Estimation of diffusion coefficients of ascorbate-based ions at infinite dilution through electrolytic conductivity measurements

4th International Conference on Water Resource and Environment

地球科学;生态环境科学

Soriano, A.N.^1 ; Dollente, K.G.R.^1 ; Tabaquero, R.J.D.^1 ; Adornado, A.P.^1

School of Chemical, Biological, and Materials Engineering and Sciences, Mapúa University, Manila

1002, Philippines^1

关键词: Electrolytic conductivity;    Fate and transport;    Infinite dilution;    Mineral salts;    Molar conductivities;    Naturally occurring;    Nernst-Einstein equation;    Self-diffusion coefficients;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/191/1/012028/pdf
DOI  :  10.1088/1755-1315/191/1/012028

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Ascorbic acid is a naturally-occurring organic compound that has high water solubility. One significant parameter that can describe the mobility and transport of ascorbic acid and its mineral salts in water systems is the diffusion coefficient. Molar conductivity data were determined from electrolytic conductivity data measured at different concentrations of ascorbate-based ions (dilute region) and temperatures (293.15 to 313.15 K). From these data, the infinite dilution diffusion coefficients of the ascorbic acid and mineral salts in water were estimated using the Nernst-Haskell Equation. The Nernst-Einstein Equation was used to predict the infinite dilution self-diffusion coefficients of the representative ascorbate-based ions ([H+], [Na+], and [Ca2+]). For most temperatures and concentrations considered, the Ca2+ cation had the highest molar conductivity but the [H+] cation had the highest correlated infinite dilution self-diffusion coefficient of 11.4105 10-9 m2/s at 313.15 K. The [Na+] and [Ca2+] cations had values of correlated infinite dilution self-diffusion coefficient of 2.6263 10-9 m2/s and 2.4045 10-9 m2/s at 313.15 K, respectively. The molar conductivity and diffusion coefficient of the ions at infinite dilution were in the order of [H+] > [Na+] > [Ca2+]. It was found that an increase in temperature also increases the diffusion coefficient. This study was able to estimate infinite dilution diffusion coefficient data for ascorbate-based ions. Thus, the results of this study can serve as a basis and reference for future researches to have a better understanding of the fate and transport of ascorbate-based ions in the environment.