Green fabrication methods and performance evaluation of eco-friendly membranes for enhanced oil-water separation

Abstract

A significant step toward sustainability in membrane technology has been made with the substitution of eco-friendly alternatives for conventional membrane fabrication techniques. A green fabrication process, which is derived from renewable and biodegradable materials, offers a promising solution to environmental concerns associated with conventional membrane fabrication. Additionally, by utilizing eco-friendly materials, the toxicity footprint of membrane fabrication techniques can be reduced considerably. This study aims to transform the non-solvent induced phase separation (NIPS) method into a green process, by utilizing a biodegradable polymeric base (polylactic acid; PLA), a green solvent (dimethyl sulfoxide; DMSO), and a green additive (deep eutectic solvents; DES). The membranes were thoroughly characterized to understand their structural transformations, and their performance was evaluated. Filtration experiments demonstrated a notable increase in the water flux using 20 wt% PLA polymer, DMSO as a solvent, and 1 wt% choline chloride: ethylene glycol (ChCl:EG) (1:2) as an additive. This resulted in a flux of 1138 L/m2.h, a notable increase compared to 554 L/m2.h achieved with 20 wt% PLA using a conventional solvent (PLA-C). This increase in flux was also complemented by an increase in the membrane's oil rejection efficiency, (oil rejection of 96 % for the modified membrane), as well as enhanced anti-fouling properties (maintained in interval flux recovery ratio; FRR of 80 %). The findings suggest that creating environmentally friendly membranes through a sustainable process has the potential to improve both ecological impact and performance, hence progressing environmentally conscious industrial practices.