NaCl盐度对活性污泥系统脱氮性能的影响

以实际含盐生活污水为处理对象,考察了不同盐度对生物脱氮性能和主导菌群的影响.采用3个平行的序批式生物处理工艺(SBR)在进水(0.17 h)/好氧(7 h)/缺氧(3 h)/沉淀(1.5 h)/排水时间(0.33 h)的运行方式下,在5,7.5,10g/L的盐度下稳定运行50 d左右.结果表明,NaCl盐度对硝化菌的抑制作用远大于反硝化菌,盐度对亚硝酸盐氧化菌群(nitrite oxidation bacteria,简称为NOB)比对氨氧化菌群(ammonia oxidation bacteria,简称为AOB)有更强的抑制作用;7.5和10 g/L系统可以在较短的时间内实现短程硝化反硝化,亚硝酸盐积累率均维持在95%以上.随着盐度的升高,3个系统稳定后的比氨氧化速率逐渐下降;5和7.5 g/L盐度的SBR系统稳定后有较高的氨氮去除率.7.5 g/L盐度可作为普通活性污泥系统实现短程硝化的理想盐度.

Influence of NaCl Salinity on Nitrogen Removal of Activated Sludge System

It was studied that treating domestic saline wastewater in sequencing batch reactors,different salinity's affection on the specific nitrification,denitrification rate and domin community in the activated sludge system.The experiment utilized three parallel SBR reactors,the ratio of influent,aerobic,anoxia, sedimentation and effluent time was 0.17 h,7 h,3 h,1.5 h and 0.33 h,the three SBR systems' salinity were 5,7.5,10 g/L,respectively.The three systems were operated for 50 days in a steady state.The results showed that:NaCl salinity had higher inhabitation to nitrobacteria than to denitrifier,NaCl salinity had higher inhabitation to NOB than to AOB,7.5 g/L and 10 g/L systems performed short-term nitrification- denitrification in a short time.Nitrite accumulation rate could be maintained above 95 %.With the raising of salinity,specific nitrification rate of three systems declined in a steady state.5 g/L and 7.5 g/L systems' had higher ammonia removal rate in a steady state.Salinity of 7.5 g/L was a perfect salinity which could result in short-term nitrification-denitrification in an activated sludge system.