In situ lubricant degradation in Antarctic marine sediments. 1. Short‐term changes

Abstract

A large-scale, in situ experiment was set up near the Bailey Peninsula area (Casey Station, East Antarctica) to monitor the natural attenuation of synthetic lubricants in marine sediments over five years. Here, we report the short-term changes after 5 and 56 weeks. The lubricants tested were an unused and used Mobil lubricant (0W/40; Exxon Mobil, Irving, TX, USA) and a biodegradable alternative (0W/20; Fuchs Lubricants, Harvey, IL, USA). Clean sediment was collected, contaminated with the lubricants, and deployed by divers onto the seabed in a randomized block design. The sampled sediments were analyzed by gas chromatography-flame-ionization detector and gas chromatography-mass spectrometry with selective ion monitoring. The base fluid of all lubricant treatments did not decrease significantly after 56 weeks in situ. Alkanoate esters of 1,1,1-tris(hydroxymethyl)propane in the biodegradable and unused lubricants were degraded extensively in situ; however, these esters constituted only a minor proportion of the lubricant volume. The additives, alkylated naphthalenes and substituted diphenylamines, were fairly resistant to degradation, which is of environmental concern because of their toxicity. The biodegradable lubricant did not break down to recognized biodegradable thresholds and, as such, should not be classified as biodegradable under Antarctic marine conditions. A separate experiment was conducted to determine the influence of sediment preparation and deployment on compound ratios within the lubricants, and we found that preparation and deployment of the contaminated sediments had only a minor effect on compound recovery. Further monitoring of this in situ experiment will provide much needed information about the long-term natural attenuation of lubricants.

On-site and in situ remediation technologies applicable to petroleum hydrocarbon contaminated sites in the Antarctic and Arctic

“…These findings are consistent with Powell et al (2007), who observed that the longevity of hydrocarbons in Antarctic marine sediments can be variable, even within a relatively small geographical area. Associated with this five-year investigation at O'Brien Bay, Thompson et al (2006) investigated the biodegradation of used, unused and biodegradable lubricants in marine sediments. After five weeks, a 37% decrease in the concentration of biodegradable lubricants was observed while used and unused lubricant concentrations decreased by 20%.…”

“…After five weeks, a 37% decrease in the concentration of biodegradable lubricants was observed while used and unused lubricant concentrations decreased by 20%. Failure of the biodegradable lubricant to break down to recognized biodegradable thresholds and the resistance of lubricant additives, alkylated naphthalenes and diphenylamines, to degradation presented concerns because of their environmental toxicity (Thompson et al 2006). Antarctic marine bacteria isolated from Terra Nova Bay have also shown to exhibit gradual mineralization of diesel at 48C, with 57% degraded compared to 86% degraded at 208C following 60 days incubation (Michaud et al 2004).…”

“…Snape et al (2001) identified petroleum-derived contamination as the most significant environmental pollution issue in the Antarctic. In recent years, several studies describing the distribution and environmental effects of petroleum-derived contamination at Antarctic research sites have addressed localized contamination at the US McMurdo Station, Australia's Casey Station, the British Rothera Station and New Zealand's Scott Base (Deprez et al 1999;Snape et al 2001;Poland et al 2003;Saul et al 2005;Stark et al 2006;Klein et al 2012).…”

Effects of diesel and lubricant oils on Antarctic benthic microbial communities over five years

“…Field methods. The site, set-up and sampling of this field experiment have been described in detail previously (Powell et al 2005b, Thompson et al 2006. Briefly, clean, uncontaminated sediment was collected from O'Brien Bay (66°18' S, 110°32' E), near Casey station, sieved at 500 µm to remove infauna and then spiked with one of 4 oils or left as a control.…”

Effects of Pollution on Marine Organisms

“…Total oil concentrations decreased between 17 and 29% compared with the initial levels and resolved n-alkanes were depleted in weathered oil fractions. Combining the assay responses with chemical data indicated that the observed declining toxicity probably was not caused by analyzed PAH, but by other specific oil constituents Thompson et al (2006). monitored natural attenuation of synthetic lubricants (Mobil lubricant 0W/40, and Fuchs lubricant 0W/20 (a biodegradable alternative)) in an Antarctica oiled sediment experiment, but they did not monitor toxicity.…”