Jiangxi Provincial Key Laboratory of Environmental Geotechnology and Engineering Disaster Control, Jiangxi University of Science and Technology, Ganzhou 341000, China.
Jiangxi Provincial Key Laboratory of Environmental Geotechnology and Engineering Disaster Control, Jiangxi University of Science and Technology, Ganzhou 341000, China.
Ultrason Sonochem. 2023 Nov;100:106642. doi: 10.1016/j.ultsonch.2023.106642. Epub 2023 Oct 11.
The fluctuation of dissolved oxygen is one of the primary cause of disruptions to the consistent operation of partial nitrification, and the level of dissolved oxygen is mainly controlled by the aeration rate. This study investigated the influence of ultrasonic treatment on the stability of partial nitrification of activated sludge under different aeration conditions. After being treated with ultrasound (energy density = 0.20 W·mL, treatment time = 10 min), partial nitrification process operated stably for 67 days, with the nitrite accumulation rate above 83.89 %. The effluent contained 42.50 mg·L of nitrite, much higher than the control reactor (0.30 mg·L). The gap between the specific ammonia and nitrite oxidation rates widened continuously as the aeration rate increased, and nitrite-oxidizing bacteria activity did not recover even under conditions with a very high oxygen content. Further analysis showed that ultrasonic treatment had obvious stripping effect on excess extracellular polymeric substances (EPS), especially loosely bound EPS and protein. Additionally, long-term ultrasonic treatment promoted the enrichment of Nitrosomonas and strongly inhibited Nitrotoga. Based on these findings, it appears that under conditions of high aeration rate, ultrasound effectively suppress the recovery of Nitrotoga activity and improve the stability of partial nitrification.
溶解氧的波动是导致部分硝化作用持续运行中断的主要原因之一，而溶解氧的水平主要由曝气速率控制。本研究探讨了超声处理对不同曝气条件下活性污泥部分硝化稳定性的影响。经过超声处理（能量密度=0.20 W·mL，处理时间=10 分钟）后，部分硝化过程稳定运行了 67 天，亚硝酸盐积累率高于 83.89%。出水含有 42.50mg·L 的亚硝酸盐，远高于对照反应器（0.30mg·L）。随着曝气速率的增加，特定氨氮和亚硝酸盐氧化速率之间的差距不断扩大，即使在氧气含量非常高的条件下，亚硝酸盐氧化菌的活性也没有恢复。进一步分析表明，超声处理对过量胞外聚合物（EPS）具有明显的去除作用，特别是松散结合的 EPS 和蛋白质。此外，长期超声处理促进了硝化菌的富集，强烈抑制了硝化菌。基于这些发现，在高曝气速率条件下，超声能有效抑制硝化菌活性的恢复，提高部分硝化的稳定性。
