title: Effects of surfactants on low-molecular-weight organic acids to wash soil zinc.
abstract: Soil washing is an effective approach to the removal of heavy metals from contaminated soil. In this study, the effects of the surfactants sodium dodecyl sulfate, Triton X-100, and non-ionic polyacrylamide (NPAM) on oxalic acid, tartaric acid, and citric acid used to remove zinc from contaminated soils were investigated. The Zn removal efficiencies of all washing solutions showed a logarithmic increase with acid concentrations from 0.5 to 10.0 g/L, while they decreased as pH increased from 4 to 9. Increasing the reaction time enhanced the effects of surfactants on Zn removal efficiencies by the acids during washing and significantly (P < 0.05) improved the removal under some mixed cases. Oxalic acid suffered antagonistic effects from the three surfactants and seriously damaged soil nutrients during the removal of soil Zn. Notably, the three surfactants caused synergistic effects on tartaric and citric acid during washing, with NPAM leading to an increase in Zn removal by 5.0 g/L citric acid of 10.60 % (P < 0.05) within 2 h. NPAM also alleviated the loss of cation exchange capacity of washed soils and obviously improved soil nitrogen concentrations. Overall, combining citric acid with NPAM offers a promising approach to the removal of zinc from contaminated soil.
authors.affiliation: College of Environment, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.|College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.affiliation: College of Environment, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China. srzhang01@aliyun.com.
authors.forename: Shirong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Environment, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Xiaoxun
authors.initials: X
authors.lastname: Xu
authors.affiliation: College of Environment, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.|College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Yao
authors.affiliation: College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: College of Environment, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.|College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Guiyin
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Agriculture, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Guoshu
authors.initials: G
authors.lastname: Gong
authors.affiliation: College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Resources, Sichuan Agricultural University, Wenjiang, 611130, People's Republic of China.
authors.forename: Ouping
authors.initials: O
authors.lastname: Deng
mesh_terms: D019343:Citric Acid / Q000494:pharmacology; D008970:Molecular Weight; D017830:Octoxynol / Q000494:pharmacology; D019815:Oxalic Acid / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013501:Surface-Active Agents / Q000494:pharmacology*; D013644:Tartrates / Q000494:pharmacology; D015032:Zinc / Q000032:analysis*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D013501:Surface-Active Agents; D013644:Tartrates; D019343:Citric Acid; D012967:Sodium Dodecyl Sulfate; D017830:Octoxynol; D019815:Oxalic Acid; D015032:Zinc; C029768:tartaric acid
keywords: Low-molecular-weight organic acid; Non-ionic polyacrylamide; Sodium dodecyl sulfate; Soil washing; Triton X-100; Zinc