The presented nanocomposites were tested for their influence on the sedimentation rate of olive oil mill and winery wastewaters. Sedimentation velocities were measured by means of a LUMiSizer instrument. The instrument records the near-infrared light transmission during centrifugation over the total length of a cell containing the suspension. It automatically determines the time dependence position of the interface panicle-free fluid/suspension or sediment by a special algorithm. The transmission profile enables characterizing the smallest deviations in size of dispersed particles and quantifying the degree of polydispersity at high-volume concentrations. Stability prediction at an accelerated rate for different dispersions at their original concentrations has been proven in previous studies [9]. The harmonic mean sedimentation velocity in the first 60 seconds of the process was chosen as a useful parameter to compare between treatments. High sedimentation velocities were measured when fast precipitation was observed. The reason to focus on the first 60 s is because in the efficient treatments, complete clarification was observed after that period of time. Such experiments allow evaluating the efficiency of the wastewater treatment by a very fast and accurate procedure as compared with the conventional “jar test” [29]. Experiments were performed three times.