The effect of a combination of impinging jets and hydrodynamic cavitation technology was investigated by a multiple impinging jets cavitation reactor (MIJCR). Zero-valent iron (ZVI) powder and rhodamine B were chosen as heterogeneous catalyst and model pollutant, respectively. ZVI addition resulted in more than five times higher decolorization efficiency compared to runs without ZVI. In situ generation of Fenton reagents suggested an advanced Fenton process to explain the enhancing effect of the applied catalyst. Impinging jets and aeration led to significant enhancement of the process, and optimum values of inter-nozzle distance and initial catalyst concentration favored the decolorization of rhodamine B.