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以聚丙烯酰胺(PAM)为絮凝剂,纳米TiO2为固定化酶载体材料,木瓜蛋白酶为酶模型制备纳米絮凝酶.结合粒度分析、SEM、EDS等表征手段,考察PAM种类、加量及体系pH对高分子凝胶絮凝与沉降动力学的影响.结果表明通过氢键、静电吸附和架桥等作用,纳米酶和PAM间产生有效的絮凝.TiO2纳米酶的絮凝沉降速度、体系浊度、絮团大小和紧实程度随PAM用量不同而改变.适量的PAM产生高沉降速度,低浊度,稳定、大絮团的强絮凝,其中nPAM絮凝酶的沉降速度最快,絮团最大.过量的絮凝剂导致絮团脱稳.调控体系酸碱度亦可有效调控PAM絮凝动力学行为.比较nPAM和cPAM,发现nPAM絮凝体对pH有较高稳定性,cPAM絮凝体受pH影响显著.故可以根据酶结构与特性,调节絮凝剂加量和体系酸碱度设计出微纳尺度可调的固定化酶.
Polyacrylamide (PAM) as flocculant, nano-TiO2 as immobilized enzyme carrier material, and papain as enzyme model for preparation of nanoflocculant.Combined with particle size analysis, SEM, EDS and other means of characterization, investigated PAM species, dosage and system pH On the flocculation and settling kinetics of the polymer gel.The results show that the flocculation and settling kinetics of the nano-enzyme and the PAM can be effectively flocculated by the action of hydrogen bonding, electrostatic adsorption and bridging, etc. The flocculation settling velocity, the turbidity, the flocculation The size of the pellets and the degree of compactness varied with the dosage of PAM.The suitable amount of PAM produced high settling velocity, low turbidity, stable and strong coagulation of large flocs, of which nPAM flocculant had the fastest settling velocity and the largest flocs. Flocculants lead to flocculation destabilization.The pH control system can also effectively control the PAM flocculation kinetics behavior.Compared with nPAM and cPAM, nPAM floc was found to have higher pH stability and cPAM floc was significantly affected by pH, Structure and properties, adjust the amount of flocculant and the system pH design of the micro-nano-scale adjustable immobilized enzyme.