Adsorption of actinides on chemically modified humic acids

Malikov, D. A.; Goryacheva, T. A.; Новиков, А. П.; Платонов, В. В.; Treityak, R. Z.

doi:10.1134/s001670291212004x

Cited by 2 publications

(1 citation statement)

References 13 publications

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“…The interaction processes between HA and metal ions, such as complexation or aggregation, have a great impact on the transport and environmental fate of metal ions in nature [24][25][26][27]. Additionally, comparative analysis of the main physico-chemical conditions, such as solution pH, ionic strength, the presence of a competing metal ion and metal ion concentration, has shown different complexation mechanisms between HA and metal ions [28]. Considerable efforts have focused on the influence of HA on the transport of metal ions in the natural environment, but still, no conclusive generalization has been drawn, primarily because of the complexity of the interactions involved.…”

Section: Introductionmentioning

confidence: 99%

Aggregation Kinetics and Mechanism of Humic Acid Reaction with Cs+ and Co2+ Metal Ions Using Batch Techniques

Tan

Wang

et al. 2022

Water

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Humic substances have a potential role in the fate and transport of toxic metal ions in the environment due to their colloidal characteristics and abundant surface functional groups. Batch techniques (DLS, EPM, FT-IR and fluorescence EEM) were developed to assess the aggregation mechanisms of humic acid (HA) reacting with Cs+ or Co2+ electrolyte ions in this work. The kinetic experimental results indicated that a much lower Co2+ ion concentration (0.03–1.50 mmol/L) induced rapid aggregation of HA compared to that of Cs+ (3.0–15 mmol/L), and the divalent Co2+ ion was far more effective in enhancing HA aggregation than monovalent Cs+. The aggregation kinetics of HA were also found to be pH-dependent, and a much lower pH condition (pH 5.0) caused more rapid aggregation (the largest hydrodynamic diameter of ~3000 nm) compared to those at pH 7.0 (the largest hydrodynamic diameter of ~2000 nm). Positively charged metal ions in the solution can lower the electrostatic repulsive force between HA molecules through charge neutralization, thus leading to the rapid aggregation of HA aggregates. Furthermore, the carboxylic and phenolic groups on the HA surface were also involved in the aggregation reaction to form inner complexes and accelerate the aggregation process.

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