Fabrication and performance analysis of graphene oxide-based composite membrane to separate microplastics from synthetic wastewater

Abstract The pervasiveness of microplastics (MPs) are jeopardizing the entire environment and need to be eradicated immediately. With such an aim, this study is highlighting the fabrication of graphene oxide (GO) - polyvinyl alcohol (PVA) based composite membrane to separate high-density polyethylene (HDPE)-based MPs from water. Here, the GO layers were stabled through the bonding with PVA by using glutaraldehyde followed by the deposition on cellulose membrane via vacuum filtration. The bonding between GO and PVA via acetalization was confirmed by FTIR while surface morphology of composite membrane was analyzed by SEM. However, during experimentation, further analysis with contact angle and zeta potential measurements were carried out to confirm the hydrophilicity and negative surface charge of membrane respectively. To control membrane thickness, optimum volume of GO-PVA composite solution was used to achieve high water flux as well as high rejection of MPs. Regarding the evaluation of membrane performance, dead-end filtration system was considered. Particularly, at pH 8, with 3.5 bar of transmembrane pressure, and 15s time duration 95% HDPE rejection was noticed while the highest permeability of fabricated membrane was 179 L m− 2 h− 1 bar − 1. The mechanisms for MP removal were electrostatic repulsion between membrane surface and MPs along with sieving capacity. So, these finding are highlighting the promising approaches of GO-based composite membrane to separate HDPE-based MPs from wastewater.