The Free On-line Aquaculture Dictionary

Ozone Destruction methods

Method Design Criteria Advantages / Disadvantages

Cross sectional area of degasser: 

2 x (0.0001 x lpm) / 3.14))-2

Height 1.5m

The air suction rate through the degasser should be at least 20% of the water flow rate.
Off gas requires to be either vented away from staffed areas or should be treated. 

Can result in high pumping costs.

Can be used as an integral part of trickle filter or carbon dioxide degasser if used within a system.

Will increase oxygen concentrations to approx 85 - 95% saturated 

Chemical dosing Dosing with sodium thiosulphate at 2mg/l to reduce each 1 mg/l ozone. This is very dependant however on oxygen content of water as the thiosulphate will also be used up reducing this. Costly to install and operate correctly.

May result in removal of some oxygen from water

Unknown effects of excessive thiosulphate on fish stocks

Activated carbon 1g of carbon will remove 6g ozone, however allowance must be made for the carbon being used up with other chemicals that it will remove. Attention to water quality is therefore important. Expensive systems not really suited to aquaculture

Costly replacement of carbon

High operating costs through pumping through carbon beds.

Ultra violet light 150,000 mW cm2 for 13 seconds to reduce 0.5 - 1.5 mg/l  O3 to safe levels Very dependant on constant water clarity / quality for effectiveness.

Expensive to install but relatively cheapo to run thereafter.

Added benefits of disinfection of the water.