Synthesis of 3D porous ferromagnetic NiFe2O4 and using as novel adsorbent to treat wastewater

► Porous NiFe2O4 was synthesized by a simple sol-gel method using egg white. ► The pore structure forming process was studied. ► Porous NiFe2O4 shows large adsorption capacity for organic dye and heavy metal ions. ► The ferromagnetic property of NiFe2O4 resulting in excellent magnetic separation.