title: Efficiency of nanoscale zero-valent iron on the enhanced low molecular weight organic acid removal Pb from contaminated soil.
abstract: The Pb removal efficiencies from contaminated soils by low molecular weight organic acid (LMWOA) and nanoscale zero-valent iron (nZVI) were investigated through batch soil washing experiments. Results showed that significant promotion on Pb-removal with the mixed solutions of LMWOA and nZVI (p < 0.05). The Pb removal efficiencies reached 64% and 83% for mine and farmland soil by addition of 0.2 M citric acid and 2.0 g L−1 nZVI, respectively. They decreased with increasing pH from 3 to 9. The mixed solutions of LMWOA and nZVI induced Pb(II) releases processes including a rapid desorption within 4 h and a slow desorption in the following hours. The second-order model was the most appropriate for describing the kinetic processes of Pb(II) desorption. The main fractions of Pb removal were exchangeable and reducible. Compared with LMWOA, the loss rates of nitrogen, phosphorus and potassium decreased after washing with the mixed solutions. Our study suggests that combining of LMWOA and nZVI would be a promising alternative approach for remediation Pb-contaminated soils.
authors.affiliation: College of Resources and Environment, Sichuan Agricultural University, Wenjiang 611130, PR China.
authors.forename: Guiyin
authors.initials: G
authors.lastname: Wang
authors.forename: Shirong
authors.initials: S
authors.lastname: Zhang
authors.forename: Xiaoxun
authors.initials: X
authors.lastname: Xu
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Ouping
authors.initials: O
authors.lastname: Deng
authors.forename: Guoshu
authors.initials: G
authors.lastname: Gong
mesh_terms: D000143:Acids / Q000378:metabolism; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007501:Iron / Q000378:metabolism*; D007854:Lead / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008970:Molecular Weight; D009930:Organic Chemicals / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D000143:Acids; D009930:Organic Chemicals; D012989:Soil Pollutants; D007854:Lead; D007501:Iron