Sustainable and green polylactic acid-based membrane embedded with self-assembled positively charged f-MWCNTs/GO nanohybrids for the removal of nutrients from wastewater

Abstract

In this study, the synthesis, and chemical-physical characterization of self-assembled positively charged multi-walled carbon nanotubes/graphene oxide (f-MWCNTs)/(GO)-nanohybrids into adsorptive PLA-based membranes were investigated. The application of the innovative PLA/f-MWCNTs/GO membrane was investigated for the removal of nutrients such as nitrogen (N) and phosphorus (P) from both synthetic and real wastewater by performing various characterization and performance tests. The positively charged nanohybrid was prepared by electrostatic self-assembly of positively charged f-MWCNTs and negatively charged GO. The amount of nanohybrid loading in the nanocomposite membranes varied from 0 to 6 wt%, and its effects on nutrient removal and water flux were investigated. It is demonstrated that with the addition of only 1.5 wt% f-MWCNT/GO nanohybrid into the PLA matrix, the water flux increased by 74% when compared to the unmodified membrane. Also, up to 90.1 ± 3.4% and 71.3 ± 3.1% removal rates of ammonium-nitrogen (NH4+-N) and phosphate (PO43−-P) ions were achieved using raw wastewater, respectively. The obtained results confirm the practical usability of the proposed innovative material for membrane fabrication in real wastewater treatment applications and can open doors to efficient and sustainable methods for nutrient removal.