摘要
针对内外回流比对A2/O工艺生物脱氮效率的效果及其局限性进行了中试研究。结果表明,通常缺氧段出水NO3-—N不为零,使TN理论去除率>反硝化理论脱氮率>TN实际去除率,并进一步分析了此时TN的理论去除率变化。当内外回流比之和为300%和500%时,出水TN稳定,分别小于20mg/L和15mg/L。当内回流比由200%上升到400%时,缺氧出水NO3-—N由1.3mg/L上升到3.8mg/L,但是反硝化速率由0.036kgNO3-—N/(kgVSS.d)上升到0.044kgNO3-—N/(kgVSS·d)。MLVSS中TN约占9.8%,通过剩余污泥排放去除TN比例随着泥龄的增加而减少,当好氧SRT为14d、8d、5d时,其均值分别为7.1%、26.2%、37.1%。
In this research, pilot study on the advantages and limitations of internal recycle ratio and returned sludge ratio on bio-denitrification in A^2/O process was investigated. The results indicated that： TN theoretical removal rate〉TN theoretical removal rate by denitrification〉TN actual removal rate, due to the fact that the NO3- -N was nonzero in anoxic section under normal circumstances. This study also discussed the change of theoretical removal rate of TN under normal circumstance with nonzero NO3- -N. The TN in effluent could be attained less than 20 mg/L when the sum of returned sludge ratio and internal recycle ratio was 300% consistently, and 15 mg/L when the sum was 500%. When the internal recycle ratio increased from 200% to 400%, the NO3- -N in anoxic effluent went up from 1. 3 mg/L to 3.8 mg/L and the denitrification rate rose from 0. 036 kgNO3- -N/（kgVSS·d） to 0. 044 kgNO3- -N/（kgVSS·d）. Furthermore, the TN concentration in MI.VSS was about 9. 80%;the removal rate of TN, which was discharged through the excess activated sludge, decreased as the SRT increased. The average removal rates of TN reached 7. 1%,26. 2% and 37. 1%respectively, when the aerobic SRTs were 14 d,8 d and 5 d respectively.
出处
《给水排水》
CSCD
北大核心
2008年第12期38-41,共4页
Water & Wastewater Engineering
基金
国家高技术研究发展计划(863)项目(2004AA601010)
关键词
内回流比
外回流比
生物脱氮
A^2/O工艺
Internal recycle ratio
Returned sludge ratio
Biol-denitrification
A^2/O process
