序批式膜生物反应器处理生活污水的特性

研究了中试规模序批式膜生物反应器处理生活污水的特性.发现其对COD_Cr、NH₃-N及TN的去除效果可分别达到95.0%、96.3%及38.0%;过膜阻力增加率为1.032 kPa•m^-1.TN去除率偏低的主要原因在于缺少搅拌装置，在静置阶段时，污泥大部分沉积在反应器底部（系统运行期间30 min沉降比均低于40%），从而使反硝化细菌不能充分与水溶液中的NO_x-N接触.采用空间排阻液相色谱法对混合液及膜污染物进行分子量分布测定，发现大量大分子物质在反应器内、膜面及膜孔内积累，相对分子质量大于10⁴的有机物分别占64.0%、38.0%.经过物理及化学清洗，膜通量恢复了73.4%，多糖含量为清洗前的30.4%，说明多糖是造成不可逆污染的主要物质.

Characteristics of membrane sequencing batch reactor for domestic wastewater treatment

The characteristics of pilot-scale membrane sequencing batch reactor (MSBR) treating synthetic wastewater were studied.The COD_Cr, NH₃-N and TN removal were 95.0%，96.3% and 38.0% respectively.The reason for low TN removal was lacking agitated equipment. During static phase, most sludge settled to the bottom of reactor (SV<40%),and consequently the denitrifying bacteria could not contact with NO_x-N completely. The trans-membrane pressure (TMP) rise rate was 1.032 kPa&#8226;m^-1. Molecular weight distribution of mixed liquid and membrane foulants were analyzed by the steric exclusion liquid chromatography method. It demonstrated that the accumulation of macromolecular matter(molecular weight＞10⁴) in reactor and membrane were 64.0% and 38.0% respectively. After physical and chemical washing, membrane specific flux was recovered by 73.4%. The concentration of polysaccharides deposited on the membrane was reduced to 30.4%. Polysaccharide was the important substance to cause irreversible fouling.