title: Degradation of phenanthrene and pyrene in spiked soils by single and combined plants cultivation.
abstract: The present study was conducted to investigate the capability of four plant species (tall fescue, ryegrass, alfalfa, and rape seed) grown alone and in combination to the degradation of phenanthrene and pyrene (polycyclic aromatic hydrocarbons, PAHs) in spiked soil. After 65 days of plant growth, plant biomass, dehydrogenase activity, water-soluble phenolic (WSP) compounds, plant uptake and accumulation and residual concentrations of phenanthrene and pyrene were determined. Our results showed that presence of vegetation significantly enhanced the dissipation of phenanthrene and pyrene from contaminated soils. Higher degradation rates of PAHs were observed in the combined plant cultivation (98.3-99.2% phenanthrene and 88.1-95.7% pyrene) compared to the single plant cultivation (97.0-98.0% phenanthrene and 79.8-86.0% pyrene). Contribution of direct plant uptake and accumulation of phenanthrene and pyrene was very low compared to the plant enhanced dissipation. By contrast, plant-promoted biodegradation was the predominant contribution to the remediation enhancement. The correlation analysis indicates a negative relation between biological activities (dehydrogenase activity and WSP compounds) and residual concentrations of phenanthrene and pyrene in planted soils. Our results suggest that phytoremediation could be a feasible choice for PAHs contaminated soil. Moreover, the combined plant cultivation has potential to enhance the process.
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, Zhejiang, PR China.
authors.forename: Sardar Alam
authors.initials: SA
authors.lastname: Cheema
authors.forename: Muhammad
authors.initials: M
authors.lastname: Imran Khan
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Shen
authors.forename: Xianjin
authors.initials: X
authors.lastname: Tang
authors.forename: Muhammad
authors.initials: M
authors.lastname: Farooq
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Congkai
authors.initials: C
authors.lastname: Zhang
authors.forename: Yingxu
authors.initials: Y
authors.lastname: Chen
mesh_terms: D001673:Biodegradation, Environmental; D029741:Brassica rapa / Q000378:metabolism; D031751:Festuca / Q000378:metabolism; D008129:Lolium / Q000378:metabolism; D019684:Magnoliopsida / Q000378:metabolism*; D000455:Medicago sativa / Q000378:metabolism; D010616:Phenanthrenes / Q000493:pharmacokinetics*; D011721:Pyrenes / Q000493:pharmacokinetics*; D012987:Soil; D012989:Soil Pollutants / Q000493:pharmacokinetics*
chemical_list: D010616:Phenanthrenes; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene; C030984:pyrene