Electrical capacitance tomography was used to follow the behavior of long and brief solitary liquid-rich waves in a trickle-bed reactor. A quantitative description of wave propagation and attenuation was attempted using a simplified two-phase Eulerian computational fluid dynamics modeling by tracking long and brief pulses as encountered in slow- and fast-mode cyclic operation strategies. The results assert the efficacy of slow mode operation since the wave attempts to preserve its identity while propagating in the bed. On the contrary, the decay time period in case of fast mode cyclic operation is prolonged and continues to attenuate down the reactor length. The predictive computational model applied in this work, in spite of many simplifications, conforms arguably well with the experimental observations.