The amount of waste, including liquid hazardous waste, is constantly increasing worldwide. In consideration of sustainability and resource conservation it is very important to reuse and recycle such type of wastes. A treatment is done, for example, by physico-chemical (CP) systems. By using these CP-plants, it should be possible to increase the quality of wastewater, so that it can be used as process water (e.g. for sewer cleaning). The need of further cleaning in external treatment plants for this specific kind of water quality should not be necessary anymore. In the present Master Thesis, the qualities of liquid hazardous wastes will be identified at various points of a physico-chemical treatment plant. The evaluation of the waste qualities allows a comparison of the waste composition before and after the treatment in the cleaning facility. The aim of this comparison is to determine whether the quality of the treated waste water is sufficient enough to use it for industrial purposes or whether it has to be further cleaned before its use or cleaned more intensively in previous steps.