膜生物反应器净化污水的硝化反硝化性能

比较了膜生物反应器(MBR)和传统活性污泥工艺(CAS)在相同运行条件下处理生活污水的硝化和反硝化性能.结果表明,MBR对NH4 -N和TN的去除率分别比CAS高54.8%和37.3%.2种工艺的亚硝化、反硝化作用均呈零级反应,对应降解速率常数MBR分别约为CAS的2.2倍和2.5倍;CAS中硝化作用为零级反应,而MBR中硝化作用随时间推移趋于平缓.MBR中的细菌总数、硝酸菌、亚硝酸菌和反硝化菌数量分别比CAS工艺中相应菌种高1~2个数量级.通过控制曝气强度或减小回流通道断面限制缺氧区溶解氧质量浓度,可提高MBR中的反硝化效果.

Characteristics of nitrification and denitrification in wastewater treatment with membrane bioreactor

Nitrification and denitrification characteristics of membrane bioreactor(MBR) and conventional activated sludge (CAS) for wastewater treatment are compared under same operation condition.Results show that removal efficiency of MBR is higher than CAS with 54.8%,37.3% for NH_4~ -N and TN respectively.Ammonium-oxidizing and denitrifying processes in MBR and CAS are in accord with zero-grade reaction formula,and the corresponding degradation rate constants of MBR are 2.2 and 2.5 times larger than that of CAS.Nitrifying process is also in accord with zero-grade reaction in CAS while it is not obvious in MBR.The amount of total bacteria,nitrifying bacteria,ammonium-oxidizing bacteria and denitrifying bacteria in MBR are 1-2 order of magnitude higher than corresponding bacteria in CAS.Restricting dissolved oxygen(DO) concentration in anoxic phase through controlling aeration intensity or circumfluence channel area is beneficial to denitrification effect of MBR.