Publication result detail

Solubility and Dissociation of Lignitic Humic Acids in Water Suspensions

KLUČÁKOVÁ, M.; PEKAŘ, M.

Original Title

Solubility and Dissociation of Lignitic Humic Acids in Water Suspensions

English Title

Solubility and Dissociation of Lignitic Humic Acids in Water Suspensions

Type

Peer-reviewed article not indexed in WoS or Scopus

Original Abstract

Behavior of humic acids extracted from lignite in water suspension was studied by means of potentiometry. Although humic acids are operationally defined as that fraction of humic substances, which is not soluble under acidic conditions, it does not mean that solid preparation easily dissolves in water. Presented results suggest that dissolving of solid humic acids in water environment is more complex than conventional solubility behaviour of sparingly soluble solids. Multi-step mechanism of solid humic acids interaction with water, including partial equilibrium dissolution as well as direct equilibrium dissociation from the solid state, was proposed and proved experimentally. Only very small part of solid humic acids can be dissolved in water and not giving necessarily saturation at the same time. In contrast to common sparingly soluble solids, solid humic phase thus possesses non-constant chemical potential even under constant temperature and pressure and its activity does not equal to unity, in general.

English abstract

Behavior of humic acids extracted from lignite in water suspension was studied by means of potentiometry. Although humic acids are operationally defined as that fraction of humic substances, which is not soluble under acidic conditions, it does not mean that solid preparation easily dissolves in water. Presented results suggest that dissolving of solid humic acids in water environment is more complex than conventional solubility behaviour of sparingly soluble solids. Multi-step mechanism of solid humic acids interaction with water, including partial equilibrium dissolution as well as direct equilibrium dissociation from the solid state, was proposed and proved experimentally. Only very small part of solid humic acids can be dissolved in water and not giving necessarily saturation at the same time. In contrast to common sparingly soluble solids, solid humic phase thus possesses non-constant chemical potential even under constant temperature and pressure and its activity does not equal to unity, in general.

Keywords

humic acid; lignite; dissociation equilibrium; solubility; polyelectrolytes; suspensions;

Key words in English

humic acid; lignite; dissociation equilibrium; solubility; polyelectrolytes; suspensions;

Authors

KLUČÁKOVÁ, M.; PEKAŘ, M.

Released

01.01.2005

Edition

xx

ISBN

0927-7757

Periodical

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

Volume

252

Number

2-3

State

Kingdom of the Netherlands

Pages from

157

Pages to

164

Pages count

8

BibTex

@article{BUT46220,
  author="Martina {Klučáková} and Miloslav {Pekař}",
  title="Solubility and Dissociation of Lignitic Humic Acids in Water Suspensions",
  journal="COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS",
  year="2005",
  volume="252",
  number="2-3",
  pages="157--164",
  issn="0927-7757"
}