不同泥龄下活性污泥絮体性状的研究

采用序批式反应器对不同泥龄下污泥絮体的化学性状(胞外聚合物成分及含量)、物理性状(表面电荷)、形态性状(粒度分布、分形维数)等进行了对比研究.结果表明:泥龄对胞外聚合物总量及各组分含量的影响规律并不明显;多糖/蛋白质愈大,污泥絮体表面电负性愈强;污泥絮体的平均粒径随泥龄的延长呈逐渐减小的趋势,且粒度分布愈来愈均匀;不同泥龄下,污泥絮体形态结构亦不相同,泥龄短时,絮体表面粗糙,结构开放疏松;泥龄长时,絮体表面平滑,结构紧凑;随着泥龄的增大,絮体分形维数逐渐增加.由于不同泥龄下所表现出的污泥絮体性状的差异,直接影响了污泥的絮凝和沉降性能.

EFFECT OF SOLIDS RETENTION TIME ON FLOC CHARACTERISTICS

The characteristics of sludge flocs formed in sequencing batch reactor under different solids retention time (SRT),such as chemical(extracelluar polymeric substances,EPS),physical(surface charge)and morpho- logical(floc size distribution,fractal dimension)parameters,were compared.The results showed that SRT had less effect on the content and component of EPS.Zeta potential value increased with the ratio of polysaccharide to protein;Furthermore,the mean floc size decreased with SRT.and the floc size distribution at higher SRT had a much more uniform distribution,as compared to lower SRT.Flocs examined by SEM at different SRTs showed diversity in morphology.Low SRT produced flocs with rough surface and loose structure.On the con- trary,high SRT produced flocs with smooth surface and dense structure;The flocs formed by different SRTs had different characteristics,and then influenced the sludge flocculation and settling performance.