劉 璽,孔少飛*,鄭淑睿,鄭 煌,嚴(yán) 沁,吳 劍,程 溢,吳方琪,牛真真,曾 昕,陳 楠,許 可,祁士華,3

春節(jié)前后華北平原農(nóng)村地區(qū)黑碳濃度及來源

劉 璽1,孔少飛1*,鄭淑睿1,鄭 煌1,嚴(yán) 沁1,吳 劍1,程 溢1,吳方琪1,牛真真1,曾 昕1,陳 楠2,許 可2,祁士華1,3

(1.中國地質(zhì)大學(xué)(武漢)環(huán)境學(xué)院,湖北 武漢 430074；2.湖北省環(huán)境監(jiān)測中心站,湖北 武漢 430072；3.中國地質(zhì)大學(xué)(武漢)生物地質(zhì)與環(huán)境地質(zhì)國家重點實驗室,湖北 武漢 430074)

在河南某農(nóng)村站點利用黑碳儀(AE33)對春節(jié)前后(2018年2月12日~3月12日)黑碳?xì)馊苣z(eBC)進行在線連續(xù)監(jiān)測,獲得其質(zhì)量濃度、晝夜變化及來源.結(jié)果表明:春節(jié)期間的eBC濃度最高,(8.22±4.17)μg/m3,該時期人為活動對eBC影響最為明顯.春節(jié)前,生物質(zhì)燃燒產(chǎn)生的eBC占其總濃度百分比最大,為(41.1±5.3)%,并隨時間推移逐漸減小,降至(26.8±12.0)%.AAE(1.40±0.16)說明,該地區(qū)春節(jié)前后eBC的化石燃料排放和生物質(zhì)燃燒貢獻程度接近.與城市點位相比,本研究的AAE值較高.春節(jié)前后,觀測地區(qū)的eBC晝夜變化存在2個明顯高值時段,分別在7:00~9:00和20:00左右.春節(jié)期間的eBC晝夜變化無明顯波動.根據(jù)濃度權(quán)重軌跡分析顯示,春節(jié)期間eBC的潛在源區(qū)有山西、陜西、安徽和江蘇等省份,其他時期集中在河南、湖北境內(nèi).本研究對于識別冬季農(nóng)村燃燒源排放黑碳演化特征及其對區(qū)域重霾形成和發(fā)展的影響具有重要意義,也可為黑碳?xì)馊苣z氣候、環(huán)境和健康模擬提供基礎(chǔ)數(shù)據(jù).

黑碳?xì)馊苣z；春節(jié)；來源；農(nóng)村地區(qū)；華北平原

黑碳(BC)是一種大氣環(huán)境中具有強吸光性的物質(zhì),通過含碳物質(zhì)的燃燒過程產(chǎn)生[1-4].黑碳通過對不同波長光線進行吸收和散射,改變局部大氣穩(wěn)定性和垂直結(jié)構(gòu),進而影響區(qū)域天氣和全球大氣循環(huán)[5-6].黑碳的大氣直接輻射強迫達0.64W/m2,對溫室效應(yīng)的貢獻率僅次于CO2[7].此外, BC還會引起多種呼吸道和心血管疾病[8],與PM10和PM2.5相比,其對人體造成的健康影響更為明顯,可將其作為空氣質(zhì)量好壞的指示物[9].

華北地區(qū)近年來經(jīng)濟發(fā)展迅速,已成為中國大氣污染最嚴(yán)重的地區(qū)之一[10].當(dāng)前對該區(qū)域冬季大氣重污染的研究主要集中在城市地區(qū)[11-14],但有研究指出農(nóng)村地區(qū)污染物排放對區(qū)域空氣質(zhì)量的影響同樣不容忽視[15-16].Wang等[17]通過一維模型計算,發(fā)現(xiàn)BC在農(nóng)村地區(qū)的穹頂效應(yīng)更為明顯,但當(dāng)前農(nóng)村地區(qū)黑碳觀測數(shù)據(jù)仍很缺乏,制約著模型模擬結(jié)果的驗證和改進.此外,周邊城市及遠(yuǎn)距離的傳輸作用也會影響農(nóng)村地區(qū)的空氣質(zhì)量[18-19].

春節(jié)是中國最重要的節(jié)日,由于春節(jié)期間大量燃放煙花爆竹,大氣中相關(guān)的顆粒物濃度顯著上升[20-23].Kong等[24]指出南京春節(jié)期間,煙花的燃放對大氣中PM2.5的貢獻率接近50%.同時,由于“假期效應(yīng)”的存在和大規(guī)模人口遷移,此期間大氣污染源排放會出現(xiàn)顯著變化[25],大中型城市中與燃煤、機動車相關(guān)的污染物排放量顯著減少[24].根據(jù)2001~ 2012年春節(jié)期間數(shù)據(jù)發(fā)現(xiàn),華東地區(qū)的PM10在春節(jié)期間下降9.24%[26].然而,目前對春節(jié)期間大氣污染物濃度及源變化的研究主要集中在城市區(qū)域,針對農(nóng)村地區(qū)的研究極為有限,相關(guān)數(shù)據(jù)集的缺乏也制約著模型模擬研究.

