Xia Zhengang, Ng How Yong, Bae Sungwoo
Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore.
Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore; Center for Water Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, PR China.
Water Res. 2025 Sep 1;283:123878. doi: 10.1016/j.watres.2025.123878. Epub 2025 May 22.
This study investigates the membrane-aerated biofilm photoreactor (MABPR) for treating aquaculture effluents with low C/N ratio and elevated salinity (0.5%-3.2%). The MABPR integrated biofilm reactors with microalgal-bacterial consortia, achieving superior total inorganic nitrogen (TIN) removal by leveraging counter-diffusional biofilm properties, bubbleless aeration, and enhanced microalgal productivity. The system consistently outperformed conventional reactors, achieving 84.7 ± 1.9% TIN removal at 3.2% salinity with TIN removal flux increasing from 0.82 ± 0.04 to 1.22 ± 0.07 g/m² d. The MABPR promoted microalgal proliferation (Chl-a/VSS: 8.08-15.04 mg/g) and higher biomass productivity (1.83 g/m² d) compared to SBBPR and MABR. Elevated salinity stimulated extracellular polymeric substance (EPS) production, reinforcing biofilm stability and microbial resilience. The MABPR demonstrated 22%-65% higher nitrogen removal efficiency than controls at the highest salinity. Canonical nitrification-denitrification remained the primary nitrogen removal pathway, with short-cut nitrification-denitrification contributing under salt stress. Metagenomic analysis revealed bidirectional adaptation between microalgae and bacteria, with enriched nitrogen assimilation (GS/GOGAT pathway) compensating for bacterial deficits. Microalgae facilitated pollutant removal through ammonia uptake and dissolved organic matter release, supporting denitrification. At 3.2% salinity, Nitrosomonas and Nitrobacter abundance increased by 42.6% and 35.8%, while denitrifiers Denitromonas and Hoeflea dominated, comprising 59.4% and 35.9% of the population. The MABPR further promoted the synthesis of growth cofactors (vitamins, phytohormones), enhancing microalgal productivity and stress resilience. These synergistic microalgal-bacterial interactions supported pollutant removal, showcasing the MABPR as a robust, sustainable solution for aquaculture wastewater treatment and resource recovery under salt stress.
本研究考察了膜曝气生物膜光生物反应器（MABPR）用于处理低C/N比和高盐度（0.5%-3.2%）的水产养殖废水。MABPR将生物膜反应器与微藻-细菌联合体相结合，通过利用反向扩散生物膜特性、无泡曝气和提高微藻生产力，实现了卓越的总无机氮（TIN）去除。该系统始终优于传统反应器，在盐度为3.2%时实现了84.7±1.9%的TIN去除，TIN去除通量从0.82±0.04增加到1.22±0.07 g/m²·d。与SBBPR和MABR相比，MABPR促进了微藻增殖（叶绿素a/挥发性悬浮固体：8.08-15.04 mg/g）和更高的生物量生产力（1.83 g/m²·d）。盐度升高刺激了胞外聚合物（EPS）的产生，增强了生物膜稳定性和微生物恢复力。在最高盐度下，MABPR的脱氮效率比对照高22%-65%。传统硝化-反硝化仍然是主要的脱氮途径，在盐胁迫下短程硝化-反硝化也有贡献。宏基因组分析揭示了微藻和细菌之间的双向适应，丰富的氮同化（谷氨酰胺合成酶/谷氨酸合酶途径）弥补了细菌的不足。微藻通过吸收氨和释放溶解有机物促进污染物去除，支持反硝化作用。在盐度为3.2%时，亚硝化单胞菌和硝化杆菌的丰度分别增加了42.6%和35.8%，而反硝化菌脱氮单胞菌和霍夫勒菌占主导地位，分别占种群的59.4%和35.9%。MABPR进一步促进了生长辅助因子（维生素、植物激素）的合成，提高了微藻生产力和抗逆性。这些微藻-细菌的协同相互作用支持了污染物去除，表明MABPR是盐胁迫下水产养殖废水处理和资源回收的一种强大、可持续的解决方案。
