Membrane photobioreactors (MPBR) have the opportunity to remove various forms of nitrogen, such as ammonium and nitrate, found in high quantities in secondary effluent. This study provides a holistic comparison of the performance of two membrane photobioreactors treating secondary effluents containing ammonium (NH₄⁺-N) or nitrate (NO₃⁻-N) as the sole nitrogen source. Sophisticated analyses, such as flow cytometry, polymerase chain reaction denaturing gradient gel electrophoresis, liquid chromatography – organic carbon detection analysis and fluorescence excitation-emission matrix spectroscopy, were used to provide insight into system characteristics and performance. In terms of treatment efficiency, NH₄⁺-N was better removed from the system (by 56%) compared to NO₃⁻-N (33%). The MPBR fed with NH₄⁺-N produced less microalgal cells (4.4 × 10⁷ cells/ml compared to 5.3 × 10⁷ cells/ml in that treating NO₃⁻-N) but higher proportion of bacteria (6.3% compared to 2.1%), leading to a higher system heterogeneity. The biomass produced from the MPBR treating NH₄⁺-N featured a higher level of extracellular materials and a lower dewaterability (as suggested by a significantly higher capillary suction time of 25.2 s than 13.1 s observed for the culture grown on NO₃⁻-N), indicating a lower harvesting potential. As a result, faster membrane fouling was observed when NH₄⁺-N was fed. This leads to a recommendation that operating conditions are optimised dependent on the form of nitrogen that needs to be treated.

膜光生物反应器（MPBR）可以去除次级废水中大量存在的各种形式的氮，例如铵和硝酸盐。这项研究对两种膜光生物反应器处理以铵（NH ₄ ⁺ -N）或硝酸盐（NO ₃ ^-- N）作为唯一氮源的二次废水的性能进行了整体比较。流式细胞术，聚合酶链反应变性梯度凝胶电泳，液相色谱-有机碳检测分析和荧光激发-发射矩阵光谱等复杂分析可用于深入了解系统特性和性能。就处理效率而言，NH ₄ ⁺与NO ₃ ^-- N（33％）相比，-N从系统中的去除效果更好（56 ％）。饲喂NH ₄ ⁺ -N的MPBR产生的微藻细胞较少（4.4×10 ⁷ 细胞/ ml，而处理NO ₃ ^-- N 则为5.3×10 ⁷细胞/ ml ），但细菌比例更高（6.3％，比2.1） ％），导致更高的系统异构性。用MPBR处理NH ₄ ⁺ -N产生的生物质具有较高水平的细胞外物质和较低的脱水性（这表明在NO _3-上生长的培养物的毛细管抽吸时间比13.1 s显着更长，为25.2 s）^。-N），表示收割潜力较低。结果，当加入NH ₄ ⁺ -N时观察到更快的膜结垢。这导致建议根据需要处理的氮气形式优化操作条件。