Guidry.LaBranche2

Useful and Reliable Methods of Creating Fresh Water


 * __Desalination__**

Water, Aqua, H2O, liquid hydration: we all need it, no matter how you think of it. Even early human settlements were dependent on the proximity to water sources. Water is vital for all living things on earth. The average human being is not deemed to survive past 4 days with no water. The average percent of water in a human body is between 50% and 60%. Carbon, is the most essential building block in humans. Water, however, is comprised of oxygen and hydrogen atoms, which are by far the most abundant elements in the human body, and it keeps our bodies functioning properly, along with other factors like enough sleep, proper food and proper care for our bodies. Without water, life wouldn't exist.

__**The Problem This World Faces Today**__ Over 50 years ago it became apparent to scientists, as well as the rest of society soon therereafter, that earth's fresh water sources are becoming scarce fast, and the issue is not getting any better. Water is used for a variety of different purposes, including industry, food, and stored chemicals. But perhaps the leading water consumption rate can hold agriculture responsible, using 70% of all freshwater. Another huge attributing factor is by personal pleasures or personal hygene like showering, brushing teeth, washing hands, flushing the toilette, watering the lawn, or filling up the pool. Every 20 years the world's water consumption rate doubles with increasing population and demand. The lack of fresh water is causing living standards to go down drastically, as well as reducing economical development. Approximately 71% of earth's surface is covered by water, with the majority being salt water. A whopping 97% of that surface water is contained in the oceans, 2.4% is in glaciers, leaving the biological bodies of usable water at a mere 0.6%. Nonetheless, salt is not the only portion being removed by desalination, another bother is minerals and elements, like Boron, which is believed to cause infertility in women.

__**A Solution**__

Desalination is a process which extracts salt, elements, minerals and other impurities from unclean water to create usable, drinkable water. There are different ways to complete this process, and depending on the contents of the water that is to be removed and purified, different methods are more effective. For example, multi-stage flash distillation is to remove the salt from sea water by heating the water, and extracting the salt, while distilling the water. This multi-stage flash distillation comprises and produces over 85% of the desalinated water in the world today, even though there are several more reverse osmosis plants. Reverse osmosis is a process which is designed to purify water by takes out minerals and harmful or unpleasant elements.


 * __How These Methods Work__**

The water eventually reaches a superheated stage, at maximum temperature, called the brine heater, to boil and evaporate the water, and then sends it back through the stages entering lower temperatures and pressures in a sequentially decreasing order. The counteraction from the hot feed water and cold sea water creates relatively little heat released from the outflow. Not only is this process convenient for making fresh water, but it is also energy efficient, reusing its recycled energy created in the stages.
 * The main method of desalination is called **multi-stage flash distillation**. This method distills sea water by using evaporation to extract the water and leave the salt behind. The unhygienic water goes through a system of separated areas, called stages, essentially leading to the purification of water. The water proceeds through different stages with varying elevated temperatures and pressures, using heat exchangers at different stages to heat the feedwater that is being pumped through the system.

This is a Reverse Osmosis Desalination Plant in Ashkelon that opened in
 * **Reverse osmosis desalination** is the process of removing unwanted ions, chemicals, or minerals by pumping the salt water under pressure through [[image:http://www.h2oindustries.com.au/Images/desalination.jpg width="361" height="279" align="left"]]filtration membranes, leaving only fresh water at the separate side. The filtration membrane is selective, which means it only allows certain molecules to pass through it, like H2O, a smaller molecule, while its pores [[image:http://www.treehugger.com/desalination-chart-01.jpg width="443" height="437" align="right"]]are designed to block and keep out larger molecules. Commonly, reverse osmosis is used to purify sea water, taking out the salt as well as removing other unwated substances from the water molecules. The process entails of a diffusion mechanism and is dependent on three main aspects: water flux rate, the concentration of solute, and pressure. Higher pressure is exerted on the highly concentrated side, about 600-1000 psi, while only 30-250 psi is on the fresh water side. This reverses the natural osmotic pressure of around 350 psi, and forces the osmotic process to work backwards.


 * __Renovating the Desalination Plant__**

Water Desalination was a huge innovation toward the end of the 20th century, even though Aristotle conjured an idea similar to todays technologies. Although desalination plants have not yet been perfected, they can and will be improved. Like the engineer from the Water Corporation of Western Australia states, "Until recently, seawater desalination was a very expensive water source solution," prices have been receeding slightly, and the government should focus on getting the information and techniques we need. Water is running out fast, and we need to help as much as we can. Maybe theoretical, but there are a few visions I see for a desalination plant in the future. I envision a plant that is capable of converting sea water to freshwater through a suctioned pipe. The plant would be right on the shoreline, and maybe even inground, using similar methods from today, but running the system automatically. When the water enters the pipe, it passes through a series of chambers and filters. When the water is all ready, it can be transferred to a modern day aqueduct sort of thing, like the ancient Romans used.

