New generation of semipermeable membranes with carbon nanotubes for water and wastewater treatment: Critical review

Abstract

Environmental applications of carbon nanotubes (CNTs) have recently attracted worldwide attentiondue to their excellent adsorption capacities and promising physical, chemical and mechanical properties, as well asthe preparation of novel membranes with attractive features for water purification. This paper critically reviews therecent progress on the preparation and applications of CNT based membranes in water and wastewater treatment. Various synthesis techniques for the preparation of CNT based membranes are discussed. The functionalization ofCNTs, which involves chemical/physical modification of pristine CNTs with different types of functional groups,improves the capabilities of CNT for water and wastewater treatment and/or removal of waterborne contaminants.The CNT-based membrane applications are found to possess a variety of advantages, including improving waterpermeability, high selectivity and antifouling capability. However, their applications at full scale are still limitedby their high cost. Finally, we highlight that CNT membranes with promising removal efficiencies for respectivecontaminants can be considered for commercialization and to achieve holistic performance for the purpose ofwater treatment and desalination. This paper may provide an insight for the development of CNT based membranesfor water purification in the future. With their tremendous separation performance, low biofouling potential andultra-high water flux, CNT membranes have the potential to be a leading technology in water treatment, especiallydesalination.

Keywords

• carbon nanotube (cnt)
• cnt functionalization
• cnt freestanding membranes
• mixed matrix cntmembranes
• water and wastewater treatment