Microalgae as a promising approach for wastewater treatment, has challenges in directly treating digested piggery wastewater (DPW) with high ammonia nitrogen (NH4+-N) concentration. To improve the performance of microalgae in DPW treatment, straw was employed as a substrate to form a straw-microalgae biofilm. The results demonstrated that the straw-microalgae biofilm achieved the highest NH4+-N removal rate of 193.2 mg L−1 d−1, which was 28.8 % higher than that of culture system without straw. The final NH4+-N concentration in the effluent met the discharge standard of 5 mg L−1. Furthermore, the total organic carbon (TOC) released from straw facilitated bacterial proliferation and the secretion of extracellular polymeric substances (EPS). The EPS and TOC increased the suspension viscosity and surface tension, thereby enhancing the residence time of CO2 in the liquid phase and promoting CO2 fixation. This study presented a novel method for the biological treatment of high-ammonia–nitrogen DPW.

中文翻译：

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秸秆与微藻协同处理高氨氮消化废水


微藻作为一种有前途的废水处理方法，在直接处理高氨氮（NH4+-N）浓度的消化养猪废水（DPW）方面面临挑战。为了提高微藻在DPW处理中的性能，采用秸秆作为基质形成秸秆-微藻生物膜。结果表明，秸秆-微藻生物膜的NH4+-N去除率最高，为193.2 mg L−1 d−1，比无秸秆培养体系提高了28.8%。出水最终NH4+-N浓度满足5mg·L−1的排放标准。此外，秸秆释放的总有机碳（TOC）促进细菌增殖和细胞外聚合物（EPS）的分泌。 EPS和TOC增加了悬浮液粘度和表面张力，从而延长了CO2在液相中的停留时间，促进了CO2的固定。本研究提出了一种生物处理高氨氮DPW的新方法。