海峽西岸典型城市大氣降塵稀土元素生態(tài)風(fēng)險(xiǎn)及來(lái)源——基于釹同位素MixSIAR模型解析

李依鴻,于瑞蓮,張瑞琦,胡恭任*,顏 妍

海峽西岸典型城市大氣降塵稀土元素生態(tài)風(fēng)險(xiǎn)及來(lái)源——基于釹同位素MixSIAR模型解析

李依鴻1,于瑞蓮1,張瑞琦1,胡恭任1*,顏 妍2

(1.華僑大學(xué)環(huán)境科學(xué)與工程系,福建 廈門 361021；2.核工業(yè)北京地質(zhì)研究院分析測(cè)試研究中心,北京 100029)

為了探明海峽西岸典型城市大氣降塵中稀土元素生態(tài)風(fēng)險(xiǎn)及其來(lái)源貢獻(xiàn),在泉州市不同功能區(qū)設(shè)置了15個(gè)采樣點(diǎn)位,對(duì)大氣降塵樣品和主要潛在污染源樣品進(jìn)行采集和分析.采用潛在生態(tài)風(fēng)險(xiǎn)指數(shù)對(duì)稀土元素的風(fēng)險(xiǎn)進(jìn)行評(píng)價(jià),采用Nd同位素MixSIAR模型進(jìn)行定性分析和定量計(jì)算.結(jié)果表明,海峽西岸典型城市降塵稀土元素的潛在生態(tài)風(fēng)險(xiǎn)指數(shù)整體處于低風(fēng)險(xiǎn)等級(jí),Lu元素在部分點(diǎn)位處于中風(fēng)險(xiǎn),工業(yè)區(qū)、商業(yè)區(qū)及交通繁忙區(qū)個(gè)別采樣點(diǎn)潛在風(fēng)險(xiǎn)指數(shù)相對(duì)較高.εNd(0) vs Eu/Eu* 和εNd(0) vsΣREEs關(guān)系圖解顯示,大氣降塵樣品中稀土元素受自然源以及汽車尾氣塵、燃煤熱電廠飛灰、水泥廠飛灰等局地人為排放的影響較大.利用Nd同位素(143Nd/144Nd) MixSIAR模型計(jì)算出各潛在源的相對(duì)貢獻(xiàn)率,泉州市大氣降塵中稀土元素受土壤母質(zhì)層(24.0%～40.9%)影響較大,其次是汽車尾氣塵(20.7%～33.3%)和燃煤塵(21.1%～29.0%),受水泥廠飛灰 (13.7%～20.0%)影響相對(duì)較小.

大氣降塵；稀土元素；生態(tài)風(fēng)險(xiǎn)；Nd同位素示蹤；MixSIAR模型

大氣降塵是城市大氣環(huán)境監(jiān)測(cè)的重要指標(biāo)之一,它能反映大氣沉降中顆粒物污染的嚴(yán)重程度,指示出重要的環(huán)境信息[1].除了自身危害外,大氣降塵還在大氣與地表交換中起著重要的作用,充當(dāng)其他污染物的運(yùn)載體和反應(yīng)床[2].稀土資源的大規(guī)模開(kāi)發(fā)和利用已將大量稀土元素釋放到各種環(huán)境介質(zhì)中,包括大氣、土壤、水和沉積物[3-4].稀土元素(REEs)由于其在生物體內(nèi)的毒理學(xué)數(shù)據(jù)稀缺,在環(huán)境中不受控制而成為新興關(guān)注的污染物[5].盡管大氣降塵中稀土元素的濃度相對(duì)較低,但通過(guò)大氣沉降后仍會(huì)對(duì)土壤、植物、水體等造成二次污染,對(duì)生態(tài)系統(tǒng)[5-6]和人類健康[7]構(gòu)成潛在威脅.而城市大氣降塵中的REEs污染物來(lái)自多種來(lái)源,包括自然和各種人為來(lái)源[8].因此,為進(jìn)行污染定向控制,有效區(qū)分污染源已成為一個(gè)至關(guān)重要的環(huán)境問(wèn)題.

