Pros and Cons of Ultraviolet Water Purification

A full water pitcher and glass sitting on a gray counter in a well-lit kitchen.

Ultraviolet water purification uses electromagnetic radiation to decontaminate the water to be treated. It is only one of the methods used for water purification. Others include chemical, physical, and biological processes. Various chemicals, bacteria, and other materials are often present in untreated water.

Whether the water is intended for consumption or some other application that requires treatment, water purification is necessary to reduce the amount of contaminants occurring in it. The use of ultraviolet light to purify water has many advantages over chemical methods like chlorination. There is a downside to the process as well which often requires secondary treatment after the fact.

Ultraviolet Water Purification

Essentially, ultraviolet light is produced by means of a germicidal or mercury vapor lamp made with glass that allows the optimal shortwave ultraviolet light a fully transparent surface through which to pass. The shortwave radiation then comes into contact with the parasite, bacteria, fungi, or other microorganism and eliminates it.

Advantages of UV Water Purification

Ultraviolet water purification possesses advantages over a more widespread treatment like chlorination. These mostly have to do with the toxicity levels of chlorine. Chlorine requires attention during the purification process while UV purification does not.

UV does not contribute to poor-tasting water like chlorine, nor is it chemically active. Chlorine may actually react with other ingredients present and form compounds of a toxic nature. Ultraviolet radiation does not use heat or chemical additives of any kind during the purification process. The simple fact that it comes into contact with the microorganism is enough to inactivate it and render it harmless.

Disadvantages of UV Water Purification

There are two main disadvantages to ultraviolet water purification. The first is that the water being treated must be in no way turbid or cloudy. Any level of color present in the water will hinder the ability of the UV radiation to penetrate it and destroy the microorganisms within. This requires water filtration prior to the purification which adds expense to the procedure. Otherwise, much of the UV light is absorbed and becomes largely ineffective.

The second main disadvantage is that ultraviolet purification offers no residual treatment. Unlike chlorine, which maintains a presence in the water after the treatment continuing to disinfect the water, ultraviolet radiation does not stay in the water. Any microorganisms that the radiation missed would remain in the water whereas chlorination would destroy them. For this reason, a chlorine compound such as chloramine is sometimes added to water purified by ultraviolet radiation after the fact.

Ultraviolet light is an effective means of disinfecting water for consumption, but an additional chemical process is sometimes necessary to ensure that all residual microorganisms are destroyed. By inactivating bacteria and other harmful particles found in untreated water, UV radiation leaves no chemical side effects. To be effective, however, it must enter clear water so as not to be absorbed. Since ultraviolet water purification does not remain in the treated water, a chemical such as a chlorine compound is added to the treated water after the fact. Although this does negate some of the advantages of ultraviolet water purification, it still manages to avoid the potential side effects of chlorination.

Having clean water is important. Now you can decide if ultraviolet purification is the right choice for you and your family.