title: Evaluation of dissipation gradients of polycyclic aromatic hydrocarbons in rice rhizosphere utilizing a sequential extraction procedure.
abstract: The aim of this study was to evaluate the spatial dissipation gradient of PAHs, including phenanthrene, pyrene, and benzo[a]pyrene, with various bioavailability represented with sequential extraction. Dissipation rates of PAHs in the rhizosphere were greater than those in the bulk soil. The n-butanol extracted fraction showed a general trend of dissipation during phytoremediation. Moreover, the formation of bound PAH residues was inhibited in the rhizosphere. While concerning the PAH toxicity, the reduction rates of PAH toxicity were significantly greater than total soil PAH concentrations. Microbial biomass was the highest at four mm away from the root surface. However, the PAH dissipation rates were the highest at one mm and two mm away from the root surface in high and low PAH treatments, respectively. These results suggest that rhizoremediation with rice is a useful approach to reduce the toxicity of PAHs in soil.
authors.affiliation: College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Wang
authors.forename: Minmin
authors.initials: M
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.forename: Haizhen
authors.initials: H
authors.lastname: Wang
authors.forename: Laosheng
authors.initials: L
authors.lastname: Wu
authors.forename: Jianming
authors.initials: J
authors.lastname: Xu
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D005591:Chemical Fractionation; D052918:Environmental Restoration and Remediation / Q000379:methods*; D012275:Oryza / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants