Abstract:
In the first section of this work we hope to add to the science of brine management in desalination. We have undertaken a feasibility analysis of a method of brine processing where the ions in solution are transported by an axial magnetic field in a long pipe, and an off-center cross-section of the flow is extracted with a lower ion concentration than that near the edges of the pipe. We constructed an apparatus that examines this process and allows us to measure the change in voltage in a solution during treatment. The goal of this process is to separate brine effluent from the desalination system into two components; one close to ocean water which can be safely injected back into the ocean or reprocessed into potable water using standard desalination techniques. The second component will have an ion concentration higher than typical waste brine, and can be more economically treated using a conventional process such as an evaporation pond or solar drying. This research addresses an emerging problem, the Achilles' heel of large-scale desalination. Specifically, systems for municipal-sized water demands can produce desalinated water in quantities exceeding a million liters per day. A basic mass balance shows that all the freshwater that is extracted from seawater will leave a nearly equal quantity of high-salt brine. Ejected brine from commercial-scale desalination facilities has been shown to cause distress and damage to marine organisms and possibly even saline gradient inversions, which lead to unpredictable solar heating of littoral ocean waters. In the second section of this work we add to the general knowledge of the science of solar desalination. We have used common and straightforward measurement techniques, physical analyses and quantitative analyses to optimize efficient methods of personal-scale solar desalination. In this research we have used simple modifications to stills of our own design that increase efficiency and output of distilled water. We also examine a theoretical efficiency model that may be useful in determining the efficiency of solar stills and offer potential predictor of solar still output efficiency.
