Seawater Desalination

965 Words2 Pages

620 Policy Paper
4/28/2013

Seawater Desalination

Drought is no stranger to the state of California especially is the southern part of the state. California has been a technological creation since the first American settlers starting migrating from the east. It naturally has a semi-arid climate. It was inevitable that prolonged severe drought would occur in such a climatic region from time to time. California has depended on redirecting natural waterways and investing an incredible amount of money into pumping water to Southern California. This is not only a California debacle but a global one as well. According to the World health Organization, 1 billion people do not have access to clean, piped water. A world Resources Institute analysis adds that 2.3 billion people, 41% of Earth’s population, live in water-stressed areas, a number expected to climb to 3.5 billion by 2025. To make matters worse, global population is rising by 80 million a year, and with it the demand for new sources of fresh water (7 pg. 1). Water affects everyone and everything including the economies of both developing and industrialized nations. “The current situation has heightened the need for reliable sources of water, especially in these type of times when there is rationing across the state, “said Paul Shoenberger, assistant general manager with the West Basin Municipal Water District in Carson and chair of a desalination subcommittee for the Association of California Water Agencies. “ Desalination is more available and isn’t linked to rain or snow pack.” The only methods to increase water supply beyond what is available from the hydrological cycle are desalination and water reuse (8).
Ocean-water desalination is the process of removing salt, other ...

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... of films on liquids” (12). What things are larger than 1 Angstrom? A few are bacteria, viruses, organic matters and small planktonic organisms but we will get into this later (1). When the membranes separate two water types, water molecules pass from the less concentrated zone into the more concentrated zone in order to balance ionic forces. To reverse the natural flow of water through the membrane, pressure greater than osmotic pressure has to be applied on the concentrated solution. Providing pressures from 70 to 84 bars, 40 to 60% of seawater or brackish water is converted into fresh water by reverse osmosis. The influent saline solution is divided into two phases. Permeate is the first which is the fresh water free of particulates and dissolved impurities and the second is the concentrate stream which is brine enriched with suspended and dissolved solids (1).

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