釹(Nd)作為一種稀土元素,其同位素組成也被證明是一種強(qiáng)大而敏感的示蹤劑[9],由于其在大氣中穩(wěn)定存在且難以分餾,能穩(wěn)定而可靠地記錄物源信息,穩(wěn)定釹同位素技術(shù)被廣泛應(yīng)用到沉積物中元素的來(lái)源研究[10],但在大氣中的應(yīng)用罕見(jiàn),通過(guò)測(cè)量143Nd/144Nd的比值可以更準(zhǔn)確地解釋稀土的來(lái)源和遷移[8].目前,針對(duì)稀土元素的來(lái)源解析多停留在與潛在源的配分模式及其地球化學(xué)特征對(duì)比的定性分析,利用同位素混合模型可以定量解析潛在源對(duì)研究對(duì)象的貢獻(xiàn)率.貝葉斯混合模型主要有3種,分別為MixSIR、SIAR和MixSIAR,MixSIAR是一種馬爾科夫鏈蒙特卡洛(MCMC)模擬方法,融合了MixSIR和SIAR模型優(yōu)勢(shì)又加入源數(shù)據(jù)輸入形式和分類變量等模塊,通過(guò)創(chuàng)建和運(yùn)行MixSIAR模型來(lái)分析同位素示蹤劑數(shù)據(jù),考慮了多種來(lái)源的不確定性,不僅能有效提高模型計(jì)算精度,而且能提供復(fù)雜環(huán)境系統(tǒng)中來(lái)源貢獻(xiàn)的明確比例[11].基于鉛同位素示蹤的多源同位素混合模型量化復(fù)雜城市環(huán)境中的Pb污染源發(fā)現(xiàn)MixSIAR可用于量化復(fù)雜環(huán)境中的污染源[12].通過(guò)MixSIAR模型對(duì)Strontium(Sr)、Neodymium(Nd)同位素和微量元素進(jìn)行分析,可以定量計(jì)算出潛在來(lái)源的相對(duì)貢獻(xiàn)[13].但利用Nd同位素MixSIAR模型定量計(jì)算大氣降塵中各潛在源對(duì)稀土元素的相對(duì)貢獻(xiàn)研究還尚未見(jiàn)報(bào)道.

中國(guó)海峽西岸經(jīng)濟(jì)區(qū)位于長(zhǎng)三角與珠三角兩大經(jīng)濟(jì)區(qū)之間,東臨臺(tái)灣省,人口密度大,城市化進(jìn)程快,海峽西岸城市中的泉州是福建省三大中心城市之一,是中國(guó)首個(gè)東亞文化之都和“一帶一路”戰(zhàn)略海上絲綢之路先行區(qū),是中國(guó)二十世紀(jì)八十年代以來(lái)經(jīng)濟(jì)發(fā)展較快的地區(qū)之一,其氣候條件、地質(zhì)背景、產(chǎn)業(yè)結(jié)構(gòu)、工業(yè)化和城市化進(jìn)程較快,在海峽西岸經(jīng)濟(jì)區(qū)城市中有典型的代表性.盡管海峽西岸典型城市泉州市的大氣環(huán)境質(zhì)量尚好[14],但隨著經(jīng)濟(jì)的飛速發(fā)展,化石燃料的消耗量不斷增加,汽車保有量的激增,使得機(jī)動(dòng)車尾氣排放數(shù)量增加,該城市空氣質(zhì)量正呈下降趨勢(shì),其大氣環(huán)境中稀土元素問(wèn)題得到越來(lái)越多的關(guān)注,生態(tài)風(fēng)險(xiǎn)狀況不清,各潛在源貢獻(xiàn)率不明等問(wèn)題亟待解決.本論文對(duì)海峽西岸典型城市泉州市大氣降塵稀土元素污染進(jìn)行生態(tài)風(fēng)險(xiǎn)評(píng)價(jià),利用稀土元素地球化學(xué)特征和Nd同位素MixSIAR模型確定城市大氣降塵的來(lái)源及貢獻(xiàn)比例.研究結(jié)果可為城市降塵中稀土元素風(fēng)險(xiǎn)水平提供科學(xué)參考,對(duì)確定城市降塵中稀土元素積累機(jī)制和污染來(lái)源的貢獻(xiàn)提供科學(xué)依據(jù),對(duì)大氣污染防治也有重要意義.

