无定形氧化铁作为嫌气下NH4+氧化时电子受体的研究

通过¹⁵N示踪试验,以及根据嫌气条件下含¹⁵NH₄⁺培养液加无定形氧化铁后全氮回收量下降(损失¹⁵N约15%),以及产生¹⁵NO₂、¹⁵N₂O、¹⁵N¹⁴NO、¹⁵NO、¹⁵N₂和¹⁵N¹⁴N等含N气体的研究结果,初步证明无定形氧化铁可作为嫌气下NH₄⁺氧化时的电子受体,这可能是引起水田土壤中铵态氮肥损失的又一机理。目前因无各种合¹⁵N氧化物标准气体,无法对其形成的含¹⁵N气体组分进行定量,这一机理对氮素损失的贡献究竟有多大?尚需进一步研究。

INVESTIGATION ON AMORPHOUS FERRIC OXIDE ACTING AS AN ELECTRON ACCEPTOR IN THE OXIDATION OF NH4+ UNDER ANAEROBIC CONDITION

The loss of nitrogen in the medium treated with amorphous ferric oxide was investigated with ¹⁵N-labelled ammonium sulfate in the incubation flasks under anaerobic condition. The gaseous composition of the atmosphere air in the upperspace above the same medium solution in the serum bustle was analyzed by Organic Mass Spectrometer during the experiment period. It was found that various gaseous fractions of ¹⁵N and nitrogen Loss occurred in the medium contaming ¹⁵NH₄-N due to applying amorphous ferric oxide under anaerobic condition. The gaseous Fractions emited from the medium involved ¹⁵NO₂, ¹⁵N₂O, ¹⁵N¹⁴NO, ¹⁵NO, ¹⁵N₂ and ¹⁵N¹⁴N. The rate of ¹⁵N lass was about 15%.It was primarily proved that the amorphous ferric oxide may act as an electron acceptor in the oxidation of NH₄⁺-N under anaerobic condition. It rnay be another mechanism for nicrogen loss in paddy soils.