3D-Printed Filters for Efficient Heavy Metal Removal from Water Using PLA@CS/HAP Composites

Abstract

Chitosan/Hydroxyapatite composites, enriched with relatively active -NH2 and -OH groups, have emerged as promising adsorbents for heavy metal removal. In this study, we harnessed the potential of CS/HAP composites by developing monolithic PLA@CS/HAP filters utilizing 3D printing and freeze-drying techniques. These filters possess both macroscopic and microscopic porous structures, endowing them with exceptional capabilities for removing heavy metals from water. The adsorption properties of CS/HAP composites were explored by varying the dosage, duration, and initial concentrations of copper ions. The maximum adsorption capacity for Cu2+ was determined to be approximately 119+/−1 mg/g at the natural pH and 298 K. Notably, the monolithic PLA@CS/HAP filters demonstrated remarkable efficiency in the removal of copper ions, with 90% of copper ions effectively removed within a mere 2-h period in a cyclic adsorption experiment. Furthermore, the PLA@CS/HAP filters exhibited a robust dynamic Cu2+ removal capacity (80.8% or even better in less than 35 min) in a dynamic adsorption experiment. Importantly, all materials employed in this study were environmentally friendly. In summary, the PLA@CS/HAP filter offers advantages such as ease of preparation, eco-friendliness, versatility, and broad applicability in diverse wastewater treatment scenarios, thereby presenting a significant potential for practical implementation.

3D bioprinting in bioremediation: a comprehensive review of principles, applications, and future directions

“…A new work using a chitosan-hydroxyapatite coupled with PLA to create monolithic filters utilizing 3D printing demonstrated robust Cu 2+ removal performance with a maximum adsorption capacity of 119 mg/g, exhibiting the ability to remove more than 80% Cu 2+ from their sample in less than 35 min ( Wang et al, 2023b ). The graphical representation of how the authors fabricate the filter can be seen in Fig.…”

“…The graphical representation of how the authors fabricate the filter can be seen in Fig. 5 (Reused with permission from ( Wang et al, 2023b )). A previous work where a reusable monolithic 3D porous adsorbing filter was 3D printed using chitosan for heavy metal removal showed an adsorption capacity of 13.7 mg/g with adsorption kinetics of 2.2 mg/m per minute for Cu 2+ removal and this is further proof for the role of 3D bioprinting in the field of bioremediation ( Zhang et al, 2019 ).…”

Biopolymeric Nanocomposites for Wastewater Remediation: An Overview on Recent Progress and Challenges

“…The study revealed that the adsorption process aligned with Freundlich and pseudo-second-order models, suggesting a multi-layer adsorption with chemisorption characteristics for the CS/HAP composite adsorbent. Cu 2+ reusability experiments demonstrated the resilience of PLA@CS/HAP filters, maintaining consistent Cu 2+ removal capacity over five consecutive adsorption–desorption cycles, with a significant removal efficiency of 97.17% [ 184 ].…”