1 材料與方法

1.1 大氣降塵樣品及潛在源樣品采集

在海峽西岸典型城市泉州市的5個(gè)不同功能區(qū)共采集15個(gè)大氣降塵樣品,用不同形狀的圖形區(qū)分不同功能區(qū)采樣點(diǎn)(圖1):居住區(qū)(1、2、3、4、5),工業(yè)區(qū)(6、7、8、9),農(nóng)業(yè)區(qū)(10、11、12),交通繁忙區(qū)(13、14),商業(yè)區(qū)(15),參照魯斯唯等[15]有關(guān)福建省大氣污染物排放清單的研究結(jié)論,詳細(xì)調(diào)查泉州市交通、工業(yè)、建筑等分布狀況,結(jié)合產(chǎn)業(yè)布局、能源消耗等可能存在的潛在污染源,采集了包括汽車尾氣塵、燃煤熱電廠飛灰、水泥廠飛灰、鋼鐵廠燒結(jié)飛灰和土壤塵共5種潛在源降塵樣品.樣品采集及預(yù)處理的具體方法參照文獻(xiàn)[16].

1.2 樣品的分析測(cè)定與質(zhì)量保證

降塵及潛在源中的稀土元素采用HCl-HNO3- HF-H2O2微波消解,用電感耦合等離子體質(zhì)譜儀(ICP-MS, Perkin Elmer ELAN DRC-e)測(cè)定稀土元素(La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu)的含量,全程以土壤標(biāo)樣ESS-3進(jìn)行質(zhì)量監(jiān)控,各元素測(cè)定相對(duì)偏差小于5%,Nd同位素測(cè)定方法參照《巖石中鉛、鍶、釹同位素測(cè)定方法》(GB/T 17672-1999)[17]提取分離后,采用熱電離質(zhì)譜儀(TI-MS)進(jìn)行測(cè)定,同位素比值的測(cè)定精度優(yōu)于0.001%,測(cè)定結(jié)果均滿足所要求的精度.相關(guān)研究中常用?Nd(0)表示樣品中143Nd/144Nd偏離球粒隕石標(biāo)準(zhǔn)樣品中143Nd/144Nd 的程度,?Nd(0)值表示為:

式中:(143Nd/144Nd)measured為實(shí)際樣品的值;(143Nd/144Nd)CHUR(0)為球粒隕石的值,用球粒隕石(143Nd/144Nd)CHUR(0)=0.512638[18]計(jì)算樣品的εNd(0)值.

1.3 潛在生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)

Hakanson[19]提出的潛在生態(tài)風(fēng)險(xiǎn)指數(shù)(PERI)已被廣泛用于估算有毒元素的潛在生態(tài)危害,然而,之前由于稀土元素的毒性因子信息缺乏,針對(duì)稀土元素的生態(tài)風(fēng)險(xiǎn)評(píng)估也很少.Chen[20]參考不同物質(zhì)中稀土元素豐度和釋放效應(yīng)原理分析了稀土元素的毒性因子,該原理已用于大氣、土壤和沉積物中稀土元素的生態(tài)風(fēng)險(xiǎn)評(píng)估.因此,為評(píng)價(jià)海峽西岸典型城市泉州大氣降塵中稀土元素的生態(tài)風(fēng)險(xiǎn),本研究采用Chen計(jì)算的毒性因子對(duì)大氣降塵中稀土元素的生態(tài)風(fēng)險(xiǎn)進(jìn)行評(píng)價(jià),具體如下:

表1 潛在生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)指標(biāo)的等級(jí)[21]

表2 稀土元素的毒性系數(shù)和元素背景值[20,22]

單個(gè)稀土元素的潛在生態(tài)風(fēng)險(xiǎn)指數(shù):

某區(qū)域多個(gè)稀土元素的綜合潛在生態(tài)風(fēng)險(xiǎn)指數(shù):

1.4 數(shù)據(jù)處理

同位素示蹤與建模軟件相結(jié)合,對(duì)不同污染源的相對(duì)貢獻(xiàn)進(jìn)行定量計(jì)算提供了巨大的潛力.本研究利用RStudio運(yùn)行MixSIAR模型以量化不同采樣點(diǎn)各潛在源的貢獻(xiàn)率,MixSIAR模型中潛在源和各采樣點(diǎn)同位素值輸入全部使用原始數(shù)據(jù),“discrimination”數(shù)據(jù)均設(shè)置為0,默認(rèn)不發(fā)生同位素分餾,MCMC運(yùn)行時(shí)長(zhǎng)設(shè)定為“very long”,模型輸出結(jié)果用平均值表示.采用 Microsoft Excel 2021和SPSS 22.0對(duì)數(shù)據(jù)進(jìn)行整理分析,用ArcGIS 10.8和Origin 2021軟件作圖.

