1. Lead was mobilized in acid silty clay loam paddy soil with potassium dihydrogen phosphate (KDP) amendment.
- Author
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Xu, Qiao, Ye, Binhui, Mou, Xiaoyu, Ye, Jien, Liu, Wenyu, Luo, Yating, and Shi, Jiyan
- Subjects
CLAY loam soils ,POTASSIUM dihydrogen phosphate ,LOAM soils ,SOIL solutions ,SOIL formation - Abstract
The immobilization effectiveness between Pb and phosphorus in soil varies with soil types. To clarify the effect of phosphate on the availability of Pb in agricultural soil, a culture experiment with three types of paddy soil was performed with potassium dihydrogen phosphate (KDP) added. EDTA, DGT and in-situ solution extraction methods were used to represent different available Pb content. Results showed that the concentration of EDTA-Pb in HN soil was slightly elevated after exogenous KDP added. The supplement of 300 mg/kg KDP significantly increased the content of soluble Pb in both acid silty clay loam soil and neutral silty loam soil (increased by 104.65% and 65.12%, respectively). However, there was no significant influence of KDP on the concentration of DGT extracted Pb. XANES results showed that Pb(OH) 2 , PbHPO 4 , humic acid-Pb and GSH-Pb were the major speciation of Pb in soil colloids. The proportion of Pb(OH) 2 and humic acid-bounded Pb in soil colloids were elevated after exogenous KDP added. Our results indicated that there was a mobilization effect of KDP on Pb by increasing the amount of colloidal Pb in soil solution, especially in acid silty clay loam paddy soil. Such colloid-facilitated transport might promote the uptake of Pb in rice and pose a potential threat to human health. Image 1 • Exogenous KDP could increase the amount of colloidal Pb in soil solution. • There was a mobilization effect of KDP on Pb by increasing the amount of colloidal Pb in soil solution. • The addition of KDP as well as submergence were conducive to the formation of soil colloids. • The proportion of Pb(OH) 2 and humic acid-Pb in soil colloids were elevated after KDP added. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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