title: Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes.
abstract: The development of an integrated strategy for the remediation of soil co-contaminated by heavy metals and persistent organic pollutants is a major research priority for the decontamination of soil slated for use in agricultural production. The objective of this study was to develop a bioremediation strategy for fields co-contaminated with cadmium (Cd), dichlorodiphenyltrichloroethane (DDT), and its metabolites 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethylene (DDE) and 1, 1-dichloro-2, 2-bis (4-chlorophenyl) ethane (DDD) (DDT, DDE, and DDD are collectively called DDs) using an identified Cd-hyperaccumulator plant Sedum alfredii (SA) and DDT-degrading microbes (DDT-1). Initially, inoculation with DDT-1 was shown to increase SA root biomass in a pot experiment. When SA was applied together with DDT-1, the levels of Cd and DDs in the co-contaminated soil decreased by 32.1-40.3% and 33.9-37.6%, respectively, in a pot experiment over 18 months compared to 3.25% and 3.76% decreases in soil Cd and DDs, respectively, in unplanted, untreated controls. A subsequent field study (18-month duration) in which the levels of Cd and DDs decreased by 31.1% and 53.6%, respectively, confirmed the beneficial results of this approach. This study demonstrates that the integrated bioremediation strategy is effective for the remediation of Cd-DDs co-contaminated soils.
authors.affiliation: MOE Key Laboratory of Environment Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Zhi-qiang
authors.initials: ZQ
authors.lastname: Zhu
authors.forename: Xiao-e
authors.initials: XE
authors.lastname: Yang
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Hua-gang
authors.initials: HG
authors.lastname: Huang
authors.forename: Xincheng
authors.initials: X
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Fang
authors.forename: Ting-qiang
authors.initials: TQ
authors.lastname: Li
authors.forename: A K
authors.initials: AK
authors.lastname: Alva
authors.forename: Zhen-li
authors.initials: ZL
authors.lastname: He
mesh_terms: D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism*; D003634:DDT / Q000378:metabolism*; D011549:Pseudomonas / Q000378:metabolism*; D031963:Sedum / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D003634:DDT