鑒于此,本研究在華北平原某農(nóng)村布點,以燃燒源排放的標(biāo)識組分BC為研究對象,利用春節(jié)期間的在線監(jiān)測數(shù)據(jù)和濃度權(quán)重軌跡分析法探討典型農(nóng)村點位BC濃度變化和區(qū)域傳輸對其產(chǎn)生的影響,對于識別春節(jié)期間華北平原地區(qū)BC的濃度、變化及來源,為識別區(qū)域重污染過程農(nóng)村點位污染物變化特征具有重要意義,也可為相應(yīng)模型模擬研究提供基礎(chǔ)數(shù)據(jù).

1 研究方法

1.1 觀測點位和時段

觀測地點位于河南省平頂山市某農(nóng)村地區(qū)(33.94°N, 113.10°E)的一戶村民房頂,采樣高度距地5m.距觀測點的西南和東北方向分別約9km、11km的位置,各有一座城鎮(zhèn).在距觀測點約4km的西南、東南和東北方向,分別有一條高速公路(G36)和2條省道(S238和S231)穿過,在其他方向還有鄉(xiāng)鎮(zhèn)公路穿過.觀測點周圍是大面積農(nóng)田,無工業(yè)污染源.具體采樣點位情況如圖1所示.

采樣時間為2018年2月12日~2018年3月12日.由于2月15日~2月21日為法定春節(jié)假期,故將整個觀測時間劃分為春節(jié)前(2月12日~2月14日)、春節(jié)期間(2月15日~2月21日)和春節(jié)后(2月22日~3月12日)3個時期.

1.2 實驗方法

1.2.1 儀器和數(shù)據(jù) 本研究利用美國Magee公司生產(chǎn)的AE-33型黑碳儀(Aethalometer Model 33, Magee Scientific)測量大氣環(huán)境中BC的質(zhì)量濃度.該儀器共有7個測量通道,測量波長分別為370、470、520、590、660、880及950nm,經(jīng)自動校準(zhǔn)后設(shè)定采樣流量為5.0L/min并連接PM2.5切割頭.由于在波長880nm下,BC的吸收效果占主要地位而其它氣溶膠體的吸收效率可被忽略[27],故本研究以在880nm下測得的eBC濃度值代表實時大氣環(huán)境中的BC質(zhì)量濃度值.

AE-33型黑碳儀的工作原理與AE-31型類似[28-29],此外還增用了“雙點位”采樣技術(shù)[30]和Virkkula提出的算法[31],來修正由“負(fù)載效應(yīng)”造成的測量誤差. Virkkula算法可通過(1)式表示:

eBCcorrected= eBCuncorrected×(1+×ATN) (1)

式中: eBCcorrected和eBCuncorrected分別為修正前和修正后的eBC濃度值;為負(fù)載補償系數(shù); ATN為由AE-33測得的光衰減量.

AE33原始數(shù)據(jù)的分辨率為1min,分析數(shù)據(jù)時將其全部處理成1h平均值,并進一步計算得到日平均值和時期均值.在數(shù)據(jù)預(yù)處理過程中,先將負(fù)值刪除,然后將異常值(與該小時平均值之差的絕對值大于3倍標(biāo)準(zhǔn)差)及人工換膜時標(biāo)記的值進行剔除,最終得到的數(shù)據(jù)有效率為95.3%.

圖1 采樣點位置示意

1.2.2 eBC源解析模型 氣溶膠對光吸收特性與波長之間的關(guān)系可用公式(2)表示,具體如下:

abs() =-AAE(2)

式中:abs是吸收系數(shù);為常數(shù);AAE是?ngstr?m指數(shù)[33];是波長.

本研究中定義BB為生物質(zhì)燃料燃燒產(chǎn)生的eBC占其總濃度的百分比,它由Sandradwei等[34]提出的模型計算得出.模型中假設(shè)eBC氣溶膠來源于生物質(zhì)(bb)燃燒和化石燃料(ff)燃燒,則eBC氣溶膠的吸收系數(shù)babs()可由這兩項主要來源表示:

abs() =abs()bb+abs()ff(3)

式中:abs()bb和abs()ff分別代表生物質(zhì)燃燒和化石燃料排放產(chǎn)生eBC所對應(yīng)的吸收系數(shù).同時,給出化石燃料和生物質(zhì)燃燒對應(yīng)的關(guān)系式:

式中:假設(shè)AAEff= 1,AAEbb= 2[34-35],并結(jié)合公式(3)~(5)最終可推算出BB.

1.2.3 濃度權(quán)重軌跡分析法 濃度權(quán)重軌跡分析法(CWT)是一種計算大氣污染物的潛在污染源區(qū)及其軌跡污染程度的方法.在該方法中,通過流經(jīng)網(wǎng)格的軌跡及各軌跡對應(yīng)的eBC濃度計算得出每個網(wǎng)格上存在的權(quán)重濃度.

式中:C是網(wǎng)格(,)上的平均權(quán)重濃度;是網(wǎng)格(,)中的總軌跡數(shù);C是經(jīng)過該網(wǎng)格第條軌跡對應(yīng)的eBC質(zhì)量濃度;是經(jīng)過該網(wǎng)格第條軌跡的停留時間.

