Hydrophilic polypropylene microporous membranefor using in a membrane bioreactor system andoptimization of preparation conditions by responsesurface methodology

In this study, the response surface methodology (RSM) based on the central composite design (CCD) was usedto optimize the preparation condition of polypropylene-grafted maleic anhydride (PP-g-MA) microporousmembrane by thermally-induced phase separation (TIPS) method. A mixture of dibutyl phthalate (DBP) and dioctylphthalate (DOP) was used as diluent. The effect of polymer composition and quenching bath temperature on themorphology and performance of the fabricated microporous membranes was investigated by using RSM. Analysisof variance (ANOVA) was used to determine which variables and interactions between variables had a significanteffect on our responses. The ANOVA revealed that the bath temperature was the most significant variable associatedwith porosity and pure water flux responses and the polymer concentration was the most significant variableassociated with tensile response. The obtained results also showed that with increasing the polymer concentrationand decreasing the quenching bath temperature, the membrane porosity and pure water flux decreased, whereas themembrane tensile increased. The regression equations were reasonably validated and used to predict and optimizethe performance of PP-g-MA membranes within the limits of the variables. Finally, the maximum responses (fluxof 115.6 L/m2h, porosity of 62% and tensile of 1.6 MPa) were obtained under the following conditions: polymerconcentration of 28.5 wt% and temperature of 329 K. Further, comparison of laboratory-made and commercialmembranes in a membrane bioreactor (MBR) system showed that the rate of membrane fouling was decreased by4.2 times. Polyolefins J (2018) 5: 97-109

Keywords:

Response surface methodology , thermally induced phase separation , polypropylene grafted maleic anhydride , membrane , morphology , MBR