泉州市PM_(2.5)时空变化特征及其影响因素

Temporal and Spatial Variation Characteristics of PM_(2.5) in Quanzhou and Their Influential Factors

为研究泉州市PM_(2.5)的时空变化特征及其影响因素,以期为有针对性地提出大气污染防治对策提供科学依据,选取2016年泉州市主城区的一城区点和一背景点大气监测站在线PM_(2.5)与污染气体数据,并同期采集PM_(2.5)样品进行综合分析.结果表明:1)城区点和背景点的年均PM_(2.5)质量浓度分别为(31.06±20.96)μg/m^3和(20.59±10.29)μg/m^3,低于我国空气质量标准中的年均质量浓度二级限值;2)PM_(2.5)的月均质量浓度在2—3月最高,其次为11月,这可能与污染物远源传输和不利天气条件的双重影响有关;3)冬、春季城区点PM_(2.5)同时受到一次排放污染物(如工业、机动车)和二次颗粒物的共同影响,而背景点PM_(2.5)则和较多的二次反应产物生成相关;4)夏、秋季两个站点PM_(2.5)和SO_2、NO_2的相关性明显提升,伴随着夏、秋季主导的西南风,验证了西南部工业区排放污染物传输的影响,此外,城区点PM_(2.5)质量浓度还受到粉尘的显著影响;5)硫氧化率和氮氧化率在冬、春季高于夏、秋季,这可能与上游区域污染物的远源传输相关.上述结果为全面掌握泉州市大气颗粒物的分布规律提供了基础数据.

To investigate temporal and spatial variation characteristics in PM2.5 in Quanzhou and their influential factors,so as to provide scientific evidences for control countermeasures on air pollution,on-line PM2.5 and pollutant gases,and concurrent PM2.5 off-line samples were collected and analyzed at two sites in Quanzhou.The results were as follows:1)The annual average PM2.5 mass concentration at the urban site and background site were(31.06±20.96)μg/m^3 and(20.59±10.29)μg/m^3,respectively,both of which met the Class 2 limit values of the National Ambient Air Quality Standard(NAAQS).2)The maximum monthly average mass concentration of PM2.5 was detected in February to March and November.The occurrence of pollution episodes might be related to the transport of pollutants as well as unfavorable meteorological conditions.3)In winter and spring,PM2.5 was affected by both the primary emission(i.e.,motor vehicle and industrial emissions)and secondary formation at the urban site,while the secondary particles formation was the main factor influencing PM2.5 mass concentrations at the background site.4)In summer and autumn,positive correlations were found between PM 2.5 and SO2,NO2 at the two sites,along with dominant southwest wind,confirming the influence of industrial production activities at the southeast.Meanwhile,PM2.5 at the urban site was also influenced by crustal matters.5)SOR and NOR in winter and spring were higher than those in autumn and summer,which may probably be related to pollutants transport from upwind areas.Overall,our study provides the basic data about the distribution of PM 2.5 in Quanzhou.