[P004] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P02-266] Synergistic Pb(II) Removal via Adsorption and Biomineralization Using Metal-Phenolic Network-Coated Biocomposite

○Ilham Maulidin¹, Kazunori Nakashima², Chikara Takano², Satoru Kawasaki² (1. Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University (Japan), 2. Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University (Japan))

Keywords:

Metal–phenolic network (MPN),Microbially induced carbonate precipitation (MICP),Biomineralization,Lead (Pb) removal,Surface functionalization

Lead (Pb) contamination in aqueous environments remains a critical environmental challenge, requiring robust and sustainable remediation strategies. Among existing approaches, microbially induced carbonate precipitation (MICP) has emerged as a promising strategy; however, its performance is often limited by slow nucleation kinetics and insufficient surface functionality for effective metal capture. Therefore, a strategy that combines controlled biomineralization with enhanced surface reactivity is required. Here, a novel hierarchical biocomposite was introduced by integrating a biologically active component with a functionalized interface that promotes both metal binding and mineral nucleation. The material was fabricated via a two-step process. First, urease-producing Sporosarcina sp. e-4 cells, responsible for driving carbonate generation in MICP, were encapsulated within alginate beads to form an active ureolytic core. Subsequently, the bead surface was functionalized through the coordination assembly of tannic acid and Fe(III), forming a metal-phenolic network (MPN) shell. This well-defined core-shell structure provides both a confined microenvironment for biomineralization and abundant phenolic functional groups for Pb(II) adsorption, thereby enabling the integration of adsorption and biomineralization into a single synergistic system. Batch experiments demonstrated rapid Pb(II) removal, reaching equilibrium within 2 hours. The MPN-functionalized biocomposite exhibited substantial removal even in the absence of urea, highlighting the contribution of surface chelation by polyphenolic functional groups. In the presence of urea, removal performance was significantly enhanced, indicating that carbonate-driven biomineralization is the dominant mechanism. The MPN coating plays a dual role by providing active sites for Pb(II) adsorption while simultaneously serving as an interfacial platform for mineral nucleation, thereby promoting localized formation of lead carbonate. This synergistic mechanism was supported by microscopic analysis, which revealed the formation of dense crystalline deposits on the coated bead surface, along with clear localization of Pb, confirming effective immobilization. Further characterization indicated that the coating maintained bacterial viability under moderate conditions and formed a stable, dense layer on the bead surface. The biocomposite also exhibited good reusability with minimal loss of performance over repeated cycles, demonstrating its structural stability and practical potential for water treatment applications. In conclusion, this study highlights that polyphenol-enabled interfacial biomineralization within MPN-functionalized ureolytic biocomposites provides a rapid and sustainable approach, offering an easily recoverable platform for heavy metal remediation and advancing the state-of-the-art in bio-based water treatment technologies.