Pollen-based liquid marble to porous ceramic beads for purification

Abstract

Porous ceramic materials prized for their superior properties are often utilised in environmental remediation. With impending clean water scarcity, wastewater treatment technologies were emphasised to alleviate the severe repercussions of harmful pollutants. The emergence of wastewater threats leads to the study of innovative fabrication of adsorbents to combat this issue. This study investigates the efficacy of pollen-induced porous ceramic beads (PCBs) for wastewater remediation using three different pollutants — nickel ions (Ni), dye, and microplastics (MPs). The aim is to evaluate the multifunctionality and selectivity of pollen-structured pores in PCBs. This study incorporates both sacrificial templates and liquid marble (LM) processes to fabricate PCBs with five different pollen species (lycopodium, sunflower, camellia, pine, and olive) as porogens and lycopodium powder as hydrophobic separating particles. PCBs were characterised to understand the controlled formation of pollen-structured pores and pollen-induced porosity. Bench tests were conducted to explore the ideal adsorption parameters and selectivity of pollutants with varying pollen-structured pores. Lycopodium PCBs exhibit a high affinity for organic pollutants (dye and MPs), whereas camellia and pine PCBs showcase a high affinity for heavy metal pollutants (Ni), demonstrating the possibility of targeted removal using varying pollen species-induced pores. In summary, this study inspires the usage of sustainable and abundant natural materials as porogens to develop controlled porosity and unique pore morphologies for adsorption technologies. Further investigation could incorporate a more efficient fabrication process, enhanced characterization techniques to understand the specific mechanisms of pore morphologies in adsorption, and a simulated real-world application test to illustrate PCBs' efficacy in industrial applications.