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通过静态吸附实验,研究了苏云金杆菌(Bt)杀虫蛋白在凹凸棒石表面上的吸附动力学和热力学规律,考察了时间、温度、pH和蛋矿比对吸附性能的影响。研究表明:Bt杀虫蛋白能够迅速被凹凸棒石吸附,30min基本达到吸附平衡。吸附动力学对准一级、准二级、内扩散和Elovich模型的符合程度依次为:准二级模型>Elovich模型>准一级模型>内扩散模型。吸附温度升高,吸附量下降。在pH 7~10范围内,pH升高吸附量下降。初始蛋矿比升高,吸附量升高但吸附率下降。在278~318 K范围内,凹凸棒石对Bt蛋白的吸附是一个自发、放热和熵增过程。吸附自由能(△G_(ads)~0)在-35.56~-38.37 k J mol-1之间,吸附焓(△H_(ads)~0)为-16.16 k J mol~(-1),吸附熵(△S_(ads)~0)为69.47 J mol~(-1)K~(-1)。利用FTIR和XRD对吸附复合物进行了表征,提示Bt蛋白被凹凸棒石吸附后其结构没有明显变化。Bt蛋白被凹凸棒石吸附后杀虫活性提高,且抗紫外光降解能力增强,这一结果为Bt高效制剂开发和凹凸棒石的应用提供了实验依据。
The adsorption kinetics and thermodynamics of Bacillus thuringiensis (Bt) insecticidal protein on the surface of attapulgite were studied by static adsorption experiments. The effects of time, temperature, pH and egg-mineral ratio on the adsorption performance were investigated. Studies have shown that: Bt insecticidal protein can be quickly adsorbed attapulgite, 30min basically reached equilibrium adsorption. The first order, second order, internal diffusion and Elovich model coincide with each other in the order of quasi-two-level model> Elovich model> quasi-first-order model> inner diffusion model. Adsorption temperature increases, the amount of adsorption decreased. In the pH range of 7 ~ 10, the pH increased adsorption decreased. Initial egg ratio increased, adsorption increased, but the adsorption rate decreased. In the range of 278 ~ 318 K, attapulgite adsorption of Bt protein is a spontaneous, exothermic and entropy increase process. (△ G_ (ads) ~ 0) was between -35.56 and -38.37 k J mol-1, and the adsorption enthalpy (△ H_ (ads) ~ 0) was -16.16 k J mol -1 Entropy (△ S_ (ads) ~ 0) was 69.47 J mol -1 K -1. The adsorption complex was characterized by FTIR and XRD, which indicated that the structure of Bt protein did not change obviously after it was adsorbed by palygorskite. Bt protein adsorbed by palygorskite insecticidal activity increased, and enhanced UV degradation ability, the results for the development of Bt efficient preparation and application of attapulgite provided an experimental basis.