连续流生物流化床中好氧颗粒污泥的形成特征

Formation of Aerobic Granular Sludge in Continuous-flow Biological Fluidized Bed

将上流式厌氧污泥床(UASB)与气升式间歇反应器(SBAR)相结合而形成连续流生物流化床,并以兰州市七里河安宁污水处理厂的活性污泥为种泥,在连续运行方式下培养好氧颗粒污泥,考察颗粒污泥的形成特征及除污效果。在反应器运行至第17-19天有小颗粒形成,生物量从0.5g/L增到约1.0g/L,MLVSS/MLSS值达到0.75左右,对COD和NH_3-N的去除率达到90%。当培养至第29天时污泥颗粒密实且具有较大的粒径,镜检时丝状菌清晰可见,此时对TP的去除率约为60%,MLVSS/MLSS值达到0.8以上。培养至第47天时发生丝状膨胀,MLVSS/MLSS值下降至0.7,对NH_3-N和TP的去除率降至40%左右;第62天丝状膨胀开始得到有效控制,MLVSS/MLSS值上升至0.8以上,生物量超过2.0g/L,对有机物的去除效果得到恢复,此后反应器中生物量和除污效果等均呈上升趋势,SVI值趋于稳定。

A continuous-flow biological fluidized bed was developed by combining up-flow anaerobic sludge bed （UASB） and airlift batch reactor. Activated sludge from Qilihe Anning WWTP in Lanzhou was used as inoculum to cultivate aerobic granular sludge in continuous operation mode. The formation characteristics of granular sludge and the removal efficiency of pollutants were investigated. The formation of granular sludge in the reactor started on the 17th to 19th day, the biomass increased from 0.5 g/L to about 1.0 g/L, MLVSS/MLSS was about 0.75, and the removal rates of COD and NH3 - N were both 90%. On the 29th day, there were large and dense sludge particles, filamentous bacteria were observed by microscopic examination, the removal rate of TP was about 60%, and MLVSS/MLSS was 0.8 or above. On the 47th day, filamentous sludge bulking occurred, MLVSS/MLSS was reduced to 0.7, and the removal rates of NH3 - N and TP were both decreased to 40%. On the 62th day, filamentous sludge bulking stabilized, MLVSS/MLSS increased to 0.8 or above, the biomass was 2.0 g/L or above, the removal efficiency of pollutants was restored. After this, the biomass and the removal efficiency of pollutants showed an upward trend, and SVI was stable.