Adv and Disadv of Iodine as Water Purifier

(i accidentally posted this on the water debate forum at first)

i am reseraching using Iodine as a swimming pool disinfectant. here is some great info on it. the most obvious advantage Iodine has over chlorine is that chlorine is toxic at any level, whereas Iodine is toxic only at large doses.

another advantage is the iodine will kill bacteria at a great ph range than chlorine. chlorine's bacteria killing powers wane at ph of 8 or above. iodine iwll still kill bacteria up to a ph of 10.

the major disadvantage is the iodine is not an algicide, whereas chlorine is. so you would have to fond another way to kill aglae if you use iodine instead of chlorine.




http://muextension.missouri.edu/xplor/envqual/wq0102.htm



Iodine

Iodine kills bacteria and disease-causing organisms, but is slow acting. Iodine is, however, ineffective as an algicide.

Iodine has been used to disinfect water since the early 1900s. In its natural state, iodine is a solid black crystal. Iodine crystals will dissolve in water, dependent on the water temperature. The higher the temperature, the more will dissolve. The simplest method of disinfecting water with iodine is by dissolving iodine in water to form a saturated solution and then injecting the iodine solution into a water system.

Iodine does not kill bacteria on contact; a holding time of at least 20 minutes is needed depending on the iodine concentration. An iodine residual of 0.5 to 1.0 milligrams per liter should be maintained, and iodine at this level gives the water little or no iodine taste or odor. Iodine can be removed from water with a carbon filter just before drinking.

Iodine dosage is very temperature dependent because iodine crystals are more soluble at higher temperatures. Iodine remains effective over a wide range of pH and does not lose effectiveness until the pH of water reaches 10. Iodine residuals in water can easily be measured using a test kit that indicates a color change.

Iodine tablets were developed during World War II to disinfect small amounts of water for emergency or temporary use. A few drops of tincture of iodine or iodine tablets are popular with campers and the military for disinfecting water.

Types of iodinators
Iodine solutions are injected into a water system using bypass saturator systems or injection pumps. A holding tank or coil of pipe is used after the iodine injection to provide the necessary holding time.

The most common type of iodinator is called a bypass saturator and consists of a solution tank containing iodine crystals. Bypass saturators do not require any electrical connections. The solution tank is connected to the water system and diverts a small amount of water through it and back into the water line. Valves are placed on either side of the iodinator to control the iodine dose. Fluctuation in water temperature affects the solubility of iodine. Adjustments in the bypass rate are needed if water temperature changes.

Chemical injection pumps can also be used to inject iodine solutions for individual water treatment. These are the same injection systems that are used for chlorine.

Iodinators are in-line systems that are sized to treat all the water used in a household.

Careful use of iodine

The question of possible health effects of iodine is still unanswered. No adverse health effects have been shown, yet continuous consumption of iodine-treated water is not recommended. Carbon filters can be used to remove iodine just before drinking. (Note: Iodine treatment is not currently approved under the Missouri Department of Health for private water supplies.) Iodine is also appropriate for occasional use in vacation homes, campgrounds and restaurants.

Iodine treatment of drinking water supplies for dairy cattle is also a concern. Because dairy cattle can drink from 15 to 30 gallons of water a day, normal levels of iodine used for disinfection may cause iodine carryover into milk.

"We've been using this water for years and we're OK"
Bacterial contamination of private water supplies is common, so why aren't more people sick?

The coliform bacteria identified in a water test do not cause disease. These bacteria are used to identify an unsanitary water supply and indicate the risk of exposure to water-borne disease.
Water-borne diseases may be mistaken for the flu or food poisoning.
Remember that coliform bacteria in your water supply is a warning of contamination. Only through routine water testing, proper water supply construction and protection, and any necessary water treatment can you ensure a safe water supply for your family and livestock.



Iodine

Not currently approved by the Missouri Department of Health for residential/private drinking water supplies.

Advantages

Does not require electricity.
Requires little maintenance.
Provides residual treatment.
Residual easy to measure.
Disadvantages

Health effects of iodine undetermined.
Concentration affected by water temperature.
Gives water a slight straw color at high levels.
Gives water an iodine taste.
Not effective as an algicide. Tweet