氣溫、相對濕度、風(fēng)速風(fēng)向和能見度等氣象參數(shù)來自當(dāng)?shù)貧庀笥^測站,時間分辨率為1h.邊界層高度數(shù)據(jù)下載自NOAA’s READY Archived Meteorology website,時間分辨率為3h.

2 結(jié)果與討論

2.1 氣象條件和eBC濃度基本特征

如圖2所示,觀測期間溫度較低(-4.4~22.6℃),相對濕度變化范圍較大(32.5%~86.0%).風(fēng)速也處于較小水平,在1.4~3.3m/s范圍內(nèi)波動.能見度較好(>10km)的天數(shù)為8日,邊界層高度波動較大(50~2324m),日均降水量約0.22mm.

如圖3所示,研究期間AAE值整體在1.5上下波動.在春節(jié)前、春節(jié)期間和春節(jié)后3個時期eBC均有峰值出現(xiàn),濃度在10μg/m3左右;eBCbb與eBCff濃度變化趨勢相似.

低溫、低風(fēng)速會導(dǎo)致形成穩(wěn)定的大氣溫度層結(jié),不利于污染物擴散[36].研究期間,eBC與風(fēng)速呈顯著負(fù)相關(guān)(=-0.12,=0.003).表1是春節(jié)前、春節(jié)期間和春節(jié)后3個時期氣象參數(shù)的對比.其中,春節(jié)前和春節(jié)后風(fēng)速無明顯區(qū)別(=0.58),但春節(jié)前的eBC濃度較高.這與春節(jié)前務(wù)工人員回鄉(xiāng),春節(jié)后農(nóng)村人口減少有關(guān).研究期間,人為活動是影響eBC濃度的重要因素.

圖2 觀測期間各氣象要素的時間序列

2.2 eBC質(zhì)量濃度、生物質(zhì)燃燒貢獻和波長吸收指數(shù)的不同時期變化特征

表2是不同時期各參數(shù)的比較.研究期間, 觀測點位及周邊的eBC質(zhì)量濃度平均值為6.78± 6.34μg/m3.圖4a是3個時期eBC濃度平均值的箱線圖.由該圖可知, eBC濃度值在春節(jié)前后差異顯著(=0.0001):春節(jié)前和春節(jié)期間,eBC濃度平均值均較春節(jié)后的eBC濃度平均值高,且春節(jié)期間的平均值最大.這可能是由于春節(jié)期間較活躍的人為活動(如燃放煙花爆竹和生物質(zhì)燃燒等),使得該時期大氣中的eBC污染物濃度在3個時期中最高.

表3所示為本次觀測eBC濃度和我國部分觀測站點的比較結(jié)果.與深圳[37]、南京[38]、廣州[39]等城市相比,該農(nóng)村站點eBC濃度明顯較高.與重污染時期的北京[40]和同為農(nóng)村站點的河北香河縣[28]的觀測結(jié)果接近,說明春節(jié)期間該區(qū)域的eBC污染情況嚴(yán)重.

圖3 AAE和eBC濃度的時間序列

表1 不同時期氣象參數(shù)比較

表2 不同時期各污染物濃度與AAE比較

圖4b是不同時期eBCbb的平均值.春節(jié)前eBCbb濃度(3.1±1.6)μg/m3最高,說明該段時期生物質(zhì)燃燒對eBC有較大影響.圖4e展示了3個時期生物質(zhì)燃燒對eBC質(zhì)量濃度的貢獻程度(BB), 3個時期BB的平均值分別為(41.1±5.3)%、(34.9±10.2)%和(26.8± 12.0)%. BB值在春節(jié)前最大表明,春節(jié)前的生物質(zhì)燃燒現(xiàn)象在整個研究期間最為明顯.可能是因為在該時期內(nèi),農(nóng)村居民進行各種年貨制備,消耗較多的生物質(zhì)燃料.

圖4 不同時期各參數(shù)的平均值

圖4c和4f分別是不同時期eBCff和其對eBC的貢獻程度(FF).不同時期的eBCff和FF分別為(4.2±2.3)μg/m3,(5.2±2.3)μg/m3,(4.3±2.7)μg/m3和(58.9± 5.3)%,(65.1±10.2)%和(73.2±12.0)%.春節(jié)后恢復(fù)工作生產(chǎn),可能是造成該時期FF值最高的原因.

圖4d是3個時期的AAE平均值.其趨勢與BB類似,在春節(jié)前有最大值,在春節(jié)后AAE平均值最小.研究期間,該農(nóng)村地區(qū)春節(jié)前、春節(jié)期間和春節(jié)后3個時期的AAE的平均值分別為(1.51±0.07)、(1.50±0.13)和(1.35±0.17),總平均值為(1.40±0.16).表4是本研究AAE值和國內(nèi)外其他站點的比較結(jié)果.與深圳[37]、南京[38]及廣州[39]等城市相比,本研究地區(qū)的AAE值偏高;但與秸稈焚燒時期的河北香河縣[28]及印度Vijayawada[41]等農(nóng)村地區(qū)相比,本研究地區(qū)的AAE值則偏低.環(huán)境和能源結(jié)構(gòu)及老化時間長短的不同會造成不同地區(qū)AAE值出現(xiàn)差異[39,42].當(dāng)AAE值接近1時,eBC以化石燃料排放為主;當(dāng)AAE值接近2時,eBC以生物質(zhì)燃燒為主[43].根據(jù)計算結(jié)果,可知該農(nóng)村地區(qū)eBC的化石燃料排放和生物質(zhì)燃燒貢獻程度接近,并且隨著時間推移,生物質(zhì)燃燒貢獻程度逐漸減小.

