This dissertation proposes a novel bubble-based aeration system known as 'Confined Tube Aeration (CTA)', which uses a Venturi injector as the bubble generation device and connects to a coiled pipe network after the Venturi outlet as a mixing chamber where the air-water mass transfer occurs. In this work, to analyze the effectiveness of this proposed system, several experiments are conducted, and numerical (Discrete Bubble Model) analyses are also performed to optimize the system performance. A lab-scale simple CTA system is built using a single pump, one 1-inch Venturi, and a coiled pipe network, and experiments are conducted to analyze its performance. Results from the numerical model also conform well with experimental results. Two sizes of Venturi injectors, 1-inch and 4-inch, are investigated numerically to identify their performances in a CTA system. Suction air flow, bubble size, volume fractions, and injector efficiency are also analyzed. The 4-inch injector is found to perform better in terms of oxygen transfer rate and per unit of power requirement for that specific oxygen transfer rate at standard conditions. CTA system with multiple injectors arranged in parallel connections is also studied. Experimental data show that the 2-injector system performs better than the 1-injector and 3-injector systems. When pump speed is slowed down using a VFD, the performance of the 1-injector system is greatly improved. It is also observed that, at a larger-sized CTA tube, the mass transfer efficacy is improved, and SAE also improves as the pump's hydraulic energy input remains constant. An additional benefit of this proposed technology is its simplistic design which may incur reduced installation and maintenance costs compared to the existing porous bubble diffuser and mechanical aerator system. This proposed technology can be easily retrofitted to the existing aeration system without requiring large-scale modifications of the treatment plant's aeration techniques. Additionally, the flexibility of this system to build outside of the aeration tank can be considered for retrofitting in existing treatment plants. Aquaculture can specifically benefit from this technology as it does not require a deep aeration pond for the bubbles to transfer oxygen to the water.