曝气量对SBAR中好氧颗粒污泥特性的影响

采用SBAR反应器对比研究了颗粒化后表观气速为1.8 cm·s-1和0.9cm·s-1时对成熟好氧颗粒污泥形态结构、粒径、强度等物理特性和硝化性能以及胞外聚合物代谢的影响.结果表明,颗粒化后降低曝气量增加颗粒形态不规则程度,空隙增大;55d试验中,与高曝气量下相比,降低曝气量使表观污泥产率提高33%,颗粒粒径平均增长速率提高25%,相对颗粒强度降低6%, EP5含量平均降低12%.两反应器颗粒污泥SVI值均在10～15 mL·g-1,沉降性能良好,且均具有良好硝化性能和降解COD能力.与高曝气量下相比,低曝气量下硝化菌群活性低,而异养菌活性高.

Effects of Aeration Intensity on Characteristics of Aerobic Granules in Sequencing Batch Airlift Reactor (SBAR)

This study investigated the physical performances of mature aerobic granules in SBAR, including granular shape and structure, mean size and granular relative strength, and cell metabolic activities to excrete extracellular polymeric substances (EPS), and nitrification and microbial activity, which performed visible differences at superficial upflow velocity of 1.8 cm·s^-1 and 0.9 cm·s^-1 respectively. Results show that granular surface was more irregular at the low aeration intensity than that at the high aeration intensity and granular interstice performed increasing with it. In 55 days, comparing with high aeration intensity, the sludge productivity and the mean size of aerobic granules at the low aeration intensity were increased by 33% and 25%, respectively, while the granular relative strength and EPS were reduced by 6% and 12%, respectively. The sludge volume index in two reactors were about between 10 mL·g^-1 and 15 mL·g^-1, which implied that granules at both aerations behaved well settling ability. The two reactors still performed well nitrification characteristic and ability to remove COD. The activity of nitrifying bacteria in aerobic granules at the low aeration intensity was lower than that at the high aeration intensity, while heterotrophs performed higher activity at the low aeration intensity.