| 以污泥发酵液与尾水混合液为补给碳源的A2/O污染物去除特性 |
| 摘要点击 1219 全文点击 746 投稿时间：2020-04-27 修订日期：2020-05-15 |
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| 中文关键词 A2/O 农村生活污水 间歇断流 发酵液与尾水 污染物去除 |
| 英文关键词 A2/O rural sewage intermittent inflow tail water and fermentation liquor nutrient removal |
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| 中文摘要 |
| 针对我国农村地区污水量波动和断流的排放特性，提出了一种在断流时段补给污水处理系统自身产出的尾水与污泥发酵液混合液的运行模式，以中试A2/O为对象，研究了系统在该运行模式下的污染物去除特性，以期为今后我国农村地区污水处理装置的设计和运行提供新的思路.结果表明，尾水与发酵液以12：1的比例混合后作为碳源与原水相比具有更好的反硝化和释/吸磷特性，具有强化脱氮除磷的功能；以尾水与发酵液混合液在断流时段作为补给碳源可改善系统对TN和TP的去除效率，其平均去除率分别由69.27%和86.94%提升到73.34%和89.94%，相应地平均出水浓度分别由15.77 mg ·L-1和0.80 mg ·L-1降低到13.76 mg ·L-1和0.64 mg ·L-1.16S rRNA基因测序结果表明，随着实验的进行，系统中5种常见的水解酸化菌属、6种聚磷菌属和4种反硝化菌属的相对丰度得到提升；通过对系统活性污泥性状的长期监测可以看出，以尾水与发酵液混合液在断流时段作为补给碳源会恶化系统活性污泥的沉降性能，系统活性污泥的平均SVI由阶段Ⅰ的106 mL ·g-1上升至阶段Ⅱ的131 mL ·g-1，然而这种恶化程度并不会对系统的污泥活性和污染物去除性能造成不利影响，在整个实验过程中系统均未出现污泥膨胀的现象. |
| 英文摘要 |
| To resolve the issue of sewage fluctuation and discontinuity in a rural district of China, a new operation mode of replenishing the mixture of fermentation liquor and tail water during the off-flow period was proposed, and the nutrient removal performance of a pilot-scale A2/O system with this operation mode was investigated. The results of beaker experiments found that the mixture of tail water and fermentation liquor at a ratio of 12:1 had better denitrification and phosphorus release/absorption characteristics than the raw water, and theoretically had the function of enhancing denitrification and phosphorus removal performances. The results of a 97 d pilot test showed that the removal efficiency of TN and TP was improved after the system was adjusted from the constant flow mode to this new operation mode, and the average removal rate of TN and TP increased from 69.27% and 86.94% to 73.34% and 89.94%, respectively. The corresponding average effluent concentration decreased from 15.77 mg·L-1 and 0.80 mg·L-1 to 13.76 mg·L-1 and 0.64 mg·L-1. The sequencing results of the 16S rRNA gene showed that this new operation mode was beneficial to the enrichment of five common hydrolytic acidizing bacteria genera, six phosphorus-accumulating organisms genera, and four denitrifying bacteria genera. This was also the main reason for the improved nutrient removal performance. According to the long-term monitoring of the characteristics of activated sludge, this new operating mode will degrade the sedimentation performance of activated sludge in the system, and the average SVI increased from 106 mL·g-1 to 131 mL·g-1. However, this degree of deterioration did not adversely affect the sludge activity and nutrients removal performance of the system, and there was no sludge bulking in the entire experiment. The results of this study have shown that the A2/O system can maintain and improve the performance of nutrients removal by replenishing the mixture of tail water and sludge fermentation liquor when the flow is cut off. This will provide new ideas for the design and operation of sewage treatment plants in rural areas in the future. |
