Arsenic removal using a sulfonated poly(ether ether ketone) coated hollow fiber nanofiltration membrane

Abstract

A new composite hollow fiber nanofiltration (NF) membrane with a thin sulfonated poly(ether ether ketone) (SPEEK) active layer was prepared and used for arsenic removal. The effects of the feed concentration, pH and transmembrane pressure on arsenic removal were systematically examined. The obtained SPEEK hollow fiber NF membrane could achieve an As(V) rejection of over 95% and water permeability of 11 L m⁻² h⁻¹ bar⁻¹. These excellent As(V) rejection and high water permeability were attributed to the highly negatively charged surface of the SPEEK membrane, which could enhance the As(V) rejection through the Donnan exclusion mechanism or electrostatic repulsion between the negatively charged arsenate species and the negatively charged SPEEK membrane surface. A preliminary techno-economic assessment of a 1000 m³ h⁻¹ plant suggests that using the proposed SPEEK hollow fiber membrane, the treatment cost was 0.15 US$ per m³, which thus could be economically viable for arsenic removal applications in China.