1500g/hr Ozone Generator for Aquaculture Disinfection in RAS
– Bali, Indonesia
Pacific Water Technology recently supplied a packaged ozone generator capable of producing 1500g /hr for treating the wastewater in a recirculating aquaculture system. The ozone treatment is based on sidestream injection and then mixing with the untreated water in the main sump. A complete package was supplied including an ozone generator, water cooling unit, ozone dissolving units, contact tanks and ozone destruct unit. The ozone generator is water cooled to ensure optimum performance in the hot tropical climate.

The scope of supply included a Corona Discharge 1500 g/hr ozone generator with integral water cooling. The ozone generator is fitted with a Siemens PLC with self-diagnostic and PID control capabilities. PID control is based on ORP measurement downstream of the contact vessels. The two contact tanks served two purposes:

• Allow sufficient contact time to react with the organics and disinfect the saline water.
• Degassing of any residual oxygen and ozone via a gas vent.

The oxygen flow required is less than 200 lpm and was supplied by existing oxygen generating utilities. This was one of the permissives for the system to operate under normal conditions. Once the set-point ORP values have been set, the operation is fully automated maintaining the required ozone levels. To use the ORP measurement to measure ozone in the water a correlation must be made.  ORP is an mV signal while ozone is a PPM signal.  If the only oxidant added to the water is ozone, a safe assumption can be made that any changes to ORP (mV) are changes in ozone in water. The ozone level in the water can be measured with a manual ozone test kit or meter. This ppm level can be correlated to the mV reading to provide an accurate ozone reading with ORP.