Priming effects on PAH degradation and ecotoxicity during a phytoremediation experiment

• Published in: Environmental pollution (1987) 2004-01, Vol.128 (3), p.429-435
• Main Authors: Joner, Erik J., Hirmann, Doris, Szolar, Oliver H.J., Todorovic, Dragana, Leyval, Corinne, Loibner, Andreas P.
• Format: Article
• Language: English
• Subjects: Aliivibrio fischeri - drug effects; Aliivibrio fischeri - metabolism; Animal, plant and microbial ecology; Animals; Applied ecology; Applied sciences; Biodegradation, Environmental; Biological and medical sciences; Bioremediation; Biotechnology; Chemical tests; Chlorophyta - drug effects; Chlorophyta - growth & development; Contamination; Creosote; Crustacea - drug effects; Crustacea - growth & development; Decontamination. Miscellaneous; Degradation; Earth sciences; Earth, ocean, space; Ecotoxicity; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Engineering and environment geology. Geothermics; Environment and pollution; Exact sciences and technology; Excavation; Fertilizing; Fundamental and applied biological sciences. Psychology; Hydrocarbons; Industrial applications and implications. Economical aspects; lucerne; Luminescent Measurements; Medicago sativa - metabolism; Miscellaneous; Ostracod test; Ostracoda; phytoremediation; Pollution; Pollution, environment geology; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - metabolism; Polycyclic Aromatic Hydrocarbons - toxicity; Priming; Reduction (chemical); Soil (material); Soil and sediments pollution; Soil Pollutants - metabolism; Soil Pollutants - toxicity; Toxicity
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2003.09.005

An experiment was conducted to distinguish priming effects from the effects of phytoremediation of a creosote-polluted soil. The concentration of 13 polycyclic aromatic hydrocarbons (PAHs), and their combined soil toxicity (using four bioassays), was determined on recently excavated, homogenized soil and on such soil subjected to a time-course phytoremediation experiment with lucerne. The results showed a high priming effect, with minor positive and synergistic effects of planting and fertilization on PAH degradation rates. At the end of the experiment, PAH degradation reached 86% of the initial 519 mg PAHs kg −1. Two of the four toxicity tests (bioluminescence inhibition and ostracod growth inhibition) corroborated the chemical data for residual PAHs, and indicated a significant reduction in soil toxicity. We conclude that priming effects can easily surpass treatment effects, and that an unintentional pre-incubation that ignores these effects can jeopardize the full quantitative assessment of in situ bioremediation of contaminated soil. Priming effects during set-up of bioremediation laboratory experiments may largely surpass treatment effects.