不同水力条件下排水管道生物膜中氮元素分布特性

在壁面剪切力为1.0,1.5,2.0Pa条件下培养排水管道生物膜,利用微电极测试技术对生物膜进行生长过程及成熟生物膜内部DO、NH4+、NO2-、NO3-分布规律进行研究.结果表明:1.0,1.5,2.0Pa条件下培养的生物膜厚度分别为(2.3±0.1),(1.9±0.1),(1.6±0.1)mm;1.0,1.5Pa条件下的生物膜内存在好氧、缺氧环境,在其中发生了硝化和反硝化反应,而2.0Pa条件下的生物膜内只存在好氧环境,只发生了硝化反应.生物膜厚度影响着溶解氧在膜内的分布,继而影响着N在膜内的迁移转化过程.

The distribution characteristics of nitrogen element in sewer biofilm under different hydraulic conditions

The processes of sewer biofilm growth and the distribution of DO, NH4+, NO2-, NO3- inside the mature biofilms cultured under wall shear stersses of 1.0, 1.5, 2.0Pa were measured by microelectrode testing technique. The results show as follows: the thicknesses of biofilms cultured under wall shear stresses of 1.0, 1.5, 2.0Pa are (2.3±0.1), (1.9±0.1), (1.6±0.1)mm, respectively;aerobic area and anoxic area were found in biofilms cultured under wall shear stresses of 1.0Pa and 1.5Pa, which indicates nitrification and denitrification existed inside the above biofilms; only aerobic area was found in biofilm cultured under 2.0Pa, indicating only nitrification existed in that biofilm. Thickness of biofilm affects the distribution of DO in biofilm, subsequently affecting the process of transport and transformation of nitrogen in biofilm.