Reinforced thin‐film composite nanofiltration membranes: Fabrication, characterization, and performance testing

Abstract

Hollow‐fiber (HF) membranes have the advantage of a higher packing density compared to flat‐sheet and spiral‐wound configurations. However, the low pressure tolerance of HF membranes limits their applications in nanofiltration (NF). In this study, reinforced thin‐film composite (r‐TFC) HF NF membranes were fabricated and evaluated in tests with water containing different salts and organic matter. Reinforced polysulfone ultrafiltration membranes were used as a support for a polyamide layer prepared from piperazine and trimesoyl chloride monomers. The interfacial polymerization conditions were optimized via selection of the trimesoyl chloride reaction time that gave the highest membrane performance. A specific permeate flux of 5.1 L m–2 h–1 bar–1, an MgSO4 rejection of 69%, and an NaCl rejection of 26% at a transmembrane pressure of 6 bars were obtained with the optimized r‐TFC membranes. Performance studies with water characterized by synthetic solution demonstrated removals of the total organic carbon, ultraviolet absorbance at 254 nm, and turbidity in excess of 65, 80, and 90%, respectively. The results of this study illustrate the feasibility of manufacturing r‐TFC HFs and using them in water‐treatment applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48001.

Effective Parameters on Fabrication and Modification of Braid Hollow Fiber Membranes: A Review

“…The hydrophilicity of the membrane increased by enhancement of the crosslinking degree of the polyamide layer and the TMC reaction time. Turken et al [51] reported the higher specific permeate flux in higher TMC reaction times for reinforced-TFC-NF membranes. The hydrophilicity of the membrane enhanced when the reaction time of TMC increased.…”

“…Reaction time is a crucial factor in interfacial polymerization that affects the structure of the coating layer and specifies the extent of polymerization between the monomers [53]. Turken et al [51] fabricated reinforced TFC-HF NF membranes. They selected the reinforced PSf ultrafiltration as a support and polyamide layer as a selective layer that was prepared from trimesoyl chloride (organic phases) and piperazine (aqueous phases) monomers.…”

“…As the reaction time increased, the −OH and −C=O would be enhanced, and bonding between the OH and C-O groups would reduce. Therefore, a membrane with a dense layer would be created [51,53].…”

“…Generally, the hollow fiber membranes are not applicable in high-pressure applications such as NF and RO processes because of their poor mechanical strength. Whereas they are good candidates for wastewater treatment, removal of heavy metals, and drinking water purification [10,15,51]. Thin-film composite (TFC) membranes are excellent candidates for RO and NF processes in water and wastewater treatment applications due to the ultrathin selective layer.…”

“…The prepared membranes could tolerate pressure up to 0.5 MPa while possessing high selectivity for divalent/monovalent ions. Turken et al [51] fabricated reinforced TFC-HF NF based on PSf ultrafiltration membranes and polyamide layer prepared from PP and TMC monomers. The membranes were investigated in solutions with different organic matter and salts.…”