Selective Removal of Boron from Aqueous Solutions Using ECH@NGM Aerogels with Excellent Hydrophilic and Mechanical Properties: Performance and Response Surface Methodology Analysis.

Abstract

The remediation of environmental boron contamination has received extensive research attention. The adsorbent ECH@NGM aerogel with high hydrophilic and mechanical properties was synthesized to remove boron. The ECH@NGM aerogel had a high adsorption capacity of 81.11 mg/g, which was 14.50% higher than that of commercial boron-selective resin Amberlite IRA743. The Freundlich model and pseudo-second-order model described the adsorption behavior well. In addition, the response surface methodology (RSM) could predict the experimental outcomes and optimize the reaction conditions, and X-ray photoelectron spectroscopy (XPS) and control tests were utilized to investigate probable adsorption mechanisms. These data showed that the B ← N coordination bond was the primary adsorption force. The adsorbent had good resistance to interference from coexisting salts, high reusability, good adsorption performance even after five reuse cycles, and a high desorption rate in a relatively short time. The adsorption performance in real brines could be maintained at 80%. Therefore, this work not only provided ECH@NGM aerogels for the removal of boron from brine but also elucidated the main adsorption processes between N-containing adsorbents and boron, facilitating the design of future adsorbents for boron removal.