Ionic Hyperbranched Poly(amido-amine)-Incorporated Nanofiltration Membranes for High-Efficiency Dye Desalination

Area of Science:

• Materials Science
• Environmental Engineering
• Chemical Engineering

Background:

• Textile industry wastewater poses risks to human health and aquatic ecosystems.
• Effective separation of dyes and salts is challenging, especially in high-salinity conditions.
• Resource recovery from industrial wastewater is increasingly important.

Purpose of the Study:

• To develop high-efficiency membranes for dye desalination in high-salinity textile wastewater.
• To synthesize and incorporate ionic hyperbranched poly(amido-amine) (HBPs) into polyamide (PA) membranes.
• To investigate the performance of these modified membranes for dye and salt separation.

Main Methods:

• Synthesized ionic hyperbranched poly(amido-amine) (HBPs) via one-step polycondensation.
• Incorporated HBPs into polyamide (PA) selective layers using interfacial polymerization (IP) on PVC-UF hollow fiber membranes.
• Evaluated membrane performance based on permeate flux and dye/salt selectivity under operational pressure.

Main Results:

• Modified membranes (HBP-TAC/PIP and HBP-PS/PIP) exhibited significantly higher permeate fluxes and dye/salt selectivities compared to unmodified membranes.
• HBP-PS/PIP membranes achieved a lemon yellow (LY)/NaCl selectivity of 664.0 at 63.7 L m^-2 h^-1 under 0.4 MPa.
• The charged nanochannels created by HBPs facilitated efficient separation of univalent salt and ionic dye.

Conclusions:

• Ionic HBPs integrated into PA membranes create effective charged nanochannels for high-efficiency dye desalination.
• The developed membranes offer a promising solution for treating high-salinity dye wastewater in the textile industry.
• This research provides a foundation for practical dye desalination processes in industrial settings.