Particle Size Analysis of Dispersed Oil and Oil‐mineral Aggregates With an Automated Ultraviolet Epi‐fluorescence Microscopy System

Abstract

This paper describes recent advances in microscopic analysis for quantitative measurement of oil droplets. Integration of a microscope with bright-field and ultraviolet epi-fluorescence illumination (excitation wavelengths 340-380 nm; emission wavelengths 400-430 nm) fitted with a computer-controlled motorized stage, a high resolution digital camera, and new image-analysis software, enables automatic acquisition of multiple images and facilitates efficient counting and sizing of oil droplets. Laboratory experiments were conducted with this system to investigate the size distribution of chemically dispersed oil droplets and oil-mineral aggregates in baffled flasks that have been developed for testing chemical dispersant effectiveness. Image acquisition and data processing methods were developed to illustrate the size distribution of chemically dispersed oil droplets, as a function of energy dissipation rate in the baffled flasks, and the time-dependent change of the morphology and size distribution of oil-mineral aggregates. As a quantitative analytical tool, epifluorescence microscopy shows promise for application in research on oil spill response technologies, such as evaluating the effectiveness of chemical dispersant and characterizing the natural interaction between oil and mineral fines and other suspended particulate matters.

Evaluating Chemical Dispersant Efficacy in an Experimental Wave Tank: 2—Significant Factors Determining In Situ Oil Droplet Size Distribution

“…1998;Tkalich and Chan, 2002;Shaw, 2003). The effects of mixing energy on dispersed oil droplet size distributions, and consequently dispersant effectiveness, have been reported in laboratory tests (Byford et al, 1984;Lewis et al, 1985;Sorial et al, 2004;Chandrasekar et al, 2005;Ma et al, 2008) and in field trials under low-and high-energy regimes caused by various wind effects (Lunel, 1993(Lunel, , 1995. The droplet size distributions are also affected by the collision frequency, which has been considered a function of system hydrodynamics, and collision efficiency, which is generally believed to represent the chemistry involved in the coalescence reactions.…”

Formation, Fate, and Impacts of Microscopic and Macroscopic Oil‐Sediment Residues in Nearshore Marine Environments: A Critical Review

“…The mixing time, or the amount of time that the oil and sediment is subjected to turbulent conditions, also has an effect on OPA formation. Droplet stabilization in OPAs occurs relatively fast, typically taking less than 24 h, and often occurring within 1–3 h under laboratory conditions (Hill et al, ; Ma et al, ; Sun et al, ). Several studies have shown that the amount of oil dispersed as OPAs rapidly increases initially, but levels out over time (Payne et al, ; Sun et al, , ).…”

“…Since the basic components of microscopic and macroscopic oil‐sediment residues are the same (oil and sediment), it is reasonable to expect that the variables that affect the formation of microscopic aggregates would also affect macroscopic agglomerate formation, albeit not necessarily to the same extent. For example, there have been several studies on how mixing energy affects the rate and degree of OPA formation (Ma et al, ; Payne et al, ; Sun et al, , ); however, beyond the conceptual idea that breaking waves facilitate SOA and SOM formation, there is no consensus in the macroscopic community about how more turbulent nearshore environments might affect macroscopic agglomerate formation. Similarly, several studies have been carried out to understand how the likelihood of OPA formation differs for different types of oils (Gustitus et al, ; Guyomarch et al, ; Kepkay et al, ; Khelifa et al, ; Omotoso et al, ; Sørensen et al, ; Stoffyn‐Egli & Lee, ); however, the macroscopic community has not carried out any such controlled studies, although it could be assumed that oil qualities such as density, polarity, and viscosity would have a significant impact on macroscopic agglomerate formation.…”

Methodologies for Investigating Natural Medicines for the Treatment of Nonalcoholic Fatty Liver Disease (NAFLD)

“…McDonough and coworkers [173] developed HCA techniques to analyze LDs in 96well dishes ± rosiglitazone, a PPAR agonist that promotes adipogenesis. Comparable approaches were described by others [175][176][177]. Similarly, Whittaker and his colleagues [174] imaged LD size and number with an automated digital microscopy workstation to screen the potential of miRNAs to reduce TG accumulation in human Huh7 hepatocytes.…”