Many studies have been made on the possibility of increasing the efficiency of the photocatalytic detoxification of water streams, since for several practical applications the need for increasing the yield of the process is important. In the present work, the integration of photocatalysis with a membrane separation process is studied in order to analyze the possibility of enhancing the efficiency. It is experimentally shown that for the integrated process, the rate of disappearance of a model pollutant (4-chlorophenol) is highly improved. Then it is demonstrated that this "process intensification" takes place through synergetic mechanisms that are identified, discussed, and optimized.