This study developed and quantitatively evaluated a Hybrid Venturi Mixer (HVM) adopting the Bernoulli principle to improve oxygen transfer efficiency in the aeration process of wastewater treatment facilities, while reducing energy consumption and CO₂ emissions. In biological wastewater treatment, the aeration process is included and typically accounts for 50-90% of the total energy consumption of the process. The HVM simultaneously performs mixing and aeration, and is designed to induce self-suction of ambient air without an external blower by utilizing the pressure difference inside the impeller during rotation. Experiments were conducted in a reactor with a volume of approximately 1.0 m³ using tap water and mixed liquor volatile suspended solids (MLVSS) concentrations of 3,000 and 6,000 mg/L, in comparison with a conventional air diffuser. Air suction of the HVM, which was initiated at a mixing speed of 75 rpm, maintained a maximum airflow rate of 14 L/min at speeds above 145 rpm. Under all tested conditions, the oxygen transfer coefficient (K_La) and oxygen dissolution rate (N) of the HVM were approximately three times higher than those of the air diffuser, while energy efficiency (E) was enhanced by up to twofold. Based on the emission factor (EF), CO₂ emissions were reduced by 50-58% depending on the operating conditions. Overall, the experimental results demonstrated that the HVM not only facilitated aeration but also enhanced oxygen dissolution through vortex formation inside the impeller. These findings indicate that the HVM is a promising alternative to conventional aeration devices, offering superior energy efficiency and oxygen transfer performance to contribute to carbon-neutral water treatment. Furthermore, the HVM exhibits potential for broader applications, including coagulation- sedimentation and microbial cultivation process.