圖1 泉州市各功能區(qū)大氣降塵采樣點(diǎn)分布示意

2 結(jié)果與討論

海峽西岸典型城市泉州市各采樣點(diǎn)大氣降塵稀土元素含量測(cè)定數(shù)據(jù)見(jiàn)圖2.

2.1 潛在生態(tài)風(fēng)險(xiǎn)指數(shù)法評(píng)價(jià)結(jié)果

海峽西岸典型城市泉州大氣降塵中單一稀土元素潛在生態(tài)風(fēng)險(xiǎn)指數(shù)評(píng)價(jià)結(jié)果如圖3所示.單一稀土元素潛在生態(tài)風(fēng)險(xiǎn)指數(shù)平均值最大為L(zhǎng)u(18.87),其次是Tm(9.35)>Tb(9.08)>Ho(8.99)>Eu (8.80)>Gd (4.45)>Er(4.43)>Pr(4.30)>Sm(3.78)>Yb(3.75)>Dy(3.49)>Nd(1.71)>La(1.27)>Ce(0.96).所有稀土元素的潛在生態(tài)風(fēng)險(xiǎn)指數(shù)平均值均小于20,處于低風(fēng)險(xiǎn)等級(jí),Lu在部分點(diǎn)位的潛在生態(tài)風(fēng)險(xiǎn)指數(shù)范圍在20～40內(nèi),處中等風(fēng)險(xiǎn),表明海峽西岸典型城市泉州的大氣降塵中大多數(shù)稀土元素并無(wú)明顯污染情況,Lu在部分點(diǎn)位有一定潛在生態(tài)風(fēng)險(xiǎn),應(yīng)引起重視.

圖3 泉州大氣降塵中單一稀土元素潛在生態(tài)風(fēng)險(xiǎn)指數(shù)(Eri)

綜合潛在生態(tài)風(fēng)險(xiǎn)指數(shù)結(jié)果顯示不同功能區(qū)大氣降塵中多元素綜合潛在生態(tài)風(fēng)險(xiǎn)的平均值排序?yàn)?工業(yè)區(qū)(107.2779)>交通繁忙區(qū)(102.5414)>商業(yè)區(qū)(72.9649)>居住區(qū)(67.1758)>農(nóng)業(yè)區(qū)(51.4678).雖然各功能區(qū)采樣點(diǎn)平均值整體處低風(fēng)險(xiǎn)等級(jí),但不難發(fā)現(xiàn)工業(yè)區(qū)和交通繁忙區(qū)的生態(tài)風(fēng)險(xiǎn)指數(shù)明顯高于其它功能區(qū),特別是泉港工業(yè)區(qū)采樣點(diǎn)的生態(tài)風(fēng)險(xiǎn)指數(shù)結(jié)果為141.0325,處中等風(fēng)險(xiǎn)等級(jí).從空間分布上看,距離交通繁忙區(qū)較近的點(diǎn)位較同功能區(qū)其它點(diǎn)位其潛在生態(tài)風(fēng)險(xiǎn)指數(shù)也較高(圖4).這說(shuō)明工業(yè)煙塵及粉塵排放、城市揚(yáng)塵及機(jī)動(dòng)車尾氣等已對(duì)泉州市各功能區(qū)大氣降塵稀土元素造成了一定的影響,應(yīng)加以控制.各稀土元素對(duì)綜合潛在風(fēng)險(xiǎn)指數(shù)貢獻(xiàn)占比如圖5所示,其中 Lu、Tm、Tb、Ho、Eu五者占比均超過(guò)10%,五者占比之和(66.6%)已達(dá)2/3,從某種程度上說(shuō)明這五種元素在降塵中富集程度較高,該規(guī)律與沉積物[23]中的結(jié)果趨于一致.雖然這五種稀土元素在泉州大氣降塵中含量不高,但其對(duì)于稀土元素的綜合潛在生態(tài)風(fēng)險(xiǎn)貢獻(xiàn)不容小覷.

