BACKGROUND The modification of an organic matrix as a bio-template (grapefruit peel) using urea and melamine was carried out to introduce amino groups on its surface and favor Ag(I) adsorption in aqueous solution for metal recovery. RESULTS Adsorption capacity in batch mode was proportional to the nitrogen content within the adsorbents, the maximum being the one obtained with the adsorbent functionalized with urea, 72.33 mg g(-1), which was tested as a fixed bed in a column to evaluate the metal adsorption in a continuous flow model. The adsorption capacity of the fixed bed was 15.14 mg g(-1), and its use was proved over three adsorption-desorption cycles. CONCLUSION Amino-functionalized adsorbent achieved a high Ag+ uptake capacity; from the characterization it is proposed that the adsorption mechanism consists in the formation of the complex R-NH2Ag+ and R-COOAg. (c) 2018 Society of Chemical Industry