Ozone in Water Treatment Application & Engineering

Because ozone can be easily generated from air, ozone disinfection has been an important water treatment method for over 100 years. Environmentally friendly, portable ozone generators are now available for remote locations, while permanent ozone disinfection tanks serve industrial or municipal wastewater treatment needs. Wastewater treatment system engineering and application influence effectiveness of ozone disinfection.

Components

• Ozone wastewater treatment systems expose an oxygen source, usually dry air or oxygen concentrators, to the ozone (electrical field) generator in a contained area. Exposing oxygen to the electrical field produces ozone atoms. Wastewater in a treatment tank is mixed with ozone, with time and amount of exposure adjusted via a control panel. Finally, a diffusion system treates water and ozone that has not degraded back to oxygen.

Applications

• Ozone can be used to disinfect drinking water, remove odors, and treat industrial and municipal wastewater. Exposure to ozone kills a variety of microbes, including Cryptosporidium, polio and Hepatitis A viruses, and E. coli, salmonella and cholera bacteria.

Advantages

• Ozone wastewater treatment systems handle various volumes and may be large and stationary or portable. Ozone, which is composed of three bonded oxygen atoms, returns quickly to breathable oxygen molecules. Unlike chlorine or other chemical treatments, wastewater treated with ozone then released into the environment will not harm natural bodies of water.

Disadvantages

• Ozone is corrosive, so wastewater must be treated in stainless steel tanks. Wastewater treatment system engineers must not inhale ozone, since it may cause respiratory trouble if breathed in high concentrations. Ozone treatment requires electricity, which may not be available or cost effective.

Effectiveness

• Humidity, air and water temperature, chemical components of the water, ozone concentration, susceptibility of and contact time with microbes effect how well ozone disinfects wastewater. Ozone "overdose" may damage desirable nutrients in water being treated, which will negatively impact plant growth if disinfected wastewater will be reused for hydroponic applications.

  Failing to use enough ozone or allow enough contact with contaminants will result in wastewater that is not disinfected and could have adverse effects on environmental or human health. Proper treatment significantly reduces the amount of solid wastes and bacteria in wastewater.