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Molecular structures of 1-hydroxyethane-1,1-diphosphonic acid for removing calcium sulfate scale under different pH conditions.

ABSTRACT: As an important descaling agent, 1-hydroxyethane-1,1-diphosphonic acid (HEDP) is capable of dissolving calcium sulfate scale when the pH of HEDP solution is adjusted from acidic to weakly alkaline. The molecular structures of Ca-HEDP complexes were determined to understand the impact of pH on the dissolution of calcium sulfate scale. The structures of the complexes revealed that the two phosphonic acid groups and the hydroxyl group of HEDP each provide one O atom to coordinate with the Ca ion to form a stable three-coordinate configuration under alkaline conditions. The electronic structures were investigated by interaction region indicator analysis, atoms in molecules analysis, electron localization function and natural population analysis. The deprotonation of the phosphonic acid group enhances the binding of coordinated O atoms and Ca ions as the pH increases, and weak alkalinity is the optimal process condition as strong alkaline conditions result in the precipitation of hydroxide and Ca ions.

SUBMITTER: Zhao X

PROVIDER: S-EPMC10288176 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature

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Molecular structures of 1-hydroxyethane-1,1-diphosphonic acid for removing calcium sulfate scale under different pH conditions.

Zhao Xiaoyang X Zhu Xingzhe X Xiao Xin X Nan Junmin J Xu Meng M Wu Chen C

RSC advances 20230623 28

As an important descaling agent, 1-hydroxyethane-1,1-diphosphonic acid (HEDP) is capable of dissolving calcium sulfate scale when the pH of HEDP solution is adjusted from acidic to weakly alkaline. The molecular structures of Ca-HEDP complexes were determined to understand the impact of pH on the dissolution of calcium sulfate scale. The structures of the complexes revealed that the two phosphonic acid groups and the hydroxyl group of HEDP each provide one O atom to coordinate with the Ca ion to ...[more]

PMID: 37362326

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Dataset Information

Molecular structures of 1-hydroxyethane-1,1-diphosphonic acid for removing calcium sulfate scale under different pH conditions.

Publications

Molecular structures of 1-hydroxyethane-1,1-diphosphonic acid for removing calcium sulfate scale under different pH conditions.

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