2.3 eBC質(zhì)量濃度、生物質(zhì)燃燒貢獻和AAE的晝夜變化特征

通常而言,eBC質(zhì)量濃度的晝夜變化特征與當(dāng)?shù)厝祟惢顒?、近地層氣象條件以及大氣邊界層的動力狀況密切相關(guān)[41,51].有研究指出在通風(fēng)系數(shù)(邊界層高度和水平風(fēng)速的乘積, VC)大的時段,黑碳濃度較小[52-53].圖5a展示了不同時期的eBC濃度晝夜變化曲線.在春節(jié)前和春節(jié)后,eBC晝夜變化均有兩個明顯高值時段.日出前后(7:00~9:00左右),eBC的峰值與清晨生物質(zhì)燃燒量和機動車輛增加有關(guān)(圖5b、5c);同時,圖5d顯示該時段VC值較小(1000m2/s左右),不利的氣象條件促使污染物積聚;日間時段(11:00~17:00),由于VC值增大以及人為源排放減少,eBC濃度呈下降趨勢,并在15:00左右出現(xiàn)谷值(春節(jié)前和春節(jié)后分別為5和4 μg/m3);夜間時刻(19:00~20:00左右),VC值降低使得黑碳污染物重新在近地面堆積出現(xiàn)峰值(10μg/m3左右),同時晚間做飯的生物質(zhì)燃燒增加(圖5b),促進了這一過程.圖5e展示了不同時期BB的晝夜變化特征.由圖知,BB與eBC濃度值的晝夜變化特征基本一致.春節(jié)前和春節(jié)后均在8:00和19:00左右出現(xiàn)BB峰值,這2個時間點正好是早飯和晚飯時間,生物質(zhì)燃料使用量較多.

與這2個時期不同的是,春節(jié)期間的eBC濃度和BB值晝夜變化波動均較小,在早中晚飯期間略微上升(eBC由7.5μg/m3上升到9μg/m3左右,BB由31%上升到38%左右).出現(xiàn)這種現(xiàn)象可能是因為春節(jié)期間較活躍的人為活動和不利的氣象條件(該時期VC 均值為(864.6±864.7) m2/s)使得全天的eBC濃度和BB均較高;此外,早中晚飯期間的生物質(zhì)燃燒較多,造成這些時間段內(nèi)的eBC濃度和BB均有增加.

圖5f是不同時期的AAE晝夜變化曲線.通過對比可知,AAE的晝夜變化趨勢與BB的晝夜變化特征曲線一致,在春節(jié)前和春節(jié)后于早晚期間各存在2個明顯高值時段,在春節(jié)期間晝夜變化波動不大.

圖5 不同時期各參數(shù)的晝夜變化特征Fig.5 The diurnal variation of each parameter

表3 我國部分站點eBC濃度對比

2.4 eBC的潛在源區(qū)分析

氣團的移動可以將遠(yuǎn)距離污染物輸送至研究區(qū)域,造成當(dāng)?shù)豦BC濃度變化[54].為得到影響觀測站點eBC的潛在源區(qū)及其相應(yīng)貢獻程度,本文采用了濃度權(quán)重軌跡分析法(CWT).計算過程中,以500m為研究地區(qū)大氣邊界層的平均流場高度,以不同研究時期24個時次(00:00~23:00)的eBC質(zhì)量濃度為研究對象,得到了每日氣團72h后向軌跡來反映觀測區(qū)域周圍的氣流和污染物運動特征.

圖6(a)~(c)是研究期間研究區(qū)域eBC的CWT計算結(jié)果.可知,春節(jié)前后氣流軌跡變化和潛在源區(qū)及貢獻均存在差異.春節(jié)前eBC主要潛在源區(qū)位于觀測點周邊區(qū)域,包括河南境內(nèi)及河南與湖北交界處,貢獻值達11μg/m3左右,此外,來自湖北境內(nèi)的污染氣團也有較大貢獻,貢獻值達9μg/m3左右;春節(jié)期間,eBC污染潛在源分布區(qū)域較廣,除河南省內(nèi)污染氣團貢獻值達9μg/m3左右之外,來自山西、陜西、安徽及江蘇的污染氣團貢獻值達10μg/m3以上.這可能是由于春節(jié)期間上述范圍內(nèi),較多的煙花燃放和生物質(zhì)燃燒等人為活動排放的污染物隨氣團擴散,造成研究區(qū)域eBC濃度較高.此外,該時期來自海上的污染氣團貢獻值達12μg/m3以上.春節(jié)后由于假期結(jié)束,以上人為活動排放減少,該時期來自當(dāng)?shù)丶捌渌麉^(qū)域的污染氣團貢獻值基本在5~8μg/m3間.研究期間,來自西伯利亞的氣團也攜帶少量eBC (0.2~ 3μg/m3).

