Effective cultivation of stable aerobic granular sludge(AGS)is a crucial step in the successful application of this technology,and the formation of AGS could be facilitated by some environmental stress conditions.Four...Effective cultivation of stable aerobic granular sludge(AGS)is a crucial step in the successful application of this technology,and the formation of AGS could be facilitated by some environmental stress conditions.Four identical sequencing batch reactors(SBRs)were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions(inorganic carbon source,temperature,N/COD).Although various superimposed conditions induced a significant difference in the size,settling velocity,mechanic strength of AGS,mature aerobic granules could be successfully obtained in all four reactors after 70 days’operation,indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation.Based on the results of redundancy analysis,the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function,while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS.In addition,superimposed stress conditions could result in the difference in the microbial population between four reactors,but the population diversity and abundance of microorganisms were not the determinants of AGS formation.This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.展开更多
基金supported by the National Natural Science Foundation of China(No.42077213)the Natural Science Foundation of Shanghai(Nos.19ZR1403700 and 20ZR1406100).
文摘Effective cultivation of stable aerobic granular sludge(AGS)is a crucial step in the successful application of this technology,and the formation of AGS could be facilitated by some environmental stress conditions.Four identical sequencing batch reactors(SBRs)were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions(inorganic carbon source,temperature,N/COD).Although various superimposed conditions induced a significant difference in the size,settling velocity,mechanic strength of AGS,mature aerobic granules could be successfully obtained in all four reactors after 70 days’operation,indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation.Based on the results of redundancy analysis,the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function,while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS.In addition,superimposed stress conditions could result in the difference in the microbial population between four reactors,but the population diversity and abundance of microorganisms were not the determinants of AGS formation.This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.
