Optimization of Flotation Efficiency of Micro Bubbles Using Low-Energy Best Available Technique

Global warming caused by urbanization, industrialization, and population growth is leading to climate change and threatening our sustainable lives. As a response to this climate crisis, a best available technique(BAT) that minimizes the emission of existing pollutants and is also economical is required. The purpose of this study is to develop a lowenergy micro bubble generator to reduce energy consumption in water treatment facilities and to evaluate its performance in comparison with dissolved air flotation(DAF) and coagulation-flocculation processes. The low-energy micro bubble generator consists of an air injector, a chamber, and a nozzle. The experimental results showed that the low-energy micro bubble generator generated micro bubbles of similar size to DAF at an air injection rate of 5 ml/min. In addition, the flocculant concentration experiments showed that the low-energy micro bubble generator had 1.3-2.5 times higher turbidity removal efficiency than DAF and coagulation-flocculation processes even with flocculant injection of 8 mg/L or less. These results suggest that the low-energy micro bubble generator is effective in removing suspended solids from water and is an optimal solution for reducing carbon emissions. This study is expected to contribute to the increased utilization of this technology in industrial sites.