We fabricated a new sea urchin-like zirconium(iv) oxide which exhibits efficient phosphate sequestration with remarkable selectivity, a large capacity and recyclability .

Artemia nauplii are important bait or food sources in aquaculture, but the egg shells after incubation are always subjected to discarding as natural wastes; therefore, application and utilization of the Artemia egg-shell wastes will be an important issue. Herein, we reported a new hybrid biomaterial by encapsulating nano-Mg­(OH)2 onto discarded Artemia egg shells for phosphate sequestration enhancement. The unique hierarchically 3D-layered structure of Artemia egg shells can endow well-defined nano-Mg­(OH)2 morphology and efficient phosphate adsorption performances. The results of the final hybrid biomaterial exhibit a wide pH dependent sorption process, strong affinity toward phosphate removal, and large sorption capacity. Moreover, the exhausted adsorbent shell–Mg-P can be further utilized as slow-release fertilizer without regular chemical regeneration. The efficient slow-release behaviors of phosphorus onto Shell–Mg–P for 30 days indicated the potential applicability as fertilizers. Additionally, the actual seedling tests further confirm that the shell–Mg–P can be readily used as a slow-release fertilizer for the soil improvement and crop productivity.