| 连续流系统中好氧段及沉淀段对污泥及其缺氧段脱氮能力的影响 |
| 摘要点击 1153 全文点击 454 投稿时间：2018-12-19 修订日期：2019-02-28 |
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| 中文关键词 连续流系统 生物脱氮 活性污泥 反硝化作用 硝酸盐还原酶活力 |
| 英文关键词 continuous-flow system biological nitrogen removal activated sludge denitrification nitrate reductase activity |
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| 中文摘要 |
| 在好氧段3种溶解氧（DO）［3.0~3.5 mg·L-1（Ⅰ阶段）、2.0~2.5 mg·L-1（Ⅱ阶段）和1.5~2.0 mg·L-1（Ⅲ阶段）］的A2/O实验系统，考察了本段及后续沉淀阶段污泥的变化，以及对系统缺氧段反硝化的影响，并与DO为1.5~2.0 mg·L-1的缺氧-好氧（A/O）系统进行了对比.结果表明，沉淀阶段污泥开始发生反硝化作用，脱氮碳源由内、外碳源同时提供；沉淀污泥优先利用外碳源进行反硝化；好氧段DO为1.5~2.0 mg·L-1时，沉淀阶段污泥的硝酸盐还原酶活力及反硝化活性最强，此时A2/O系统缺氧段的反硝化效果也最佳；在与A2/O系统相同污泥负荷下的A/O系统中，好氧段后污泥中细菌胞内残留的PHB含量要高于A2/O系统； A2/O系统沉淀段污泥的反硝化活性高于A/O系统，其硝酸盐还原酶活力是A/O系统的1.08倍；该污泥回流后，尽管硝态氮充分但A/O系统缺氧段反硝化效果却较A2/O系统差；沉淀阶段污泥的脱氮性能直接关系到缺氧段反硝化效果.因此，本研究认为在保证沉淀污泥反硝化不严重影响泥水分离的前提下，污水生物脱氮工程中应适当控制好氧段运行、维持沉淀池污泥适当反硝化来提升系统的脱氮效能，而不能仅仅是考虑控制缺氧段. |
| 英文摘要 |
| Using an A2/O process with three dissolved oxygen (DO) levels[3.0-3.5 mg·L-1(Ⅰ stage), 2.0-2.5 mg·L-1(Ⅱ stage), 1.5-2.0 mg·L-1(Ⅲ stage)], the sludge and denitrification characteristics of its aerobic unit and sedimentation unit were investigated and compared with that of an anoxic-aerobic (A/O) process with a DO content of 1.5-2.0 mg·L-1. The results showed that denitrification in the sedimentation unit was accomplished with both internal and external carbon sources, but sludge's denitrification was more efficient with the use of external carbon sources. Nitrate reductase activity and denitrification activity in the sludge in sedimentation unit were highest when DO content was 1.5-2.0 mg·L-1 under aerobic conditions, and the denitrification efficiency of the A2/O process was greatest under anoxic conditions. The residual PHB in the aerobic A/O process was higher than that in the A2/O process with experimental sludge loading. The denitrification activity of the sludge in the A/O process was higher, and the nitrate reductase activity was 1.08 times higher than that in the A/O process. After returnning of the sludge, denitrification in the anoxic A/O process was poor, although the removal of nitrate nitrogen was sufficient. In comparison, denitrification in the anoxic unit of the A2/O process was better. Denitrification of the sludge in the sedimentation unit was directly related to denitrification in the anoxic unit. Therefore, to ensure that denitrification in sedimentation unit does not seriously affect the separation of sludge and water, appropriate control of the aerobic operation and the maintenance of denitrification in the sedimentation unit will contribute more to the denitrification efficiency of the system rather than simply controlling the level of anoxia. |
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