DNFB-MBR工艺挂膜启动及脱氮除碳性能

Start-up of Biofilm Formation and Performance of Nitrogen and Organic Carbon Removal in the DNFBMBR Process

构建反硝化固定式生物膜-膜生物反应器(DNFB-MBR)工艺处理硝酸盐废水,通过快速排泥和提高底物浓度的方式,强化培养载体生物膜,成功实现工艺的挂膜启动。整个运行过程中,NO_(3)^(-)-N与COD的去除率维持在95%、80%以上,TN去除负荷(NRR)和COD去除负荷(CRR)分别达到0.200、0.785 kg/(m^(3)·d);载体生物膜逐渐变厚,颜色由浅黄色变为深褐色,最大附着生物量达到1.545 gSS/g;NO_(3)^(-)-N与COD最大比降解速率分别为81.8、188.4 mg/(gMLSS·d),表明生物膜具有较高的脱氮除碳性能;载体附着生物量与生物膜EPS中的PS、PN含量密切相关,两者分别由6.48、15.44 mg/g增至10.76、21.19 mg/g,三维荧光光谱分析结果进一步表明色氨酸、芳香族蛋白类物质和腐殖酸类物质在生物膜的形成过程中发挥重要作用。

A denitrifying fixed biofilm-membrane bioreactor(DNFB-MBR)process was constructed to treat nitrate-rich wastewater.The biofilm formation process was successfully started up by discharging sludge rapidly and increasing the substrate concentration to strengthen the biofilm cultivation on the carriers.During the whole operation,the removal efficiency of NO_(3)^(-)-N and COD remained above 95%and 80%,and the nitrogen removal rate(NRR)and COD removal rate(CRR)reached 0.200 kg/(m^(3)·d)and 0.785 kg/(m^(3)·d),respectively.The carrier biofilm gradually thickens and the color of that changed from light yellow to dark brown with the maximum attached biomass reaching 1.545 g AS/g.The maximum specific degradation rates of NO_(3)^(-)-N and COD were 81.8 mg/(g MLSS·d)and 188.4 mg/(g MLSS·d)respectively,indicating that the formed biofilm exhibited high activity of nitrogen and carbon removal.The attached biomass on the carriers was closely related to PS and PN contents in the biofilm EPS,which increased from 6.48 mg/g,15.44 mg/g to 10.76 mg/g,21.19 mg/g respectively.The three-dimensional fluorescence spectroscopic analysis results showed that tryptophan,aromatic proteins-like and humic acid-like substances played important roles in the biofilm formation.