Formation of Fe3O4@ZrO2 nanocomposite and its performance as a magnetic adsorbent for phosphate uptake: Influences of end-point pH and stirring rate during synthesis process

•Hydrous zirconia-coated magnetite nanocomposite (Fe3O4@ZrO2) was synthesized.•Magnetization increased with raising end-point pH or reducing stirring rate.•Formation behavior of magnetite under the conditions determined the magnetization.•The P adsorption capacity decreased with raising end-point pH.•Stirring rate had little effect on P adsorption capacity by Fe3O4@ZrO2.