2.2 Nd同位素示蹤解析降塵來(lái)源

2.2.1 降塵及潛在源中REE特征參數(shù)與Nd同位素組成 對(duì)海峽西岸典型城市泉州市部分大氣降塵樣品中Nd同位素組成進(jìn)行測(cè)定,并對(duì)大氣降塵樣品中ΣREEs、LREE/HREE、Eu /Eu?等特征參數(shù)進(jìn)行統(tǒng)計(jì)(表3).ΣREE、ΣLREE/ΣHREE、Eu/Eu*等稀土元素的特征參數(shù)可以表征源區(qū)稀土元素的分布規(guī)律、分異特征,通常用于提供有關(guān)物源成分的重要信息,在一定程度上能夠反映稀土元素的地球化學(xué)特征.ΣREE是稀土元素的總含量,LREE/HREE為樣品中輕稀土(LREE)含量總和與重稀土(HREE)含量總和的比值.Eu則是一種特殊的稀土元素,其在酸性條件下極易水解,遷移能力也隨之改變,從而與其他稀土元素發(fā)生分異,表現(xiàn)為Eu/Eu?的異常情況.泉州市部分大氣降塵樣品的143Nd/144Nd比值分布在0.51211～ 0.51253,εNd的值分布在-10.36～-2.09,潛在源樣品的143Nd/144Nd比值分布范圍稍寬,在0.51161～0.51215, εNd的值分布在-19.99～-9.52,即大部分樣品中Nd同位素的值都分布在潛在源對(duì)應(yīng)值的范圍內(nèi).

圖5 泉州大氣降塵中各稀土元素對(duì)潛在生態(tài)風(fēng)險(xiǎn)指數(shù)的貢獻(xiàn)

表3 大氣降塵及潛在源中Nd同位素組成及稀土元素特征參數(shù)統(tǒng)計(jì)

續(xù)表3

注:Eu/Eu?=Eu/(Sm×Gd)ΣREE=ΣLREE+ΣHREE=(La+Ce+Pr+ Nd+Pm+Sm+Eu)+(Gd+Tb+Dy+Ho+Er+Tm+Yb+Lu)LREE/HREE= (La+Ce+Pr+Nd+Pm+Sm+Eu)/(Gd+Tb+Dy+Ho+Er+Tm+Yb+Lu)

2.2.2 Nd同位素與稀土元素地球化學(xué)特征解析稀土來(lái)源 (1)稀土元素地球化學(xué)特征結(jié)合Nd同位素示蹤定性分析降塵中稀土來(lái)源如圖6所示,5個(gè)功能區(qū)的大氣降塵中釹同位素含量存在一定差異,相同功能區(qū)不同采樣點(diǎn)也有不同.大氣降塵與燃煤塵、水泥廠飛灰、土壤塵較為靠近,而汽車尾氣塵Nd元素含量遠(yuǎn)低于各采樣點(diǎn),說(shuō)明汽車尾氣塵對(duì)大氣降塵中釹元素影響有限.大氣降塵中143Nd/144Nd 和1/[Nd]線性關(guān)系不顯著,說(shuō)明其受多種潛在源混合影響,需要進(jìn)一步研究討論.

圖6 泉州各功能區(qū)大氣降塵和潛在源樣品143Nd/144Nd vs 1/[Nd]關(guān)系圖

稀土元素地球化學(xué)參數(shù)結(jié)合Nd同位素組成可以具體示蹤稀土元素的來(lái)源[24-25].通過(guò)分析海峽西岸典型城市泉州的大氣降塵樣品及潛在源樣品的Nd同位素組成,繪制各功能區(qū)大氣降塵和潛在源樣品εNd(0) vs×Eu/Eu*和εNd(0) vs×ΣREEs關(guān)系圖進(jìn)一步揭示其物源.綜合兩個(gè)關(guān)系圖發(fā)現(xiàn),大氣降塵樣品點(diǎn)更靠近燃煤熱電廠飛灰、汽車尾氣塵、土壤母質(zhì)層以及水泥廠飛灰,距鋼鐵廠燒結(jié)飛灰樣品點(diǎn)較遠(yuǎn),表明該城市大氣降塵稀土元素受鋼鐵廠的影響較小,燃煤源、交通源、土壤母質(zhì)層以及水泥塵的排放可能是其主要來(lái)源.

