Fate and Impacts of Vegetable Oil Spills in Aquatic Environments

Fate and Impacts of Vegetable Oil Spills in Aquatic Environments

Bibliographic Details
Main Author: Salam, Darine
Language:English
Published: University of Cincinnati / OhioLINK 2011
Subjects:
Sanitation
Vegetable Oil Spills
Aerobic Biodegradation
Autoxidation
Polymerization
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321367790
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-ucin13213677902021-08-03T06:15:05Z Fate and Impacts of Vegetable Oil Spills in Aquatic Environments Salam, Darine Sanitation Vegetable Oil Spills Aerobic Biodegradation Autoxidation Polymerization The kinetics and ecological impacts of the aerobic biodegradation of vegetable oils in contaminated aquatic environments were studied in respirometric microcosms at different oil loadings (100, 333, and 1,000 gal acre-1) and mixing regimes (fully, moderately, and non-mixed microcosms). No significant difference in the extent of oil biodegradation was observed between the fully and moderately mixed microcosms at 100 and 333 gal acre-1 loadings, indicating minimal influence of enhanced mixing in these cases. Furthermore, comparable oxygen uptake rates were measured initially in the moderately and non-mixed microcosms at the 100 and 333 gal acre-1 loadings, suggesting an initial dependence of the microbial activity on the oil surface available for emulsification rather than on the oil concentration. Regardless of the mixing condition, reduced initial oxygen uptake rates were measured at 1,000 gal acre-1 loading and were associated with an initial oxygen mass transfer limitation. The results of the Microtox® assay showed no major toxicity at the 100 gal acre-1 loading. Furthermore, oxygen was not completely depleted from the water column at this oil coverage. At higher oil loadings, oxygen was fully depleted from the mixed and non-mixed water columns. A transient toxicity in the aqueous phase was observed in the case of the moderately mixed microcosms at 333 gal acre-1 and was maintained at moderate levels (EC50 ~30%) in the non-mixed microcosms. A substantial increase in toxicity (EC50 ~10 %) was observed in both mixing conditions when the initial oil loading was increased to 1,000 gal acre-1. Furthermore, the effect of antioxidants on the fate and impacts of vegetable oils in contaminated aquatic media was investigated. Respirometric experiments on the effect of increasing concentrations of butylated-hydroxytoluene (BHT) (0, 50, 100, 200, 400, and 800 ppm) on the biodegradability of glyceryl trilinoleate (333 gal acre-1), revealed the formation of intractable rigid polymers unavailable for bacterial degradation in all BHT treatments and particularly in the microcosms not supplemented with the antioxidant. In this case, limited oil mineralization was observed after 19 weeks of incubation (41%) compared to the microcosms supplemented with BHT (> 67 %). In these microcosms, no significant difference in the achieved oil mineralization was observed with increasing BHT concentrations, suggesting minimal additional protective effect of BHT above 50 and up to 800 ppm.In addition, the effect of BHT on the biodegradability and toxicity of purified canola oil (333 gal acre-1) was investigated in the absence and presence (200 ppm) of the antioxidant. Substantial oil mineralization was achieved after 16 weeks of incubation (> 77%) and was not significantly different between the two BHT treatments. Furthermore, for both treatments, a transient toxicity was observed and was attributed to the combined effect of toxic biodegradation intermediates and autoxidation products. Autoxidation in the microcosms initially supplemented with the BHT, was supported by the disappearance of the antioxidant after only 2 weeks of incubation. Intractable solid polymers were formed in all biotic microcosms and were attributed to an interaction between the oil autoxidation products and the degrading biomass rather than to oil polymerization. 2011 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321367790 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321367790 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Sanitation
Vegetable Oil Spills
Aerobic Biodegradation
Autoxidation
Polymerization
spellingShingle Sanitation
Vegetable Oil Spills
Aerobic Biodegradation
Autoxidation
Polymerization
Salam, Darine
Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
author Salam, Darine
author_facet Salam, Darine
author_sort Salam, Darine
title Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
title_short Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
title_full Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
title_fullStr Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
title_full_unstemmed Fate and Impacts of Vegetable Oil Spills in Aquatic Environments
title_sort fate and impacts of vegetable oil spills in aquatic environments
publisher University of Cincinnati / OhioLINK
publishDate 2011
url http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321367790
work_keys_str_mv AT salamdarine fateandimpactsofvegetableoilspillsinaquaticenvironments
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