摘要重金属超标能够抑制甚至毒害毒性污水生物处理系统中的微生物。鉴于厌氧氨氧化的前景十分广阔,这项工作详细介绍了一种新的修复方法以防止厌氧氨氧化由于重金属超负荷(此研究中以铜(II)为例)而失败。该策略采用乙二胺四乙酸(EDTA)洗涤并通过低强度超声刺激生物活性。利用动力学试验和批次活性测定法来确定EDTA的最佳浓度和洗涤时间,并通过连续流监测跟踪了反应器长期的运行性能和颗粒特性的改变。两步解吸过程显示,厌氧氨氧化颗粒中的铜主要是通过吸附作用引入的(约84.9%),其中低能量吸附位点占主要(占58.6%)。进入细胞的铜(约12.5%)可随后扩散出细胞并在20天内逐步洗出反应器。此后,每间隔8天进行超声照射测定其增速表现,发现其脱氮率(NRR)增加到0.1971 kg N m-3 d-2。该NRR在64天能恢复到正常水平,而脱氢酶TTC-DHA的恢复比较滞后,大约需要110天。同时还观察到粒径、沉降性能、胞外聚合物和血红素含量的提高。总的来说,这些结果表明,对于污水处理单元而言,去除胞外吸附的铜然后修复胞内的代谢是一种重要并可行修复方法。44176
Excessive heavy metals are inhibitory or even toxic to microorganisms in biological wastewater treatment systems. Given the promising prospects of anaerobic ammonium oxidation (anammox), this work details a novel remediation strategy for preventing anammox failure due to heavy metal overload (in this study, Cu(II) overload). The strategy involves combining ethylenediamine tetraacetic acid (EDTA)
washing with bioactivity stimulation via low-intensity ultrasound. Kinetic experiments and batch activity assays were employed to determine the optimal concentration of EDTA and washing time, and changes in reactor performance and granule characteristics were tracked by continuous-flow monitoring to evaluate the long-term effects. The two-step desorption process revealed that the Cu in anammox granules was primarily introduced via adsorption (approximately 84.9%) and that low-energy adsorption sites were predominant (accounting for 58.6%). The Cu internalized in the cells (approximately 12.5%) could then diffuse out of the cells and
be gradually washed out of the reactor within 20 days. Thereafter, ultrasound irradiation at intervals of 8 days contributed to accelerated performance, with a nitrogen removal rate (NRR) increasing rate of 0.1971 kg N m-3 d-2. The NRR was able to return to normal levels within 64 days, whereas the recovery of TTC-DHA was hysteretic, requiring approximately 110 days. Gradual improvements in granule diameter, settling properties, extracellular polymeric substances and heme content were also detected. Overall, these results demonstrate that external removal of the adsorbed Cu followed by internal repair of the metabolic system may represent an important and useful recovery method in wastewater treatment plant operation.
毕业论文关键词:厌氧氨氧化;抑制铜;回收;超声波照射;解吸动力学;生物修复
Keywords: anammox; copper inhibition; recovery; ultrasound irradiation; desorption kinetics; bioremediation
目 录
摘 要 2
1引言 4
2 介绍 4
3 材料和方法 5
3.1合成废水和污泥接种 5
3.2厌氧氨氧化反应器和操作策略 6
3.3批次优化试验 6
3.4 超声辐射 6
3.5 EPS提取 6
3.6脱氢酶活性测定法 7
3.7分析方法