Fabrication of electrospun LTL zeolite fibers and their application for dye removal

Abstract

Zeolites are potential adsorbents for dyes removal in wastewater; however, separation of the zeolite particles from the wastewater after adsorption is tedious. Structured zeolites in the form of fibers offer faster and easier adsorbent separation. Herein, we applied electrospinning (ES) technique to fabricate LTL zeolite fibers. To improve the mechanical stability of the zeolite fibers, aluminum chloride was added in the suspension prior to ES. Thermal analyses of the as-spun fibers suggest that calcination at 700 °C is sufficient to decompose polymers and chloride ions. After calcination, the fibers contain (ca. 66 %) of LTL zeolite and (ca. 34 %) of alumina phases, while the diameter is below 1 µm. The alumina phase is very dense; the surface area of the fibers depends mainly on the zeolite content. Dyes sorption studies show that while the fibers exhibit significant adsorption toward cationic methylene blue (MB), it is ineffective for anionic orange G. The maximum MB adsorption capacity (Q m) for the zeolite fibers was found to be 30 mg g−1 lower than bare zeolite powder (72 mg g−1). The fibers fibrous nature was retained to certain degree after sorption makes them easier and faster for separation and reuse.