Effects Of Enzyme And Thermal Pressure Treatment On The Distribution Characteristics Of Protein And Polysaccharides In Sludge

Sludge,as an inevitable product of sewage treatment,has a large amount of organic material with rich varieties,and has great potential for reuse.However,it's moisture content is high and difficult to remove.Therefore,how to effectively remove the water has always been a key issue in the development of sludge disposal technologies.In this paper,we investigated the extraction of protein and polysaccharides in concentrated sludge and mechanical dewatered sludge under different extraction methods.It was found that the amount of protein and polysaccharides in the concentrated sludge was much higher than that of mechanical dewatered sludge.As a polymer biopolymer,the sludge extracellular organic polymer combines with the most organic components and moisture in the sludge,plays a crucial role in sludge formation and structural stability,and has an important influence on the dewatering performance of sludge.In this paper,the content and distribution of protein and polysaccharide in extracellular polymeric substances before and after treated with different additives were compared.The study found that the decrease of water content was obvious after treated with thermal pressure,and the temperature has a greater impact than the pressure.After pretreatment with four different types of surfactant,the optimum dosage of SDS,CTAB and TX-100 were 0.10 g/g TSS,and the optimum dosage of Betaine was 0.15 g/g TSS.After pretreated with 0.03 g/g TSS neutral protease,the content of protein in three layers of sludge extracellular polymer increased by 172%,136% and 189%,respectively,while the content of polysaccharides increased by 152%,55% and 80%.When the sludge was combined pretreated with 0.03 g/g TSS neutral protease and 0.15 g/g TSS SDS,the content of protein increased by 258%,277% and 274%.The ratio of PN/PS increased after the treatment,which indicating the sludge dewatering performance has been improved.The extracted protein was hydrolyzed and 17 kinds of common amino acids were found,of which the content of lysine was the highest.