The invention relates to a device and method for removal of impurities from, and recirculation of, cleaning agent in a printing machine. Contaminated cleaning agent is purified by passing it through a series of sedimentation devices. In these sedimentation devices, gravity is used to separate the cleaning agent into its constituent parts. Once the impurities have been removed from the cleaning agent, the constituent parts that can be reused are recirculated to the washing devices of the printing machine while the impurities are disposed appropriately.