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__**Cloud Seeding**__

__**History**__

In July of 1946, a man named Vincent Schaefer unearthed the principle of cloud seeding. Along with nobel prize recipient Irving Langmuir, unvealed a way to experiment with supercooled clouds using a deep freeze unit, with a handful of potential agents that would help stimulate ice crystal growth. After making several attempts to produce supercooled clouds in a research lab at General Electric with his deep freezer, he figured he needed to decrease the temperature even more. He added a chunk of dry ice to get the job done, and that's when he saw the tiny ice crystals formed around the entire chill chamber. He was overwhelmed by the scientific breathrough, and immediately shared his news with his research employer, Mr. Langmuir. Together, with Langmuir's silver iodide innovation in cloud seeding, as well as a select few, they received a patten and went on their way to modify and improve their findings. Dry ice and silver iodide are the two substances they applied to cloud seeding.

media type="youtube" key="Sn5g4Gt_EJw?fs=1" height="385" width="640" Cloud seeding is similar to the process known as **hygroscopic cloud seeding**, which consists of a substance that is able to draw in and cling to water molecules. Even to chemists, this is sort of a chemical phenonmenon, with the molecules of one substance in one phase being completely overtaken by molecular material of another state. Often the hygroscopic seeding substance is salt. Hygroscopic material most commonly causes rain droplets in the clouds to form into larger droplets, summoning rain through coalescence. This method is only effective in warm cloud seeding, which only forms rain, not snow.
 * __Different Types of Cloud Seeding__**

Another method of cloud seeding is called **static cloud seeding**. This involves the dispersion of chemicals, such as silver iodide, in the clouds, providing crystals that moisture will form around and condense. The silver iodide is effective in forcing the clouds to be more efficient at dispensing the moisture that latched onto the silver iodide molecules. Dry ice and silver iodide can only be successful in cold cloud seeding, which will generally only form snow flakes.


 * Dynamic cloud seeding** is an approach which exercises approximately 11 stages leading to boosting vertical air currents. Copious amounts of ice crystals are formed this way, which in turn. converts to more rain. Although seeming to be an extremely successful method, dynamic cloud seeding is by far the most tedious operation. If any of the steps fail or malfunctions, the whole process is ended.


 * __Cloud Seeding Projects__**

Project Stormfury was an experiment conducted by the U.S. military in the 1960's, in attempt to modify hurricanes. Unfortunately, the evidence of any effect on the hurricane was unclear, perhaps for a short amount of time, but it never lasted. In the 1970's another project was initiated in Stillwater, Oklahoma. The project was to increase the warm cloud rainfall into the Lake Carl Blackwell, which was Stillwater's primary source of water, and was very low. Unluckily, again the results were insignificant. There have been many other attempts since then on this sight to help the lake. Cloud seeding is more successful today, with updated techniques, and it appears to be a sufficient basis to rely on for increased rainfall, reducing fog around airports, condensing the size of hail chunks, and it's even used in major ski-resorts to generate snowfall.


 * __Sponsored Today__**

Two world-recognized organiztions have supported and sponsored cloud seeding since the 60's. First, the United States Bureau of Reclamation sponsered Project Skywater from 1964 to 1988. In 1979 to 1993, the National Oceanic and Atmospheric Administration (NOAA) organized the Atmospheric Modification Program. Regrettably, in the last two decades, funding for the matter has decreased adequately. Although the tactics are used today, few studies have been conducted since then, and the United States National Academy of Sciences pushed for research to be performed in 2003, because there are still unanswered questions that need explanation. Many countries, including the United States, use Cloud seeding tactics today as a way to produce fresh water. Rainwater is the largest natural source of freshwater on the planet. Cloud seeding can help gather rain, and help contribute to keeping mankind on this earth a short while longer.


 * __Changes in Cloud Seeding__**

The techniques that are used for cloud seeding today seem to be effective and resourceful. In China, they are big on experimenting with the weather, they were said to have stopped any rain that may have been in the forecast for the 2008 Summer Olympics in Beijing. Zhang Qiang, the top weather-modification bureaucrat in Beijing states that, "reservoirs in Beijing have shown an increase of 10-13%, one directly attributable to the efforts of her rainmakers." This increase was judged on the time they began these weather experimients was goes as far back 1958. I wouldn't know how to change or improve the procedure, but maybe in the future it will change again. It doesn't seem likely to change drastically in the future because the whole cloud seeding process is pure chemistry. Chemistry is what it is, unless someone can alter the compounds, molecules and ions so much that hey become completely different and more convenient molecules that work just as good or better.