title: Transmission electron microscopic observations of nanobubbles and their capture of impurities in wastewater.
abstract: Unique properties of micro- and nanobubbles (MNBs), such as a high adsorption of impurities on their surface, are difficult to verify because MNBs are too small to observe directly. We thus used a transmission electron microscope (TEM) with the freeze-fractured replica method to observe oxygen (O2) MNBs in solutions. MNBs in pure water and in 1% NaCl solutions were spherical or oval. Their size distribution estimated from TEM images close to that of the original solution is measured by light-scattered methods. When we applied this technique to the observation of O2 MNBs formed in the wastewater of a sewage plant, we found the characteristic features of spherical MNBs that adsorbed surrounding impurity particles on their surface.PACS: 68.03.-g, 81.07.-b, 92.40.qc.
authors.affiliation: Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan. t-uchida@eng.hokudai.ac.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Uchida
authors.forename: Seiichi
authors.initials: S
authors.lastname: Oshita
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ohmori
authors.forename: Takuo
authors.initials: T
authors.lastname: Tsuno
authors.forename: Koichi
authors.initials: K
authors.lastname: Soejima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shinozaki
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Take
authors.forename: Koichi
authors.initials: K
authors.lastname: Mitsuda