Japan Geoscience Union Meeting 2016

Presentation information

International Session (Poster)

Symbol A (Atmospheric and Hydrospheric Sciences) » A-GE Geological & Soil Environment

[A-GE05] Subsurface Mass Transport and Environmental Assessment

Mon. May 23, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Shoichiro Hamamoto(Department of Biological and Environmental Engineering, The University of Tokyo), Yasushi Mori(Graduate School of Environmental and Life Science, Okayama University), Hirotaka Saito(Department of Ecoregion Science, Tokyo University of Agriculture and Technology), Ken Kawamoto(Graduate School of Science and Engineering, Saitama University), Ming Zhang(Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology)

5:15 PM - 6:30 PM

[AGE05-P09] Effects of Water Flux and Bubble Characteristics on Nano-Bubbles Transport in Porous Media

*Akihide Ejiri1, Shoichiro Hamamoto1, Hiromi Imoto1, Taku Nishimura1 (1.Department of Biological and Environmental engineering, University of Tokyo)

Keywords:nano-bubbles, transport, porous media

Potential applications of nano-bubbles (NBs) have drawn more attention, especially in environmental engineering fields such as soil/groundwater remediation. Understanding a transport mechanism of NBs in soils is essential to effectively pursue remediation techniques using NBs. In this study, one-dimensional column transport experiments using glass beads were conducted, where NBs water created by either air or oxygen were injected to the column with different water fluxes. The turbidity, pH, EC, DO, and bubble size distribution in the effluent were measured. Effects of water fluxes and bubble characteristics such as (gas species, bubble concentration, and bubble size distribution) on the NBs transport were investigated based on the column experiments. The results showed that relative turbidities (measured turbidity in the effluents / turbidity in the initial NBs water) during the NBs water injection were lower at lower water flux condition. Higher relative turbidities in the effluents were observed for O2-NBs at the same water flux condition that those for Air-NBs, suggesting higher mobility of O2-NBs in porous media. Column experiment with NBs with lower average bubble size and higher bubble concentration showed more gradual increase of relative turbidity in the effluents with time.