title: Spatial nitrifications of microbial processes during composting of swine, cow and chicken manure.
abstract: Composting is a widely-used method to recycle the nutrients in livestock manure for agriculture. The spatial stratifications of microbial processes inside the manure particle that determine organic and nitrogen transformation are virtually unclear. Here, we show the evolution of the interior microenvironment of swine, cow and chicken manure by using microelectrodes during forced-aeration composting. Composting has generally been regarded as an aerobic bioprocess, however, the long-existing of a large anoxic zone inside these manures was confirmed during the active phase in this study. The profile of the oxidation-reduction potential dramatically decreased first and then gradually increased. The spatial difference in the ammonia concentration was not significant, but nitrate concentration continuously decreased with depth. The anoxic condition within the manure particle was demonstrated to be a primary cause of the severe ammonia emission and the long composting period. These founding provided a new insight toward "aerobic" composting process and a sound foundation for the development of efficient composting technology.
authors.affiliation: School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resource and Environment (SKLUWER), Harbin Institute of Technology, 73 Huanghe road, Harbin, Heilongjiang 150090, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.affiliation: School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resource and Environment (SKLUWER), Harbin Institute of Technology, 73 Huanghe road, Harbin, Heilongjiang 150090, China.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resource and Environment (SKLUWER), Harbin Institute of Technology, 73 Huanghe road, Harbin, Heilongjiang 150090, China.
authors.forename: Xiangkun
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resource and Environment (SKLUWER), Harbin Institute of Technology, 73 Huanghe road, Harbin, Heilongjiang 150090, China.
authors.forename: Nanqi
authors.initials: N
authors.lastname: Ren
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D008372:Manure / Q000382:microbiology*; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D012037:Refuse Disposal / Q000379:methods*; D013552:Swine
chemical_list: D008372:Manure; D009584:Nitrogen