Innovative 3D-printed devices for water pollutant removal: Comprehensive review on printing parameters, composition, properties and performances of the latest 3D-systems

Water pollution is one of the most pressing problems of our time; in fact, it contributes to 24 % of global deaths. Therefore, finding an effective and efficient solution is crucially important. In this regard, systems based on polymers and containing, often, fillers, intended for potential water pollutant removal are well established. Recently, simultaneously with the impressive spread of 3D printing, the production of these systems by various additive manufacturing processes is gaining popularity, enabling the rapid production of complex geometries, high porosity, large surface area and mechanical strength. These systems, to date, are becoming particularly competitive with 2D or 1D systems produced by other methods, so understanding them fully is essential. Therefore, here we provide a review of the most recent advances in the field of manufacturing 3D systems for water remediation. First, a brief introduction is proposed on the cathegory of 3D printing, making a distinction between Material Extrusion (MEX) and non-Material Extrusion (non-MEX) systems, and the main performance parameters of water pollutant removal. Next, the process parameters, composition, and morphological and chemical-physical properties of the latest 3D systems are discussed in detail. In the last part, an overview is given of the functional properties of these systems, in terms of removal efficiency and reusability, which is crucial in an ideal life cycle of such systems. In conclusion, the main outcomes and future perspectives for the production of more efficient systems are provided.