Fe-0 and Fe3O4 nano-particles (FFNPs) were synthesized, simultaneously, and stabilized by the cross-linked pectin with adipic acid (CPA) to obtain FFNPs-CPA with the ability of Amaranth (AM) removal. Fe-0 and Fe3O4 nanoparticles in FFNPs-CPA had a smaller average size than one, when used to connect CPA, separately. About 73% of nano-particles in Fe(0)NPs-CPA and 85% of nano-particles in Fe(3)O(4)NPs-CPA had the size of 25 to 45 nm and 17 to 47 nm, respectively, while about 100% of nano-particles in FFNPs-CPA had the size 5 to 24 nm. These results showed that the simultaneous presence of Fe-0 and Fe3O4 nano-particles in the synthesis process reduces the crystal growth of nano-particles. The removal percent of AM was determined 89.1 and 81.3 by Fe(0)NPs-CPA and Fe(3)O(4)NPs-CPA, respectively, for a dye initial concentration of 150 ppm, while it was determined 98.2 by FFNPs-CPA. The removal of Amaranth by the pointed agents was as the first and second-order kinetic model for 0-8 and 8-80 min, respectively. (C) 2014 Elsevier B.V. All rights reserved.