title: Mechanism and kinetics of aluminum dissolution during copper sorption by acidity paddy soil in South China.
abstract: Soil aggregates were prepared from a bulk soil collected from paddy soil in the Taihu Lake region and aluminum (Al) dissolution, solution pH changes during copper (Cu(2+)) sorption were investigated with static sorption and magnetic stirring. Kinetics of Cu(2+) sorption and Al dissolution were also studied by magnetic stirring method. No Al dissolution was observed until Cu(2+) sorption was greater than a certain value, which was 632, 450, 601 and 674 mg/kg for sand, clay, silt, and coarse silt fractions, respectively. Aluminum dissolution increased with increasing Cu(2+) sorption and decreasing solution pH. An amount of dissolved Al showed a significant positive correlation with non-specific sorption of Cu(2+) (R(2)>0.97), and it was still good under different pH values (R(2)>0.95). Copper sorption significantly decreased solution pH. The magnitude of solution pH decline increased as Cu(2+) sorption and Al dissolution increased. The sand and clay fraction had a less Al dissolution and pH drop due to the higher ferric oxide, Al oxide and organic matter contents. After sorption reaction for half an hour, the Cu(2+) sorption progress reached more than 90% while the Al dissolution progress was only 40%, and lagged behind the Cu(2+) sorption. It indicated that aluminum dissolution is associated with non-specific sorption.
authors.affiliation: College of Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: liupeiya1990@163.com.
authors.forename: Peiya
authors.initials: P
authors.lastname: Liu
authors.affiliation: College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yujiao
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Qinliang
authors.initials: Q
authors.lastname: Wen
authors.affiliation: College of Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: dongcx@njau.edu.cn.
authors.forename: Changxun
authors.initials: C
authors.lastname: Dong
authors.affiliation: Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Genxing
authors.initials: G
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D000383:Agriculture; D000535:Aluminum / Q000737:chemistry*; D002681:China; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012275:Oryza / Q000254:growth & development; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D012995:Solubility
chemical_list: D012987:Soil; D012989:Soil Pollutants; D003300:Copper; D000535:Aluminum
keywords: Aggregate; Aluminum dissolution; Cu(2+) sorption; pH