This research aimed at synthesizing polyethersulfone/alpha-zirconium phosphate (PES/ alpha-ZrP) flat-sheet nanocomposite ultrafiltration (UF) membranes. The impact of alpha-ZrP nanoparticle (NP) addition on the morphology, functionalities, hydrophilicity, and surface charge of the membrane, among others, were investigated. Different concentrations of alpha-ZrP NPs (0.25, 0.50, 0.75, and 1.00 wt.%) were tested. Membranes surface morphology was investigated by Fourier-transform infrared (FT-IR), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Microscopic analyses affirmed that the alpha-ZrP NPs were successfully incorporated into the PES membranes. Also, the composite membranes were hydrophilic reporting increased mechanical strength, porosity, and thermal stability than the pristine PES membrane. An overall removal efficiency of 70.2 +/- 1.0, 99.7 +/- 0.2, 81.7 +/- 1.1, 74.4 +/- 1.5, and 91.5 +/- 2.0 % for Cd2+ Cu2+, Ni2+, Pb2+, and Zn2+ was reported, respectively when 0.25 wt.% of alpha-ZrP NPs was added. The enhanced capabilities of the composite membranes in the heavy metal removal was ascribed to the increased electrostatic attraction forces with the metal ions in the solution and the surface of the PES/alpha-ZrP composite membrane. Lastly, the developed membranes demonstrated less fouling with self-cleaning properties which can be very beneficial in the field of industrial wastewater treatment. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.