关键词: 高岭土, 动态膜, 含污泥水, 错流微滤

Abstract: The performance of kaolin dynamic membrane (DM) formed on ceramic membrane was studied in detail in treatment of sludge-containing wastewater. The effects of cross-flow rate, thansmembrane pressure and concentration of mixed liquid suspending solid (MLSS) on the flux and quality of fitrate were examined. The results indicated that the flux of filtrate increased with increase of cross-flow rate and transmembrane pressure, while increase of concentration of MLSS led to decrease of the flux. DM may be brushed off when cross-flow rate was greater than 2.0 m/s. Filtrate turbdity would be nearly zero in the first 30 min, and chemical oxygen demand removal would be 50% in an hour for the most part. The resistance of DM and held foulant accounted for 90% of the total filtration resistance. Based on analysis of the foulant attached on the DM surface, it was found that phosphorus and calcium were the main foulant elements, their mass contents were 23.77% and 20.60% respectively. Total organic carbon was about 4370 mg/m2, the main inorganic foulant elements calcium and magnesium were 1240 and 886 mg/m2 respectively in the fouled ceramic membrane through analysis of the extractant of fouled ceramic membrane. The flux of filtrate could restore to 85% of the clear ceramic membrane through chemical washing with 0.2 mol/L sodium hydroxide aqueous solution and 0.1 mol/L hydrogen chloride aqueous solution in series.

Key words: kaolin, dynamic membrane, sludge-containing wastewater, crossflow microfiltration