| 亚硝酸盐积累对A2O工艺生物除磷的影响 |
| 摘要点击 1916 全文点击 1193 投稿时间：2009-11-17 修订日期：2010-01-27 |
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| 中文关键词 A2O工艺 生活污水 亚硝酸盐 短程脱氮 除磷 |
| 英文关键词 A2O process domestic wastewater nitrite short-cut nitrification and denitrification phosphorus removal |
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| 中文摘要 |
| 常温条件下，通过控制好氧区DO浓度为0.3～0.5 mg/L，同时增大系统内回流比以降低系统好氧实际水力停留时间(actual hydraulic retention time，AHRT)，在处理低C/N比实际生活污水的A2O工艺中成功启动并维持了短程硝化反硝化.但随着系统出水亚硝酸盐含量的升高，系统对磷的去除效果逐渐恶化.当好氧区亚硝酸盐浓度>19 mg/L时，系统出水磷浓度大于进水磷浓度，系统处于净释磷状态.通过对原水COD浓度、反应区温度、pH值、游离亚硝酸浓度(free nitrous acid，FNA)等分析，表明碳源不足及短程硝化引起的亚硝酸盐积累影响了聚磷菌厌氧释磷和好氧吸磷；尤其是好氧区较高的FNA浓度(HNO2-N 0.002～0.003 mg/L)对聚磷菌好氧吸磷的抑制是导致系统除磷效果恶化的直接原因.通过外投碳源提高原水COD浓度，提高了聚磷菌厌氧释磷合成PHA的能力；同时增强了系统的反硝化能力，降低好氧区亚硝酸盐浓度，从而降低FNA对聚磷菌好氧吸磷的抑制程度，系统的除磷性能可迅速恢复；系统对磷的去除率可达96%以上. |
| 英文摘要 |
| At normal temperature, short-cut nitrification and denitrification was achieved in a lab-scale A2O process treating low C/N ratio domestic wastewater by controlling DO concentration of 0.3-0.5 mg/L and increasing the internal reflux ratio to decrease the actual aerobic HRT. However, the phosphorus removal in A2O process was deteriorated with the increasing of the nitrite concentration in the effluent. The factors causing phosphorus removal deterioration, such as the influent COD concentrations, temperature, pH and free nitrous acid (FNA) were systematically analyzed. Experimental results showed that the nitrite accumulation resulting from short-cut nitrification affected anaerobic P release and aerobic P uptake. Especially, the higher FNA concentration (HNO2-N 0.002-0.003 mg/L) in the aerobic zone significantly inhibited the aerobic P uptake, which was the major reason causing P removal deterioration. Through adding the carbon sources in influent to enhance anaerobic P release and denitrification, the nitrite and FNA concentrations in the aerobic zone were decreased, and the P removal was recovered. More than 96% of PO3-4-P could be removed in A2O process. |
