Membrane photoreactors (MPRs) for photocatalysts separation and pollutants removal: Recent overview and new perspectives

ABSTRACT

This paper provides a comprehensive review on membrane photoreactor (MPR) systems with TiO₂ in suspension for water treatment and reclamation. Two MPR configurations including separated and combined MPR systems are compared. Both bench–scale and pilot–scale MPR applications for photocatalysts separation and pollutants removal are summarized. The MPR performances are evaluated in terms of photocatalysts separation and photodegradation efficiency and permeate quality. As an important practical issue for commercial applications of MPR systems, membrane fouling has been critically assessed. Accordingly, some membrane fouling mitigation strategies have been recommended for further improvements on the MPR systems. New perspectives for commercial applications of MPR systems are proposed, in order to make good use of the solar energy and indoor lights with good light distribution. Two novel submerged TiO₂–coated optical fiber and membrane photoreactors (s–TOF–MPRs) are also proposed with the potential to improve solar energy utilization efficiency, eliminate the need for TiO₂ separation step, and reduce mass transfer limitation.

KEYWORDS:

• Photocatalyst separation
• membrane photoreactor
• solar light
• optical fiber

Acknowledgements

The author is grateful for Dr. Teik-Thye Lim for providing constructive suggestions during the manuscript preparation and vetting through its final version.

Funding

The research support from the Nanyang Environment & Water Research Institute (NEWRI) is also gratefully acknowledged.

Additional information

Funding

The research support from the Nanyang Environment & Water Research Institute (NEWRI) is also gratefully acknowledged.