溶菌酶和蛋白酶对活性污泥脱水性能的影响

Effects of Lysozyme and Protease on Activated Sludge Dewatering Performance

通过溶菌酶和蛋白酶调理污泥,考察其对脱水性能的影响,采用毛细吸吮时间(CST)、污泥比阻(SRF)、脱水泥饼含水率(MC)表征污泥脱水性能,采用污泥上清液和胞外聚合物(EPS)中蛋白质和多糖浓度表征污泥破解效果,采用Zeta电位表征污泥凝聚性质。结果表明溶菌酶投加量增加到0.20 g/g干泥时,CST、SRF和WC分别从原泥的38.7 s、2.6×10^(8)s^(2)/g和90.7%降低到20.5 s、1.3×10^(8)s^(2)/g和84.2%。投加蛋白酶时,上述指标分别升高到了62.6 s、7.0×10^(8)s^(2)/g和94.8%。溶菌酶使上清液中蛋白质、EPS中多糖和蛋白质含量增加显著,蛋白酶则使上清液中多糖和蛋白质、EPS中多糖增加显著。当酶投加0.20 g/g干泥时,溶菌酶组Zeta电位升高至-0.03 mV,蛋白酶组Zeta降低至-12.4 mV。溶菌酶可通过破坏污泥细胞结构、增加凝聚性能提高污泥脱水性能。

The effects of lysozyme and protease on sludgedewaterability were investigated.Using the capillary suction time(CST),sludge specific resistance(SRF),cement cake moisture content(MC) to characterize sludge dewatering performance, using the sludge supernatant and extracellular polymers(EPS) on the concentration of protein and polysaccharide in characterization of sludge cracking effect, Zeta potential was used to characterize the coagulation properties of sludge.The results showed that when the lysozyme dosage increased to 0.20 g/g of dry sludge, CST,SRF and WC decreased from 38.7 s, 2.6×10^(8) s^(2)/g and 90.7% to 20.5 s, 1.3×10^(8) s^(2)/g and 84.2%,respectively.These indexes increased to 62.6 s, 7.0×10^(8) s^(2)/g and 94.8%,respectively.Lysozyme significantly increased the contents of protein in supernatant and EPS,while protease significantly increased the contents of polysaccharide in supernatant and EPS.The Zeta potential of lysozyme group increased to-0.03 mV,while that of protease group decreased to-12.4 mV when adding 0.20 g/g dry sludge enzyme.Lysozyme can improve sludge dewatering ability by destroying sludge cell structure and increasing coagulation ability.