连续流气提式流化床启动过程中好氧颗粒污泥的形成机制

探讨连续流气提式好氧颗粒污泥流化床(CAFB)反应器的运行特征,对该工艺颗粒污泥形成过程、形成机理和颗粒性质进行分析。以市政污泥为接种污泥,以醋酸钠为碳源,在连续运行方式下培养好氧颗粒污泥。研究结果表明:CAFB反应器启动的第4-5天即有大量颗粒污泥形成,颗粒直径800～1 000μm,比重1.006,生物相丰富,能够分泌大量胞外聚合物。当COD有机负荷高达8和13kg/(m3.d)时,对COD处理效率均维持在93%～97%,COD出水质量浓度仅为30～80mg/L,引起启动后期丝状菌的大量繁殖,污泥流失。进一步提高污泥负荷有望控制污泥膨胀。

Preliminary Approach on Formation Mechanism of Aerobic Granular Sludge During the Continuous Airlift Fluidized Bed Start-Up

Operational characteristics of a continuous airlift aerobic granular sludge fluidized bed(CAFB)were discussed.The formation,mechanism and characteristics of the granule sludge in the reactor were investigated and analyzed.The reactor was operated continuously by inoculating with municipal sewage sludge and the synthetic wastewater mainly consisted of sodium acetate as carbon source.The results showed that dense and compact granules were formatted at 4-5days,much more quickly than other reported aerobic granule sludge process.The diameter of granules is 800-1 000μm,specific gravity is 1.006or so,and accompanied with multi-biofacies and many extracellular polymeric substances produced.These characteristics contributed to the fast formation of the granules to some extent.As the COD loading of 8and 13kg COD/(m3.d)were employed,COD removal efficiency of CAFB maintained at 93%-97%.Due to the COD concentration of effluent was as low as 30-80mg/L,eading to an overgrowth of filamentous and sludge washout eventually.These results showed that CAFB is more applicable for treatment of wastewater with higher organic loading rate.