School of Agriculture and Biology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
Water Res. 2010 Mar;44(5):1627-35. doi: 10.1016/j.watres.2009.11.013. Epub 2009 Nov 20.
The effects of addition of six types of flocculants (aluminium sulfate, ferric chloride, polyaluminium chloride, polymeric ferric sulfate, Chitosan, polyacrylamide) on mitigation of membrane fouling in membrane bioreactors (MBR) were investigated respectively. The biomasses in various MBRs were characterized by morphological properties (mean floc size (d(p)), fractal dimension (df)), physical parameters (surface charge, relative hydrophobicity (RH), dynamic viscosity) and the biochemical components of the mixed liquor (extracellular polymeric substances (EPS), soluble microbial products (SMP)). Statistical methods such as normalization, nondimensionalization and multiple linear regressions were used to identify the dominant membrane-fouling contributors and to simulate membrane-fouling rates. The results demonstrated that addition of flocculants had significant impact on sustainable filtration time and the key factors affecting membrane fouling varied in different flocculants added MBRs. For the organic flocculants added MBRs, membrane-fouling alleviation was mainly due to the decrease in SMP and df as well as the increase in d(p). For the inorganic flocculants added MBRs, the lower fouling rate could be mainly attributed to the decrease in SMP and surface charge as well as the increase in RH. For each type of flocculants, the empirical equations of sustainable filtration time (Gamma(45)) were simulated to predict membrane-fouling rates in different MBRs.
分别考察了六种絮凝剂（硫酸铝、三氯化铁、聚合氯化铝、聚合硫酸铁、壳聚糖、聚丙烯酰胺）对膜生物反应器（MBR）中膜污染缓解的影响。通过形态特性（平均絮体大小（d(p)）、分形维数（df））、物理参数（表面电荷、相对疏水性（RH）、动态粘度）和混合液中的生化成分（胞外聚合物物质（EPS）、可溶性微生物产物（SMP））来对不同 MBR 中的生物量进行了特征描述。采用归一化、无量纲化和多元线性回归等统计方法，识别出主要的膜污染贡献因素，并模拟膜污染速率。结果表明，添加絮凝剂对可持续过滤时间有显著影响，而不同添加絮凝剂的 MBR 中影响膜污染的关键因素也不同。对于添加有机絮凝剂的 MBR，膜污染缓解主要归因于 SMP 和 df 的降低以及 d(p)的增加。对于添加无机絮凝剂的 MBR，较低的污染速率主要归因于 SMP 和表面电荷的降低以及 RH 的增加。对于每种类型的絮凝剂，模拟了可持续过滤时间（Gamma(45)）的经验方程，以预测不同 MBR 中的膜污染速率。
