Characteristics and kinetics of ammonia and N_2O emissions of aged refuse irrigated from landfill leachate

摘要

This is the first attempt to report the gaseous nitrogen emissions from landfill leachate filtration methods by irrigating the aged refuse. A first-order reaction model was a good fit for the increase in ammonia emissions from aged refuse, clay and sandy soil incubated for 120 h after adding the leachate-N solution. The emissions of ammonia and N_2O by the three experimental materials fit well to first-order and zero-order models, respectively. The maximum ammonia emission from aged refuse was approximately 1.17 mg NH_4~+-N kg~(-1) d.w. and the calculated emission factor was 1.95‰ which was 3.76 and 2.67 times lower than that of sandy and clay soils, respectively. The tendencies of NH_4~+-N nitrification and NO_3~--N generations fit well to the zero-order reaction model and the net nitrification rate by the aged refuse was 1.30 (p ＜ 0.05) and 1.71 (p ＜ 0.05) times that of clay soil and sandy soil, respectively. At the same time, the net NO_4~--N generation rate by the aged refuse was 1.56 (p ＜ 0.05) and 2.33 (p ＜ 0.05) times that of clay soil and sandy soil, respectively. The quantity of nitrogen emitted by aged refuse as N_2O was 2.46 times greater than that emitted as ammonia. The emission factor for N_2O from aged refuse was 8.28 (p ＜ 0.05) and 16.11 (p ＜ 0.05) times greater than that of clay and sandy soils, respectively. For the leachate irrigation, N_2O emissions should be of greater concern than ammonia emissions.