表4 農(nóng)村、城市和背景點位黑碳?xì)馊苣z的波長吸收指數(shù)(AAE)對比

圖6(d)~(f)和6(g)~(i)分別是eBCbb和eBCff的CWT結(jié)果.在春節(jié)前和春節(jié)期間,其與eBC的CWT結(jié)果類似,外來污染氣團對研究區(qū)域的eBCbb和eBCff貢獻值(分別為3~5μg/m3和6~7μg/m3)較本地的高,且主要潛在源區(qū)與eBC的源區(qū)分布范圍基本相同;但在春節(jié)期間,河南境內(nèi)的eBCbb貢獻值(3~5μg/m3)較外來污染氣團的高,說明該期間河南及周邊區(qū)域存在較多的生物質(zhì)燃燒現(xiàn)象;春節(jié)后,來自東北及西伯利亞方向的污染氣團攜帶較多eBCbb(3~5μg/m3)進入研究區(qū)域.該期間對eBCff貢獻較多的區(qū)域主要為湖北、湖南及江西三省交界處(7~8μg/m3).

圖6 不同時期eBC、eBCbb和eBCff濃度權(quán)重軌跡分布

3 結(jié)論

3.1 研究期間,eBC平均濃度為(6.78±6.34)μg/m3.春節(jié)前和春節(jié)期間的eBC濃度較春節(jié)后高,且在春節(jié)期間有最大值,(8.22±4.17)μg/m3,這與春節(jié)期間較活躍的人為活動(如燃放煙花爆竹和生物質(zhì)燃燒等)有關(guān).

3.2 生物質(zhì)燃料燃燒產(chǎn)生的eBC占其總濃度百分比(BB)在春節(jié)前有最高值(41.1±5.3)%,并隨時間推移逐漸減小,表明在春節(jié)前,生物質(zhì)燃燒貢獻程度最大.AAE變化趨勢與BB保持一致,整體在1.5上下波動.說明該地區(qū)春節(jié)前后eBC污染物的化石燃料排放和生物質(zhì)燃燒貢獻程度接近.與城市點位相比,本研究的AAE值(1.40±0.16)偏高,eBC受生物質(zhì)燃燒影響較大.

3.3 在春節(jié)前和春節(jié)后,觀測地區(qū)的eBC晝夜變化存在2個明顯高值時段,分別在7:00~9:00和20:00左右,這2個時段較小的通風(fēng)系數(shù)和較多的生物質(zhì)燃燒是主要影響因素.由于頻繁的人為活動,使得春節(jié)期間全天的eBC質(zhì)量濃度較大,無明顯波動.

3.4 根據(jù)濃度權(quán)重軌跡分析(CWT)的結(jié)果顯示,春節(jié)期間eBC的潛在源區(qū)有山西、陜西、安徽和江蘇等省份,其他時期集中在河南、湖北境內(nèi).

[1] Crippa M, Decarlo P F, Slowik J G, et al. Wintertime aerosol chemical composition and source apportionment of the organic fraction in the metropolitan area of Paris [J]. Atmospheric Chemistry and Physics, 2013,13(2):961-981.

[2] Cooke W F, Liousse C, Cachier H, et al. Construction of a 1° × 1° fossil fuel emission data set for carbonaceous aerosol and implementation and radiative impact in the ECHAM4model [J]. Journal of Geophysical Research, 1999,104:22137-22162.

[3] Zhang Y, Yuan Q, Huang D, et al. Direct Observations of Fine Primary Particles From Residential Coal Burning: Insights Into Their Morphology, Composition, and Hygroscopicity [J]. Journal of Geophysical Research: Atmospheres, 2018,123(22):12,912-964,979.

[4] Liu L, Kong S, Zhang Y, et al. Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste [J]. Scientific reports, 2017,7(1):5047.

[5] Huang R, Yang L, Cao J, et al. Brown Carbon Aerosol in Urban Xi’an, Northwest China: The Composition and Light Absorption Properties [J]. Environmental Science and Technology, 2018,52(12):6825-6833.

[6] Menon S, Hansen J E, Nazarenko L, et al. Climate effects of black carbon aerosols in China and India [J]. Science, 2002,297(5590): 2250-2253.

[7] Ipcc. Climate change 2013: the physical science basis. In: Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel Climate change 2013: the physical science basis. In: Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [M]. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press, 2013.

[8] Koelmans A A, Jonker M T O, Cornelissen G, et al. Black carbon: The reverse of its dark side [J]. Chemosphere, 2006,63(3):365-377.

[9] Janssen N A H, Hoek G, Simic-Lawson M, et al. Black Carbon as an Additional Indicator of the Adverse Health Effects of Airborne Particles Compared with PM10and PM2.5[J]. Environmental Health Perspectives, 2011,119(12):1691-1699.

