3D-Printed MOF and Carbon Monoliths for Urban Water Resilience: Materials, Devices, and System-Level Challenges

Urban water systems face acute disruptions, including drinking-water advisories and wildfire-related contamination, alongside chronic pressures from climate variability, ageing infrastructure, and limited institutional capacity. Decentralized treatment components may complement centralized infrastructure at point-of-use, point-of-entry, building, and district scales. Within these systems, compact adsorbent and catalytic modules could provide targeted polishing or emergency-treatment functions; however, many candidate materials are still evaluated as powders in batch tests. Three-dimensional (3D) printing can instead shape them into recoverable monoliths with tunable, interconnected flow channels. This review evaluates 3D-printed metal–organic framework (MOF), porous carbon, and MOF-derived carbon monoliths for resilient urban water treatment. We assess material selection, fabrication, and performance across four linked scales: active material, engineered monolith, treatment device, and urban water system. The evidence shows that additive manufacturing can improve material recovery, control macroscopic flow, expose active phases, and enable regenerable modules. Nevertheless, most studies remain laboratory-scale demonstrations based on model contaminants, batch operation, simplified matrices, or short cycling. Long-term continuous-flow performance, pressure drop, active-material release, transformation products, potable-water safety, device-specific life-cycle impacts, and field economics remain poorly characterized. Progress requires geometry-controlled comparisons, realistic-water breakthrough tests, service-relevant regeneration, leachables assessment, and accountable maintenance and end-of-life strategies. Resilience therefore depends on integrating material chemistry, hydraulic design, treatment-train compatibility, environmental performance, and equitable service delivery.