School of Environmental Science and Engineering, Shandong University, Jinan 250061, China.
J Hazard Mater. 2010 Jun 15;178(1-3):397-403. doi: 10.1016/j.jhazmat.2010.01.094. Epub 2010 Jan 25.
Sludge dewatering is a key part of sludge disposal since it can greatly reduce the volume of sludge and thus improve the treatment effect for handling and disposing. This study investigated the potential benefits of enzymatic pretreatment on activated sludge dewatering with protease and cellulase as a protein and polysaccharide degrading enzyme, respectively. Capillary suction time (CST) and the solid content after centrifugation were used to evaluate sludge dewatering. The particle size distribution, extracellular polymeric substances (EPS) content, infra-red (IR) spectrometry and microscope image were determined in an attempt to explain the observed changes in sludge dewaterability. The results indicated that adding protease and cellulase separately leads to an increase in CST and the increased value is higher with protease. Protease and cellulase both promote the degradation of protein and polysaccharide in the solids of activated sludge, leading to a smaller particle diameter and poorer dewaterability. However, due to the limited effects on the protein and polysaccharide content, the difference in sludge dewaterability is not large. Compared to the control, enzymatic pretreatment had no obvious effect on sludge IR spectrometry, while there was a detectable structure difference at a colloidal scale.
污泥脱水是污泥处置的关键环节，因为它可以大大减少污泥的体积，从而提高处理效果，便于处理和处置。本研究探讨了蛋白酶和纤维素酶分别作为蛋白质和多糖降解酶对活性污泥脱水的潜在益处。采用毛细吸留时间（CST）和离心后固体含量来评价污泥的脱水性能。通过测定粒径分布、胞外聚合物（EPS）含量、红外（IR）光谱和显微镜图像，试图解释污泥脱水性能观察到的变化。结果表明，分别添加蛋白酶和纤维素酶会导致 CST 增加，且蛋白酶的增加幅度更高。蛋白酶和纤维素酶都促进了活性污泥固体中蛋白质和多糖的降解，导致粒径更小，脱水性能更差。但是，由于对蛋白质和多糖含量的影响有限，污泥脱水性能的差异不大。与对照组相比，酶预处理对污泥的 IR 光谱没有明显影响，但在胶体尺度上存在可检测到的结构差异。
