Application of 3D-Printed Membranes in Wastewater Treatment: A Review of Specific Waste Streams and Membrane Performance

Membranes produced by 3D printing represent a groundbreaking technology for industrial and municipal wastewater treatment, enabling the fabrication of complex, customized architectures tailored to specific environmental challenges. Compared to conventional membranes fabricated via phase-inversion, 3D printing alternatives offer superior pore control and active catalytic functionality despite the higher initial costs. This review demonstrates how material selection and 3D printing methodologies establish improved structural and geometrical characteristics in the resulting membranes. Furthermore, it discusses the suitability of various membrane fabrication approaches relative to the specific demands of each application. Specifically, material selection—spanning polymers, ceramics, biopolymers, and nanocomposites—is discussed in light of printability requirements dictated by ink rheology, resolution, and post-processing across both light- and extrusion-based methods. Practical applications consider factors such as surface hydrophilicity tuning, pollutant affinity, structural durability, and the mitigation of microplastic release. In addition, leveraging biomimetic and minimal surface geometries can optimize hydrodynamics, reduce module size, and generate local fluid shear to suppress biofouling. A summary of reported case studies highlights the strong potential of 3D-printed membranes in applications such as membrane bioreactors, oil–water emulsion separations, organic dye degradation, and the removal of persistent micropollutants like PFAS. Finally, emerging trends—including 4D stimuli-responsive materials, AI-driven fluid dynamics, and upcycled green inks—are expected to guide 3D-printed membrane technology toward commercial scalability, particularly for decentralized water treatment solutions.