title: The use of wide-band transmittance imaging to size and classify suspended particulate matter in seawater.
abstract: An in situ particle imaging system for measurement of high concentrations of suspended particles ranging from 30μm to several mm in diameter, is presented. The system obtains quasi-silhouettes of particles suspended within an open-path sample volume of up to 5cm in length. Benchmarking against spherical standards and the LISST-100 show good agreement, providing confidence in measurements from the system when extending beyond the size, concentration and particle classification capabilities of the LISST-100. Particle-specific transmittance is used to classify particle type, independent of size and shape. This is applied to mixtures of oil droplets, gas bubbles and oil-coated gas bubbles, to provide independent measures of oil and gas size distributions, concentrations, and oil-gas ratios during simulated subsea releases. The system is also applied to in situ measurements of high concentrations of large mineral flocs surrounding a submarine mine tailings placement within a Norwegian Fjord.
authors.affiliation: Department of Environmental Technology, SINTEF Materials and Chemistry, Brattorkia 17c, Trondheim, Norway. Electronic address: emlyn.davies@sintef.no.
authors.forename: E J
authors.initials: EJ
authors.lastname: Davies
authors.affiliation: Department of Environmental Technology, SINTEF Materials and Chemistry, Brattorkia 17c, Trondheim, Norway.
authors.forename: P J
authors.initials: PJ
authors.lastname: Brandvik
authors.affiliation: Department of Environmental Technology, SINTEF Materials and Chemistry, Brattorkia 17c, Trondheim, Norway.
authors.forename: F
authors.initials: F
authors.lastname: Leirvik
authors.affiliation: Department of Environmental Technology, SINTEF Materials and Chemistry, Brattorkia 17c, Trondheim, Norway.
authors.forename: R
authors.initials: R
authors.lastname: Nepstad
mesh_terms: D004784:Environmental Monitoring; D008906:Mining; D009664:Norway; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D012623:Seawater / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D052638:Particulate Matter; D014873:Water Pollutants
keywords: Gas; Measurement; Mine tailings; Monitoring; Oil; Size distribution