某再生水厂反硝化滤池脱氮性能与生物膜特征解析  

Nitrogen Removal and Biofilm Characteristics of a Post-denitrifying Biofilter in a Full-scale Reclaimed Wastewater Treatment Plant

作　　者：邬甘霖 任翔宇 吴光学 

机构地区：[1]深圳水务<集团>有限责任公司,广东深圳518030 [2]清华大学深圳研究生院深圳市环境微生物利用与安全控制重点实验室,广东深圳518055

出　　处：《中国给水排水》2017年第19期21-27,共7页China Water & Wastewater

基　　金：深圳市科技创新委员会技术开发项目(JSKF20150717163429311)

摘　　要：反硝化滤池是污水处理厂强化脱氮的重要技术途径之一。研究了进水碳氮比(COD/N)和空床停留时间(EBRT)对某再生水厂后置反硝化滤池反硝化脱氮性能的影响,同时考察了生物膜特征及其活性。在进水COD/N值为4.5、EBRT为28.2 min时,NO_3^--N去除率最高为72.69%,去除负荷为0.42 g N/(m^2·d);在相近EBRT(27.7 min)下,提高进水COD/N值至6.5和7.5,NO_3^--N去除负荷明显提高,分别为0.75和0.73 g N/(m^2·d)。在反硝化滤池底部滤层NO_3^--N的沿程降解符合半阶动力学方程,半阶动力学系数随EBRT的降低和进水COD/N值的提高而增大。反硝化所需COD/N值平均为5.67。中层滤料生物膜的生物量及其厚度最大(分别为8 678.43 mg/m^2和131.25μm)。生物膜密度由下至上逐渐增大,分别为52.58、66.12和104.59mg/cm^3。反硝化活性由下至上略微增大,分别为11.34、11.44和13.47 mg N/(g VSS·h)。生物膜微生物以Beta变形菌为主,相对丰度大于85%;Methylophilaceae科菌群相对丰度最高(42.1%);所检测到的主要菌属包括Georgfuchsia(24.3%)和Sulfuricella(4.6%)。Denitrifying biofiher is one type of the enhanced nitrogen removal technology. The nitrogen removal efficiency of a full-scale post-denitrifying biofilter （PDN） was examined under different EBRTs （empty bed retention times） and different COD/N （carbon/nitrogen） ratios. Meanwhile, the biofilm characteristics （density and thickness） and the maximum surface denitrifying rate were evaluated. Under the COD/N ratio of 4.5 and EBRT of 28.2 min, the nitrate removal rate was 72.69%, with the corresponding removal load of 0.42 gN/（ m2 · d）. Under similar EBRT （27.7 rain）, enhancing COD/N ratios to 6.5 and 7.5, the nitrate removal load was improved to 0.75 and 0.73 gN/（ m2 · d）, respectively. In the bottom layer of PDN, the dynamics of nitrate removal fitted well with the half-order reaction, and the half-order coefficient increased with decreasing EBRTs and increasing COD/N ratios. The required COD/N ratio for denitrification was averagely 5.67. The biofilm in middle layer of PDN pos- sessed the highest biofilm biomass and thickness （8 678.43 mg/m^2, 131.25 μm）. The biofilm densities in different PDN depths were 52.58, 66.12 and 104.59 mg/cm^3 respectively, increasing from the bottom layer to the upper layer. The maximum denitrifying rate in the bottom, middle and upper layers of PDN were 11.34, 11.44 and 13.47 mgN/（ gVSS · h）, respectively. The dominating bacteria in biofilm was Beta-proteobacteria with the abundance over 85%. Methylophilaceae had the highest abundance （42.1% ） at the family level. The main detected bacteria at the genus level were Georgfuchsia （24.3 % ） and Sulfuricella （4.6 % ）.

关 键 词：反硝化滤池 生物膜性质 反硝化活性 沿程动力学 微生物种群 

分 类 号：X703[环境科学与工程—环境工程]