Rotating reverse osmosis: a dynamic model for flux and rejection

Area of Science:

• Water treatment technologies
• Membrane science and engineering
• Fluid dynamics in separation processes

Background:

• Reverse osmosis (RO) is effective for water purification but suffers from flux decline and fouling.
• Concentration polarization and membrane fouling significantly hinder RO performance and application.
• Novel approaches are needed to mitigate these challenges in RO systems.

Purpose of the Study:

• To theoretically investigate a rotating cylindrical RO membrane as a solution to reduce polarization and fouling.
• To predict the performance of a rotating RO system using a dynamic model.
• To analyze the impact of operating parameters on flux and rejection in rotating RO.

Main Methods:

• Development of a dynamic model for RO membrane transport, including concentration polarization.
• Theoretical investigation of a rotating cylindrical RO membrane configuration.
• Calculation of flux and rejection across a range of operating pressures and rotational speeds.

Main Results:

• Rotational speed is critical for reducing concentration polarization and membrane fouling.
• The generation of Taylor vortices at sufficient rotational speeds is essential for high flux and rejection.
• Performance predictions show the influence of rotational speed and transmembrane pressure on RO efficiency.

Conclusions:

• A rotating cylindrical RO membrane offers a promising approach to enhance water purification efficiency.
• Optimizing rotational speed is key to overcoming flux decline and rejection deterioration in RO.
• This method has the potential to improve the applicability and performance of RO technology.