Abstract: Phenol is removed from waste waters that occur in the manufacture of phenol by the cumene process wherein cumene is used as an extractant. The cumene which is used for extracting the phenol from the waste water and which is thereafter washed with sodium hydroxide to remove the phenol is treated prior to this washing with an aqueous solution of 1 to 20 wt-% preferably 5 to 10 wt-% sodium carbonate. If desired the aqueous solution can also contain sodium sulphate in amounts of 1 to 15% by weight. The sodium carbonate solution may also contain a non-ionogenic, surface-active substance such as aryl polyglycol ethers in amounts of from 0.001 to 1% by weight.