超声对Cd冲击后短程硝化污泥活性的影响

Effect of ultrasound on partial nitrification sludge activity after cadmium shock

以短程硝化污泥为研究对象,以活性污泥比耗氧速率(Specific Oxygen Uptake Rate,SOUR)为表征指标,通过批次实验,考察了受Cd冲击后的短程硝化污泥在不同超声波强度、运行方式和辐照时间下的活性变化,探究了不同辐照时间下的超声波对污泥内Cd的迁移转化及氧化应激水平的影响。结果表明,超声波能加快Cd冲击后的短程硝化污泥活性恢复速度,提高受抑制后的氨氧化菌(AOB)活性。在超声波强度为0.20 W/mL、运行方式为工作2 s间歇2 s、辐照时间为15 min的超声处理下,与对照组(未经超声处理)相比,AOB活性提高了220.90%,超声波加快Cd从污泥中脱离,其稳定态占比略有提高,同时,抗氧化系统的响应水平显著提升,使活性氧(ROS)水平最高下降了26.55%,最终减轻因Cd胁迫带来的负面效应。

Batch experiments were conducted to investigate the activity changes of partial nitrification sludge under different ultrasound intensities,operation modes and irradiation times,taking the specific oxygen uptake rate(SOUR)as the characterization index,and to explore the effects of ultrasound on the migration and transformation of Cd in sludge and the level of oxidative stress.The results show that ultrasound can accelerate the recovery of partial nitrification sludge activity after Cd impact,especially improving the activity of ammonia-oxidizing bacteria(AOB)after inhibition.Compared with that of the control group,the activity of AOB increased by 220.90% when the ultrasound intensity was 0.20 W/mL,the working time was intermittent for 2 s and the irradiation time was 15 min.The partial nitrification sludge impacted by Cd at different irradiation times was studied.The results also show that ultrasound accelerates the detachment of Cd from sludge,and the proportion of Cd in its stable state is slightly increased.At the same time,the response level of the antioxidant system was significantly improved,and the level of reactive oxygen species(ROS)decreased by 26.55% at the highest,finally alleviating the negative effects caused by Cd stress.