Roles of abiotic losses, microbes, plant roots, and root exudates on phytoremediation of PAHs in a barren soil.
Phytoremediation is an emerging technology for the remediation of polycyclic aromatic hydrocarbons (PAHs). In this study, pot experiments were conducted to evaluate the efficacy of phytoremediation of phenanthrene and pyrene in a typical low organic matter soil (3.75 g kg(-1)), and the contribution proportions of abiotic losses, microbes, plant roots, and root exudates were ascertained during the PAHs dissipation. The results indicated that contribution of abiotic losses from this soil was high both for phenanthrene (83.4%) and pyrene (57.2%). The contributions of root-exudates-enhanced biodegradation of phenanthrene (15.5%) and pyrene (21.3%) were higher than those of indigenous microbial degradation. The role of root exudates on dissipation of phenanthrene and pyrene was evident in this experiment. By the way, with the increasing of ring numbers in PAHs structures, the root-exudates-enhanced degradation became more and more important. BIOLOG-ECO plate analysis indicated that microbial community structure of the soil receiving root exudates had changed. The removal efficiency and substrate utilization rate in the treatment with plant roots were lower than the treatment only with root exudates, which suggested that possible competition between roots and microbes for nutrients had occurred in a low organic matter soil.
Sun
Tian-Ran
TR
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Cang
Long
L
Wang
Quan-Ying
QY
Zhou
Dong-Mei
DM
Cheng
Jie-Min
JM
Xu
Hui
H
D001673:Biodegradation, Environmental; D010616:Phenanthrenes / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology*; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism; D012987:Soil; D012989:Soil Pollutants / Q000378:metabolism*
D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C031181:phenanthrene; C030984:pyrene