TITLE:
Effects of Heavy Metal Ions (Fe3+, Cu2+, Zn2+ and Cr3+) on the Productivity of Biogas and Biomethane Production
AUTHORS:
N. B. Golub, A. V. Shynkarchuk, O. A. Kozlovets, M. V. Kozlovets
KEYWORDS:
Heavy Metal, Iron, Zinc, Copper, Сhromium, Biogas, Biomethane
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.13 No.1,
January
29,
2022
ABSTRACT: It was shown that the concentration of heavy metal
ions Fe3+, Cu2+, Cr3+ and Zn2+,
which are contained in the fermentation medium, affects the process of biogas
production. The aim of this paper was to establish the concentration of ions,
which makes it possible to increase the yield of biogas and the methane content
in it. The total yield of biogas per unit of dry organic matter, methane and
the kinetics of changes in the yield of biogas during fermentation of cattle
manure in the presence of different concentrations of metal ions in the
anaerobic environment. It was established that the content of Fe3+,
Cu2+ is up to 80 mg/dm3, Cr3+ and Zn2+ is up to 50 mg/dm3 in the medium lead to increased methane
production by anaerobic association of microorganisms due to the effect on the activity of enzyme systems in
comparison with the sample without the addition of metal ions. It was
found that the rational concentrations to increase the methane yield in the
biogas obtained by fermentation of cattle manure are: Fe3+-20 - 40 mg/dm3,
Cu2+-40 - 60 mg/dm3, Cr3+-10 mg/dm3.
The increase in the concentration of metal ions above rational values leads to
a decrease in the methane content in biogas. It was shown that zinc ions have a
positive effect on methane production, but reduce the total biogas yield and, accordingly, the degree of conversion of
organic raw materials. Therefore, the rational concentration of Zn2+ in the fermentation medium is 10 mg/dm3.