Pollution Characteristics And Source Analysis Of Atmospheric Particulate Matter In Turpan City

Turpan is one of the main transportation hubs of the new Silk Road in "the Belt and Road" and also an important tourist city in China.The excellent atmospheric environment quality is an important aspect of a tourist city.Based on the needs of the"Turpan City Atmospheric Environmental Quality Limits Compliance Plan",the present study aims to provide a scientific basis for the planning and implementation of this plan in order to reach the goals of the Blue Sky Protection Campaign in Turpan.The research conducted includes the pollution characteristics,source pathways and different seasonal characteristics of the atmospheric particulate matter in Turpan and also includes source analysis methods relevant to this case study.The main research questions to be solved in this study are:how to characterize the pollution characteristics of atmospheric particulate matter in Turpan,and what methods are suitable to analyze the sources of pollution of atmospheric particulate matter.Based on environmental monitoring data from December 2016 to November 2017,this study analyzed the pollution characteristics of atmospheric particulate matter,including the concentration characteristics of particulate matter at different time resolutions,and their relationship with meteorological elements.The emission inventory method and the backward trajectory model were used to analyze the pollution sources of PM2.5 and PM10,and the key sources of atmospheric particulate matter were comprehensively identified from both local emission sources and potential external source areas.The main conclusions are as follows:(1)During the study period,the annual average concentrations of PM10 and PM2.5 in Turpan were respectively 157?g/m3 and 66?g/m3,exceeding their respective standards of 124.3%and 88.6%.In terms of seasonal changes,PM2.5 showed winter>autumn,spring>summer,and PM10 concentration showed winter>spring>autumn>summer.The high values of PM2.5 mainly occured in the heating season and lasted for a long time.The high value of PM10 mainly occurs in the dusty season and has a short duration.The hourly concentration change of particulate matter showed a "double peak"distribution,and the traffic peaks in the morning and evening had a great influence.The high concentration period was around 11:00 AM and 10:00 PM;the lower concentration period was between 02:00-06:00AM and 02:00-05:00PM.The hourly concentration of PM10 had more variability than PM2.5,and the daily variation characteristics were evident.The hourly concentration of PM2.5 was as follows:winter>spring,autumn>summer.The correlation between PM2.5 and PM10mass concentration was significantly higher in spring or summer than in autumn or winter,indicating that the pollution sources of PM10 and PM2.5 in winter were different,while in spring and summer they were more similar.(2)During the study period,the average temperature in Turpan was 18.1 ?,a maximum of 41.7 ?,was and a minimum of-4.8 ? in winter.The pressure was relatively high,with an average of 1012.1 hpa;the annual average humidity was 29.2%,and the relative humidity in winter was high.The west wind from the inland was the prevailing trend during the entire period,followed by the northwest wind.Changes in atmospheric particulate matter were affected by a combination of meteorological elements.The degree of response of atmospheric particulate matter with different particle sizes to changes in meteorological elements was also different.(3)Atmospheric particulate pollution in Turpan is affected by local sources.The contribution rate of atmospheric particulate matter emissions in Turpan in 2017 was as follows:dust source>industrial source>living source>non-road mobile source>road moving source.Among them,the soil dust source was the most important source of emission contribution,and other sources with high PMio emission were the industrial processes source,the yard dust,and coal burning and industrial furnaces;the PM2.5 emission mainly comes from combustion.Coal burning,industrial processes source,and yard dust.Compared with PM10,the particulate matter discharged from coal burning is mainly composed of fine particulate matter PM2.5,which significantly contributes to the emissions of PM2.5 in Turpan.(4)Atmospheric particulate matter in Turpan is also influenced by the transport of pollution from remote sources.The high-value areas of PSCF and CWT of PM2.5 were the most widely distributed in winter,contributing to the daily average mass concentration of PM2.5 of 172.6 ?g/m3,followed by spring and autumn,and the lowest in summer.During the process,the distribution of PSCF was characterized by dense to evacuated and dense,and Turpan was significantly affected seasonally by the transport of exogenous pollutants.Southeastern Kazakhstan,northeastern Aksu and Korla,Hami West and Urumqi significantly contributed to atmospheric particulate pollution,which is the main potential source area of PM2.5 in Turpan,Among them,Korla,the northeast of Aksu and the western part of Hami contributed most to the pollution levels in winter.Long-distance transport airflow from the west and northwest thus has an important influence on atmospheric particulate matter.