Fate, Transport and Transformation of Ammonia Emissions from Animal Feeding Operations and Their Impacts on Air-Soil Health

在美国，动物饲养业务(AFO)每年排放约250万吨氨，占全国氨排放总量的85%。由于氨对空气和水质量、土壤健康和生态系统健康的不利影响，从AFO释放的氨的去向、运输和转化越来越受到关注。该项目将促进对氨的去向和迁移的科学了解，以更好地了解AFO排放的氨对生态和环境的影响。这些知识将通过各种教育和推广计划传递给学生、行业、监管机构和公众，这些计划将增加公众对AFO释放氨的环境影响的了解，并为决策者提供信息，以更好地保护人类和生态健康。该项目将完成三个具体目标：(1)量化AFO环境中氨排放、土地利用和气象条件对氨和颗粒物干沉降量的影响；(2)估计排放的氨转化为二次无机细颗粒物的情况，即氨排放、源距离、大气化学条件和气象条件的影响；以及(3)量化氨和铵离子沉积对土壤化学和生物性质的影响，包括微生物生物量、氮素转化的化学计量和pH。将在北卡罗来纳州的一个家禽设施通过多学科、多媒体方法同时调查氨排放、沉积和转化以及空气-土壤属性。将使用微气象和阻力方法来确定氮沉积速率。将考察土壤质量指标和氮素循环速率对氮素沉积的响应。根据对酸性气体、氨和二次无机细颗粒物离子的同时测量，将量化氨中和势，以评估颗粒物形成的潜力。这项工作如果成功，将产生关于以下方面的新知识：(1)减少氮沉积对农村地区土壤生态系统的影响；(2)由于AFO氨排放和环境气象和化学条件而形成的次生无机细颗粒物；(3)热力学平衡模型ISORROPIA-II在模拟农业环境中次生无机细颗粒物形成的适用性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，认为值得支持。

In the United States, animal feeding operations (AFOs) emit approximately 2.5 million tons of ammonia per year, contributing 85% of the total ammonia emissions in the nation. The fate, transport, and transformation of ammonia released from AFOs are an increasing concern due to the adverse effects of ammonia on air and water quality, soil health, and ecosystem health. This project will advance the scientific understanding of ammonia fate and transport to better understand the ecological and environmental impacts of ammonia emissions from AFOs. This knowledge will be transferred to students, industries, regulators, and the public through various educational and outreach programs that will increase the public's understanding of the environmental impacts of ammonia release from AFOs, as well as to inform policy makers to better protect human and ecological health.This project will accomplish three specific objectives: (1) Quantify ammonia and particulate ammonium ion dry deposition impacted by ammonia emissions, land usage and meteorological conditions in AFO environments; (2) Estimate the transformation of emitted ammonia to secondary inorganic fine particulate matter as impacted by ammonia emissions, distance from source, atmospheric chemical conditions, and meteorological conditions; and (3) Quantify the impacts of ammonia and ammonium ion depositions on soil chemical and biological properties, including the microbial biomass, thestoichimetry of nitrogen transformations, and pH. Ammonia emission, deposition and transformation, and air-soil properties will be simultaneously investigated through a multi-discipline, multi-media approach at a poultry facility in North Carolina. Micrometeorological and resistance methods will be used to determine nitrogen deposition rate. Response of the soil quality metrics and nitrogen cycling rates to nitrogen deposition will be examined. Based upon simultaneous measurements of acidic gases, ammonia, and secondary inorganic fine particulate matter ions, ammonia neutralization potential will be quantified to assess the potential for particulate matter formation. This work, if successful, will produce new knowledge about: (1) the impact of reduced nitrogen deposition on soil ecosystems in rural areas; (2) the formation of secondary inorganic fine particulate matter in response to AFO ammonia emissions and ambient meteorological and chemical conditions; (3) applicability of thermodynamic equilibrium model ISORROPIA-II for the simulation of secondary inorganic fine particulate matter formation in agricultural environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.