Alternative Technologies for Inland Desalination

Abstract

Water scarcity is one of the biggest issues we have to face as population and water consumption levels increase despite a fixed supply of renewable fresh water. Meeting the challenges that water scarcity poses to food production, ecosystem health, and political and social stability will require new approaches to using and managing water. Desalination already plays an essential role in water management. It constitutes a secure source of safe drinking water supply once demand management measures are fully implemented. Overcoming problems related to brine minimization and disposal is key to sustainable, efficient inland water desalination. The main focus of this was the investigation of technical limits and improvements for application in inland desalination. The first part of the dissertation covers the study of Membrane Distillation (MD) for desalination of water. The second part provides a broad perspective of Reverse Osmosis (RO), pretreatments -comparison of slow sand filtration and microfiltration-, post-mortem study of membranes to determining fouling and scaling causes, and RO brine minimization via Vibratory Shear Enhance Processing (VSEP®) for use in RO brine minimization. The study of Vacuum Membrane Distillation in a hollow fiber membrane was studied. Experimental work is supported by an original mathematical model to expose the physics of VMD and support predictions that extend VMD results beyond these generated in the laboratory. The advantages and disadvantages of each pretreatment, including their effects the effect on the performance of RO, a post-mortem membrane study and an economic analysis. The post-mortem study of membranes used during Yuma Desalting Plant operation. This work was used to identify the best pretreatment and more suitable membrane to treat saline water in the lower Colorado River. The work performed during the brine minimization study using VSEP®. This study included experimental data and an extensive economic analysis comparing Ion Exchange (IX) as pretreatment and VSEP® as post-treatment for RO.