Study of PAH dissipation and phytoremediation in soils: Comparing freshly spiked with weathered soil from a former coking works

• Published in: Journal of hazardous materials 2011-09, Vol.192 (3), p.1219-1225
• Main Authors: Smith, M.J., Flowers, T.H., Duncan, H.J., Saito, H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodegradation, Environmental; Chrysenes - chemistry; coal; Coal tar; Coal Tar - analysis; Coke; Coking; Coking soil; Contamination; Decontamination. Miscellaneous; Dissipation; Environmental Pollution; Exact sciences and technology; Fluorenes - chemistry; Gases; Greenhouse trial; Industrial Waste; Models, Statistical; PAH dissipation; Phytoremediation; Plant degradation; planting; polluted soils; Pollution; Polyallylamine hydrochloride; polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; prediction; Reduction; Soil - analysis; soil amendments; Soil and sediments pollution; Soil Pollutants - analysis; Soils; Time Factors; Weather
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.06.033

• Dissipation of PAHs in soil was studied in greenhouse experiments. • Freshly applied PAHs (pure chemicals or a coal tar mixture) dissipated more rapidly than PAHs in historically contaminated soil. • There was evidence of increased dissipation of coal tar PAHs in planted soil compared to unplanted soil. • There was no increased reduction of PAH levels in historically contaminated soil due to growing plants. A comparison was made between the dissipation of polycyclic aromatic hydrocarbons (PAHs) in soil freshly spiked with pure PAHs, soil spiked with a coal tar mixture and a contaminated soil from a former coking works where the PAHs had been present for more than a century. The potential of five selected plant species for phytoremediation was investigated. The levels of all 7 PAHs in chemically amended soil, both planted and unplanted, fell significantly (>80% reduction) over the 12 weeks of the growing trial. In the coal tar treated soils all PAHs were significantly reduced. In both the planted and unplanted soils the 2–3 ringed compounds demonstrated much greater loss (>77%) than the 4–6 ringed (16–39%). The 3–4 ringed compounds demonstrated strong evidence of phytoremediation but not the 5–6 ringed. The coking soil showed limited reduction (7–24%) of all 12 PAHs present. There was little difference in dissipation between the PAHs and little evidence of a phytoremediation effect in coking soil. The results demonstrated that the form in which PAHs were added to soil influenced their susceptibility to dissipation. Therefore, predictions of PAH dissipation from laboratory amended soil do not reflect the true situation in the field.