研究了胞外多聚物对酶催化污泥溶解效果和催化过程中污泥化学组分变化的影响.向原污泥及去除胞外多聚物的剩余污泥外加酶,并与未加酶组水解效果进行对比.结果表明,酶浓度〈20 mg/g时仅水解污泥胞外物质,加大酶量能显著引起污泥破解.溶菌酶用于原污泥水解效果较好,SCOD/TCOD最高可达28.14%,投加量60 mg/g,反应48 h后VSS去除率达51.66%,DNA浓度(以VSS计)为68.34 mg/g,分别比空白组提高了29.01%与59.63 mg/g,比去除胞外多聚物组提高了24.86%与53.39 mg/g,且NH4+-N、PO34--P、SCOD溶出效果良好,最大累积量分别为503、78.9、3 171 mg/L.污泥去除胞外多聚物后投加蛋白酶与纤维素酶溶胞效果较好,VSS去除率最高分别达到49.95%、39.85%,溶出DNA浓度与SCOD、NH4+-N及PO34--P线性相关系数在0.9以上,6 h左右水解效率最高,达到最大水解速率时刻比原污泥组提前了3 h左右,且较小的酶量可达到好的溶胞效果.
The effect of extracellular polymeric substance(EPS) on the enzymatic solubilisation of sludge and the changes of chemical components was investigated.Sludge solubilization with and without EPS was studied in the enzymatic system,and in the normal system without enzyme addition,respectively.The result indicated that only EPS could be hydrolyzed when the enzyme addition less than 20 mg/g,while the cell lysis occurred significantly with the doses of enzymes increasing.Treatment with lysozyme for the original sludge was proved to have a higher hydrolysis efficiency,and the SCOD/TCOD rate reached up to 28.14%.And at the enzyme dosage of 60 mg/g,the VSS removal rate increased to 51.66% and the concentration of DNA attained 68.34 mg/g(calculated by VSS) after 48 h reaction,which were 29.01% and 59.63 mg/g higher than the control test,respectively,and were 24.86% and 53.39 mg/g higher than that with EPS removed in advance,respectively.Meanwhile,NH+4-N,PO3-4-P and SCOD showed high dissolution efficiency,and the maximal concentrations achieved to 503 mg/L,78.9 mg/L and 3 171 mg/L,respectively.After removal of extracellular polymers,higher lysis efficiency was also observed by protease and cellulose,by which VSS reduction rate reached to 49.95% and 39.85%,respectively.The concentration of DNA showed a correlation coefficient of more than 0.9 with the concentrations of SCOD,NH+4-N and PO3-4-P.And the highest hydrolysis rate obtained in 6 hours,which was about 3 hours earlier than the control test.Moreover,under those condition,sludge hydrolyzation could be well realized by only small amount of the enzyme addition.