Challenges and opportunities in functional carbon nanotubes for membrane-based water treatment and desalination

• Published in: The Science of the total environment Vol. 646; pp. 1126 - 1139
• Main Authors: Ali, Sharafat, Rehman, Syed Aziz Ur, Luan, Hong-Yan, Farid, Muhammad Usman, Huang, Haiou
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-01-2019
• Subjects: Antifouling; Carbon nanotube membranes; Desalination; Electrochemical degradation; Functionalization; Water treatment; Water treatment; Functionalization; Electrochemical degradation; Antifouling; Desalination; Carbon nanotube membranes
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2018.07.348

Environmental applications of carbon nanotubes (CNTs) have grabbed worldwide attentions due to their excellent adsorption capacities and promising physical, chemical and mechanical properties. The functionalization of CNTs, which involves chemical/physical modification of pristine CNTs with different types of functional groups, improves the capabilities of CNT for desalination and/or removals of waterborne contaminants. This paper intends to provide a comprehensive review of functional CNT materials (f-CNT) and their existing and potential applications in membrane-based water treatment and desalination processes, with focuses on critical evaluation of advances, knowledge gaps and future research directions. CNT nanocomposite membranes have been studied at bench scale to efficiently remove a variety of waterborne contaminants and salts, while future improvement is under way with development in CNT functionalization techniques. The CNT-based membrane applications are found to possess a variety of advantages, including improve water permeability, high selectivity and antifouling capability. However, their applications at full scale are still limited by their high cost. Finally, we highlight that f-CNT membranes with promising removal efficiencies for respective contaminants be considered for commercialization and to achieve holistic performance for the purpose of water treatment and desalination.
[Display omitted]
•The current state-of-the-art functional CNT membranes are reviewed.•Methods of CNT functionalization and types of functional CNT membranes are discussed.•Modification of polymeric membranes by functional CNTs enhanced the removal of water born pollutants are reported.•Modification of membranes with functional CNTs is stated to significantly improved the antifouling behaviors.•Challenges and opportunities of each part are reviewed and commented to explore the future direction for research.