ANAEROBIC MICROBIOLOGICAL PROCESSES IN ANIMAL MANURE MANAGEMENT
Location: Bioenergy Research Unit
Title: Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions
Submitted to: American Society for Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 27, 2010
Publication Date: May 27, 2010
Citation: Spence, C., Whitehead, T.R., Cotta, M.A., Von Bernuth, R., Hengemuchle, S.M., Penner, D., Yokoyama, M.T. 2010. Borax and octabor treatment of stored swine manure to reduce sulfate reducing bacteria and hydrogen sulfide emissions [abstract]. American Society for Microbiology. Paper No. Q-1484.
Odorous gas emissions from stored swine manure are becoming serious environmental and health issues as the livestock industry becomes more specialized, concentrated, and industrialized. These nuisance gasses include hydrogen sulfide (H2S), ammonia, and methane, which are produced as a result of anaerobic digestion of materials present in the manure. Additionally, H2S is toxic and can reach hazardous levels during manure storage and handling. The objective of this study was to test the effectiveness of two boron derivatives, borax and octabor, on stored swine manure in an effort to target bacterial groups responsible for odor production and reduce odorous emissions. Borax and octabor treatments ranged from 0.1% to 1% and 0.05% to 0.5%, respectively. Swine manure was treated and stored for 30 days at ambient temperature and monitored every 72 hours for gas emissions. Aliquots of manure were taken at the start and end of the study for bacterial enumeration using quantitative polymerase chain reaction (qPCR). Total bacteria, as quantified by 16S rDNA-targetted qPCR, were significantly reduced by treatment of manure with 0.1%, 0.5%, and 1% borax and 0.25% octabor, as compared to an untreated control. The population of sulfate-reducing bacteria (SRB), measured by SRB-targeted qPCR analyses, was also reduced with treatments of 0.5% and 1% borax and by 0.1% octabor. Reduction in SRB also correlated with a reduction in H2S emissions. One percent borax was most effective in inhibiting H2S production, by almost 100% over 30 days. As borax was reduced from 1% to 0.1%, the magnitude of H2S reduction was correspondingly decreased in a dose dependent manner. Similar results were seen with octabor treated manure. Volatile fatty acid profiles of borax and octabor treated manure showed no marked differences to untreated controls. This study demonstrates that borax and octabor are effective at reducing both H2S emissions and bacterial populations in the manure. Controlling toxic emissions from livestock manure using non-toxic and environmentally friendly treatments such as boron derivatives will reduce the hazard of toxicity for farmers and livestock and also reduce the problem of nuisance odors.