R&D result detail

Original Title

Mean Activity Coefficients of Humic Acids as Physicochemical Characteristics of their Behavior in Water Environment

English Title

Mean Activity Coefficients of Humic Acids as Physicochemical Characteristics of their Behavior in Water Environment

Type

WoS Article

Original Abstract

In this work, the dissociation of humic acids is investigated in point of view of their mean activity coefficients. They are determined on the basis of two different concepts: sparingly soluble substance and multi-step mechanism. It was found that the mean activity coefficients are generally higher, if the traditional concept is applied on the data, excepting HA-A sample. Both used concepts provide the mean activity coefficients dependent on the ionic strength, the amount of dissolved humic acids and the types of electrolyte added in the studied suspensions. Their values based on the concept of multi-step mechanism and determined for humic acids in NaCl and NaI form continuous curve and the individual character of their ions did not assert. It means that activity coefficients were affected only by ionic strength and valence factor of electrolytes irrespective of their chemical composition. The mean activity coefficients obtained for humic acids in HCl are lower in comparison with NaCl and NaI due to the common ion H+. Comparing results obtained for individual humic acids we can state that results obtained for HA-E sample are very different from those of other samples. It seems that its solubility is very high but the majority of dissolved particles remained in the molecular form and only small amount of ions are formed.

English abstract

In this work, the dissociation of humic acids is investigated in point of view of their mean activity coefficients. They are determined on the basis of two different concepts: sparingly soluble substance and multi-step mechanism. It was found that the mean activity coefficients are generally higher, if the traditional concept is applied on the data, excepting HA-A sample. Both used concepts provide the mean activity coefficients dependent on the ionic strength, the amount of dissolved humic acids and the types of electrolyte added in the studied suspensions. Their values based on the concept of multi-step mechanism and determined for humic acids in NaCl and NaI form continuous curve and the individual character of their ions did not assert. It means that activity coefficients were affected only by ionic strength and valence factor of electrolytes irrespective of their chemical composition. The mean activity coefficients obtained for humic acids in HCl are lower in comparison with NaCl and NaI due to the common ion H+. Comparing results obtained for individual humic acids we can state that results obtained for HA-E sample are very different from those of other samples. It seems that its solubility is very high but the majority of dissolved particles remained in the molecular form and only small amount of ions are formed.

Keywords

Activity coefficient; Humic acids; Dissociation; Acidic functional group; Solubility product

Key words in English

Activity coefficient; Humic acids; Dissociation; Acidic functional group; Solubility product

Authors

KLUČÁKOVÁ, M.

RIV year

2021

Released

15.12.2020

Publisher

American Chemical Society

ISBN

2470-1343

Periodical

ACS Omega

Volume

5

Number

49

State

United States of America

Pages from

31518

Pages to

31524

Pages count

7

URL

https://pubs.acs.org/doi/pdf/10.1021/acsomega.0c03311

Full text in the Digital Library

http://hdl.handle.net/

BibTex

@article{BUT165758,
  author="Martina {Klučáková}",
  title="Mean Activity Coefficients of Humic Acids as Physicochemical Characteristics of their Behavior in Water
Environment",
  journal="ACS Omega",
  year="2020",
  volume="5",
  number="49",
  pages="31518--31524",
  doi="10.1021/acsomega.0c03311",
  issn="2470-1343",
  url="https://pubs.acs.org/doi/pdf/10.1021/acsomega.0c03311"
}