Electro-responsive PVA/PAMPS hydrogel draw agents for high-flux forward osmosis desalination with efficient...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Conventional forward osmosis (FO) draw solutes face limitations in water flux and regeneration efficiency.
• Developing advanced materials is crucial for enhancing FO performance in desalination and wastewater treatment.

Purpose of the Study:

• To develop novel electro-responsive PVA-based composite hydrogels for FO applications.
• To investigate the properties and performance of these hydrogels as draw agents.

Main Methods:

• Fabrication of PVA-based composite hydrogels using free-radical polymerization and freeze-thaw.
• Characterization of hydrogel morphology, mechanical strength, and swelling behavior.
• Evaluation of FO performance, including water flux and salt rejection, under varying voltages.

Main Results:

• The developed PVA/PAMPS hydrogels exhibit enhanced mechanical strength (96.18 kPa) and macroporous structure.
• Hydrogels demonstrated rapid electro-deswelling under low voltage and non-Fickian diffusion behavior.
• Achieved a maximum pure water flux of 2.19 L/(m² h) and significant salt rejection in FO tests.

Conclusions:

• Electro-responsive AMPS/PAMPS hydrogels are efficient, regenerable, and mechanically robust draw agents.
• These hydrogels hold potential for next-generation FO desalination and wastewater treatment.
• The study addresses key limitations of conventional FO draw solutes.