Efficient Pb(II) removal in batch and continuous flow adsorption systems based on chitosan-functionalized melamine foam monolithic material

Monolithic adsorbents have become promising materials for removing contaminants in wastewater. By combining the macrostructural advantage of monolithic materials with their excellent surface function, these materials offer significant potential for practical applications. This study proposes an efficient and economical preparation method for developing high-performance chitosan-based monolithic adsorbent for Pb 2+ removal. In brief, melamine foam (MF) was pre-modified with polydopamine (PDA), and chitosan (CS) was uniformly loaded onto the modified foam via a “crosslinking-surface deposition” process. The resulting monolithic adsorbent (CS/PDA@MF) exhibited a high adsorption capacity for Pb 2+ (174 mg g −1 ) and achieved equilibrium adsorption time (<120 min) in batch adsorption experiments. The material demonstrated excellent elastic properties, allowing for easy manual collection using tweezers. Six cycles of adsorption/desorption experiments proved satisfying reusability. Additionally, a fixed-bed column was prepared using CS/PDA@MF to investigate the continuous flow adsorption behavior, showing excellent potential for practical applications. The adsorption mechanism was explored by ATR FT-IR and XPS characterization. This study provides a technical foundation for research into high-performance CS-based monolithic adsorbents, which are expected to be promising candidates for environmental remediation.