藻菌固定化用于市政污水深度脱氮除磷及藻体产油研究

Removal of nitrogen and phosphorus and the lipid production by co-immobilized microalgae and bacteria in municipal wastewater

污水再生利用是解决水资源与能源危机的重要途径,采用微藻深度处理污水并生产生物质能源是一大热点。针对市政污水深度处理,以活性污泥为固定化细菌,采用小球藻和栅藻,分别比较了固定化藻菌、固定化微藻,以及悬浮态微藻在藻体生长、污水脱氮除磷和微藻产油方面的差异,拟实现对市政污水深度脱氮除磷的同时实现微藻油脂的诱导富集。结果表明,固定化藻菌对氮磷的去除效果优于固定化微藻和悬浮态微藻,且固定化藻菌中微藻油脂质量分数最高。当市政污水NH_4^+-N和PO_4^(3-)-P的初始质量浓度分别为25和3 mg/L时,固定化栅藻菌培养4 d后能够完全去除水体中的氮磷,而固定化藻菌中小球藻的油脂质量分数可达到16.5%。

The wastewater reuse is an important way out facing the water resource and energy crisis, and the coupled process of the advanced wastewater treatment and the microalgal energy production is an important issue in this respect. In this paper, the activated sludge as the fixing bacteria is immobilized with Chlorella vulgaris and Scenedesmus obliquus, respectively, for the enhanced municipal wastewater treatment. The microalgal growth, the nitrogen and phosphorus removal and the oil production of the coimmobilized microalgae and bacteria, the immobilized microalgae, and the suspended microalgae are then compared. It is shown that the co-immobilized bacteria and algae are better than the immobilized bacteria and the immobilized algae in their effect on the nitrogen and phosphorus removal, and better than the non immobilized algae and bacteria as well, while the co-immobilized bacteria and algae produce much more lipid. When the concentrations of the NH4^＋ - N and PO4^3--P in the municipal wastewater are about 25 mg/ L and 3 mg/L, the NH4^＋ -N and PO4^3--P in the wastewater are removed completely by the co-immobilized Secenedesmus obliquus and bacteria, whereas the lipid yield of C. vulgaris reaches 16.5%.