title: Evaluation of enhanced soil washing process and phytoremediation with maize oil, carboxymethyl-β-cyclodextrin, and vetiver grass for the recovery of organochlorine pesticides and heavy metals from a pesticide factory site.
abstract: An innovative ex situ soil washing technology was developed in this study to remediate organochlorine pesticides (OCPs) and heavy metals in a mixed contaminated site. Elevated temperature (60 °C) combined with ultrasonication (40 kHz, 20 min) at 50 mL L(-1) maize oil and 45 g L(-1) carboxylmethyl-β-cyclodextrin were effective in extracting pollutants from the soil. After two successive washing cycles, the removal efficiency rates for total OCPs, mirex, endosulfans, chlordanes, Cd, and Pb were approximately 94.7%, 87.2%, 98.5%, 92.3%, 91.6%, and 87.3%, respectively. Cultivation of vetiver grass and addition of nutrients for 3 months further degraded 34.7% of the residual total OCPs and partially restored the microbiological functions of the soil. This result was indicated by the significant increase in the number, biomass C, N, and functioning diversity of soil microorganisms (p < 0.05). After the treatment, the residual OCPs and heavy metals existed as very slowly desorbing fraction and residual fraction, as evaluated by Tenax extraction combined with a first-three-compartment model and sequential extraction. Moreover, the secondary environmental risk of residual pollutants in the remediated soil was at an acceptable level. The proposed combined cleanup strategy proved to be effective and environmentally friendly.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: yemao@issas.ac.cn.
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.affiliation: Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: sunmingming@njau.edu.cn.
authors.forename: Mingming
authors.initials: M
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Zongtang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Ni
authors.initials: N
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Yinwen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: cggu@issas.ac.cn.
authors.forename: Chengang
authors.initials: C
authors.lastname: Gu
authors.affiliation: Department of Chemistry, Maseno University, Private Bag Maseno 40105, Kenya.
authors.forename: Fredrick Orori
authors.initials: FO
authors.lastname: Kengara
authors.affiliation: Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Huixin
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: jiangxin@issas.ac.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
mesh_terms: D002104:Cadmium / Q000032:analysis / Q000737:chemistry; D049930:Chrysopogon / Q000378:metabolism; D003314:Corn Oil; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis / Q000378:metabolism; D007854:Lead / Q000032:analysis / Q000737:chemistry; D010575:Pesticides / Q000032:analysis / Q000378:metabolism; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D013010:Sonication; D047392:beta-Cyclodextrins
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D047392:beta-Cyclodextrins; C441457:carboxymethyl-beta-cyclodextrin; D002104:Cadmium; D007854:Lead; D003314:Corn Oil
keywords: Heavy metal; Mixed-contaminated site; Organochlorine pesticide; Soil washing; Tenax extraction; Vetiver grass cultivation