炭膜曝气生物膜反应器硝化作用及其微生物群落结构分析

Nitrification Performance and Microbial Community Analysis in Carbon Membrane-Aerated Biofilm Reactor

采用炭膜曝气生物膜反应器处理无机含氮废水,通过改变进水氨氮浓度和水力停留时间,研究了反应器硝化性能、氧利用情况以及氨氮去除负荷,并对生物膜表面特性和硝化菌优势菌种进行分析.结果表明,在膜内气压0.017 MPa,进水NH4+-N50 mg/L,HRT为8 h条件下,NH4+-N去除率达到96%,出水NO2--N平均为17 mg/L,一定程度上实现了短程硝化,炭膜所供给氧气被生物膜全部消耗;系统比表面氨氮最大去除速率为9.7 g/(m2.d),炭膜表面有限的生物量制约了去除速率的进一步提高;荧光原位杂交技术分析揭示生物膜内亚硝化单胞菌(Nitrosomonas)和亚硝化螺菌(Nitrosospira)为亚硝化细菌优势菌种,分别占细菌总菌数的19%和21%,硝化螺菌(Nitrospira)为硝化细菌优势菌种,占总菌数的20%,未检测到硝化杆菌(Nitrobacter)的存在.

A carbon membrane-aerated biofilm reactor was developed to treat nitrogenous inorganic wastewater.Influent NH4^＋-N concentrations and HRT were changed to investigate nitrification performance of reactor,oxygen utilization and NH4^＋-N＇s removal loading.Biofilm＇s surface characteristics and dominant bacteria of nitrifier were analyzed.The results show that under the conditions of intra-membrane pressure of 0.017 MPa,influent NH4^＋-N of 50mg/L and HRT of 8 h NH4^＋-N removal efficiency reaches 96% and effluent average nitrite is 17mg/L, which benefits short-cut nitrification to a certain extent.The bacteria within biofilm consume all oxygen supplied through carbon membrane.The maximum specific removal rate of NH4^＋-N is 9.7g/（m^2·d）, which is limited by the amount of bacteria grown onto carbon membrane＇s surface.Fluorescent in situ hybridization analysis indicates that within the biofilm Nitrosomonas and Nitrosospira are main ammonia-oxidizing bacteria and occupy about 19% and 21% of the total bacteria number,respectively.The Nitrobacter are not observed and Nitrospira are dominant nitrite-oxidizing bacteria,the fraction of which is 20 % of total bacteria.