Reduction of nitrous oxide emission from pig manure composting by addition of nitrite-oxidizing bacteria.
Nitrous oxide (N2O) is emitted from pig manure composting, and the emission correlates with nitrite (NO2-) accumulation in the composting material. In the present study, we added nitrite-oxidizing bacteria (NOB)to inhibit NO2- accumulation and evaluated its effect on N2O emission in a laboratory-scale composting experiment. Mature pig manure compost (MPMC) containing NOB at 10(6) MPN g(-1) WM or cultured MPMC (cul-MPMC) NOB at 10(11) MPN g(-1) WM was added after the thermophilic phase of composting. The addition of these materials prevented NO2- accumulation, promoting oxidation to nitrate (NO3-), whereas the accumulation of NO2- occurred in the material to which NOB was not added as the result of the delayed growth of indigenous NOB compared with that of ammonia-oxidizing bacteria (AOB). The pattern of NO2- in the material agreed with that of N2O emission; therefore, N2O emission ceased rapidly when NOB was added. Emission rates of N2O were 88.5 (no addition), 17.5 (MPMC addition), and 20.2 (cul-MPMC addition) g N-N2O kg(-1) TNinitial, respectively. Improving composition of nitrifying communities for complete nitrification promotion would be useful to establish a composting method with low N2O emission.
Fukumoto
Yasuyuki
Y
Pollution Control Research Team, National Institute of Livestock and Grassland Science, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan. yasuyuki@affrc.go.jp
Suzuki
Kazuyoshi
K
Osada
Takashi
T
Kuroda
Kazutaka
K
Hanajima
Dai
D
Yasuda
Tomoko
T
Haga
Kiyonori
K
D000641:Ammonia / Q000737:chemistry; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D003247:Conservation of Natural Resources; D005740:Gases; D008372:Manure; D009566:Nitrates; D009573:Nitrites / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D017672:Nitrogen Compounds / Q000737:chemistry; D009609:Nitrous Oxide / Q000032:analysis*; D012037:Refuse Disposal; D013552:Swine; D013696:Temperature; D013997:Time Factors
D005740:Gases; D008372:Manure; D009566:Nitrates; D009573:Nitrites; D017672:Nitrogen Compounds; D000641:Ammonia; D009609:Nitrous Oxide; D009584:Nitrogen