Publications Details

Experimental Determination of Lead Interactions with Citrate and EDTA in NaCl and MgCl2 Solutions to High Ionic Strength and Its Applications

Xiong, Yongliang X.; Kirkes, Leslie D.; Westfall, Terry; Marrs, Cassandra M.; Knox, Jandi L.; Burton, Heather L.

For this study, the interactions of lead with citrate and ethylenediaminetetraacetate (EDTA) are investigated based on solubility measurements as a function of ionic strength at room temperature (22.5 ± 0.5°C) in NaCl and M_gCl₂ solutions. The formation constants (log β₁⁰ ) for Pb[C₃H₅O(COO)₃]– (abbreviated as PbCitrate^–) and Pb[(CH₂COO)₂N(CH2)₂N(CH₂COO)₂)]^2– (abbreviated as PbEDTA^2–) Pb²⁺ + [C₃H₅O(COO)₃]^3– = Pb[C₃H₅O(COO)₃]^– (1) Pb²⁺ + (CH₂COO)₂N(CH₂)₂N(CH₂COO)₂)^4- = Pb[(CH₂COO)₂N(CH₂)₂N(CH₂COO)₂)]^2– (2) are evaluated as 7.28 ± 0.18 (2σ) and 20.00 ± 0.20 (2σ), respectively, with a set of Pitzer parameters describing the specific interactions in NaCl and M_gCl₂ media. Based on these parameters, the interactions of lead with citrate and EDTA in various low temperature environments can be accurately modelled.