规模化蛋鸡养殖舍颗粒物排放特性、源解析及二次无机气溶胶形成机制研究

Particulate matter (PM) emissions from livestock housing have been a global issue for influencing the health of livestock and people, also the health of ambient environment. With the upgrade of livestock house structure and farm management, also the deeper knowledge of PM hazard on health as well as the high intention on the relationship between the NH3 emission and the haze event, the former monitoring information of PM emissions in livestock house can’t meet the urgent demand for evaluating and mitigating of the housing PM emissions nowadays. .The PM emissions (including TSP, PM10 and PM2.5) from a typical concentrated layer house would be studied here, including exploring the PM emission characteristics, constructing models for the housing PM emissions. Also the source profiles and receptor profiles would be built with the analysis of morphological, chemical and spectroscopic of the housing PM and the possible emission sources; then PM source apportionment would be conducted through Positive Matrix Factorization method (PMF) and Multiple Linear Regression method (MLR), thus identifying the key sources for the housing PM emissions also the according contributions. Finally, combining the emission characteristics of NH3, SO2 and NO2 in house, the formation mechanism of secondary inorganic PM2.5 and PM10 in house can be elucidated. .The results of this study would be of great significance for compiling the PM emission inventory for livestock industry, the precisely designing of mitigation strategies, as well as understanding and controlling for the secondary inorganic PM2.5 formation in ambient environment.

畜舍颗粒物(PM)排放已成为影响人畜健康及环境健康的全球性问题。随着畜舍结构、管理的升级，以及近年来对于PM特性危害，对畜禽养殖NH3排放与环境灰霾形成相关性的高度关注，前期对于畜舍PM排放的监测已远不能满足当前对于畜舍PM排放评价、防控的迫切需求。本研究拟以典型规模化蛋鸡舍为研究对象，在典型生产周期内对舍内PM(包括TSP、PM10和PM2.5)的排放特性规律进行研究，构建舍内PM排放模型；同时通过对PM物理形态、光谱特征、化学组成特性的分析，构建PM源成分谱和受体谱；采用正定矩阵法(PMF)和多元线性模型法(MLR)对PM排放进行源解析，识别其关键排放源及相应贡献率；同时结合对舍内NH3、SO2、NO2排放的分析，对舍内二次无机PM2.5、PM10粒子生成机制进行探讨。研究结果对于畜禽养殖业PM排放清单的编制，减排策略的精确制定，以及环境二次无机粒子形成机理的认识和防控均具有重要意义。

针对畜舍PM排放特性不清，规律不明，源解析研究缺乏，以及舍内富NH3条件下二次PM形成特性不明等问题，本研究于德青源一单栋存栏量为10万羽蛋鸡的规模化清粪带蛋鸡舍对相关内容开展了研究。研究结果为：.1）通过对养殖舍夏秋冬三季PM、NH3等气体的持续监测，得到夏秋冬PM2.5，PM10排出浓度为100-144，354-828μg/m3，排放通量为1.9-9，10.9-32.1 mg/hen/d；冬季TSP排出浓度为3280±1320μg/m3，通量为27.6±12.5 mg/hen/d。清粪操作、鸡采食、走动等导致了对饲料、鸡粪等PM主要源的扰动，导致PM排放升高。舍外环境温度通过影响通风量成为影响PM浓度及排放的关键因素。夏季温度高，通风量大，PM浓度低，但是排放通量大。舍外环境温度、舍外CO2本底浓度，以及舍内PM2.5浓度等是构成蛋鸡舍PM2.5和PM10排放模型的关键参数。.2）构建养殖舍PM源解析方法一套。采集舍内190组PM样品，对其上31种元素，9种离子，及2种C组分共42种物种的分析，构建了鸡舍PM2.5和PM10的受体谱。此外，通过对鸡粪、饲料、鸡舍尘土等鸡舍PM可能源的采集及再气溶胶化，以及结合对本底进气PM上相应组分的解析，构建了舍内PM源成分谱。通过模型进行源解析，发现饲料和粪便对于PM2.5合计贡献了47.1%；此外，本底进气，鸡舍尘土，及二次无机气溶胶离子（SIAs）对舍内PM2.5的贡献分别为26.4%，21.3%和5.1%。饲料，粪便，舍内尘土，SIAs对PM10贡献分别为52%，31.8%，13.5%和2.7%。.3）结合对鸡舍SIAs（NO3-, SO42-, NH4+）的解析，发现SIAs对于PM2.5的贡献更大，且SIAs形成的季节特性差异大。SIAs对于夏季舍内PM2.5和PM10的贡献分别为11.4%和9.6%，但是在秋冬季贡献比例低于1.4%。同时通过对舍内及环境本底NH3，SO2，NOx等SIAs前体气体的监测，认为SO2和NOx主要来源于环境本底进气；此外，夏季NOX可能部分来自粪便分解。舍内SIAs的形成主要是在夏季较高的温度和湿度条件下，舍内丰富的NH3与舍内NOx和SO2等反应形成大量的SIAs。.研究结果对于畜牧业PM排放清单的编制，减排策略的精确制定，及养殖NH3对二次PM形成贡献的认识和防控具有重要意义。