How is pure ozone obtained from ozonised oxygen?

Explanation

Ozone is prepared by passing silent electrical discharge through stream of dioxygen.
`3O_(2)to 2O_(3.) DeltaH^(@)=+42` kJ/mole.
It consists of glass cylinders, each surrounding a cylinder of aluminium fitted in a metal box. These are connected with an insulator at the bottom of the metal box. Cold water keeps pouring into the box which after cooling goes out. Ionized oxygen is cooled with liquid air when ozone condenses as a deep blue liquid while oxygen remains as a gas at this temperature. Pure ozone is obtained by the fractional distillation of deep blue liquid obtained. Pure ozone can be recovered by passing ionized oxygen through silica gel which absorbs ozone, leaving behind oxygen gas. The absorbed ozone can be recovered by passing N or Ar through the silica gel.