陶瓷膜用于杜仲叶提取液澄清的分离特性与膜污染机制研究

Eucommia ulmoides is a rare Chinese herbal medicine tree specie unique to China and is affluent in resources. Its leaves are rich in active substances such as chlorogenic acid and flavonoids. However, the content of gutta percha, protein, polysaccharide and other impurities in the extract of Eucommia ulmoides leaves is high. There is a lack of efficient separation technology for active substances. Ceramic membrane has been widely used in the clarification process of plant extract due to its advantages of high separation efficiency and good anti-pollution performance. At present, there are few reports on the application of ceramic membrane in the separation of Eucommia ulmoides leaf extract. It is of great application value to develop an efficient clarification technology of Eucommia ulmoides leaf extract by ceramic membrane. In this paper, the research was carried out from two aspects of membrane material and membrane process. The pore size of ceramic membrane was optimized. The effects of operating pressure, membrane surface velocity and temperature on the clarification process of ceramic membrane were systematically investigated. The membrane fouling mechanism was analyzed by Hermia model. The results showed that the ceramic microfiltration membrane with an average pore size of 100 nm had higher turbidity removal rate, active component transmittance and permeation flux, which was suitable for the clarification process of Eucommia ulmoides leaves extract. Under the optimized operating conditions, the stable flux of ceramic microfiltration membrane was about 58 L·m^-2·h^-1, the total transmittance of chlorogenic acid and flavonid was 75.3%, the turbidity removal rate was nearly 100%, and the flux recovery rate was over 85% after cleaning. Ceramic membrane separation technology has shown a good application prospect in the clarification process of Eucommia ulmoides leaves extract.