Hydrodynamic cavitation is a promising application in wastewater treatment due to its simple reactor design and capacity in large‐scale operation. Theoretical studies including the basic mechanism of pollutant degradation, modeling of pressure distribution in the cavitation reactor, and bubble dynamics models coupled with chemical reactions are evaluated. Experimental setups with different cavitation reactors and operation parameters are compared for degrading specific kinds of pollutants. The effort directions for both theoretical and experimental investigations are suggested on the basis of the reviewed contents. Easy large‐scale operation, effective combination with intensified strategies, and capability to deal with biorefractory or toxic compounds contribute to the great potential of hydrodynamic cavitation.

An improved model to predict OH• yield in hydrodynamic cavitation for wastewater treatment is developed. Relaxing the chemical equilibrium assumption, the model can estimate the global average OH• yield during the whole oscillation cycle of all bubbles by considering radicals diffusion, cavitation event rate, and bubble radius distribution. Reliability of the model is verified by comparing with experimental data from literature in terms of geometric and operating parameters. The results show that the maximum OH• yield is achieved at optimal upstream pressure of 3.6 × 105 Pa, while increasing downstream pressure always enhances OH• yield. Decreasing the hole and pipe diameters benefits the OH• yield. Finally, a relevant correlation is developed for the design of cavitation reactors.

Antibiotics degradation remains a longstanding challenge in wastewater treatment. Towards this objective, we have developed a novel technique combining cavitating jets impingement with multiple synergetic methods, i.e., UV/Fenton, analogous Fenton, and photocatalytic oxidation in the present work. Three kinds of antibiotics namely amoxicillin, doxycycline and sulfadiazine sodium, are selected as model pollutants. Individual application of cavitating jets impingement is firstly conducted to evaluate the effects of jets impinging forms and nozzle inlet pressure. The effects of impingement on promoting antibiotics degradation and weakening the coalescing effects of cavitation bubbles are confirmed. Perpendicular double cavitating jets impingement is proved to be the most effective impinging form and brought a COD (chemical oxidation demand) reduction of 30.04% with the impinging effect index 1.22 at jet inlet pressure 10 MPa. Increasing the jet inlet pressure can improve the COD reduction and the effectiveness of impingement. Subsequently, UV/Fenton process is introduced to intensify the degradation process. The effects of important parameters are investigated by means of orthogonal experiments and the maximum COD reduction is up to 71.16% under the optimum conditions. Then, analogous Fenton process and photocatalytic oxidation are adopted for further enhancing the COD reduction. Different approaches used in the present work are assessed in view of multiple aspects. With COD reduction of 79.92%, the combination of cavitating jets impingement, UV/Fenton, analogous Fenton and photocatalytic oxidation is proved to be optimum method for antibiotic wastewater treatment.