包埋法固定化细胞技术用于三维电极生物膜反应器

Application of Entrapping Method in Three-dimensional Biofilm-electrode Reactor for Advanced Nitrogen Removal

为强化三维电极生物膜反应器(3DBER)氢自养反硝化菌的优势,提高再生水深度脱氮效率,采用聚乙烯醇(PVA)包埋法固定3DBER活性炭填料表面的生物膜,并与常规3DBER进行对比,分析在不同电流强度条件下的脱氮效率、有效电流强度和电流效率。结果表明,包埋填料生物膜3DBER的脱氮效率、有效电流强度和电流效率均高于常规3DBER。在C/N值为2、HRT为10 h、电流为80 m A的条件下,包埋填料生物膜3DBER对NO_3^--N和TN的去除率分别为89. 4%和77. 0%,比常规3DBER均提高10%以上。通过扫描电镜观察活性炭表面的生物膜,发现表面分布的主要为短杆状(1～2μm)反硝化细菌。因此,包埋填料生物膜3DBER能够在增加氢自养优势菌属浓度的同时,提高电流的利用效率,从而强化3DBER工艺对再生水的深度脱氮效果。

In order to enhance the dominant position of hydrogen autotrophic denitrifying bacteria in three-dimensional biofilm-electrode reactor（3DBER）and improve the nitrogen removal efficiency of re- claimed water, biofilm on the surface of activated carbon fillings of 3DBER were wrapped by polyvinyl al- cohol （PVA） imbedding method. The operational effect was compared with that of conventional 3 DBER, and the denitrification efficiency, effective current intensity and current efficiency were analyzed under different current conditions. The results indicated that the new 3DBER with the imbedded biofilm on the fillings had higher denitrification efficiency, effective current intensity and current efficiency than that of the conventional process. Under the condition of C/N = 2, HRT = 10 h and I = 80 mA, the NO3 - N and TN removal rates of the new 3DBER reached 89.4% and 77.0% respectively, which was over 10% higher than the conventional 3DBER. Meanwhile, microbial morphological characteristic of the biofilm was observed by scanning electron microscope technology. It was found that the short rods （1 -2 μm） denitrifying bacteria mainly distributed on the surface of the biofilm. The results illustrated that the imbedded biofilm on the surface of activated carbon fillings of 3DBER not only increased the dominant hydrogen autotrophic denitrifying concentration, but also improved the current efficiency. Therefore, advanced nitrogen removal efficiency of reclaimed water by the new 3DBER was enhanced.