| A study was conducted to evaluate the efficiency of a treatment strategy to bioremediate weathered Arabian light crude oil in wetland microcosms. A set of eighteen microcosms were constructed with wetland sediment, divided into two treatment sets of nine each, and sampled at three different sampling events--day 0, day 63, and day 106. A precise volume of artificially weathered Arabian light crude oil (corresponding to a sediment concentration of 5{dollar}mu{dollar}g/g) was spilled in these microcosms. The efficiency of treatment-((NH{dollar}sb4{dollar}){dollar}sb3{dollar}PO{dollar}sb4{dollar} + KNO{dollar}sb3{dollar}) was evaluated relative to intrinsic bioremediation. (NH{dollar}sb4{dollar}){dollar}sb3{dollar}PO{dollar}sb4{dollar} and KNO{dollar}sb3{dollar} was added at day 0, and on a weekly basis from day 49 in the treatment set. The sediment cores extruded at the different sampling events were processed for analysis using a HP 5980 GC/HP 5972 Mass spectrometer, and Iatrascan. Overall, the treatment series showed a higher removal of the crude oil, and higher biomass levels compared to the intrinsic series. The study also revealed the relative biodegradability of two isoprenoids--pristane, and phytane. The biomass levels in the treatment series were also a few magnitudes higher in the treatment series. Although the removal of the crude oil cannot be attributed to biodegradation alone, the greater removal of the target compounds and increased biomass levels indicated that the treatment strategy was effective, and hence worthwhile to examine in a meso-scale simulation. |
