title: Combined effects of low-molecular-weight organic acids on mobilization of arsenic and lead from multi-contaminated soils.
abstract: A batch experiment was conducted to examine the combined effects of three common low-molecular-weight organic acids (LMWOAs) on the mobilization of arsenic and lead in different types of multi-contaminated soils. The capacity of individual LMWOAs (at a same molar concentration) to mobilize soil-borne As and Pb varied significantly. The combination of the organic acids did not make a marked "additive" effect on the mobilization of the investigated three elements. An "antagonistic" effect on element mobilization was clear in the treatments involving oxalic acid for some soils. The acid strength of a LMWOA did not play an important role in controlling the mobilization of elements. While the mobilization of As and Pb was closely associated with the dissolution of soil-borne Fe, soil properties such as original soil pH, organic matter contents and the total amount of the element relative to the total Fe markedly complicated the mobility of that element. Aging led to continual consumption of proton introduced from addition of LMWOAs and consequently caused dramatic changes in solution-borne Fe, which in turn resulted in change in As and Pb in the soil solution though different elements behaved differently.
authors.affiliation: School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom.
authors.forename: Olaronke O
authors.initials: OO
authors.lastname: Onireti
authors.affiliation: School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom. Electronic address: C.Lin@salford.ac.uk.
authors.forename: Chuxia
authors.initials: C
authors.lastname: Lin
authors.affiliation: School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom; College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
authors.forename: Junhao
authors.initials: J
authors.lastname: Qin
mesh_terms: D000144:Acids, Acyclic / Q000032:analysis* / Q000737:chemistry; D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D019343:Citric Acid / Q000032:analysis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D008962:Models, Theoretical; D008970:Molecular Weight; D019815:Oxalic Acid / Q000032:analysis / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
chemical_list: D000144:Acids, Acyclic; D012987:Soil; D012989:Soil Pollutants; D019343:Citric Acid; D007854:Lead; D019815:Oxalic Acid; D001151:Arsenic
keywords: Arsenic; Contaminated soils; Lead; Low-molecular-weight organic acids; Mobilization