Biofouling control of membrane distillation for seawater desalination: Effect of air-backwash and chemical cleaning on biofouling formation

Abstract

This study explored the applicability of chemical cleaning and air-backwash to alleviate biofouling on seawater membrane distillation (SWMD). Membrane performance and wettability properties maintained at optimum duration and frequency of the treatments, as indicated by low permeate conductivity throughout the tests. The cleaning of the membrane using 2% NaOH by immersing the membrane for 30 min after 240 min operation removed the biofouling layer, indicated by low permeate conductivity of 370 µScm⁻¹ after cleaning. However, more frequent membrane cleaning led to membrane damage, more severe wetting, and membrane hydrophobicity reduction. Ten-second air-backwash after 240 min of operation was also effective in controlling the biofouling, particularly when conducted at air pressure of 1 bar. More frequent air-backwash resulted in more aggravated inorganic fouling and accelerated biofouling formation due to the recurring introduction of air, leading to rapid membrane wetting.

Keywords:

• air-backwash
• chemical cleaning
• biofouling
• seawater desalination
• membrane distillation

Acknowledgement

This research was supported under Program Penelitian, Pengabdian kepada Masyarakat dan Inovasi Institut Teknologi Bandung (P3MI ITB) 2020 funding scheme.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported under Program Penelitian, Pengabdian kepada Masyarakat dan Inovasi Institut Teknologi Bandung (P3MI ITB) 2020 funding scheme.