An aerator has a housing which contains a fluid inlet nozzle and a fluid discharge nozzle positioned on either side of an air inlet formed in a T-pipe. The gas cleaning unit further comprises a wet scrubber in which the effluent gas is brought into contact with an absorption liquid containing water for removing further pollutants from the effluent gas. The writing implement exhibits improved handling without major structural modification, so that the writing implement can be brought into the writing position and also extended in a single hand movement.