Investigating the Effect of Medicago sativa L. and Trifolium pratense L. Root Exudates on PAHs Bioremediation in an Aged-Contaminated Soil

• Published in: Water, air, and soil pollution Vol. 230; no. 12; p. 296
• Main Authors: Davin, Marie, Starren, Amandine, Marit, Emilie, Lefébure, Kévin, Fauconnier, Marie-Laure, Colinet, Gilles
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2019; Springer; Springer Nature B.V
• Subjects: Alfalfa; Analysis; Aromatic compounds; Aromatic hydrocarbons; Atmospheric Protection/Air Quality Control/Air Pollution; Beads; Bioavailability; Biodegradation; Biological activity; Bioremediation; Brownfields; Carbon dioxide; Carbon dioxide emissions; Clean technology; Climate Change/Climate Change Impacts; desorption; Earth and Environmental Science; Environment; Environmental monitoring; enzyme activity; enzymes; Exudates; Exudation; greenhouse gas emissions; Hydrogeology; Investigations; Kinetics; Medicago sativa; Microbial activity; Microcosms; Microorganisms; Organic compounds; Phytoremediation; polluted soils; Polycyclic aromatic hydrocarbons; root exudates; Soil; Soil contamination; Soil improvement; Soil microbiology; Soil pollution; Soil remediation; soil sampling; Soil Science & Conservation; Soils; sustainable technology; Trifolium pratense; Water Quality/Water Pollution; Bioaccessibility; Tenax® extraction; Bioremediation; Brownfield soil; Plant root exudates; PAH
• DOI: 10.1007/s11270-019-4341-4
• ISSN: 0049-6979

Polycyclic aromatic hydrocarbons (PAH) are persistent organic compounds of major concern that accumulate in the environment, especially soils, and require remediation. Researches to develop bioremediation and phytoremediation (alternative eco-friendly technologies) are being conducted. First, a bioaccessibility measurement protocol was adapted to a brownfield soil using Tenax® beads in order to compare PAHs bioaccessibility in soil samples. PAHs desorption kinetics were established, described by a site distribution model, and a common extraction time was calculated (48 h). Second, the role of two Fabaceae ( Medicago sativa L. or Trifolium pratense L.) root exudates in enhancing PAHs bioaccessibility and biodegradation in the studied soil was evaluated during microcosms experiments (28 °C). The CO 2 emissions were significantly higher in presence of T. pratense exudates; the dehydrogenase activities showed improvements of the soil microbial activity in presence of two types of root exudates compared to untreated soil samples; the PAHs residual contents decreased more in untreated samples than in the presence of T. pratense exudates; and M. sativa exudates lowered PAHs bioaccessibility but not residual contents.