title: Assessment of EDTA heap leaching of an agricultural soil highly contaminated with heavy metals.
abstract: The efficiency of heavy metal removal from soil by EDTA leaching was assessed in a column leaching experiment at the laboratory scale and field heap leaching at the pilot scale using a sandy loam sierozem agricultural soil contaminated with Cd, Cu, Pb, and Zn. Soil amendment and aging were conducted to recover leaching soils. The percentages of Cd, Cu, Pb, and Zn removed by column leaching were 90%, 88%, 90%, and 67%, respectively, when 3.9 bed volumes of 50mM EDTA were used. At the pilot scale, on-site metal removal efficiencies using the selected leaching procedure were 80%, 69%, 73% and 62% for Cd, Cu, Pb and Zn, respectively. EDTA leaching decreased soil CEC, total P, total K and available K concentrations but increased organic matter and total Kjeldahl N concentrations. The subsequent amendment and soil aging further reduced the DTPA-extractable heavy metals in the leached soils. Growth of the first crop of pak choi in the leached soil was inhibited but the second crop grew well after the soil was aged for one year and the concentrations of Cd and Pb in the edible parts were below the Chinese statutory limits. The results demonstrate the potential feasibility of the field leaching technique using EDTA combined with subsequent amendment and soil aging for the remediation of heavy metal-contaminated agricultural soils.
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Pengjie
authors.initials: P
authors.lastname: Hu
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Bingfan
authors.initials: B
authors.lastname: Yang
authors.affiliation: Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Changxun
authors.initials: C
authors.lastname: Dong
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Like
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Hunan Normal University, Changsha 410006, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Cao
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: lhwu@issas.ac.cn.
authors.forename: Longhua
authors.initials: L
authors.lastname: Wu
authors.affiliation: Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Peter
authors.initials: P
authors.lastname: Christie
mesh_terms: D002681:China; D018556:Crops, Agricultural / Q000254:growth & development; D004492:Edetic Acid / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019216:Metals, Heavy / Q000737:chemistry*; D010865:Pilot Projects; D012989:Soil Pollutants / Q000737:chemistry*; D014675:Vegetables / Q000254:growth & development
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants; D004492:Edetic Acid
keywords: Agricultural soil; Amendment; Column leaching; EDTA; Ecological risk; Field leaching