旋流选择作用及K_La对污泥颗粒化的影响研究

Impacts of Swirl Selection and Volumetric Oxygen Transfer Coefficient on Formation of Aerobic Granular Sludge

采用3个结构不同的SBR反应器R1、R2和R3,研究了旋流选择作用和体积溶解氧系数(KLa)在低负荷条件下对絮体污泥颗粒化过程的影响。试验结果表明,3个反应器内的污泥颗粒化的时间与颗粒污泥的孔隙率依次为53 d、41 d、25 d和82%~95%、92%~97%、60%~75%;3个反应器的化学需氧量(COD)平均去除率都在92%以上;R1和R2中氨氮(NH3-N)的平均去除率都在97%以上,而R3中氨氮的平均去除率从反应器启动初期的99%下降到完全颗粒化后的56%。说明旋流选择作用延缓了好氧污泥颗粒化的时间并对出水水质影响不大;较高的KLa促进了好氧颗粒污泥的形成并对于COD的处理基本没有影响,但对于氨氮去除效果的负面影响较大。

Three bench scale SBRs, R1, R2 and R3, with different structures were used to investigate the effect of swirl se-lection and volumetric oxygen transfer coefficient （KLa） on the formation of aerobic granular sludge under low loading condi-tions. Results of the experiment showed that the formation time were 53 d, 41 d, 25 d in R1, R2 and R3 respectively, and the porosity of aerobic granular sludge 82%-95%, 92%-97%, 60%-75% for R1, R2 and R3 respectively; average removal rates of COD were more than 92% in all the three reactors; and average removal rates of NHz-N were more than 97% in R1 and R2, but in R3 a decrease of NH^-N removal rate from 99% to 56% since the reactor startup was noted. In conclusion, swirl selec- tion delayed the aerobic granular sludge formation time and did not very much affect the removal rates of COD and NH3-N; and higher KLa could promote formation of aerobic granular sludge and had less influences on the treatment capacity of COD, but the treatment capacity of NHa-N declined remarkably.