复合酶生物促进剂强化生物处理模拟PVA废水研究

Kinetics study of enhanced bio-treatment of simulated PVA wastewater by multi-enzyme reagent

采用连续流活性污泥系统(以下简称系统)处理模拟聚乙烯醇(PVA)废水,对比了投加复合酶生物促进剂的加药系统与对照系统对PVA降解效果的差异,讨论了复合酶生物促进剂强化作用的原因,并通过动力学角度深入分析了PVA降解过程。结果表明,投加复合酶生物促进剂可以有效提高PVA的去除率。加药系统平均PVA去除率为94.4%,平均COD去除率为92.8%,较对照系统分别提高了2.1%和2.6%。模拟PVA废水在系统内的降解过程符合Monod模型,胞外聚合物降解PVA模拟废水遵循一级反应动力学。加药系统PVA半饱和常数和最大比降解速率为112.4mg/L和0.589h-1,对照系统PVA半饱和常数和最大比降解速率分别为142.6mg/L和0.509h-1。投加复合酶生物促进剂可以减少胞外聚合物糖类含量,强化PVA降解酶等胞外蛋白质的分泌。胞外聚合物构成的改变是复合酶生物促进剂强化生物降解模拟废水中PVA的根本原因。

The bio treatment of simulated polyvinyl alcohol （PVA） wastewater was studied from the view point of kinetics. The treatment performances of the continuous activated sludge systems with and without dosing multi-enzyme reagent were compared. The results showed that the presence of multi-enzyme reagent could increase the efficiency of PVA degradation and improve the affinity between PVA and sludge. The system with dosing multi-enzyme reagent given the average of degradation rate of PVA and COD were 94.4% and 92.8% respectively, which were more than that of blank system. The degradation of PVA in activated sludge systems could be well fitted by Monod model; the process of PVA degradation by sludge extracellular polymeric substance （EPS） followed the first-order kinetics. The Ks and Vmax of PVA in the system with dosing multi-enzyme reagent were 112.4 mg/L and 0. 589 h^-1 , while that of the control were 142.6 mg/L and 0. 509 h^-1. The presence of multi-enzyme reagent decreased the content of EPS carbohydrate while enhanced the secretion of protein such as PVA degrading enzyme. The variation of EPS component was the key factor for multi-enzyme reagent enhanced bio treatment of PVA wastewater.