Temporal ecological assessment of oil contaminated soils before and after bioremediation

• Published in: Chemosphere (Oxford) 2000-02, Vol.40 (4), p.419-426
• Main Authors: Dorn, Philip B, Salanitro, Joseph P
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Avena sativa; bioassays; Biodegradation of pollutants; Biological and medical sciences; bioremediation; Biotechnology; Decontamination. Miscellaneous; Ecology; Ecotoxicology, biological effects of pollution; Eisenia; Eisenia fetida; Eisenia foetida; Environment and pollution; Environmental Monitoring - methods; Exact sciences and technology; Fuel Oils - analysis; Fuel Oils - toxicity; Fundamental and applied biological sciences. Psychology; hydrocarbons; Hydrogen-Ion Concentration; Industrial applications and implications. Economical aspects; Microtox; microtox assay; monitoring; mortality; Oily soil; Oligochaeta; petroleum; phytotoxicity; Plant Development; Plant toxicity; Plants - drug effects; polluted soils; Pollution; sandy soils; seed germination; seedling growth; Sensitivity and Specificity; Soil and sediments pollution; Soil Pollutants - analysis; Soil Pollutants - toxicity; soil pollution; Soil toxicity; Terrestrial ecotoxicity; Terrestrial environment, soil, air; toxicity; Triticum aestivum; United States; Vibrio; Waste Management; Zea mays
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/S0045-6535(99)00304-5

Ecotoxicity methods were used to assess different soil and oil combinations before, during and after laboratory bioremediation with associated hydrocarbon analysis. Heavy, medium and light crude oil (API gravity 14, 30, and 55) was spiked (ca. 5% w/w) into two sandy soils in the laboratory having organic carbon concentrations of 0.3 (Norwood) and 4.7% (Norwood/Baccto). The earthworm ( Eisenia fetida) 14-d lethality assay, the modified Microbics Microtox ® Solid-Phase assay, and the 14-d plant seed germination and growth assays using corn, wheat and oats, were spiked and tested during a 360-d laboratory remediation. Eisenia was the most sensitive of the three methods utilized with survival increasing throughout bioremediation with fastest toxicity reduction in the high carbon Norwood/Baccto soils where LC50’s were 100% or greater at the end of 90-d whereas, >150-d were required to achieve a similar result in the low carbon soil. Analysis of the undiluted treatments with oily soil alone showed that earthworm survival was high after 90-d in all high organic carbon soils, and after eight months in the low carbon soils, except for the Norwood soil-light oil treatment, which required 360-d to achieve 100% survival. The Microtox assay was less sensitive with EC50’s 100% or greater observed after 90-d in high carbon soils and after 240-d for all low carbon soils. After bioremediation, no effects on seed germination were observed, although some plant growth inhibition effects remained. There was no direct correlation between total petroleum hydrocarbon concentrations and toxicity.