Abstract:

Firstly, the pure water flux, average pressure of bubble point minus maximum pressure of bubble point, the pure water flux plus average pressure of bubble point minus maximal pressure of bubble point were selected as the performance indices of poly (vinylidene fluoride) (PVDF)/cellulose acetate (CA) blend microfiltration membrane.An orthogonal table with nine factors and four levels L₃₂(4⁹) for the PVDF/CA system was designed to study the performance of PVDF/CA blend microfiltration membrane.Secondly, the linear multi-regression model with standardized coefficients matrix was used to study the effects of nine factors.The results showed that: when pure water flux was taken as the objective function, blend ratio of PVDF/CA, solid content, additive content and gelation temperature were the major influence factors; when average pressure of bubble point minus maximum pressure of bubble point was taken as the objective function, solid content was the major influence factor; when the pure water flux plus average pressure of bubble point minus maximal pressure of bubble point was taken as the objective function, solid content was the major influence factor.After analyzing the SEM photographs and experimental results, the optimum condition for preparing the PVDF/CA blend microfiltration membrane was as follows: blend ratio of PVDF/CA 4∶1，solid content 12%, additive content 2%—3%, gelation temperature 30—35℃.