Common water disinfection technologies
Every technique has its specific advantages and its own application area.
- Ozonation – Dissolving a low concentration of ozone into the water, providing rapid and efficient water disinfection.
- Ultraviolet (UV) – Irradiating the water with UV-beams.
- Chlorination – Dosing chlorine compounds to the water resulting in a residual disinfecting chemical concentration.
Ozone advantage in water disinfection
Disinfection of water using ozone is advantageous compared to more traditional methods, such as chlorine or UV disinfection. As an oxidising agent it is 51% stronger than chlorine and has a kill rate of 3.125 times faster. Ozone owes its biocidal effectiveness to its ability to oxidise organic material in bacterial membranes, which weakens the cell wall and leads to cell rupture causing immediate death of the cell.
Ozone is also produced on site and does not require shipping or handling, thus removing complications like safety and environmental issues associated with chemical handling.
Here is a short list of the most important advantages of ozone water disinfection:
- Ozone dissolved in water will not irritate skin, nose, or ears, nor will it dry out or leave a chemical film on skin.
- Ozone leaves no unpleasant chemical taste or smell.
- You cannot over-dose with ozone as unused ozone escapes out of the water and reverts to oxygen
- Unlike chlorine, ozone leaves no harmful chlorinated by-products in the water, ozone quickly reverts back to pure oxygen if unused.
- Chemical water treatment leaves long-term chemical effects on the environment, some of which are negative. Ozone does not.
The formation of oxygen into ozone occurs with the use of energy. This process is carried out by an electric discharge field. In general, an ozonation system includes passing dry, clean air through a high voltage electric discharge. The raw water is passed through a venturi throat which creates a vacuum and pulls the ozone gas into the water or the air is then bubbled up through the water being treated. Since the ozone will react with metals to create insoluble metal oxides, post filtration is required
Is Ozone water safe?
Yes, oxidation is a natural process and eliminates the need for chemicals. Ozone water treatment has been used around the world for many years, with major beverage companies relying heavily on the technology. Ozone has a unique property of auto-decomposition and will leave no toxic residues. Never the less ozonation by-products are still being evaluated and it is possible that some by-products may be carcinogenic.
According to the U.S. Council Of Environmental Quality, “Cancer risk among people drinking chlorinated water is 93% higher than among those whose water does not contain chlorine.”
Ozone seams like the perfect alternative to the chlorination of water but there are higher equipment and operational costs and it may be more difficult to find professional proficient in ozone treatment and system maintenance.
Small scale ozone generators have developed a lot in the last decade making it much more economic and energy effective to produce ozone in small scale. So we might see more and more applications and real use of this technology in the future.
If you are curious and want to know what you can do to make a chlorine free consumption of your tap water possible check out the Osmo from Osmosys.