title: Mitigation of nitrous oxide (N2 O) emission from swine wastewater treatment in an aerobic bioreactor packed with carbon fibers.
abstract: Mitigation of nitrous oxide (N2 O) emission from swine wastewater treatment was demonstrated in an aerobic bioreactor packed with carbon fibers (CF reactor). The CF reactor had a demonstrated advantage in mitigating N2 O emission and avoiding NOx (NO3  + NO2 ) accumulation. The N2 O emission factor was 0.0003 g N2 O-N/gTN-load in the CF bioreactor compared to 0.03 gN2 O-N/gTN-load in an activated sludge reactor (AS reactor). N2 O and CH4 emissions from the CF reactor were 42 g-CO2 eq/m(3) /day, while those from the AS reactor were 725 g-CO2 eq/m(3) /day. The dissolved inorganic nitrogen (DIN) in the CF reactor removed an average of 156 mg/L of the NH4 -N, and accumulated an average of 14 mg/L of the NO3 -N. In contrast, the DIN in the AS reactor removed an average 144 mg/L of the NH4 -N and accumulated an average 183 mg/L of the NO3 -N. NO2 -N was almost undetectable in both reactors.
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Tsukuba, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Ryoko
authors.initials: R
authors.lastname: Yamamoto-Ikemoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kawahara
authors.forename: Akifumi
authors.initials: A
authors.lastname: Ogino
authors.forename: Takashi
authors.initials: T
authors.lastname: Osada
mesh_terms: D000332:Aerobiosis; D000641:Ammonia; D000818:Animals; D019149:Bioreactors; D002244:Carbon; D000077482:Carbon Fiber; D058440:Denitrification; D005740:Gases; D008969:Molecular Sequence Data; D009585:Nitrogen Dioxide; D009589:Nitrogen Oxides; D009609:Nitrous Oxide / Q000032:analysis; D012722:Sewage / Q000032:analysis / Q000382:microbiology; D013552:Swine; D062065:Wastewater / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D000641:Ammonia; D002244:Carbon; D000077482:Carbon Fiber; D005740:Gases; D009585:Nitrogen Dioxide; D009589:Nitrogen Oxides; D009609:Nitrous Oxide; D012722:Sewage; D062065:Wastewater; C031701:nitrogen trioxide
keywords: carbon fibers; denitrification; nitrous oxide emission; swine wastewater