Hierarchically porous poly(amidoxime)/bacterial cellulose composite aerogel for highly efficient scavenging of heavy metals

Developing cheap, green, efficient and renewable adsorbents to address the issue of heavy metal pollution is highly desired for satisfying the requirements of economy sustainability and water security. Herein, a composite aerogel composed of bacterial cellulose (BC) and poly(amidoxime) (PAO) has been fabricated via a facile and scalable self-assembly and in situ oximation transformation for heavy metals removal. Benefiting from the unique three-dimensional (3D) interconnected porous architecture and high density of amidoxime functional moieties, the developed PAO/BC composite aerogel is capable of efficiently sequestrating heavy metals with exceptional sorption capacities, e.g. 571.5 mg g −1 for Pb 2+ , 509.2 mg g −1 for Cu 2+ , 494 mg g −1 for Zn 2+ , 457.2 mg g −1 for Mn 2+ , and 382.3 mg g −1 for Cd 2+ , outperforming most reported nano-adsorbents. Meanwhile, the sorption equilibrium for the investigated five heavy metals is achieved within 25 min with high removal efficiencies. Significantly, the developed PAO/BC composite aerogels possess superior reusability performance. Furthermore, the PAO/BC aerogels-packed column can continuously and effectively treat the simulated wastewater with multiple heavy metals coexisting to below the threshold value in the drinking water recommended by World Health Organization (WHO), highlighting its feasibility in the complex environmental water.