Presentation
Assessing Dissolved and Particulate Oil in Water Accommodated Fractions and their Impacts on Oil Toxicity
SessionMeet the Poster Authors
DescriptionThe risk of oil spills to aquatic species is often determined by toxicity testing with varying concentrations of oil mixed with water known as water accommodated fractions (WAFs). However, differences in preparation methods can influence the concentrations of dissolved and particulate oil in the WAF, possibly leading to variable toxicity results. A study was conducted to assess three WAF preparation methods with varying proportions of dissolved and particulate oil (low energy/slow-stir or Slow-WAF, low energy with variable/spiked loading or Spiked-WAF, and high energy or HE-WAF) and evaluate their toxicity to a standard test species (Americamysis bahia). Filtered and unfiltered WAF samples were characterized for droplet size distribution, fluorescence, turbidity, extinction and traditional hydrocarbon concentration measures (alkanes, Polycyclic Aromatic Hydrocarbons, hopane and Total Petroleum Hydrocarbons).
Results showed that particulate oil is only present in HE-WAF with a median diameter of 8µm. The Spiked-WAF which utilized variable oil loading as a substitution for serial dilution attained saturation of highly toxic and abundant BTEX and PAHs at lower oil loading suggesting higher toxicological impacts. Oil concentrations measured with sensors produced speedy results with high correlation to traditional chromatographic measurements. Varying WAF preparation methodologies affected acute toxicity (from least to most toxic – Slow < Spiked < HE WAF). By systematically comparing different WAFs and toxicity test conditions, researchers can better understand the toxicity of varying proportions of dissolved/particulate oil and provide insight into the ecological relevance of laboratory toxicity tests as oil would be present in both forms in a real spill scenario.
Results showed that particulate oil is only present in HE-WAF with a median diameter of 8µm. The Spiked-WAF which utilized variable oil loading as a substitution for serial dilution attained saturation of highly toxic and abundant BTEX and PAHs at lower oil loading suggesting higher toxicological impacts. Oil concentrations measured with sensors produced speedy results with high correlation to traditional chromatographic measurements. Varying WAF preparation methodologies affected acute toxicity (from least to most toxic – Slow < Spiked < HE WAF). By systematically comparing different WAFs and toxicity test conditions, researchers can better understand the toxicity of varying proportions of dissolved/particulate oil and provide insight into the ecological relevance of laboratory toxicity tests as oil would be present in both forms in a real spill scenario.
Event Type
Poster
TimeMonday, May 13th5:00pm - 6:00pm CDT
LocationExhibit Hall G
Preparedness
Prevention
Remediation
Response
Restoration