Effect of magneto-active filling on the effectiveness of methane fermentation of dairy wastewaters

ABSTRACT

The goal of this study was to determine the effectiveness of methane fermentation in dairy wastewaters in terms of the volume and qualitative composition of biogas produced in an anaerobic reactor with magneto-active filling (MAF) mounted in the zone of hydrolysis and acidogenesis. Experiments were conducted on the fractional-technical scale in a vertical fermentation reactor with a labyrinth flow. Synthetic dairy wastewaters prepared based on milk powder were used as a substrate. The analyzed filling was made of plastic covered with iron and copper powders and was additionally equipped with fluid magnetizers (FM) in the form of neodymium magnets. The study demonstrated that MAF incorporation into the technological system significantly improved the effectiveness of biogas production, increased methane concentration and lowered the content of hydrogen sulfide in gaseous metabolites of fermentative bacteria. A significant increase was also observed in the effectiveness of COD removal from dairy wastewaters. The reported experiments proved a correlation between the effectiveness of methane fermentation and the number of MAF elements introduced into the anaerobic reactor.

KEYWORDS:

• Constant magnetic field
• active filling
• methane fermentation
• dairy wastewaters
• biogas

Acknowledgments

The study was conducted as part of the Strategic Programme, Innovative Systems of Technical Support for Sustainable Development of Economy, within the Innovative Economy Operational Programme.

Abbreviations

cm3/g CODrem	=	biogas production in cubic centimeter per gram of chemical oxygen demand removal,
COD	=	chemical oxygen demand,
FM	=	fluid magnetizers,
HSD	=	honestly significant difference test,
LFAR	=	labyrinth flow anaerobic reactor,
o.d.m.	=	organic dry matter,
MAF	=	magneto-active filling,
Oe	=	Oersted,
PE-HD	=	high-density polyethylene,
PHA	=	polyhydroxyalkanoates,
PHB	=	poly-3-hydroxybutyrate,
PHV	=	poly-3-hydroxyvalerate,
ppm	=	parts per million,
SBR	=	sequencing batch reactor,
SMF	=	stable magnetic field,
T	=	Tesla,
TCD	=	thermal conductivity detector,
UAF	=	upflow anaerobic filter,
V	=	volume,
v/v	=	volume per volume

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Strategic Programme, Innovative Systems of Technical Support for Sustainable Development of Economy, within the Innovative Economy Operational Programme no. POIG.01.01.02-14-034 fundedby National Centre for Research and Development.