Publication detail

Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids

VLČKOVÁ, Z. GRASSET, L. ANTOŠOVÁ, B. PEKAŘ, M. KUČERÍK, J.

Original Title

Type

journal article in Web of Science

Language

English

Original Abstract

Humic acids originating from South-Moravian lignite were subjected to a comparative study with the aim to assess the alteration of their physico-chemical properties after various lignite pre-treatments. Physical modification was achieved with two organic acids, such as acetic acid and citric acid and chemical modification by nitric acid and hydrogene peroxide in various concentrations. Elemental analysis, solid-state NMR, GC-MS analysis of polyols and size exclusion chromatography were carried out for chemical-physical characterization of obtained humic acids. Their biological effect, in form of potassium and ammonium humates, was tested on maize (Zea mays) seedlings. In these tests, potassium humates achieved far better overall results than ammonium humates. Results were inter-correlated in order to appraise the influence of humic acids physical and chemical properties on biological activity. Surprisingly, fractions with the lowest molecular size (0-35 kDa) showed no correlation with bioactivity results (Pearson coefficient from 0.05 to -0.4). On the contrary, middle-sized fractions (35-175 kDa) showed highly significant positive correlation (Pearson coefficient up to 0.92) and the highest molecular-size-fractions (275-350 kDa) showed negative correlation (Pearson coefficient up to -0.75). These findings were identical for both potassium and ammonium humates. No connection was found between bioactivity of humates and polyols content which was remarkably high; it reached 150 mg per g of humic acids in the most extreme case of 5% hydrogene peroxide pre-treatment. In the final analysis, the preparation mode bore pivotal responsibility for the control of humic acids biological effect and showed the best results for potassium humates obtained from lignite pre-treated by acetic acid and by 2% hydrogen peroxide.

Keywords

Lignite humic acids; Oxidation; Modification; Biological activity; Acetic acid; Citric acid

Authors

VLČKOVÁ, Z.; GRASSET, L.; ANTOŠOVÁ, B.; PEKAŘ, M.; KUČERÍK, J.

RIV year

2009

Released

7. 9. 2009

Publisher

Elsevier

Location

England

ISBN

0038-0717

Periodical

SOIL BIOLOGY & BIOCHEMISTRY

Year of study

Number

State

United Kingdom of Great Britain and Northern Ireland

Pages from

1894

Pages to

1901

Pages count

BibTex

@article{BUT49730,
  author="Zoja {Vlčková} and Laurent {Grasset} and Barbora {Antošová} and Miloslav {Pekař} and Jiří {Kučerík}",
  title="Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids",
  journal="SOIL BIOLOGY & BIOCHEMISTRY",
  year="2009",
  volume="41",
  number="9",
  pages="1894--1901",
  issn="0038-0717"
}