The effects of four spill-treating agents (STAs) (CytoSol, Finasol(®) OSR 51, Agma OSD 569 and OD4000) on the growth kinetics of three marine microalgae (Isochrysis galbana, Chaetoceros gracilis, Phaeodactylum tricornutum) were studied. Chlorophyll a concentration and optical density at 700 nm were assessed to describe the logistic growth of algae in batch cultures. The optical density data were initially analyzed as described for standard algal growth inhibition tests and subsequently modelled by a bivariate model, as a function of time and dose, to assess the toxic effects on growth parameters. Increasing trends in EC50 and EC10 values with time were found with the standard approach. In 8 of the 11 tests, the lag phase (λ) or the time required to achieve half the maximum biomass (τ) was significantly dependent on the STA concentration. A global parameter (EC50,τ) was calculated to summarize the effects of STAs on growth parameters in the bivariate model. The ranking of sensitivity as EC50,τ values was I. galbana>C. gracilis>P. tricornutum. For all species tested, the least toxic agent was Agma OSD 569, followed by CytoSol. The mathematical model allowed successful ecotoxicological evaluation of chemicals on microalgal growth.
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http://dx.doi.org/10.1016/j.jhazmat.2013.07.010 | DOI Listing |
Chemosphere
June 2024
Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, A1B 3X5, Canada. Electronic address:
Marine oil spills directly cause polycyclic aromatic hydrocarbons (PAHs) pollution and affect marine organisms due to their toxic property. Chemical and bio-based dispersants composed of surfactants and solvents are considered effective oil spill-treating agents. Dispersants enhance oil biodegradation in the marine environment by rapidly increasing their solubility in the water column.
View Article and Find Full Text PDFMar Pollut Bull
November 2023
Natural Resources Canada, CanmetENERGY Devon, 1 Oil Patch Drive, Devon, Alberta T9G 1A8, Canada.
Planning for effective response to crude oil spills into water depends on evidence of oil behavior, including its tendency to become distributed throughout an aquatic system. An improved laboratory method is employed to quantitatively assess crude oil distribution among different layers that form after mixing within a multi-phase system of water and sediment. Mixtures of conventional crude oil or diluted bitumen with different water types in the presence or absence of mineral sediment are first mixed by a standard end-over-end rotary agitation protocol.
View Article and Find Full Text PDFJ Hazard Mater
October 2022
Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3×5, Canada.
The emerging demand for the enhancement of biodegradation of persistent organic pollutants from marine oil spills using oil-treating agents to minimize the environmental impacts promotes the development of green dispersants. Shrimp waste is a potential raw material to generate green dispersants. The biodegradability of dispersed oil and dispersants themselves are key factors for the national consideration of the approval, stockpile, and usage of dispersants.
View Article and Find Full Text PDFFront Microbiol
April 2022
Northern Region Persistent Organic Pollutant Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, Canada.
There is an urgent call for contingency planning with effective and eco-friendly oil spill cleanup responses. burning, if properly applied, could greatly mitigate oil in water and minimize the adverse environmental impacts of the spilled oil. Chemical herders have been commonly used along with burning to increase the thickness of spilled oil at sea and facilitate combustion.
View Article and Find Full Text PDFLangmuir
November 2014
Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States.
Naturally occurring halloysite clay nanotubes are effective in stabilizing oil-in-water emulsions and can serve as interfacially-active vehicles for delivering oil spill treating agents. Halloysite nanotubes adsorb at the oil-water interface and stabilize oil-in-water emulsions that are stable for months. Cryo-scanning electron microscopy (Cryo-SEM) imaging of the oil-in-water emulsions shows that these nanotubes assemble in a side-on orientation at the oil-water interface and form networks on the interface through end-to-end linkages.
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