上海市浦东新区大气细颗粒物中重金属污染特征及来源解析

Characteristics and Sources of Heavy Metals in Air Fine Particulate Matter in Pudong New Area,Shanghai

于2017年对浦东城区和郊区大气PM2.5中的重金属特征和来源进行了分析。结果表明,K、Fe、Na、Ca、Mg、Al等矿物元素为浦东新区PM2.5中含量最高的金属元素,其中K的年均值为297.3 ng/m^3。浦东城区的不同元素在季节变化上呈现较为不同的变化规律,郊区的金属元素值大部分呈现春季先逐月下降,在夏、秋季有起伏波动,在10月之后逐渐上升;沙尘+道路源+建筑扬尘、煤燃烧、工业排放、金属冶炼、船舶排放、海盐+垃圾焚烧+生物质燃烧为浦东城区PM2.5中重金属元素的6大类主要来源。其中沙尘+道路源+建筑扬尘对Ca的贡献率为82.7%,煤燃烧对As的贡献率为86.6%,工业排放对SO4^2-的贡献率达到65.9%,金属冶炼对Cr的贡献率为75.7%,船舶排放对V的贡献率为97.5%、海盐+垃圾焚烧+生物质燃烧对Cl^-的贡献率为93.0%。煤燃烧和金属冶炼主要来自于西部方向。船舶排放分布在长江口及其延伸带。浦东新区PM2.5中重金属元素的质量浓度与本地源排放强度、外界传输和大气扩散条件均有密切关系。

The characteristics and sources of heavy metals in PM2.5 of Pudong urban and suburban areas in 2017 were analyzed.The results showed that K,Fe,Na,Ca,Mg and Al were the dominant metal elements in PM2.5.The annual mean value of K was 297.3 ng/m^3.In Pudong urban area,different elements showed different variation characteristics.While most of the elements in suburban area varied as follows:there was a monthly decline during spring,and fluctuations were observed in summer and in fall,but an increase was found after October.Source analysis showed that:dust+road source+construction dust,coal combustion,industrial emissions,metal smelting,ship emissions,sea salt+garbage incineration+biomass combustion were the six main sources of heavy metal elements in PM 2.5 in urban areas of Pudong new area.The contribution rate of dust+road source+construction dust to Ca was 82.7%,coal combustion to As was 86.6%,industrial emissions to SO4^2- was 65.9%,metal smelting to Cr was 75.7%,ship emissions to V was 97.5%,sea salt+garbage incineration+biomass combustion to Cl^- was 93.0%.The main sources of coal combustion and metal smelting were from the west.Ship discharge distributed in the Yangtze estuary and its extension zone.The concentration of heavy metal elements in PM2.5 in Pudong New Area is closely related to the emission intensity of local sources,external transmission and atmospheric diffusion conditions.