Highly Efficient and Rapid Lead(II) Scavenging by the Natural <i>Artemia</i> Cyst Shell with Unique Three-Dimensional Porous Structure and Strong Sorption Affinity

Abstract

Heavy metal purification of water is a worldwide issue. In this work, we first find that the discarded <i>Artemia</i> cyst shell exhibits a unique three-dimensional porous structure, which can be recycled for efficient toxic Pb­(II) removal. The hierarchical skeleton comprised of the macro–meso–micropore confirmation as well as 17 types of amino acid species provides fast ion accessibility and a strong sorption affinity. The results prove that an extremely rapid Pb capture is obtained in less than 2 min, strong adsorption occurs in the presence of high concentration of Ca/Mg/Na ions, and selectivity is far beyond that of the commercial 001x7 (greater than 50 times). More importantly, an efficient application is achieved with a treatment capacity of 9100 kg wastewater/kg sorbent, which is 45 times greater than the performance of commercially activated carbon and ion-exchange resin. The effluent can be dramatically reduced to below 10 μg/L level (WHO). In addition, we can also regenerate the exhausted biomaterial <i>Artemia</i> shell for several cycles. All the results demonstrate that the unique structure and amino acid skeletons make discarded <i>Artemia</i> shells a new application for trace lead removal at low cost