Water And Oceanography

Best Treatments for Making Natural Water Drinkable



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Many governments have standards in place for potable (drinking) water. These standards will set the minimum and maximum limits of contaminants. Many governments require a certain amount of disinfectants such as chlorine to be in the water after it is treated. The reason for this is so the water cannot become recontaminated while flowing through to its end user.

It should be noted that one cannot tell just by looking at water if it is safe to drink. Procedures such as boiling and the use of a charcoal filter on your home water are not sufficient for treating all the possible contaminants that could be in your water. The only way to find out what type of treatment necessary for your water is laboratory testing.

Our water can come from several different sources. Water can come from lakes, wells, and rivers. Each of these would require a lot of the same processes for making it drinkable but there would be some differences as well.

Treatment starts in the pretreatment stage. In this stage you will make sure your pumping and storage facility is made from materials that avoid adding contaminants to the water. Stainless steel is preferred but PVC (polyvinylchloride) pipe is often used in this process.

If surface water is the water of choice to be treated the first thing that must be done is to screen the water to remove large pieces of debris such as sticks, trash and leaves. Most groundwater doesn't need screening after it is pumped. Although there is usually a screen on the bottom of the pump.

The next step is pre-conditioning. This is where water is tested and if it is hard meaning it contains alot of salts it is treated with sodium carbonate. Often times the next step is to treat the water with some chlorine while it is being stored. This is to try to keep the growth of bacteria down inside the storage tanks and lines.

The next step in the process is to adjust the ph of the water. Ideally distilled water will have a ph of around 7. This means it is not acidic or alkaline. Usually, if the water is acidic, lime will be added to make it more alkaline. This helps with the clarification process and also helps to keep the water from dissolving the lead in pipes and fittings.

Next comes clarification. This is the process of removing color or turbidity from the water and making it clear. This is done by raising the ph of water above 7 and adding an iron compound then filtering this through a filter usually containing anthracite. Anthracite can remove most of the odor, taste and organic matter in the water.

Next comes the filtration where any remaining sediment is removed from the water. The most common type of filter is the sand filter. The water is moved vertically through the sand which normally has a layer of activated carbon on top of it. This layer of carbon removes taste and odor. To keep the filter in working order, it is occasionally back flushed. This is a process where the water flow is reversed through the filter and allowed to push the contaminants back to the other side of the filtration medium where it can be drained off the filter housing.

The last step in purifying drinking water is disinfection. This is a critical process as water does contain or possibly can contain many bacteria and viruses. Usually water is disinfected using chlorine. The main reason chlorine is used id because most governments require that a certain concentration of the disinfectant remain in the water until it is used. Another way to disinfect water is by using ozone. Ozone is a very strong disinfectant that is widely used in Europe and in the manufacture of bottled water. The main drawback is that it does dissipate and does not stay in the water. It should also be noted that although some bromine should be in water, ozonation does produce a small amount of bromate.

If water is low in flouride, flouride is added to help prevent tooth decay. In some areas the amount of flouride in water may be to high and has to be removed. The process of flouridation or flouride removal usually occurs right after disinfection.

Water may also be treated by a process called reverse-osmosis. This is where a pressure is exerted on an impure solution to push it through an semi-permeable membrane. In theory this is the best method of water purification. One must keep all membranes maintained very well because it is possible for algae and other forms of pathogens to begin to grow in the membranes.

Other ways to treat water are boiling, and distillation. Boiling water can not remove all solutions in it. It will only help to remove those with a boiling point less than that of water. Water must not be boiled and then kept on hand for any period of time. Pathogens will begin to regrow in the water.

Distillation is a process where water is heated and turned into steam. The steam then comes in contact with a cooler surface and returns to a liquid state. This process can not completely clean water but one can get 99.9% pure water from distillation.

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