GDT Process


In the GDT™ Contacting Process, 1) ozone gas is created from air or pure oxygen with an ozone generator. 2) Ozone gas is then aspirated via the high efficiency Mazzei® Venturi Injectors providing dynamic mixing and mass transfer. 3) The Back Pressure Control Valve adjusts injector outlet pressure to optimize ozone mass transfer. 4) Dissolution is enhanced in a Flash Reactor™, which is sized for each application on the basis of feed gas concentration, operating pressure, reaction rates and desired transfer efficiency.

After leaving the Flash Reactor, the contacted two-phase flow then travels to the patented 5) Degas Separator (DS) for additional mixing and entrained gas removal to appropriate off gas processing. As the entrained gas/water mixture enters the Degas Separator, it is accelerated to a velocity that exerts 4-10 Gs in a lateral force creating a water film at the separator wall and a gas vortex at the central, gas extraction core. The Degas Relief Valve releases the captured entrained gases for processing or venting. 6) Then the Mass Transfer Multiplier™ (MTM) Mixing Nozzles force dissolved ozone to thoroughly mix with the untreated water in the pipeline or basin.

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No other system transfers ozone into solution faster than
Mazzei’s patented GDT Contacting Process.


  • Ozone Concentration – Concentration and solubility are directly proportional — higher ozone concentrations promote the transfer of more ozone into solution
  • Gas-to-Liquid Ratio – A lower gas-to-liquid ratio (Vg/Vl) allows for greater ozone mass transfer efficiency
  • Water Pressure – Higher pressure yields increased ozone solubility
  • Water Temperature – Higher temperature reduces solubility and increases the chemical reaction rate
  • Mixing – Intense, forceful mixing allows for the rapid renewal of the gas-liquid interface — increasing the mass transfer rate and the reaction rate


  • Raising the ozone concentration while lowering the gas-to-liquid ratio
  • Operating under the highest water pressure available
  • Including the most aggressive mixing components
  • Using an integrated system, with intelligent design – Mazzei System components work best together to optimize performance

GDT Ozone Contacting Skid

Steps in Designing an Ozone System:

1. Provide our application engineer with your water analysis: COD, BOD, coliform count, heterotropic plate count, metals, color, pH, temperature, suspended solids.

2. State your effluent goals (for example: desired coliform count < 300 mpn, or to reduce COD 75%).

3. Ozone dosage and ozone system costs are determined.

4. Custom ozone disinfection system design is finalized.

To aid in system design, use our Ozone Application Questionnaire
and then contact a Mazzei engineer to start the process