Antifouling and Chemical-Resistant Nanofiltration Membrane Modulated by a Functionalized MWCNT Interlayer for...

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Textile wastewater treatment requires efficient dye and salt separation.
• Membrane filtration is a sustainable technology for wastewater remediation.
• Existing membranes face challenges in selectively separating dyes from high salt concentrations.

Purpose of the Study:

• To develop a novel thin-film composite membrane for selective dye/salt separation.
• To enhance membrane performance using a tannic acid-modified carbon nanotube interlayer and graphene quantum dots.
• To evaluate the membrane's efficiency in treating high-salinity textile wastewater.

Main Methods:

• Fabrication of a composite membrane via interfacial polymerization.
• Incorporation of a tannic acid-modified multiwalled carbon nanotube (M-TA) interlayer.
• Modification with amino-functionalized graphene quantum dots (NGQDs) as aqueous monomers.
• Testing of pure water permeability, dye rejection, and salt rejection.

Main Results:

• The M-TA-NGQDs membrane showed enhanced hydrophilicity, smoothness, and pure water permeability (9.32 L m⁻² h⁻¹ bar⁻¹).
• High rejection rates were achieved for methyl orange (97.79%), Congo red (99.61%), and brilliant green (96.04%).
• Excellent selective separation of dyes from high NaCl concentrations (50,000 mg/L) was demonstrated, with low salt rejection (<15%).

Conclusions:

• The fabricated M-TA-NGQDs membrane demonstrates superior performance for dye/salt separation in textile wastewater.
• The membrane offers high water permeability, excellent dye selectivity, and robust chemical stability.
• This technology holds significant promise for effective wastewater treatment and water recycling in the textile industry.