摘要
基于2017年12月25日至2018年1月16日1 h时间分辨率的在线监测数据,对华南沿海城市——阳江市的大气PM_(2.5)质量浓度、化学组分和来源进行了分析.结果表明,采样时段阳江市PM_(2.5)中主要化学组分为OM、NO_(3)^(-)、SO_(4)^(2-)、NH_(4)^(+)和EC,质量浓度占比分别为32.75%、25.59%、16.41%、12.37%和4.82%.相比清洁过程,两次污染过程期间NO_(3)^(-)质量浓度均为清洁过程时段的6倍以上,增量明显高于其他组分,占比则均为清洁过程时段的2倍以上,分别占29.38%和30.81%.PMF解析结果表明,二次转化源是最主要的源,其分担率高达51.41%,其中NO_(x)二次转化源分担27.18%,是阳江市PM_(2.5)分担率最大的二次转化源.首要的一次排放源是机动车源(15.11%).污染过程期间NO_(x)二次转化源的分担率显著提升,从11.85%分别增至33.15%和36.96%,是阳江市大气PM_(2.5)污染形成的主要原因.本研究表明阳江市冬季PM_(2.5)污染特征已类似于大型和特大城市,即面临严峻的二次污染,应着重加强对硝酸盐的防治,同时注重机动车管控.
Based on the online measurements from December 25,2017 to January 16,2018,we investigated the chemical composition and sources of PM_(2.5)in Yangjiang,a South China coastal city.PM_(2.5)in Yangjiang mainly consisted of OM,NO_(3)^(-),SO_(4)^(2-),NH_(4)^(+)and EC,with proportions of 32.75%,25.59%,16.41%,12.37%and 4.82%in mass fraction,respectively.In two pollution events,the mass concentration of NO_(3)^(-)increased to over 6 times of that during clean period,much higher than the increments of other components.The mass fractions of NO_(3)^(-)in two polluted events increased to 29.38%and 30.81%,over twice of that in clean period.Source apportionment of PM_(2.5)were performed by Positive Matrix Factorization,which pointed out that secondary formation was the main source/process(51.41%)for PM_(2.5)in winter in Yangjiang.The secondary formation from NO_(x),contributing 27.18%to the total PM_(2.5)mass concentration,was the dominating secondary source.Vehicle exhausts were the biggest primary source(15.11%).In the pollution events,the contribution of the secondary formation from NO_(x)sharply increased from 11.85%to 33.15%and 36.96%,which should be considered as the dominating source of PM_(2.5)pollution in winter of Yangjiang.This study revealed that,as a coastal city,Yangjiang exhibited similar characteristics to those big cities and mega-cities in terms of the PM_(2.5)sources,i.e.,dominated by the secondary formation.It suggested that more effort for pollution control should be put into the reduction of nitrates as well as their precursor NO_(x),meanwhile a persistent control of vehicles in Yangjiang city is recommended.
作者
蒋斌
黄山
莫立志
黄钢
伍莉娜
刘袁
李光辉
张展毅
唐静玥
钟流举
邵敏
JIANG Bin;HUANG Shan;MO Lizhi;HUANG Gang;WU Lina;LIU Yuan;LI Guanghui;ZHANG Zhanyi;TANG Jingyue;ZHONG Liuju;SHAO Min(Institute for Environmental and Climate Research,Jinan University,Guangzhou 511443;Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality,Jinan University,Guangzhou 511443;JNU-QUT Joint Laboratory for Air Quality Science and Management,Jinan University,Guangzhou 511443;Yangjiang Environmental Monitoring Station,Yangjiang 529500;Focused Photonics Inc.,Hangzhou 310052;Guangdong Polytechnic of Environmental Protection Engineering,Foshan 528216)
出处
《南京信息工程大学学报（自然科学版）》
CAS
北大核心
2022年第2期137-147,共11页
Journal of Nanjing University of Information Science & Technology（Natural Science Edition）
基金
国家自然科学基金(41807302)
广东省自然科学基金(2018A030313384)
广东省科技创新战略专项(2019B121205004)。
关键词
华南沿海城市
PM_(2.5)在线监测
污染特征
来源解析
South China coastal city
PM_(2.5)
online measurement
pollution characteristics
source apportionment
