Quantifying N2O emissions and production pathways from fresh waste during the initial stage of disposal to a landfill

Autor: Shaohua Chen, Mingsheng Jia, Han Zhang, Xiaojun Wang, Chih Ming Kao, Songqing Pan
Rok vydání: 2017
Předmět:
Zdroj: Waste Management. 63:3-10
ISSN: 0956-053X
Popis: Intensive nitrous oxide (N 2 O) emissions usually occur at the working face of landfills. However, the specific amounts and contributions of the multiple pathways to N 2 O emissions are poorly understood. N 2 O emissions and the mutual conversions of N-species in both open and sealed simulated landfill reactors filled with fresh refuse were examined during a 100-h incubation period, and N 2 O sources were calculated using 15 N isotope labelling. N 2 O peak fluxes were above 70 μg N kg −1 waste h −1 for both treatments. The sealed incubation reactors became a N 2 O sink when N 2 O in the ambient environment was sufficient. The total amount of N 2 O emissions under sealed conditions was 2.15 ± 0.56 mg N kg −1 waste, which was higher than that under open conditions (1.91 ± 0.34 mg N kg −1 waste). The NO 2 − peak appeared prior to the peak in N 2 O flux. The degree and duration of total nitrogen reduction in open incubations were larger and longer than those of sealed incubations and could possibly be due to oxygen supplementation. Denitrification (DF) was a major source of N 2 O generation during these incubations. The contribution of the DF pathway decreased from 89.2% to 61.3% during the open incubations. The effects of nitrification (NF) and nitrification-coupled denitrification (NCD) increased during the increasing phase and the decreasing phase of N 2 O flux, contributing 24.1–37.4% and 31.7–34.4% of total N 2 O emissions, respectively. In sealed treatments, the DF pathway accounted for more than 90% of the total N 2 O emission during the entire incubation.
Databáze: OpenAIRE
Externí odkaz: