MOF@Cell: 3D printed biobased filters anchored with a green metal-organic framework for effluent treatment

Multifunctional, biobased materials processed by means of additive manufacturing technology can be highly applicable within the water treatment industry. This work summarizes a scalable and sustainable method of anchoring a green metal-organic framework (MOF) SU-101 onto the surface of 3D printed, biobased matrices built of polylactic acid (PLA)-based composites reinforced with TEMPO-oxidized cellulose nanofibers (TCNFs). The two tested anchoring methods were hydrolysis via either concentrated hydrochloric acid treatment or via a photooxidation reaction using UV-ozone treatment. Stable deposition of SU-101 distributed homogenously over the filter surface was achieved and confirmed by FT-IR, XPS and SEM measurements. The obtained 3D printed and functionalized MOF@PLA and MOF@TCNF/PLA (aka MOF@Cell) filters exhibit high efficiency in removing heavy metal ions from mine effluent and methylene blue from contaminated water, as demonstrated through batch adsorption experiments. In addition to their potential for removal of contaminants from water, the MOF@Cell filters also exhibit excellent mechanical properties with a Young's modulus value of about 1200 MPa, demonstrating their potential for use in practical water treatment applications. The MOF@Cell filters were able to maintain their structural integrity and filtration performance even after multiple cycles of use and regeneration. This study highlights the potential of multifunctional, biobased materials processed by additive manufacturing technology as a cost-effective alternative to traditional water treatment methods. The MOF@Cell filters presented in this study demonstrate high efficiency, durability, and reusability, making them promising candidates for practical applications in the modern water treatment industry.