[10] Xu Z, Huang X, Nie W, et al. Influence of synoptic condition and holiday effects on VOCs and ozone production in the Yangtze River Delta region, China [J]. Atmospheric Environment, 2017,168:112- 124.

[11] Ru-Jin H, Yanlin Z, Carlo B, et al. High secondary aerosol contribution to particulate pollution during haze events in China [J]. Nature, 2014,514(7521):218-222.

[12] Chang X, Wang S, Zhao B, et al. Assessment of inter-city transport of particulate matter in the Beijing-Tianjin-Hebei region [J]. Atmospheric Chemistry and Physics, 2017:1-28.

[13] Wu S, Deng F, Wei H, et al. Association of cardiopulmonary health effects with source-appointed ambient fine particulate in Beijing, China: a combined analysis from the Healthy Volunteer Natural Relocation (HVNR) study [J]. Environmental Science and Technology, 2014,48(6):3438-3448.

[14] 李珊珊,程念亮,徐 峻,等.2014年京津冀地區(qū)PM2.5濃度時空分布及來源模擬 [J]. 中國環(huán)境科學(xué), 2015,35(10):2908-2916. Li S S, Cheng N L, XU J.Spatial and temporal distrubions and source simulation of PM2.5in Beijing-Tianjin-Hebei region in 2014 [J]. China Environmental Science, 2015,35(10):2908-2916.

[15] Chen H, Wang H. Haze Days in North China and the Associated Atmospheric Circulations Based on Daily Visibility Data from 1960 to 2012 [J]. Journal of Geophysical Research Atomosphere, 2015,120 (12):5895-5909.

[16] Wang W, Simonich S, Giri B, et al. Atmospheric concentrations and air–soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in remote, rural village and urban areas of Beijing–Tianjin region, North China [J]. Science of The Total Environment, 2011,409(15):2942- 2950.

[17] Wang Z, Xin H, Ding A. Dome effect of black carbon and its key influencing factors: A one-dimensional modelling study [J]. Atmospheric Chemistry and Physics, 2018,18(4):1-29.

[18] Chen D, Liu X, Lang J, et al. Estimating the contribution of regional transport to PM2.5air pollution in a rural area on the North China Plain [J]. Science of The Total Environment, 2017,583:280-291.

[19] 楊 浩,白永清,劉 琳,等.基于軌跡聚類河南地區(qū)大氣污染過程空氣輸送通道研究 [J]. 氣象與環(huán)境學(xué)報, 2017,33(4):29-39. Yang H, Bai Y Q, Liu L, et al. Analysis of air transport channels during pollution process in He'nan province based on trajector clustering [J]. Journal of Meteorology and Environment, 2017,33(4): 29-39.

[20] Feng J, Yu H, Su X, et al. Chemical composition and source apportionment of PM2.5during Chinese Spring Festival at Xinxiang, a heavily polluted city in North China: Fireworks and health risks [J]. Atmospheric Research, 2016,182:176-188.

[21] Ji D, Cui Y, Li L, et al. Characterization and source identification of fine particulate matter in urban Beijing during the 2015 Spring Festival [J]. Science of the Total Environment, 2018,s628–629:430- 440.

[22] Zhao S, Chen L, Yan J, et al. Characterization of lead-containing aerosol particles in Xiamen during and after Spring Festival by single-particle aerosol mass spectrometry [J]. Science of the Total Environment, 2017,580:1257-1267.

[23] Tian Y Z, Wang J, Peng X, et al. Estimation of the direct and indirect impacts of fireworks on the physicochemical characteristics of atmospheric PM10and PM2.5[J]. Atmospheric Chemistry and Physics, 2014,14(18):9469-9479.

[24] Kong S F, Li L, Li X X, et al. The impacts of firework burning at the Chinese Spring Festival on air quality: insights of tracers, source evolution and aging processes [J]. Atmospheric Chemistry and Physics, 2015,15(4):2167-2184.

[25] Huang K, Zhuang G, Lin Y, et al. Impact of anthropogenic emission on air quality over a megacity – revealed from an intensive atmospheric campaign during the Chinese Spring Festival [J]. Atmospheric Chemistry and Physics, 2012,12(23):11631-11645.

[26] Jiang Q, Sun Y L, Wang Z, et al. Aerosol composition and sources during the Chinese Spring Festival: fireworks, secondary aerosol, and holiday effects [J]. Atmospheric Chemistry and Physics Discussions, 2014,14(14):20617-20646.

[27] Ramachandran S, Kedia S. Black carbon aerosols over an urban region: Radiative forcing and climate impact [J]. Journal of Geophysical Research, 2010,115(D10):1-11.

[28] Ran L, Deng Z Z, Wang P C, et al. Black carbon and wavelength- dependent aerosol absorption in the North China Plain based on two-year aethalometer measurements [J]. Atmospheric Environment, 2016,142:132-144.

[29] 吳 兌,毛節(jié)泰,鄧雪嬌,等.珠江三角洲黑碳?xì)馊苣z及其輻射特性的觀測研究 [J]. 中國科學(xué)(D輯:地球科學(xué)), 2009,39(11):1542-1553. Wu D, Mao J T, Deng X J, et al. Black carbon aerosols and their radiative properties in the Pearl River Delta region [J]. Sci China Ser D-Earth Sci, 2009,39(11):1542-1553.

