| As a solid product of wastewater treatment,dewatered sludge is not only has the characteristics of high organic matter content and moisture content,but also has a poor dehydration performance,the problem of difficult to effectively reduce high moisture content,is the bottleneck of dewatered sludge disposal.Extracellular polymeric substance(EPS),a high molecular weight biological polymer that can bind to a large amount of organic matter and moisture,plays an important role in the process of sludge formation and structural stability,affecting sedimentation and dewatering performance of sludge.Therefore,the study of EPS is particularly important.The aim of this study was to observe the changes in the key components of EPS extracted from mechanical dewatered sludge.In this paper,the effects of SDS and enzyme on promoting the extraction of sludge EPS were investigated,and the adding amount of SDS and enzyme were studied,When the adding amount of SDS was 0.1 g/g TSS,the content of soluble PN of SEPS,LB and TB layer respectively increased by 94.3%,97.4% and 60.7%;the content of soluble PS respectively increased by 170%,128% and 86%;The results also showed that the soluble protein content increased by 160% and 110% and the polysaccharide content increased by 180% and 200% after adding 0.03 g/g total suspended solid(TSS)neutral protease and alpha-amylase,respectively.The effect of compound enzyme treatment was better than that of single enzyme treatment.Furthermore,the effects of combined pretreatment of enzyme and thermal pressure on dewatered sludge were also investigated.3D-EEM indicated the presence of tryptophan and aromatic-like proteins,and FT-IR infrared spectroscopy showed that the types of functional groups exhibited a sharp decrease in the loosely bound-EPS layer after thermal pressure treatment. |
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