Surface properties of sludge and their role in bioflocculation and settleability
Surface properties of sludge and their role in bioflocculation and settleability
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DOI：
10.1016/s0043-1354(00)00277-3
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发表时间：
2001-02-01
期刊：
影响因子：
12.8
通讯作者：
Liss, SN
中科院分区：
文献类型：
--
作者：
Liao, BQ;Allen, DG;Liss, SN
采用实验室规模的SBR反应器（SBR），以葡萄糖和无机盐混合废水为进水，研究了污泥停留时间（SRT）对污泥胞外聚合物（EPS）和污泥理化性质（疏水性和表面电荷）的影响。污泥表面更疏水（更大的接触角）和更少的负电荷在较高的SRT（16和20天）比在较低的SRT（4和9天）。污泥EPS中蛋白质与碳水化合物的比例随着SRT从4 d增加到12 d而增加，这与污泥理化性质的变化相对应。蛋白质：碳水化合物的比例保持恒定的SRT为16和20天。在污泥性质的过渡出现之间发生的上限范围的低（9天）和较低范围的高SRT。然而，总EPS含量是独立的SRT。较高的污泥体积指数（SVI），较差的沉降性或压缩的指示，与大量的总EPS，但SVI和污泥的表面性质之间没有显着的相关性进行了观察。一个更疏水和带负电荷的表面对应于较低水平的ESS。这些结果表明，它是表面性质，疏水性，表面电荷和EPS的组合物，污泥，而不是EPS的数量，管理biodocculation。相反，EPS含量在控制污泥沉降性方面更重要。(C)2000爱思唯尔科技有限公司版权所有。
The influence of sludge retention time (SRT) on the extracellular polymeric substances (EPS) and physicochemical properties (hydrophobicity and surface charge) of sludge was studied using laboratory-scale sequencing batch reactors (SBRs) fed a synthetic wastewater containing glucose and inorganic salts. Sludge surfaces were more hydrophobic (larger contact angle) and less negatively charged at higher SRTs (16 and 20 d) than at lower SRTs (4 and 9 d). The ratio of proteins to carbohydrates within the EPS of the sludges increased as the SRT increased from 4 to 12 d corresponding to the changes in the physicochemical properties of the sludge. The protein: carbohydrate ratio remained constant at SRTs of 16 and 20 d. A transition in sludge properties appeared to occur between the upper range of low- (9 d) and lower range of high- SRTs. The total EPS content, however, was independent of the SRT. A higher sludge volume index (SVI), an indication of poorer settleability or compression, was associated with a larger amount of total EPS but no significant correlation between SVI and the surface properties of sludge was observed. A more hydrophobic and less negatively charged surface corresponded to lower levels of ESS. These results indicate that it is the surface properties, hydrophobicity, surface charge and composition of EPS , of sludge, rather than the quantity of EPS, that govern biodocculation. In contrast, the EPS content is more important in controlling the settleability of sludge. (C) 2000 Elsevier Science Ltd. All rights reserved.