典型石化园区及周边区域大气PM_(2.5)组成和来源差异性

Composition and Source Difference of Atmospheric PM_(2.5)in Typical Petrochemical Park and Surrounding Areas

为完善中国典型石化园区及周边区域大气PM_(2.5)源解析数据库,探究不同功能区PM_(2.5)组成及来源差异性,文章利用单颗粒气溶胶质谱仪(SPAMS)分别采集连云港市徐圩新区生活区和石化区具有完整质谱信息细颗粒物8万个和22.9万个,并结合同期PM2.5浓度和气象数据对不同功能区内PM_(2.5)质谱特征、化学组分、总体源解析及内源贡献差异性进行了系统分析。结果表明,生活区和石化区SPAMS观测点PM_(2.5)平均质谱特征表现为均以碱金属Na^(+)和K^(+)、元素碳、有机碳、硝酸盐、硫酸盐为主要特征信号;化学组分方面,各功能区PM_(2.5)均以元素碳为首要组分,其中生活区最高占比达到58.3%,左旋葡聚糖占比次之,石化区占比最高达到20.2%;各功能区PM_(2.5)均主要受到机动车尾气源的影响,石化区的工业工艺源贡献更为显著,最高占比达到43.2%;在排除外源影响条件下,石化区受工地扬尘源影响最大,PM_(2.5)月均贡献值高达7μg/m^(3),工业工艺源月均贡献值最高达0.55μg/m^(3),主要源于石化企业排放的挥发性有机污染物的二次转化。生活区仍受车辆尾气影响最大(2.60μg/m^(3))。

To improve the analytical database of atmospheric PM_(2.5)sources in China’s typical petrochemical parks and surrounding areas,and explore the composition and source diversity of PM_(2.5)in different functional areas,single particle aerosol mass spectrometer(SPAMS)was used separately in the living area and petrochemical area of Xuwei New District,Lianyungang,for the collection of complete mass spectrum information of 80000 and 229000 fine particles.Combined with PM_(2.5)concentration and meteorological data over the same period,the mass spectrum characteristics,chemical components,total source analysis and endogenous contribution differences of PM_(2.5)in different functional areas were systematically analyzed.The results showed that the main characteristic signals of PM_(2.5)at SPAMS observation points in living and petrochemical areas were Na^(+)and K^(+),elemental carbon,organic carbon,nitrate and sulfate.In terms of chemical components,elemental carbon is the primary component of PM_(2.5)in all functional areas,among which the highest proportion of living areas is 58.3%,followed by levoglucosan,and the highest proportion of petrochemical areas is 20.2%.PM_(2.5)in each functional area is mainly affected by motor vehicle exhaust source.The industrial process source contribution in the petrochemical area is more significant,accounting for up to 43.2%.Under the condition of excluding the influence of external sources,the petrochemical area was most affected by the dust source of the construction site,with the monthly contribution of PM_(2.5)up to 7μg/m^(3),while industrial process source was as high as 0.55μg/m^(3),which was mainly due to the secondary conversion of volatile organic compounds(VOCs)emitted by petrochemical enterprises.The living area was still most affected by vehicle exhaust(2.60μg/m^(3)).