The Role of Inorganic and Carbon Nanomaterials in Surface Modification to Attain Antibiofouling Polymeric Membranes for Water Treatment─A Review
Nkosingiphile Zikalala, Sithembela A. Zikalala, Shohreh Azizi, Ilunga Kamika, Edward N. Nxumalo, Ali Akbar Zinatizadeh, Evans M. N. Chirwa, Malik Maaza
Abstract
Membrane biofouling is a major stumbling block in membrane technology and particularly in the water treatment industry. Biofouling, in particular, is a serious concern because it is irreversible and thus cuts the lifespan of the polymeric membranes. This review, therefore, explores the fundamentals of biofouling development and the factors that promote biofilm growth in polymeric membrane systems. In this pursuit, we discuss avenues through which antibiofouling polymeric membranes have been fabricated using inorganic and carbon-based nanomaterials as membrane nanofillers to enhance the hydrophilicity and antibiofilm properties of the resultant composite membranes without significantly compromising the membrane filtering abilities. We further elucidate the chemistry by which the membrane nanofillers mitigate or inhibit the formation and growth of the undesirable biofilms on the surface and pores of the membranes. In achieving this, recent works on polymeric membrane biofouling are reviewed, with a particular focus on the correlation between the membrane performance and the physicochemical properties of the filler nanomaterials. The merits and demerits of inorganic and carbon-based nanomaterials as fillers to confer an antibacterial effect to the membranes are presented and perspectives and opinions on the future direction of biofouling mitigation in membranes are outlined.