A novel corrugated wall channel module for external concentration polarization mitigation in forward osmosis process

Area of Science:

• Membrane Science and Technology
• Chemical Engineering
• Water Treatment Technologies

Background:

• Forward osmosis (FO) is a promising water separation technology, but its efficiency is often limited by external concentration polarization (ECP).
• Mitigating ECP is crucial for enhancing water flux and overall performance in FO systems.
• Existing studies have limited focus on practical ECP mitigation strategies within FO module design.

Purpose of the Study:

• To introduce and evaluate a novel corrugated wall channel module (CWCM) for mitigating ECP in FO.
• To investigate the impact of CWCM design on water flux enhancement and membrane fouling.
• To analyze the fluid dynamics within the CWCM using computational fluid dynamics (CFD).

Main Methods:

• Fabrication and testing of a corrugated wall channel module (CWCM) for FO applications.
• Comparative analysis with a traditional flat membrane module (FMM) under identical conditions.
• Utilizing computational fluid dynamics (CFD) to simulate and understand fluid behavior within the CWCM.

Main Results:

• The CWCM demonstrated significant mitigation of ECP, leading to enhanced water flux in both FO and PRO modes.
• Water flux enhancement ranged from 15.92% to 18.51% depending on the mode and feed solution concentration.
• CFD analysis confirmed that the CWCM induces vortex flow, promoting solution mixing and increasing water flux, with more tortuous designs showing higher flux and reduced fouling.

Conclusions:

• The corrugated wall channel module (CWCM) is an effective structural modification for mitigating ECP in forward osmosis.
• CWCM design enhances water flux and shows potential for reducing membrane fouling.
• The study highlights the importance of module geometry in optimizing FO system performance.