| Title |
Evaluation of Initial Collision-Attachment Coefficient and Flotation Characteristics Using Population Balance in Microbubble Flotation Process for Microplastics Separation |
| Authors |
정흥조 ( Heung Joe Jung ) ; 이재욱 ( Jae Wook Lee ) ; 곽동희 ( Dong Heui Kwak ) |
| DOI |
https://doi.org/10.15681/KSWE.2021.37.1.10 |
| Keywords |
Bubble; Flotation; Microplastics; Particle; Population balance |
| Abstract |
In the flotation process to remove microplastic (MP) particles, the attachment and separation efficiency is determined by the basic physicochemical characteristics of MP particles as well as bubbles. To evaluate the flotation characteristics of MP particles, we carried out a series of simulations using the population balance (PB) model. The initial attachment coefficient (αo) of MP particles was in the range of 0.2-0.275, and it was slightly lower than that of typical particles, such as clay, debris and algae particles, which exist in water bodies, αo, 0.3-0.4. The relative bubble number (RBN) attached to the surface of the typical number of bubbles was 0.30 and 0.32 for MP 30 μm and MP 58 μ m, respectively. In comparison, the RBN of larger MP particles (138 μm) was as high as 0.53. Furthermore, smaller microbubbles were required to separate properly or additional treatment needed to be applied to enhance collision and attachment efficiency since the flotation of MP particles was found to be difficult to treat as high-rate. As a result of comparing the removal rate (experimental value) of MP particles obtained from the batch-type flotation apparatus and the flotation removal rate (predicted value) of MP obtained through the PB model, the final particles by the particle size of MP overall except for the initial separation time area. With respect to the removal efficiency, the observed and predicted values were similar, and it was confirmed that the floating separation characteristics and evaluation of the MP particles through the PB model could be possible. |