[30] Drinovec L, Mo?nik G, Zotter P, et al. The "dual-spot" Aethalometer: an improved measurement of aerosol black carbon with real-time loading compensation [J]. Atmospheric Measurement Techniques Discussions, 2014,7(9):10179-10220.

[31] Aki V, Timo M K, Risto H, et al. A simple procedure for correcting loading effects of aethalometer data [J]. Journal of the Air and Waste Management Association (1995), 2007,57(10):1214-1222.

[32] Lin C Q, Liu G, Lau A K H, et al. High-resolution satellite remote sensing of provincial PM2.5trends in China from 2001 to 2015 [J]. Atmospheric Environment, 2018,180:110-116.

[33] Kirchstetter T W, Novakov T, Hobbs P V. Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon [J]. Journal of Geophysical Research: Atmospheres, 2004,109 (D21):1-12.

[34] Sandradewi J, Prév?t A S H, Szidat S, et al. Using Aerosol Light Absorption Measurements for the Quantitative Determination of Wood Burning and Traffic Emission Contributions to Particulate Matter [J]. Environmental Science and Technology, 2008,42(9):3316-3323.

[35] Zotter P, Herich H, Gysel M, et al. Evaluation of the absorption ?ngstr?m exponents for traffic and wood burning in the Aethalometer based source apportionment using radio carbon measurements of ambient aerosol [J]. Atmospheric Chemistry and Physics Discussions, 2016,17(6):1-29.

[36] 孫歡歡,倪長健,崔 蕾.成都市黑碳?xì)馊苣z污染特征及與氣象因子的關(guān)系 [J]. 環(huán)境工程, 2016,34(6):119-124. Sun H H, Li C J, Cui L. Characteristics of black carbon aerosol pollution in Chengdu and the relationship between meteorological factors [J]. Environmental Engineering, 2016,34(6):119-124.

[37] 程 丁,吳 晟,吳 兌,等.深圳市城區(qū)和郊區(qū)黑碳?xì)馊苣z對比研究 [J]. 中國環(huán)境科學(xué), 2018,38(5):1653-1662. Cheng D, Wu S, Wu D, et al. Comparative study on the characristics of black carbon aerosols in urban and suburban area of Shenzhen [J]. China Environmental Science, 2018,38(5):1653-1662.

[38] 肖思晗,于興娜,朱 彬,等.南京北郊黑碳?xì)馊苣z的來源解析 [J]. 環(huán)境科學(xué), 2018,37(9):3280-3289. Xiao S H, Yu X N, Zhu B, et al. Source apportionment of black carbon aerosols in the North suburb of Nanjing [J]. Environmental Science, 2018,37(9):3280-3289.

[39] 程 丁,吳 晟,吳 兌,等.廣州市城區(qū)干濕季黑碳?xì)馊苣z污染特征及來源分析 [J]. 環(huán)境科學(xué)學(xué)報, 2018,38(5):2223-2232. Cheng D, Wu S, Wu D, et al. Characteristics of black carbon aerosols in urban Guangzhou: influencing factors in dry and rainy seasons [J]. Acta Scientiae Circumstantiae, 2018,38(5):2223-2232.

[40] 張宸赫,程興宏,趙天良,等.不同季節(jié)氣象條件對北京城區(qū)高黑碳濃度變化的影響 [J]. 環(huán)境科學(xué)學(xué)報, 2017,37(6):227-236. Zhang Z H, Cheng X H, Zhao T L, et al. Impact of meteorological conditions on high black carbon concentrations in urban area of Beijing in different seasons [J]. Acta Scientiae Circumstantiae, 2017, 37(6):227-236.

[41] Prasad P, Roja Raman M, Venkat Ratnam M, et al. Characterization of atmospheric Black Carbon over a semi-urban site of Southeast India: Local sources and long-range transport [J]. Atmospheric Research, 2018,213:411-421.

[42] 鐘玉婷,劉新春,何 清,等.烏魯木齊冬季黑碳?xì)馊苣z污染特征及來源的初步研究 [J]. 沙漠與綠洲氣象, 2014,8(6):36-40. Zhong Y T, Liu X C, et al. Pollution Characteristics and Source of Black Carbon Aerosols in Urumqi in Winter [J].Desert and Oasis Meteorology, 2014,8(6):36-40.

[43] Martinsson J, Abdul Azeem H, Sporre M K, et al. Carbonaceous aerosol source apportionment using the Aethalometer model – evaluation by radiocarbon and levoglucosan analysis at a rural background site in southern Sweden [J]. Atmospheric Chemistry and Physics, 2017,17(6):4265-4281.

[44] 夏蕓潔,武云飛,郭振海,等.華東鄉(xiāng)村站點氣溶膠吸收特性的觀測研究 [J]. 中國粉體技術(shù), 2017,23(6):17-23. Xia Y J, Wu Y F, Guo Z H, et al. Observational study on aerosol absorption at a rural site in Northern China [J]. China Powder Science and Technology, 2017,23(6):17-23.

