Mordenite zeolite-Polyethersulfone composite fibers developed for decontamination of heavy metal ions

- Mordenite zeolite - polymer composite fibers were fabricated by phase inversion technique.
- Properties and adsorption behavior of composite fibers were investigated.
- Lead ion was selectively adsorbed from mixed solution containing cadmium, copper, nickel and potassium nitrate by using composite fibers.

Mordenite zeolite was composited in polyethersulfone fibers with mordenite zeolite loading of 27.0, 45.5, 58.8, and 69.0 wt%. Phase inversion was used to prepare porous composite fibers. During the process, mordenite zeolite powders were mixed in polyethersulfone (PES) - N-methyl-2-pyrrolidone (NMP) solution. Then the PES mixed solution was coagulated in water to prepare composite fibers. The composite fiber morphology provided evidence that mordenite zeolite powders were embedded well in the PES scaffold. Characterization results implied that mordenite zeolite interacted and composed with PES matrix. With increased mordenite zeolite loading amounts, the composite fiber surface was increased respectively by 11.7 and 145 m2/g for 0 and 69.0 wt% loading. Their composite fibers exhibited thermostability and heavy metal adsorbability. The adsorption behavior of heavy metal ions, especially to Pb2+, was investigated because their composite fibers were immersed in a batch solution of single or quaternary mixed heavy metal ions of Pb2+, Cd2+, Cu2+, and Ni2+. Composite fibers with 58.8 wt% and 69.0 wt% of mordenite zeolite showed high adsorption capacity to lead by fitting with the Langmuir isotherm model. The maximum adsorption capacity and Langmuir constant of heavy metal ions follows the order of Pb2+ > Cd2+ > Cu2+ > Ni2+ at pH 5. Adsorption selectivity of Pb2+ was observed in a heavy metal mixed solution and high concentration of KNO3 solution using composite fiber.