西安节日期间PM_(2.5)及其重金属浓度变化特征

The Variation Characteristics of Concentration of PM_(2.5) and Heavy Metals During Festivals in Xi'an

采用Mini Vol便携式采样器采集西安北稍门、格物楼和南斗角村2015年元旦、劳动节及节日前后各两天大气颗粒物样品,并利用电感耦合等离子体光学发射仪(ICP—OES)测量元素As、Cr、Cu、Mn、Ni、Pb和Zn的含量,分析节日浓度变化特征.结果表明,元旦期间,PM_(2.5)浓度表现为节假日大于节前及节后;南斗角村大气中PM_(2.5)浓度于三个采样期间内均低于其他两个点.大气PM_(2.5)中Cu、Pb和Zn浓度变化与PM_(2.5)一致;As、Mn和Ni含量变化较小;Cr浓度呈现显著上升的趋势.七种重金属空间表现不完全一致.劳动节期间,由于降雨影响,大气PM_(2.5)浓度表现为节假日期间最小,三个采样点空间差异相比元旦减小.细颗粒中重金属Cr、Ni、Pb和Zn与其PM_(2.5)的浓度变化一致;而As、Cu和Mn呈现逐渐递减趋势.空间表现为,BSM大气PM_(2.5)中Cu、Pb和Zn较高;其他四种重金属表现为在NDJC大气细颗粒物中浓度较高.

In order to analyze the variation characteristics of concentration of PM2.5 and heavy metals during festivals,samples of PM2.5 were collected by mini-volume samplers during the period of New Year’s Day and May Day（fromtwo days before the festivals and two days after the festivals）in Beishaomen（BSM）,Gewu building（GWL）andNandoujiao（NDJC）village in Xi’an and the concentrations of As,Cr,Cu,Mn,Ni,Pb and Zn in PM2.5 were measuredby ICP-OES. The results showed that the variation of concentration of PM2.5 during the period of New Year’s Daywas highest than the period of before and after the festival and the concentrations of PM2.5 in the three period of timein NDJC were lower than other sample sites. The variations of concentration of Cu,Pb and Zn in PM2.5 were consistentwith PM2.5;the varieties of concentration of As,Mn and Ni were not significant;the trend of concentration of Crincreases graudally. The space expressions of these seven metals were not sane. Because of the impact of raining,the concentration of PM2.5 during the period of May Day was lowest than the period of before and after the festivaland the special difference of three samples sites became smaller then New Year’s Day. The variations of concentrationof Cr,Ni,Pb and Zn in fine particulate matter were consistent with PM2.5 and the varieties of concentration of As,Cuand Mn decreased graudally. The expressions of space of Cu,Pb and Zn in BSM were higher than other sites and theother four heavy metals in NDJC were higher than other sample sites.