[45] Wu D, Wu C, Liao B, et al. Seasonal variation of black carbon over the South China Sea and in various continental locations in South China [J]. Atmospheric Chemistry and Physics, 2013,13(7):17375- 17405.

[46] 湯 潔,溫玉璞,周凌晞,等.中國西部大氣清潔地區(qū)黑碳?xì)馊苣z的觀測研究 [J]. 應(yīng)用氣象學(xué)報, 1999,10(2):160-170. Tang J, Wen Y P, Zhou L X, et al. Observational study of black carbon in clean air area of Western China [J]. Quarterly Journal of Applied Meteorology, 1999,10(2):160-170.

[47] Dumka U C. Scattering and absorption properties of near-surface aerosol over Gangetic–Himalayan region: the role of boundary-layer dynamics and long-range transport [J]. Atmospheric Chemistry and Physics, 2015,15(15):1555-1572.

[48] Segura S, Estellés V, Esteve A R, et al. Multiyear in-situ measurements of atmospheric aerosol absorption properties at an urban coastal site in western Mediterranean [J]. Atmospheric Environment, 2016,129:18-26.

[49] Wang P, Che H, Zhang X, et al. Aerosol optical properties of regional background atmosphere in Northeast China [J]. Atmospheric Environment, 2010,44(35):4404-4412.

[50] Devi J J, Bergin M H, Mckenzie M, et al. Contribution of particulate brown carbon to light absorption in the rural and urban Southeast US [J]. Atmospheric Environment, 2016,136:95-104.

[51] Begam G R, Vachaspati C V, Ahammed Y N, et al. Measurement and analysis of black carbon aerosols over a tropical semi-arid station in Kadapa, India [J]. Atmospheric Research, 2016,171:77-91.

[52] Goyal P, Anand S, Gera B S. Assimilative capacity and pollutant dispersion studies for Gangtok city [J]. Atmospheric Environment, 2006,40(9):1671-1682.

[53] Sujatha P, Mahalakshmi D V, Ramiz A, et al. Ventilation coefficient and boundary layer height impact on urban air quality [J]. Cogent Environmental Science, 2016,2(1):1125284.

[54] Rajesh T A, Ramachandran S. Black carbon aerosols over urban and high altitude remote regions: Characteristics and radiative implications [J]. Atmospheric Environment, 2018,194:110-122.

Levels and sources of black carbon around the spring festival at a rural site of the North China Plain.

LIU Xi1, KONG Shao-fei1*, ZHENG Shu-rui1, ZHENG Huang1, YAN Qin1, WU Jian1, CHENG Yi1, WU Fang-qi1, NIU Zhen-zhen1, ZENG Xin1,CHEN Nan2, XU Ke2, QI Shi-hua1,3

(1.School of Environmental Studies, China University of Geosciences, Wuhan 430074, China；2.Hubei Environmental Monitoring Center, Wuhan 430072, China；3.State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China)., 2019,39(8)：3169~3177

To obtain the mass concentrations, diurnal variations and sources of black carbon (eBC) aerosol around the Chinese spring festival (SF) in rural regions of the North China Plain, one-month (2018-2-12~2018-3-12) online continuous measurement of black carbon was conducted at a rural site in Henan province. During the SF, the eBC concentration was highest, (8.22±4.17)μg/m3, suggesting intensive emissions from anthropogenic activities. Before the SF, the contribution of biomass burning was the largest (41.1±5.3)%, and then gradually decreased down to (26.8±12.0)%. During the study period, the calculated AAE value (1.40±0.16) indicated that the contribution of biomass burning to eBC was close to that of fossil fuel in this area. Compared with some urban sites, the AAE value in this study was higher. Before and after the SF, the eBC mass concentrations show significant diurnal variations, with 2 peak values occurring at 07:00~09:00 and around 20:00 (local time). During the SF, the diurnal variation of eBC mass concentration did not fluctuate obviously. According to the concentration-weighted trajectories analysis, the main potential source regions of eBC were Shanxi, Shaanxi, Anhui, and Jiangsu provinces during the SF. In other two periods, Henan and Hubei provinces could be the main impact regions. This study is meaningful to identify the impact of BC emitted from rural combustion sources on regional haze formation and evolution, and it can also supply the dataset for corresponding modeling of BC’s impacts on climate, air quality and human health.

black carbon aerosol；the spring festival；sources；rural region；North China Plain

X513

A

1000-6923(2019)08-3169-09

劉 璽(1995-),男,湖南郴州人,碩士研究生,主要從事大氣污染源排放清單研究.

2019-01-22

科技部國家重點研發(fā)計劃課題(2016YFA0602002; 2017YFC0212602);湖北省科技廳技術(shù)創(chuàng)新專項重大項目(2017ACA089);國家自然科學(xué)基金資助重點項目(41830965);湖北省環(huán)保廳環(huán)保科研項目(2017HB11);中國地質(zhì)大學(xué)(武漢)高層次人才科研啟動經(jīng)費資助項目(201616;201802);中央高?；究蒲袠I(yè)務(wù)費專項資金資助項目-騰飛計劃(162301182756)

* 責(zé)任作者, 教授, kongshaofei@cug.edu.cn