Amino-functionalized material from a bio-template for silver adsorption: process evaluation in batch and fixed bed: Amino bio-template for silver adsorption: process evaluation

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. © 2018 Society of Chemical Industry