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

Heavy metal purification of water is a worldwide issue. In this work, we first find that the discarded Artemia 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 Artemia shell for several cycles. All the results demonstrate that the unique structure and amino acid skeletons make discarded Artemia shells a new application for trace lead removal at low cost.