Abstract This study investigated the effects of microalgae and light on nitrifying bacteria. The oxygen production rates of microalgae were measured at various cell concentrations, and it was observed that 500–2000 mg/L of microalgal concentration supplied sufficient oxygen for bacterial nitrification without forced aeration. The effects of light on nitrification were investigated by determining the ammonia oxidation rate (AOR) and nitrate production rate (NPR) of enriched nitrifiers in the absence of microalgae with forced aeration, and it was observed that those rates were significantly lowered in the presence of light. However, the inhibitory effects of light on AOR and NPR were partially reduced in the co-culture owing to the self-shading effect. AOR and NPR of co-cultures with Chlorella vulgaris and Scenedesmus quadricauda were high at a low mass ratio of microalgae to enriched nitrifiers, while those with Desmedesmus communis increased as the mass ratio increased. These species-specific phenomena could be attributed to the different production of reactive oxygen species. Despite the negative effects of light and reactive oxygen species, it was estimated that the energy consumption of the co-culture was lower than that of the mechanically-aerated nitrifiers.

中文翻译：

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微藻和硝化菌的光质比对氨氧化速率和硝酸盐生成速率的影响

摘要 本研究探讨了微藻和光照对硝化细菌的影响。在不同的细胞浓度下测量了微藻的产氧率，观察到 500-2000 mg/L 的微藻浓度为细菌硝化提供了足够的氧气，而无需强制曝气。通过在没有微藻和强制曝气的情况下测定富集硝化菌的氨氧化率 (AOR) 和硝酸盐生成率 (NPR) 来研究光照对硝化作用的影响，观察到这些速率在存在强制曝气的情况下显着降低。光。然而，由于自遮蔽效应，光对 AOR 和 NPR 的抑制作用在共培养中部分降低。与普通小球藻和四角栅藻共培养的 AOR 和 NPR 在微藻与富集硝化菌的质量比较低时较高，而与 Desmedesmus community 的共培养物随着质量比的增加而增加。这些物种特异性现象可归因于活性氧物种的不同产生。尽管存在光和活性氧的负面影响，但据估计，共培养的能量消耗低于机械曝气硝化菌的能量消耗。