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This work presents fabrication of eco-friendly, 3D printable, antimicrobial composites that capture toxic heavy metal ions from contaminated water bodies. Chitosan, a biopolymer having heavy metal chelating sites was incorporated into polylactic acid (PLA), a 3D printable, biodegradable thermoplastic matrix. Using the heat-press method, a series of composites was prepared by altering the wt% of chitosan. Using moderately polluted water, the composites were subjected to Pb 2+ , Cu 2+ , and Cd 2+ adsorption at ambient temperature and neutral pH. The 30 and 60 wt% chitosan (C) loaded composites (30 C/PLA and 60 C/PLA) reduced Pb 2+ below the environmental protection agency (EPA) recommended action level (AL) before 5 min. The 60 C/PLA reduced Cu 2+ below EPA-AL within 30 min. All the composites adsorbed the metal ions significantly higher than neat PLA, the control. Reusability studies for Pb 2+ removal with the 30 C/PLA indicated that ca 96% of the original Pb 2+ adsorption efficiency could be achieved even after the fifth regeneration cycle. Moreover, 30 C/PLA and 60 C/PLA indicated inhibition zones for Escheichia coli , a bacterium that could live in water. No inhibition zone was detected with the control. In addition, the 10, 20, and 30 C/PLA were successfully 3D printed into cup-like shapes. Ultimate compressive strength, toughness, and Young’s modulus of the 3D printed 30 C/PLA cups were significantly higher than that of the control. An object with complex geometry was also successfully 3D printed using the 30 C/PLA composite. As per the overall results, this is the first work to report a 3D printable eco-friendly antimicrobial material (30 C/PLA) that reduces toxic Pb 2+ below EPA-AL before 5 min while retaining ca 96% of the original Pb 2+ adsorption efficiency even after the fifth cycle. The approach lays a foundation for future development of cost-effective, eco-friendly water filtration devices with free-standing complex geometries via 3D printing.
Wijenayake et al. (Sat,) studied this question.