或生成之亞硝酸氮太少不敷反應，所有反應即行終止。較高溶氧濃度 （DO0 = 2.01 mg/L, 3.29 mg/L） 系統中，對ANAMMOX 菌產生抑制作用，更利於硝化菌之反應，反應過程完全硝化，降低脫氮之功用。當氨氮與亞硝酸氮共存系統中，固定反應條件 （pH = 7 ± 0.2,Temp = 35°） 及NH4+-N = 25 mg/L, NO2--N = 25 mg/L濃度時，不同初始溶氧濃度對ANAMMOX反應影響則與前僅氨氮之系統相似。唯氨氮與亞硝酸氮共存時，較低溶氧 （DO0 = 0.18 mg/L），愈利於厭氧氨氧化反應，脫氮效果顯著；溶氧增加 （DO0 = 1.3 mg/L, 2.48 mg/L） 時，硝化作用轉趨活躍，脫氮效果明顯減少甚至停滯。

In this study, anaerobic ammonium oxidizing bacteria were acclimatedfrom activated sludge of a domestic wastewater treatment plant, and batchexperiments were conducted to investigate the effects of different concentrationsof dissolved oxygen on the nitrogen removal of anaerobic ammoniaoxidation (ANAMMOX). The results showed that controlling thereaction conditions (pH = 7 ± 0.2, Temp = 35°C) and NH4+-N = 25 mg/L, the nitrogen removal of ANAMMOX were apparently affected withdifferent concentrations of DO. Low concentrations of DO (DO0 = 0.37,1.13 mg/L), partial nitrification can occur by a mixed culture of bacteria.When the dissolved oxygen was exhausted, the ANAMMOX reaction wasthen proceeded with. At higher concentrations of DO (DO0 = 2.01, 3.29mg/L) conditions, complete nitrification occurred as ANAMMOX bacteriawere inhibited to remove the nitrogen. If the reaction conditions (pH = 7± 0.2, Temp = 35°C) and concentrations of NH4+-N = 25 mg/L and NO2--N= 25 mg/L were fixed, the effects of DO concentrations on ANAMMOXreaction were similar to previous experiments. Low concentrations of DO(DO0 = 0.18 mg/L), ANAMMOX reaction may still be carried out in thisreaction periods. In higher concentrations of DO (DO0 = 1.3 mg/L, 2.48mg/L), ANAMMOX reaction in system was evidently retarded. Thenitrification reaction dominated when the concentration of DO was raised.This situation markedly inhibits the ANAMMOX bacteria; the capability ofnitrogen removal cannot be achieved.