Preparation of polyethylene terephthalate/xanthan nanofiltration membranes using recycled bottles for removal of diltiazem from aqueous solution

Abstract

The massive amount of post-consumer polyethylene terephthalate (PET) bottles highlights the need for increasing their recycling rate. So far, there is no report on using waste PET bottles in preparing membranes for the nanofiltration of aqueous media. The present work demonstrates an environmentally-friendly nanofiltration membrane with high performance prepared by recycled PET bottles. During the membrane fabrication, water and methanol were used as two different coagulation baths, and xanthan gum (XA) was incorporated into the membranes as a hydrophilic additive. The obtained membranes were applied in the nanofiltration of an aqueous solution containing diltiazem. Using similar XA loading, PET/XA membranes prepared in methanol were more hydrophilic and generally performed better in the nanofiltration of diltiazem aqueous solution than the PET/XA membranes obtained in water. Among the membranes prepared in this study, the highest rejection value (97.6%) was achieved using the PET/XA membrane prepared with 0.25 wt% of XA in the methanol coagulation bath.