饮用水生物处理小试工艺中NH+4-N的非硝化去除途径分析 |
摘要点击 3708 全文点击 2042 投稿时间:2007-04-19 修订日期:2007-07-12 |
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中文关键词 饮用水 生物处理 NH+4-N 氮亏损 硝化作用 自养脱氮 |
英文关键词 drinking water biological processes NH+4-N nitrogen loss nitrification autotrophic removal of nitrogen |
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中文摘要 |
通过计算N和DO的质量平衡,研究饮用水生物处理小试工艺中是否存在NH+4-N的非硝化去除途径,并探讨其可能机制.结果表明,当生物流化床和生物滤池进水NH+4-N浓度大于2 mg/L时,前者进水的NH+4-N、NO-2-N和NO-3-N之和比出水高出0.91 mg/L,后者理论上消耗的DO比实际多约2.90 mg/L,说明这2种工艺中均有氮亏损现象发生,一部分NH+4-N通过与DO无关的非硝化作用被去除.对非硝化去除途径的分析表明,因为反应器对磷元素和有机物的利用不随氮亏损发生变化,可以排除掉同化作用和反硝化作用;因为反应器进水低碳高氮的特性和NO-2-N的积累与发生氮亏损的废水生物处理系统相似,据此提出在生物膜缺氧内部发生、通过短程硝化和厌氧氨氧化的偶联(或OLAND反应)将NH+4-N和NO-2-N同时转变为N2脱除的自养脱氮是饮用水生物处理中氮亏损的可能途径. |
英文摘要 |
The non-nitrification pathway for NH+4-N removal in pilot-scale drinking water biological treatment processes and its possible mechanism were investigated through calculating N and DO stoichiometric balance. With more than 2 mg/L NH+4-N in the influent, for the fluidized bed bioreactor (FBBR), the total of NH+4-N, NO-2-N, NO-3-N in the influent was 0.91 mg/L higher than that in the effluent, and for the biofilter, its DO consumption was 2.90 mg/L less than the stoichiometric amount. The results suggested that nitrogen loss occurred in both reactors and a part of NH+4-N was removed through non-nitrification pathway. Because the utilization of phosphorus and organic matters was independent of nitrogen loss, the assimilation and denitrification could be excluded from the possible mechanisms. Because the very low C/N in the influent and the accumulation of NO-2-N in the reactors were similar with the wastewater biological processes, the “autotrophic removal of nitrogen" was regarded as the most probable non-nitrification pathway. In this mechanism, the couple of short-cut nitrification and ANAMMOX (or OLAND) leading to the transformation of NH+4-N and NO-2-N into gaseous N2 was responsible for the nitrogen loss in drinking water biological processes. |