Shifts in environmental microbial community during membrane distillation for water production and wastewater treatment: a review

Biofouling formation on the membrane surface is a critical problem in membrane-based systems. Recently, membrane distillation (MD) has been applied to water production and wastewater treatment. This article reviewed MD studies published in recent two decades using bibliometric assay focusing on biofouling, wetting, and microbial community analysis. The analytical resolution of the biofouling was enhanced by separating the detailed characteristics of the organics and microbes with time. The physical, chemical, and biological analysis methods used to examine biofouling in the MD process were summarized. Since 2011, MD biofouling studies have been classified according to water sources, such as freshwater, wastewater, and saline water. Microbes surviving the MD process possess characteristics such as thermophilic and halophilic abilities, and extracellular polymeric substance production. Moreover, the relationship with biofouling with the wetting was investigated. Finally, the overall concepts and methods for biofouling tests during the MD operation were suggested. • Biofouling and wetting studies on the MD membrane were reviewed. • Microbial community analysis becomes essential for MD biofouling characterization. • Analytical methods on biofouling for MD paper have been varied and increased. • Microbial information and experimental conditions for MD biofouling were investigated. • Wetting induced by the biofouling in MD studies was investigated.