부상분리 공정의 접촉영역 모델을 이용한 이산화탄소와 공기 기포의 충돌 및 입자 분리효율 비교 평가

In recent years, carbon dioxide (CO 2 ) bubbles emerged as the most widely applied material with the recycling of sequestrated storage to decrease global warming. Flotation using CO 2 as an alternative to air could be effective in overcoming the high power consumption in the dissolved air flotation (DAF) process. The comparison of DAF and DCF system indicated that, the carbon dioxide flotation (DCF) system with pressurized CO 2 only requires 1.5 ~ 2.0 atm, while the DAF system requires 3.0 ~ 6.0 atm. In a bid to understand the characteristics of particle separation, the single collector collision (SCC) model was used and a series of simulations were conducted to compare the differences of collision and flotation between CO 2 bubbles and air bubbles. In addition, laboratory experiments were sequentially done to verify the simulation results of the SCC model. Based on the simulation results, surfactant injection, which is known to decrease bubble size, cloud improved the collision efficiency of CO 2 bubbles similar to that of air bubbles. Furthermore, the results of the flotation experiments showed similar results with the simulation of the SCC model under anionic surfactant injection. The findings led us to conclude that CO 2 bubbles can be an alternative to air bubbles and a promising material as a collector to separate particles in the water and wastewater.