ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1：1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.
以黄连为原料,用正交设计法优化了小檗碱的超声波提取工艺,考察了超声提取时间、温度和乙醇浓度三个因素对小檗碱提取量的影响。同时对超声波提取进行了数学模拟,模拟值与实验结果吻合良好。结果表明,优化的超声波提取工艺条件为:超声处理时间32 m in,温度51℃,乙醇浓度78%。在该优化条件下,小檗碱提取率为8.38%。
用正交实验法研究了酶法提取小檗碱的最佳工艺条件。以小檗碱提取率为指标,分别考察了温度、时间、酶解pH值、加酶量对酶解反应的影响。确定了酶解黄连的最佳工艺条件:温度40℃、时间90 m in、pH 4.0、酶用量30 mg/g。在此条件下,对酶法提取小檗碱与传统乙醇浸提法进行比较,结果表明,酶法提取工艺比传统乙醇浸提法小檗碱产量提高了49%。
