Conventional wastewater treatment (WWT) systems face persistent challenges in simultaneous ammonium (NH4+-N) and nitrate (NO3--N) removal due to substrate competition and energy-intensive multi-stage processes. This study presents an innovative strategy leveraging encapsulated microalgal systems to achieve synchronous 94.45 % NH4+-N and 98.47 % NO3--N removal within a single reactor through spatial reprogramming of photosynthetic energy allocation. By exploiting the structural heterogeneity within alginate-encapsulated beads, depth-stratified metabolic zones were created that challenge the long-held dogma of microalgae’s inherent NH4+-N preference. Multidimensional analyses, including spatial distribution mapping, molecular dynamics simulations, metagenomic profiling and photosynthetic regulation, further revealed that light-modulated oxygen gradients, polymer-mediated solute transport, and stratified photo-metabolic specialization synergistically reprogramed microalgal nitrogen metabolism, enabling co-utilization of NH4+-N and NO3--N. The system demonstrated robust dual-nitrogen assimilation efficiencies under varying environmental conditions, transcending conventional substrate utilization hierarchies. This transformative approach not only resolves the dilemma of mixed nitrogen pollution but also advances sustainable WWT by integrating pollutant removal with biomass valorization. The findings provide mechanistic insights into microalgal metabolic plasticity and offer a scalable, energy-efficient solution to upgrade traditional denitrification technologies, aligning with urgent demands for circular economy in water resource management.

中文翻译：

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包封微藻的层特异性光代谢特化：从废水中同步消除多氮的策略

由于基质竞争和能源密集型多级工艺，传统的废水处理 （WWT） 系统在同时去除铵 （NH4+-N） 和硝酸盐 （NO3--N） 方面面临着持续的挑战。本研究提出了一种创新策略，利用封装的微藻系统，通过光合能量分配的空间重编程，在单个反应器内实现同步 94.45% NH4+-N 和 98.47% NO3--N 去除。通过利用藻酸盐封装珠子内的结构异质性，创建了深度分层代谢区，挑战了微藻固有的 NH4+-N 偏好的长期教条。多维分析，包括空间分布映射、分子动力学模拟、宏基因组分析和光合作用调节，进一步揭示了光调制氧梯度、聚合物介导的溶质运输和分层光代谢特化协同重编程微藻氮代谢，使 NH4+--N 和 NO3--N 能够共利用。该系统在不同的环境条件下表现出强大的双氮同化效率，超越了传统的底物利用层次结构。这种变革性的方法不仅解决了混合氮污染的困境，而且还通过将污染物去除与生物质价值化相结合，推进了可持续的污水处理。这些发现为微藻代谢可塑性提供了机制见解，并为升级传统反硝化技术提供了一种可扩展、节能的解决方案，符合水资源管理中对循环经济的迫切需求。