碳量子点/壳聚糖@维纶纤维载体强化藻菌生物膜净化农村污水及脂质积累效能

本文针对微藻净化污水效率低、藻水分离困难以及微藻含油量低等系列问题，设计制备碳量子点/壳聚糖@维纶纤维(CQDs/CS@PVF)附着载体强化藻菌生物膜系统对污水净化协同产油。结果表明，CQDs/CS@PVF添加形成的藻菌生物膜系统与对照组相比，对污水中的COD、TN和TP的去除速率分别提高了68.2%、120.2%、79.2%，这是由于CQDs/CS@PVF藻菌生物膜系统提高了42.3%的微藻比生长速率，出水达到北京《农村生活污水处理设施水污染物排放标准》一级A标准。污水中的有机物被微藻利用转化为生物质油脂，其含量达到30.1%，脂肪酸C16~C18含量占比为96%，此组份的脂质更适合作为底物合成生物柴油，实现污染物向生物柴油优质原料的转化。CQDs/CS@PVF微藻生物膜快速去除有机物的同时高效生产油脂的机理是藻菌生物膜体系微藻与细菌细胞间距小，从而提高了O₂-CO₂气体与营养组分交换效率；此外，CQDs/CS@PVF通过拓展藻30%的可吸收光谱可提升20.9%的光合作用效率，非光化学淬灭系数提升了98.0%。以上研究结果可为CQDs/CS@PVF载体强化藻菌生物膜系统高效率处理农村污水同步收获油脂提供参考。

The efficiency of carbon quantum dots/chitosan @ vinylon fiber carrier enhanced algae and bacteria biofilm in purification of rural wastewater and lipid accumulation

In this study, carbon quantum dots/chitosan @ poly (vinyl alcohol) fibers (CQDs/CS@PVF) were designed and prepared to address a series of issues such as low efficiency in sewage purification by microalgae, difficulty in algae water separation, and low oil content in microalgae. Synergistic oil production by attaching carriers to enhance algal biofilm systems for wastewater purification. The results show that CQDs/ CS@PVF compared with the control group, the removal efficiencies of COD, TN, and TP in wastewater by the added algal biofilm system increased by 68.2%, 120.2% and79.2 %, respectively, which was due to CQDs/ CS@PVF-loaded algal biofilm system increased the growth rate of microalgae by 42.3%, and the effluent could meet the Class I A standard of Beijing Water Pollutant Discharge Standard for Rural Domestic Sewage Treatment Facilities. The organic matter in sewage was utilized by microalgae and converted into biomass oil with a content of 30.1%, and the content of fatty acid C16-C18 accounted for 96%. The lipid of this component was more suitable as a substrate for the synthesis of biodiesel, realizing the conversion of pollutants into high-quality raw materials for biodiesel. The mechanism of CQDs/CS@PVF-loaded microalgae biofilm for rapid removal of organic matter and efficient production of oil was small distance between microalgae and bacterial cells in the algal bacterial biofilm system, thereby improving the exchange efficiency of O2-CO2 gas and nutrient components. In addition, CQDs/ CS@PVF could expand the absorbable spectra of algae by 30%, which could lead to the increase of the photosynthetic efficiency by 21%, and the increase of non photochemical quenching coefficient by 98%. This study provides a reference for CQDs/CS@PVF carrier-enhanced algal biofilm system to efficiently treat rural sewage and simultaneously harvest oil.