淀粉酶促进剩余污泥热水解的研究

Promoting thermal hydrolysis of excess sludge with external amylase.

考察了微好氧条件下,外加淀粉酶对污水处理剩余污泥热水解的影响,以及水解过程中污泥上清液各成分的变化情况,并对酶水解过程的动力学进行了分析.结果表明,淀粉酶的加入对剩余污泥的热水解有促进作用.在最适温度50℃,酶投加量0.5g/L条件下,水解4h后,污泥中SCOD/TCOD达到30.98%,比未加酶时高7.68%.在淀粉酶催化作用和热水解的共同作用下,污泥固体溶解,大分子碳水化合物被水解成小分子糖类,固相蛋白质溶出,并进一步水解.污泥水解过程中,上清液糖、蛋白质浓度均呈现先增加后降低趋势.加酶后污泥上清液中糖、蛋白质浓度分别于4h、6h达到最大值271.43mg/L和1437.37mg/L.污泥水解反应前4h内,VSS溶解率和SCOD/TCOD增加迅速,符合一级反应动力学,4h后反应趋于平衡.4h时VSS溶解率达到22.01%.

The effects of α-amylase on excess sludge thermal hydrolysis under aerobic conditions were investigated.It was found that sludge hydrolysis efficiency could be enhanced by amylase.When treated at the dosage of 0.5g/L of amylase,SCOD/TCOD in sludge could reach 30.98% under the optimal temperature 50℃,which was 7.68% higher than the control experiment.As a result of the interaction of amylase and thermal hydrolysis,sludge solids dissolved first and subsequently macromolecular carbohydrate was hydrolyzed into small-molecular sugar,and the protein in solid-phase released and further was hydrolyzed.The concentrations of both sugar and protein in supernatant showed an increase in the initial stage and then decrease later.After the addition of amylase,the highest concentration of sugar in supernatant could reach 271.43mg/L at 4h,while the protein reach 1437.37mg/L at 6h under 50℃ respectively.Furthermore,VSS dissolution rate and SCOD/TCOD were proved to be consistent with first-order reaction dynamic within prior 4h at 50℃ and reached balance after 4h,at which the VSS dissolution rate reached 22.01%.