The main goal of this Master Thesis is to develope and investigate a process for wastewater treatment that consist of proven process steps in a new combination that permits the reuse of the treated wastewater. The chosen treatment system combines the adsorption of pollutants on activated carbon with a two-step revers osmosis process in addition to conventional physico-chemical processes. The main differences compared to conventional revers osmosis exist in the recirculation of the concentrate flow. The increasing pollutant concentration in the feed benefits the adsorption. The fact that the permeat flow is the only export from the system indicates that the new process could theoretically lead to a „wastewaterfree physico-chemical treatment plant―. In the course of this Master Thesis, a small scale technical plant was installed and pilot tests with a larger equipment system have been carried out as well. The results of chemical analyses done for laboratory- and pilot-tests suggest that the generated permeate could be used in processes like car washing and conduit flushing. To guarantee a sufficient quality of the permeate, certain requirements have tob e met. Beside the description of the laboratory- and pilot tests, in this Thesis the existing conventional, small- and large scale physico-chemical treatment processes are described. The results are discussed and recommendations for industrial applications are made.