Sustainable biowaste-derived carbon aerogel/MXene composite for mercury removal from water

Abstract

Mercury is a major global health concern; it is widespread across all environmental media and it affects all forms of life. There is strong interest in materials that can effectively remove Hg from water. This study investigates a novel and sustainable approach for mercury removal that consist of macroporous aerogel composite derived from rice husk lignin and modified with MXene. The composite developed high specific surface area (320 m²/g) and remarkable potential for Hg²⁺ removal. Notably, 20 wt.% MXene modification increased the maximum adsorption capacity of the bare sorbent (lignin aerogel) from (82.4 mg Hg²⁺/g) to 135.8 mg Hg²⁺/g, which surpasses commercial adsorbents. The composite effectively removed Hg²⁺ even from tap water spiked with high metal concentrations (10 mg/L). These findings highlight the significance of lignin-MXene aerogels for real-world application in water purification and environmental remediation.