Electrospun nanofibers membranes of La(OH)3/PAN as a versatile adsorbent for fluoride remediation: Performance and mechanisms

Abstract

Excessive existence of fluoride in water resources can lead to harmful impacts on ecosystems and organisms. Electrospun polyacrylonitrile (PAN) nanofiber membranes loaded with La(OH)3 nanorods composites (La(OH)3/PAN electrospun nanofiber membranes [ENFMs]) are fabricated and used as an efficient fluoride scavenger. Adsorbent fabricate protocols, pH, initial F− concentration, adsorbent dosage, and adsorption time, in addition to coexisting anions, were systematically evaluated. The investigation unveils that a pH of 3.0 is optimal for F− remediation. The adsorption kinetics and isotherm of La(OH)3/PAN ENFMs are well described by the pseudo-second-order model (R 2 > 0.997) with characteristics of chemisorption and Langmuir isotherm (R 2 > 0.999) with the feature of single-layer coverage. The existence of Cl−, SO4 2−, NO3 −, and CO3 2− does not significantly hinder fluoride removal by La(OH)3/PAN ENFMs with the exception of PO4 3−. Calculations of ΔH, ΔG, and ΔS reveal that the nature of F− adsorption onto La(OH)3/PAN ENFMs is endothermic and favorable at a higher temperature.

Keywords

• electrospun nanofiber membrane
• la(oh)3
• defluoridation
• kinetics
• water treatment