【摘要】 氨是大气中的碱性活性氮气体,其与酸性前体物反应形成的二次无机气溶胶是PM2.5的重要成分,影响着PM2.5重污染事件的发生.为响应我国在2017年开始实施的总理基金"农业排放状况及强化治理方案"研究目标和2018年《打赢蓝天保卫战三年行动计划》中提出的氨减排行动计划,开展了全国尤其是京津冀及周边地区农业氨减排工作助力区域农业资源高效利用及大气污染治理.我国2018年氨排放为9.90×10⁶ t其中京津冀及周边地区"2+26"城市是我国氨排放强度较大的区域（2018年其氨排放量为1.41×10⁶ t）这与观测到的大气氨浓度结果相吻合.农业排放是主要的大气氨来源农业源中畜禽养殖业约占50%种植业约占30%,但在对城市大气氨来源的解析中发现,贡献较大的是非农业源氨.通过模型模拟氨减排对大气污染物的影响发现在减排40%的情景下,可削减华北地区大气中50%的硝酸根离子和15%～20%的PM_2.5峰值浓度.在整合分析的农业氨减排技术清单中,优化氮肥投入总量是种植业控制氨排放的基础结合氮肥深施,或通过有机肥、低挥发性氮肥和添加脲酶抑制剂的稳定性氮肥来替换普通氮肥可获得较好的控氨效果;养殖业方面,对猪、鸡、牛等主要畜禽养殖场以低蛋白日粮为基础,通过改善圈舍管理、优化粪尿处理处置、提升有机肥农田施入技术等可实现畜牧养殖的全链条氨减排.结合我国氨排放现状和减排潜力提出了针对我国的氨减排目标建议强化大气氨监测并结合溯源技术定量化氨来源加强重点区域氨减排技术的推广和示范,为打赢蓝天保卫战提供科学理论和技术支撑.更多还原

【Abstract】 Ammonia is an alkaline reactive nitrogen gas in the atmosphere.A large amount of ammonia is emitted due to increasing anthropogenic activities such as intensive farming and livestock production in agriculture,causing a series of eco-environmental problems.Ammonia can react with acidic precursors（such as SO₂ and NO_x） to form secondary inorganic aerosols,which are the main components of PM_2.5,leading to severe haze episodes that reduce air quality and affect public health.In response to the research objectives of the Premier’s Fund ‘Agricultural Emission Status and Enhanced Governance Plan’ implemented in 2017,and the ammonia emission reduction action plan proposed in the ’Three-year Action Plan for Winning the Blue Sky Defense War’ in 2018,research on the reduction of agricultural ammonia emission in China,especially in the Beijing-Tianjin-Hebei and surrounding areas,was carried out to improve the efficient utilization of regional agricultural resources and air pollution control.In 2018,China’s total ammonia emissions were 9.90×10⁶ t,with the largest emissions in the Beijing-Tianjin-Hebei and surrounding regions（’2+26’ cities）（1.41×10⁶ t）,which was consistent with the measured ammonia concentration distribution across China.For example,high ammonia concentrations occurred in the North China Plain,where the ’2+26’ cities are located.Agricultural emissions were the main ammonia sources,and 50% and 30% of total ammonia emissions came from livestock and crop production systems,respectively.However,non-agricultural sources（such as industry and traffic） made a larger contribution in urban areas,based on nitrogen isotope source apportionment.We simulated an ammonia mitigation scenario（40% reduction） in the North China Plain,which reduced NO₃^-concentration by 50% and the peak concentration of PM_<sub>2.5 by 15%-20%.Effective ammonia mitigation actions should be taken urgently to improve air quality.For ammonia emission reduction in crop production,there is an urgent need to control synthetic fertilizer application rates.However,using deep placement of fertilizers or replacing traditional fertilizers（such as urea） with organic manures,nitrate-based fertilizers and enhanced efficiency fertilizers could achieve a higher reduction.For livestock production systems,we identified a series of ammonia reduction options for pigs,broilers and beef production,using a low protein diet as the base measure,followed by improved housing and manure/waste management with optimized field application of manure,urine and slurry.Based on the ammonia emission status and the reduction potential,we propose an ammonia reduction goal for China.This must be accompanied by improved atmospheric ammonia monitoring and isotope source apportionment to identify sources to prove effectiveness of the technologies in key areas（ammonia pollution hot spots） and improve their uptake.This research will provide theoretical and technological support for better control of air pollution and a return to the ’blue skies’.更多还原