太湖地区井水中溶解N_2O及其排放的研究

Dissolved N_2O concentrations and its emissions of well water in Taihu Lake Region.

水体是氧化亚氮(N_2O)排放的重要来源,连续监测太湖地区井水水面N_2O排放通量和井水中溶解N_2O浓度以及不同深度水样N_2O浓度结果表明,井水N_2O-N年均排放通量为90.85μg/m^2·h,井水中溶解N:O-N浓度年均高达13.09μg/kg,不同层次水样N_2O浓度差异明显,且时间差异显著,暖季井水有作为N_2O汇的趋势,但仍以N_2O源为主导作用。水体N_2O排放通量与井水中溶解N_2O浓度呈显著正相关,且N_2O-N浓度与NO_3^--N浓度和水温呈显著正相关,井水中的反硝化作用强烈,井水是N_2O的重要来源。

Aquatic systems are an important source of nitrous oxide emissions. N2O concentrations and fluxes from water surface and its concentrations at both the top and the bottom of well water were monitored in Taihu Lake Region. The results show that high N2O-N concentrations (13. 09μg/kg) are dissolved in well water, resulting in high N2O-N fluxes (90.85μg/m2·h) from well water surface. Analysis of N2O concentration dissolved at the top and the bottom of water suggests that during the warm season, the well water may be served as a sink for N2 O and there is an obvious difference between the top and the bottom water and between different sampling times. There exists a significant positive relationship among dissolved N2O concentration, N2O flux, nitrate concentration and water temperature. The well systems are an important source of N2O and denitrification is proceeding actively in the well water.