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The Best Ways to Purify Water in Large Quantities

How precisely you need to purify water depends on what you intend to use it for. Most commonly, however, raw water needs to be purified for drinking, which means removing particulate matter, heavy metals, and biological contaminates like bacteria and viruses. You can scale many purification methods up or down for various amounts of water.

  1. Mechanical Filtration

    • Mechanical methods of filtration physically sift out the bacteria and other contaminates from water. The best mechanical filtration method is reverse osmosis, but this filter produces large amounts of waste water. Other mechanical filters use porous sheets to sift out particulate matter and bacteria. Another method is to use a deep layer of sand. Water passes through and larger contaminates are caught in the sand. This does not remove biological contamination.

    Activated Carbon

    • To boost sand filters and to help remove heavy metals as well as biological contaminates, you can add activated carbon or charcoal to the mechanical filter. For example, in a sand filter, a layer of activated carbon below the sand helps yield the benefits of both materials. Granular activated carbon (GAC) is a common component in filtration systems for the purification of household water.

    Chlorine

    • The addition of certain chemicals kill biological agents in the water, but do not remove heavy metals and toxins. One familiar chemical additive is chlorine. You can use chlorine bleach to purify contaminated water in both small and larger quantities. Add 1/2 tsp. of bleach to 5 gallons of raw water to make it safe to drink. You can scale this measurement up to larger quantities of water. One gallon of chlorine bleach treats around 3,800 gallons of raw water.

    Iodine

    • Iodine is another chemical that sanitizes water. However, this method should not be used if you are pregnant, have an allergy to iodine, or a thyroid condition. There are iodine tablets used by hikers and campers, but another method is to use an iodine tincture. Tinctures are available at most grocery stores as 2% iodine with alcohol and water. Five drops of iodine sanitizes one liter of water in about 15 minutes. Scaling up, 1 tsp. iodine tincture treats around 90 liters of water.

    Ultraviolet Light

    • Ultraviolet light kills living things in the water, including viruses. Since it does not remove particulate matter, it is a good idea to use mechanical filtration first. There are ultraviolet filters available for use in home aquariums. A water pump moves water through the filter, which uses a bright ultraviolet light inside a tube to kill organisms. The rate of water through the filter depends on the brand of filter you're using and is listed in the manufacturer's directions.

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