大气中酰胺的研究进展与展望

Research progress and prospect of amide in atmosphere

综述了近几十年酰胺的相关研究成果,对其基本性质、检测分析手段、浓度水平和分布特征、源和汇、环境和健康效应进行了系统地总结和探讨.外场检测结果表明大气中的酰胺主要分布于城市地区.气态酰胺的来源除自然源的一次排放及二次转化外,还包括污水和废物处理、机动车尾气、工业过程、烹饪等餐饮行业的生物质燃烧、烟草燃烧等人为一次源以及在碳捕获和农业等人为过程中的二次转化.二次转化的化学反应机制主要包括胺的氧化转化以及RO2与NO3自由基的反应等.大气中的酰胺在白天会被OH自由基有效去除,在晚上会被NO3自由基有效去除,在Cl自由基浓度较高的沿海地区或工业排放地区,会被Cl自由基有效去除.与自由基的反应均遵循相似的反应机制,即自由基夺取酰胺分子中的氢原子.此外,酰胺可通过参与新粒子生成(NPF)过程,对二次有机气溶胶(SOA)的生成、大气环境和人体健康产生影响.基于目前对大气中酰胺的研究现状分析,提出了研究展望,未来要加强大气复合污染背景下的检测和分析方法的完善,及对生-消反应机制以及环境健康效应的探讨.

In the present study,we reviewed the relevant researches on amide over the past few decades.The basic properties,observation and analysis techniques,concentration levels and distribution characteristics,sources and sinks,environmental and health effects of amides have been systematically summarized and discussed.Field observation result indicates that atmospheric amide is predominantly distributed in urban areas.The sources of gaseous amides include not only primary emissions from natural sources and secondary transformations,but also primary emissions from sewage and waste treatment,vehicle exhaust,industrial processes,biomass combustion in catering industries and tobacco smoke.Additionally,gaseous amides can be formed through secondary transformations in artificial processes such as carbon capture and agriculture.The chemical reaction mechanism of secondary transformations primarily involves the oxidation of amines and the reactions of RO2 with NO3 radicals.Atmospheric amides undergo efficient degradation by OH radical during daylight,by NO3 radical during nighttime,and by Cl radical in coastal or industrial regions with high Cl radical concentrations.The detailed degradation mechanism involves the H-atom abstraction by free radicals OH,NO3 and Cl from amide.Moreover,amides have the ability to participate in the new particle formation(NPF)to further affect the formation of secondary organic aerosols(SOA),atmospheric environment and human health.Based on the existing research of amides in the atmosphere,we put forward to improve the detection and analysis methods under the background of air pollution complex,to explore the mechanisms of sources and sinks reactions mechanism,to discover the environmental and health effect in the further researches.