Behavior characteristics of phosphorus and capping effect of microbubble flotation to control phosphorus release in the benthic sediment. Issue 2 (13th May 2022)

• Record Type: Journal Article
• Authors: Choi, Yong-Ho; Jeong, Yong-Hoon; Jang, Min-Ho; Kwak, Dong-Heui
• Is Part Of: Water quality research journal. Volume 57:Issue 2(2022)
• Page Start: 91
• Page End: 106
• Publication Date: 2022-05-13
• Subjects: bubble -- capping -- eutrophication -- lake -- phosphorus release -- sediment; Water quality -- Research; Water quality management -- Research; Periodicals; 363.61072
• DOI: 10.2166/wqrj.2022.027
• Languages: English
• ISSNs: 2709-8044

Abstract

Abstract: Microbubbles were applied to remove phosphorus (P) and improve environmental water conditions on the surface of the benthic sediment in a eutrophic lake. Microbubble flotation (MF) was used to remove P in a laboratory-scale experiment device from the benthic sediment and overlying water field samples. The results of P tracing observation for MF treatment, which were identified based on the mass balance, showed P accumulated at a higher concentration in the floated scum than in the deposited sludge. Furthermore, while the amount of soluble P separated was insignificant, the removal efficiency of soluble P in the floated scum was higher than total P. As an additional effect, P release was suppressed by the injection of microbubbles, which reduced anaerobicization and improved environmental conditions in the overlying water of the lake. We also confirmed that the sludge that settled after flotation separation caused capping, which restrained P release by forming a layer on the surface of the sediment. The direct P flotation separation, provision of oxygen by injected microbubbles, and capping effect of re-deposited sludge are advantages associated with MF, and our results show that field application studies are warranted. HIGHLIGHTS: MF can be applied to reduce P in the benthic sediment and overlying water of a lake. Soluble P was removed more easily than T-P. MF accumulated P at a higher concentration in the floated scum than in the deposited sludge. MF reduced anaerobicization and improved environmental conditions in the overlying water. While MF is not efficient at T-P removal, the process does effectively separate soluble P. Graphical Abstract