Evaluation of different chemical procedures to phytoremediate hydrocarbon-contaminated soils (Patagonia, Argentina)

FUCHS JULIO S.; LUQUE, JORGE; ZULETA, GUSTAVO A.

Mérida

Conferencia; SER 2011 4th World Conference on Ecological Restoration; 2011

Society for Ecological Restoration-Ibero-American & Caribbean Ecological Restoration Network

Soil pollution due to hydrocarbons (PH) spills is one of the most serious environmental impacts of the oil industry in arid ecosystems of Patagonia. Since remediation solutions are a priority measure for the sector, we investigated the performance of alternative chemical procedures in phytoremediation experiments to determine which parameters better reflect HC degradation over time. A three-factor experiment was conducted on nursery infrastructure, being the treatments: plant species (two native shrubs and two exotic grasses, both perennial), fertilization (with or without), and Total PH (TPH) content (4.1% or absent) in soils from coastal temporary watercourses adjacent to Comodoro Rivadavia city (Chubut province). At three different times (start, 180, and 350 days), PH degradation rates were quantified by five techniques: TPH direct injection (GC-FID) and gravimetric methods, discriminated fractions, BTEX, and PAH´s. The TPH decreased significantly in all treatments after 350 days. The light fractions (GC-FID) were degraded 80% at the end of the experiment, while the degradation of heavy TPH (gravimetric) was more selective and phytoremediation and biostimulation processes were recorded. The "saturated" fraction was the most reduced by degradation (58-65%), while the aromatic ones decreased 15-33%. PAH´s showed phytoremediation performance. The gravimetric method adequately reflected the daily degradation rates unlike the Pr/nC17-Ph/nC18 ratios. TPH gravimetric determination was the method that more accurately reflected both TP degradation and phytoremediation performance of the plants. These results allowed us to develop technical procedures and practical recommendations for arid environments in Patagonia.