Effective adsorption and removal of malachite green and Pb2+ from aqueous samples and fruit juices by pollen–inspired magnetic hydroxyapatite nanoparticles/hydrogel beads

To deal with the environmental pollution caused by dyes and heavy metals, it is vital to design and prepare adsorbents with efficient adsorption and removal capabilities for the regulated removal of contaminants in the environment. In this work, biomimetic apatite hydrogel beads inspired by the structure of petunia pollen were produced in order to efficiently remove lead ions (Pb2+) and malachite green (MG) by adsorption. Utilizing an ionic cross-linking approach, magnetic hydroxyapatite nanoparticles (MHNPs) were encapsulated in sodium alginate gels to make hydrogel beads (MHSB) with the structure of petunia pollen. The MG and Pb2+ adsorption capacities of MHNPs were 208.06 mg/g and 475.50 mg/g, respectively, demonstrating a satisfactory adsorption ability. In addition, the magnetic hydroxyapatite nanoparticles/hydrogel microspheres demonstrated effective MG and Pb2+ adsorption and removal in mixed adsorption studies, environmental water samples, and fruit juices, as well as in real application. Due to their sound adsorption capability and stability, magnetic MHNPs and MHSB are regarded as fairly promising composite materials for the adsorption and removal of dyes and heavy metal pollutants.