Arsenic contamination due to anthropogenic and natural activities has posted a great risk to humans through several pathways. As such, development of cost-effective technologies for arsenic decontamination is very important from both social and economic standpoints. In this paper, we are reporting a novel adsorptive yttrium nanoparticles (YNPs)/polyvinyl alcohol (PVA) modified polysulfone (PSF) membrane for the efficient treatment of arsenic. In the preparation of membrane, the porous PSF membrane fabricated with hydrophilic polyacrylic acid (PAA) polymer was coated by a PVA thin layer and then loaded with YNPs through an in-situ precipitation method using an ammonia vapor. We found that spherical YNPs were uniformly distributed onto the surface and within the matrix of membrane. The adsorption capacity as high as 35.56 mg-As/g was obtained at pH around 7. The membrane worked well across pH 4.0-8.0, with the best performance at pH 5.0. 90% of ultimate adsorption capacity was achieved in 2 h with the initial arsenic concentration of 10 mg/L and at the membrane dosage of 0.2 g/L. The kinetics data can be better fitted by the pseudo-second-order model. The Langmuir isotherm well described the adsorption isothermal data. The filtration studies with an initial arsenate concentration of 94.8 mu g/L showed that the treatment capacities of the composite membrane at pH 7.0 and 5.0 were 296 and 692 L/m(2), respectively. The X-ray photoelectron spectroscopy (XPS) analysis suggested that ligand exchange between yttrium-hydroxyl groups and arsenate species may play as the main adsorption mechanism. Our study demonstrates that the membrane is a better material for arsenic decontamination than previously reported adsorptive membranes. (C) 2018 Elsevier Inc. All rights reserved.