Boron recovery from seawater with a new low-cost adsorbent material

Abstract

A new adsorbent [chiFer(III)] for boron recovery from seawater was prepared using chitosan and iron(III) hydroxide. Experiments were carried out in a column system. Seawater samples were collected from the Mediterranean Sea off the coast of Vilanova i la Geltru, Spain (coordinates: 41.18; 1.75). Several adsorption-desorption cycles were performed to evaluate the efficiency of the adsorbent, and a desorption step was carried out using MilliQ-water of pH 12 (0.01M NaOH solution). The molar ratio between the mass of adsorbed boron in the five consecutive cycles and the mass of iron(III) hydroxide present in the adsorbent beads was 10.7mmolB·(molFe(OH)3)-1. The experimental results were evaluated using the Thomas, Yoon and Nelson, and Bohart-Adams models, which fitted the experimental data adequately. The adsorbent was characterized by SEM-EDX analyses and BET surface; porosity studies confirmed that the chiFer(III) composite is a mesoporous material.