The primary difference between the types of water mentioned above is in the amount of total dissolved solids TDS they contain. In a reverse-osmosis system, the greater the TDS concentration of the water, the higher the pressure needed for the pumps to push water through the membranes, and consequently, the higher the energy costs. Desalinating seawater is, therefore, usually more costly than desalinating brackish water see Question 4 , below.
Development of seawater desalination along the Texas Gulf Coast will help relieve stress on existing conventional surface water and groundwater supply sources in coastal areas which in turn could make these resources available to water users located away from the coast. In this context, seawater desalination can indirectly benefit people living hundreds of miles away from the coastline. These studies concluded that all three proposed projects were technically feasible and outlined the financial requirements necessary to implement the projects.
In , TWDB considered these conclusions and recommended that the state continue advancing toward implementation of a large-scale demonstration seawater desalination facility in Texas. The month study began in fall and is expected to be completed in late Desalinated water cost is a function of capital costs, debt service, and operating costs.
The time required for full implementation of a desalination plant varies from project to project. Obviously, it depends on the size and complexity of the plant, and whether it has to be built from scratch or can use existing water intake structures. Texas does not yet have a seawater desalination plant, but using an example of a large brackish groundwater desalination plant the El Paso-Fort Bliss plant that is presently under construction it may take at least 5 years. Planning for the Desalinating seawater involves some processes that could impact marine life.
However, those impacts can be avoided or minimized by implementing environmental safeguards at every phase of the project from planning its location to operating it in a manner that results in acceptable water quality and brine loading at the discharge. For example, intake of seawater can entrain marine life, but screens placed at intake locations at power plants and industrial facilities have successfully demonstrated that this type of impact can be significantly reduced.
If required by the National Environmental Policy Act NEPA , an Environmental Impact Statement for such a desalination project will need to consider and evaluate all potential impacts to the environment, and identify the best management practices to eliminate or reduce adverse impacts. It needs to be safely disposed off. Concentrate management can become one of the most important factors in determining the feasibility of a plant.
Concentrate produced during seawater desalination can be disposed through deep well injection on land or returned to the ocean in a controlled process to avoid detrimental effect to the environment or marine life. For concentrates produced in inland facilities, a few other options exist. These include disposal to surface water bodies, evaporation ponds, or to wastewater treatment plants.
In some instances, the concentrate can also be utilized beneficially for industrial processes. Desalinated seawater could be piped directly to non-coastal customers using existing or new pipelines. Potentially, once desalinated seawater becomes available in the coastal areas, there would be a ripple effect benefit for the environment and water users located away from the coast. The state financial assistance programs, federal appropriations, and private participation may be used for funding desalination projects.
A full-scale plant was not built as result of these two studies. There are about brackish groundwater desalination plants in the United States. Almost half of them 45 percent are in Florida, 14 percent in California, and 9 percent in Texas Mickley and others, and Nicot and others, Classes of brines include chloride brines calcium and sodium , bromides, and formates.
See: aquifer , completion fluid , producing formation. A general term that refers to various salts and salt mixtures dissolved in an aqueous solution. Brine can be used more strictly, however, to refer to solutions of sodium chloride. We prefer to use brine as a general term. The emulsified calcium chloride [CaCl 2 ] solution or any other saline phase in an oil mud is referred to as "brine" or "brine phase.
Clear brines are salt solutions that have few or no suspended solids. Synonyms: clear brine. A water-based solution of inorganic salts used as a well-control fluid during the completion and workover phases of well operations. Brines are solids free, containing no particles that might plug or damage a producing formation. In addition, the salts in brine can inhibit undesirable formation reactions such as clay swelling.
Brines are typically formulated and prepared for specific conditions, with a range of salts available to achieve densities ranging from 8. Common salts used in the preparation of simple brine systems include sodium chloride, calcium chloride , and potassium chloride. More complex brine systems may contain zinc, bromide, or iodine salts.
These brines are generally corrosive and costly.
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