Integrating seawater desalination and wastewater reclamation forward osmosis process using thin-film composite mixed matrix membrane with functionalized carbon nanotube blended polyethersulfone support layer

• Published in: Chemosphere (Oxford) Vol. 185; pp. 1181 - 1188
• Main Authors: Choi, Hyeon-gyu, Son, Moon, Choi, Heechul
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2017
• Subjects: Carbon nanotube; Effluent organic matter fouling; Electrostatic repulsion; Forward osmosis; Hydrophobic and Hydrophilic Interactions; Membranes, Artificial; Nanotubes, Carbon - chemistry; Osmosis; Polymers - chemistry; Seawater - chemistry; Seawater desalination and wastewater reclamation; Sulfones - chemistry; Thin-film composite membrane; Waste Water - chemistry; Water; Water Purification - methods; Carbon nanotube; Seawater desalination and wastewater reclamation; Electrostatic repulsion; Thin-film composite membrane; Forward osmosis; Effluent organic matter fouling
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2017.06.136

Thin-film composite mixed matrix membrane (TFC MMM) with functionalized carbon nanotube (fCNT) blended in polyethersulfone (PES) support layer was synthesized via interfacial polymerization and phase inversion. This membrane was firstly tested in lab-scale integrating seawater desalination and wastewater reclamation forward osmosis (FO) process. Water flux of TFC MMM was increased by 72% compared to that of TFC membrane due to enhanced hydrophilicity. Although TFC MMM showed lower water flux than TFC commercial membrane, enhanced reverse salt flux selectivity (RSFS) of TFC MMM was observed compared to TFC membrane (15% higher) and TFC commercial membrane (4% higher), representing membrane permselectivity. Under effluent organic matter (EfOM) fouling test, 16% less normalized flux decline of TFC MMM was observed compared to TFC membrane. There was 8% less decline of TFC MMM compared to TFC commercial membrane due to fCNT effect on repulsive foulant–membrane interaction enhancement, caused by negatively charged membrane surface. After 10 min physical cleaning, TFC MMM displayed higher recovered normalized flux than TFC membrane (6%) and TFC commercial membrane (4%); this was also supported by visualized characterization of fouling layer. This study presents application of TFC MMM to integrated seawater desalination and wastewater reclamation FO process for the first time. It can be concluded that EfOM fouling of TFC MMM was suppressed due to repulsive foulant–membrane interaction. [Display omitted] •TFC MMM was synthesized with fCNT-blended PES layer.•TFC MMM was firstly applied to integrating seawater desalination & wastewater reclamation FO process.•Performances of TFC MMM were enhanced in FO test.•EfOM fouling resistance was enhanced for TFC MMM due to electrostatic repulsion.