红外光谱技术测量氨排放的研究进展

Research progress of measuring ammonia emission using infrared spectroscopy

氨气(NH_(3))是大气中重要的碱性气体,可与空气中的酸性气体结合,从而导致雾霾的产生,因此空气中NH_(3)的含量是衡量空气质量优劣的重要依据之一。NH_(3)的人为排放源主要分为农业源和非农业源,其中农业源NH_(3)排放量占NH_(3)排放总量的80%,主要来源包括畜禽养殖业、畜牧业的排泄物和种植业(农田)的氮肥施用。鉴于NH_(3)的重要环境效应,如何精准测量NH_(3)排放通量成为建立NH_(3)排放清单与控制NH_(3)排放的重要前提与基础。本文主要总结了傅里叶变换光谱、光声光谱和可调谐吸收光谱三种红外光谱技术测量NH_(3)的基本原理和测量技术的最新研究进展,并对适用于农业NH_(3)排放通量估算的涡度协方差法(EC)和后向拉格朗日法(bLS)进行了介绍。

Ammonia(NH_3)is an important alkaline gas in the atmosphere,which can react with acid gas in the air leading to the formation of haze through dry and wet deposition.Therefore,the content of NH_(3)in the air is one of the important criteria for measuring the quality of air.The anthropogenic emission sources of NH_(3)are mainly divided into agricultural and non-agricultural sources,with agricultural sources accounting for 80%of the total NH_(3)emission,and the main agricultural sources include livestock and poultry breeding,animal husbandry excreta and nitrogen fertilizer application in cropland.Given the significant environmental effects of NH_3,accurate measurement of NH_(3)emission flux from agriculture has become an important research field for establishing NH_(3)emission inventory and controlling NH_(3)emission.In this paper the basic principle of measuring ammonia by three infrared spectroscopy measurement techniques,namely Fourier transform spectrum,photoacoustic spectrum and tunable absorption spectrum,and the development status and applicable scenarios of the corresponding measurement techniques at home and abroad are summarized.The principle and application of eddy covariance method(EC)and backward Lagrange method(bLS),which are widely used in the estimation of ammonia emission flux from animal husbandry and cropland,and several mature NH_(3)flux calculation software based on EC or BLS algorithm are also introduced.Finally,the future development direction of NH_(3)measurement technology and ammonia flux emission estimation is prospected.