Effect of poly(ethylene glycol) on the properties of mixed matrix membranes for improved filtration of highly concentrated oily solution

Abstract

Mixed matrix membrane (MMM) composed of organic and inorganic materials has been widely studied for its potential use in water and wastewater treatment, owing to its improved properties compared to the pristine membrane. In this work, the filtration performance of MMM composed of polyethersulfone (PES) and hydrous manganese oxide (HMO) nanoparticles was further improved by adding pore forming agent -poly(ethylene glycol) (PEG) into dope solution to improve membrane hydrophilicity and structural morphology so as the developed membranes are suitable for handling highly concentrated oily solution (30,000 ppm oil concentration). Compared to the structure of control PES membrane that was composed of irregular microvoids, the presence of PEG and hydrophilic nanomaterial in the MMM was able to form extended finger-like structure from top to the bottom section of membrane and enhance its surface hydrophilicity, significantly improving water permeability. The improved water flux of MMM did not compromise the rejection rates of oil and chemical oxygen demand (COD) as the MMMs achieved comparable separation efficiency like the control membrane. The findings of this work revealed the potential use of MMM for the treatment of highly concentrated oily wastewater.