# Practical Methodology for a Three-Dimensional-Printed Hybrid Desalination System
## 4 Discussion  
This study presents a practical methodology for the development of a hybrid desalination system based on 3D-printed RED and ED reactors. The primary objective was to demonstrate the feasibility of creating a functional desalination system in a laboratory setting using accessible technologies like additive manufacturing. This work aims to bridge the gap between concept and application, offering a detailed pathway for developing electrochemical flow reactors that can be tailored for various purposes, including desalination. The results demonstrate that the hybrid RED-ED system is functional, achieving a salt removal efficiency of 15% in one hour. While this efficiency may not be among the highest for desalination systems, it serves as a proof of concept, showing that the hybrid configuration is capable of effective operation, even at a basic level with single-unit cells. The modular design of the system also implies that its efficiency could be improved significantly by adding more unit cells, increasing the reactor size, employing profiled membranes, or reducing the distance between the membranes, all of which would enhance ion transport, reduce energy losses, and improve overall desalination performance. An analysis of variance (ANOVA) conducted on the experimental data, detailed in Appendix A, confirmed that the observed effects were statistically significant, with \(p\)-values below 0.05, indicating that the variations were not random. This statistical robustness supports the reliability of the reactor performance under different operational conditions. Additionally, Pearson correlations showed linear relationships between key variables. In the context of desalination technology development, this approach offers an alternative methodology by leveraging 3D printing for rapid prototyping and design iteration. Unlike conventional fabrication techniques, which can be costly and time-consuming, 3D printing allows for quick adjustments and the exploration of multiple design configurations. This adaptability not only accelerates the prototyping process but also reduces costs associated with manufacturing. Furthermore, by enabling rapid design iteration, the methodology makes it possible to optimize system configurations more efficiently, contributing to the advancement of hybrid desalination technologies. Future research directions could involve exploring the long-term operational stability of the system, particularly comparing batch and continuous modes for the RED reactor. The short-term experiments showed that batch mode resulted in better desalination performance, but for extended durations, maintaining a consistent salinity gradient through continuous operation might prove more effective. Additionally, investigating the use of alternative, more cost-effective printing materials and optimizing membrane materials could further improve the economic viability of the system. This study highlights the potential of 3D printing for developing hybrid RED-ED desalination systems. The flexibility offered by this technology, combined with rapid prototyping capabilities, enables researchers to iterate quickly and adapt the design to specific research needs, advancing the development of hybrid systems and opening avenues for further research on scaling and optimization. Z.D.I.C.-B. : conceptualization, experimental activities, formal analysis, writing--original draft preparation. E.S.-S.: experimental activities, methodology, writing--original draft preparation. J.I.H.-H.: data curation, visualization. M.M.-H.: writing--review and editing, project administration. E.M.: writing--review and editing, project administration. All authors have read and agreed to the published version of the manuscript. This research was funded by the PAPIIT-DGAPA-UNAM project, grant number IN112724 and by the Instituto de Ingenieria, UNAM, Grupos Interdisciplinarios de Investigacion (GII), Project: \"Sostenibilidad del Caribe mexicano: Cambiando debilitades en fortalezas\".