| Cu2+对以NO2-为电子受体反硝化过程的影响 |
| 摘要点击 1620 全文点击 561 投稿时间：2018-12-15 修订日期：2019-01-12 |
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| 中文关键词 Cu2+ NO2- 反硝化 短期影响 长期影响 |
| 英文关键词 Cu2+ NO2- denitrification short-term effect long-term effect |
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| 中文摘要 |
| 短程生物脱氮工艺在废水处理中已经得到较为广泛的应用，其反硝化过程是实现氮去除的关键步骤，而关于废水中常见重金属离子Cu2+对以NO2-为电子受体反硝化过程的影响尚无系统研究.选取A/O反应器内具有良好短程生物脱氮特性的污泥，通过批次试验及SBR长期试验分别探究了Cu2+对以NO2-为电子受体反硝化过程的短期及长期影响.短期试验结果表明，Cu2+对以NO2-为电子受体反硝化过程具有明显抑制作用，对污泥反硝化活性的半抑制浓度EC50为4.79mg·L-1.在长期影响试验中逐渐提高污泥对Cu2+的耐受浓度，当Cu2+浓度为0.5 mg·L-1和1 mg·L-1时，污泥反硝化活性降低后均能够通过驯化恢复至原有水平；而Cu2+浓度升高至3 mg·L-1后污泥反硝化性能遭到破坏且难以恢复，NO2--N去除率降低至10%以下，反硝化系统遭到严重抑制.但是，停止投加Cu2+后污泥反硝化活性在第14 d恢复至原有水平.同时，在Cu2+的长期影响过程中，EPS含量增多，对微生物抵御Cu2+的毒害起到重要保护作用，促使污泥粒径增大，污泥沉降性得到提高. |
| 英文摘要 |
| The short-cut biological nitrogen removal process has been widely used in industrial wastewater treatment, and denitrification is a crucial step for removing nitrogen on which the effect of Cu2+, a common heavy metal ion in wastewater, has not been studied. In this study, sludge with good short-range biological nitrogen removal characteristics in an A/O reactor was selected to investigate the short-term and long-term effects of Cu2+ on denitrification using NO2- as an electron acceptor. The results showed that Cu2+ had a significant inhibitory effect on denitrification process using NO2- as an electron acceptor, and the semi-inhibitory concentration EC50 of sludge activity was 4.79 mg·L-1. In the long-term experiment, the concentration of Cu2+ was gradually increased. When the concentration of Cu2+ was 0.5 mg·L-1and 1 mg·L-1, the denitrification activity of the sludge could be restored to the original level after acclimation. When the concentration of Cu2+ was increased to 3 mg·L-1, the denitrification performance was destroyed and difficult to recover, at which point the NO2--N removal rate was reduced to less than 10% and the denitrification system was severely inhibited. However, there was some recovery of sludge denitrification capacity after the addition of Cu2+ had been stopped for 14 days. At the same time, during the long-term effect of Cu2+, the EPS content increased, which played an important role in protecting the microorganism against Cu2+ toxicity, and increased the sludge particle size and, as a result, sludge sedimentation. |
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