The hyperfiltration membrane permeability and the rejections of the alcohol and electrolyte components of ternary aqueous solutions by a zirconium (IV) hydrous oxide-polyacrylate membrane were studied. For dilute isopropanol and KCl, both components were modestly rejected and both rejections decreased as the concentration of either solute increased. At high concentrations of isopropanol large negative rejections of KCl were obtained. The membrane was used in solutions with the mole fraction of isopropanol as high as 59%(w/w) for many hours over several months with good maintenance of membrane hyperfiltration properties. The performance was upgraded once by a simple deposition of poly(acrylic acid).