Poly(vinylidene fluoride-hexafluoropropylene)/bayerite composites membranes for efficient arsenic water removal

Abstract

Polymer composite membranes based on poly(vinylidene fluoride-hexafluoropropylene), PVDF-HFP, with different aluminum hydroxide filler content, bayerite polymorph, were prepared by solvent casting for arsenic removal from water by filtration and adsorption. Morphological, structural and mechanical characterization of the membranes were performed. The arsenic removal efficiency of the membranes was also evaluated. Composite membranes presented homogeneous porous structures with a degree of porosity between 65 and 75%. They were hydrophobic e (contact angle >90°), showed a compressive strength >100 kPa and water flux ranging from 65 to 215 L/h m2. Further, arsenic rejections around 60% were found after 1 h reaction in dead-end cell filtration tests of an arsenic standard solution of 100 μg/L. A bayerite arsenic adsorption mechanism was also proposed. Thus, the PVDF-HFP/bayerite composite membranes showed a suitable performance for arsenic removal in water purification systems.