Researchers: Achintya N. Bezbaruah
Project sponsors: National Institute of Food and Agriculture (NIFA) of USDA (01/2015-01/2018)
Due to increasing feed costs and environmental concerns livestock production facilities are employing technologies to improve feed efficiency and reduce their environmental impact. Silver and zinc nanoparticles (NPs) are added to animal feeds to control microbial proliferation and promote animal growth, respectively. Nanoparticles are excreted and their impacts on livestock manure management are unknown. Digestion of manures is dependent on microbial populations that can be adversely effected by the presence of these metals. Microorganisms exposed to metals associated with NPs, particularly ones coated with polymers have reduced exposure response relative to metals and uncoated NPs. Such novel technologies are capable of reducing gaseous emissions during anaerobic storage of manure due to their adsorption of H2S. Very limited published reports address the transformations taht NPs undergo in waste systems and/or the exposure response of bacteria to NPs in these systems. The aims of this researh were to: (1) design and employ permeable polymers to entrap nanoparticles that adsorb H2S from manure and reduce their biocidal properties, (2) quantify H2S and GHGs emissions and determine the chemical and biological reactions controlling these emissions during anaerobic storage of manure containing NPs, (3) study the fate and transport of NPs in livestock manure. This research was conducted by a cross-disciplinary team consisting of agricultural engineers, environmental engineers, and microbiologists.