Pharmaceutical wastewater treatment using polypropylene membranes incorporated with carboxylated and PEG-grafted nanodiamond in membrane bioreactor (MBR)

The aim of this work is to prepare polypropylene (PP) membrane by embedding carboxylated(-COOH) and also polyethylene glycol(-PEG) functionalized nanodiamond to improve membrane hydrophilicity and decline membrane fouling in pharmaceutical wastewater treatment. Porosity, contact angle, mechanical strength, field emission scanning electron microscopy (FESEM) and membrane pure water permeation analysis were performed for the characterization of the membranes. The membranes with 0.75 wt.% of nanoparticles introduced the highest water flux, porosity and mechanical strength. The performance of PP, PP/ND-COOH (0.75 wt.%) and PP/ND-PEG (0.75 wt.%) membranes was studied in a lab-scale membrane bioreactor (MBR). COD removal was more than 91% in all cases. It was found that antifouling characteristics, membrane resistance (R-m) and specific cake layer resistance (alpha) of nanocomposite membranes were better than of neat PP membrane. PP/ND-PEG (0.75 wt.%) membrane exposed highest hydrophilicity and maximum critical flux and anti-fouling characteristics. The results indicated that embedding nanodiamond in PP membrane can reduce membrane fouling in MBR.

Automated summary

By embedding carboxylated and polyethylene glycol functionalized nanodiamond in polypropylene membrane, this study successfully enhanced membrane water flux, hydrophilicity, and anti-fouling properties, showing significant potential for pharmaceutical wastewater treatment.