Yu Guang-Hui, He Pin-Jing, Shao Li-Ming, He Pei-Pei
State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
Environ Sci Technol. 2008 Nov 1;42(21):7944-9. doi: 10.1021/es8016717.
Sludge dewatering has proven to be an effective method to reduce the volume of sludge. In this study, a novel stratification approach aimed at better understanding the factors influencing the sludge dewaterability (as determined by capillary suction time, CST) was developed. The sludge flocs from 14 different full-scale wastewater treatment plants (WWTPs), including sewage, leachate, industry, and special-source sludge, were stratified through centrifugation and ultrasound into five layers: (1) supernatant, (2) slime, (3) loosely bound extracellular polymeric substances (LB-EPS), (4) tightly bound EPS (TB-EPS), and (5) pellet. The results showed that the distribution pattern of proteins (PN) in the sludge flocs differed from that of polysaccharides (PS). The normalized CST correlated with PN (R2 > 0.72, p < 0.01) and PN/PS (R2 > 0.51, p < 0.01) in the supernatant, slime, and LB-EPS, but not with PN and PN/ PS in the pellet and the sludge flocs as a whole or with PS in any of the fractions and or the sludge flocs as a whole. The results suggest that PN and PN/PS in the supernatant and slime layers, which are usually decanted due to their assumed lower content of organic matter, markedly impact sludge dewaterability.
污泥脱水已被证明是一种减少污泥体积的有效方法。在本研究中，开发了一种新的分层方法，旨在更好地理解影响污泥脱水性能（通过毛细吸水时间，CST来确定）的因素。来自14个不同的全尺寸污水处理厂（WWTPs）的污泥絮体，包括污水、渗滤液、工业和特殊来源污泥，通过离心和超声分层为五层：（1）上清液，（2）黏液，（3）松散结合的胞外聚合物（LB-EPS），（4）紧密结合的EPS（TB-EPS），以及（5）沉淀。结果表明，污泥絮体中蛋白质（PN）的分布模式与多糖（PS）不同。归一化的CST与上清液、黏液和LB-EPS中的PN（R2>0.72，p<0.01）和PN/PS（R2>0.51，p<0.01）相关，但与沉淀和整个污泥絮体中的PN和PN/PS无关，也与任何组分或整个污泥絮体中的PS无关。结果表明，上清液和黏液层中的PN和PN/PS，通常因其假定的较低有机物含量而被倾析，对污泥脱水性能有显著影响。