(2)Nd同位素MixSIAR模型定量解析降塵中稀土來(lái)源為了定量計(jì)算潛在來(lái)源對(duì)大氣降塵中稀土元素的具體貢獻(xiàn),將143Nd/144Nd與MixSIAR模型相結(jié)合.在所有研究采樣點(diǎn)中,土壤母質(zhì)層成為影響大氣降塵中稀土元素來(lái)源的主要部分(24.0% ～ 40.9%),其次是汽車尾氣塵(20.7% ～ 33.3%)、燃煤塵(21.1% ～ 29.0%)、水泥廠飛灰 (13.7% ～20.0%) (圖8).圖4的空間分布所示,人為源相對(duì)貢獻(xiàn)率較高的點(diǎn),其生態(tài)風(fēng)險(xiǎn)指數(shù)也相對(duì)較高,說(shuō)明汽車尾氣塵、燃煤塵、水泥廠飛灰等人為源對(duì)泉州市大氣降塵中稀土元素的潛在生態(tài)風(fēng)險(xiǎn)具有不可忽略的影響.進(jìn)一步將各采樣點(diǎn)按功能區(qū)整合分析可知(圖8),商業(yè)區(qū)受汽車尾氣塵影響最大,這可能與商業(yè)區(qū)綠地面積小,車流量較大有關(guān).而其余功能區(qū)雖然土壤母質(zhì)的相對(duì)貢獻(xiàn)率最大,但汽車尾氣和燃煤塵的貢獻(xiàn)率均位于23%～29%,說(shuō)明交通源和工業(yè)源對(duì)泉州市大氣環(huán)境的影響應(yīng)引起重視.

圖7 泉州各功能區(qū)大氣降塵和潛在源樣品(a) εNd(0) vsΣREEs和(b) εNd(0) vs Eu/Eu*關(guān)系圖

圖8 泉州市不同潛在源對(duì)各功能區(qū)大氣降塵中稀土元素的相對(duì)貢獻(xiàn)率

3 結(jié)論

3.1 潛在生態(tài)風(fēng)險(xiǎn)指數(shù)法評(píng)價(jià)大氣降塵中單元素平均生態(tài)危害程度:Lu(18.87)>Tm(9.35)>Tb(9.08)> Tb(9.08)>Ho(8.99)>Eu(8.80)>Gd(4.45)>Er(4.43)>Pr(4.30)>Sm(3.78)>Yb(3.75)>Dy(3.49)>Nd(1.71)>La(1.27)>Ce(0.96),所有稀土元素的潛在生態(tài)風(fēng)險(xiǎn)指數(shù)平均值均處于低風(fēng)險(xiǎn)等級(jí),但Lu部分點(diǎn)位處于中風(fēng)險(xiǎn),需要引起重視.

3.2 海峽西岸典型城市泉州的各功能區(qū)大氣降塵稀土元素潛在生態(tài)風(fēng)險(xiǎn)程度大多數(shù)處于低風(fēng)險(xiǎn)等級(jí),但工業(yè)區(qū)、商業(yè)區(qū)及交通繁忙區(qū)個(gè)別采樣點(diǎn)潛在風(fēng)險(xiǎn)指數(shù)相對(duì)較高,說(shuō)明工業(yè)活動(dòng)和交通源等已經(jīng)對(duì)泉州市大氣降塵造成了一定的影響.

3.3 Nd同位素示蹤表明大氣降塵樣品中稀土元素受自然源以及汽車尾氣塵、燃煤熱電廠飛灰、水泥廠飛灰等局地人為排放的影響較大,受鋼鐵廠排放物影響較小.

3.4 Nd同位素MixSIAR模型計(jì)算結(jié)果表明降塵中稀土元素受土壤母質(zhì)層(24.0%～40.9%)影響較大,其次是汽車尾氣塵(20.7%～33.3%)和燃煤塵(21.1%～29.0%),受水泥廠飛灰(13.7%～20.0%)影響相對(duì)較小.

[1] 郭 婧,徐 謙,荊紅衛(wèi),等.北京市近年來(lái)大氣降塵變化規(guī)律及趨勢(shì) [J]. 中國(guó)環(huán)境監(jiān)測(cè), 2006,(4):49-52. GUO J, Xu Q, Jing H et al. The changing law and trend of dustfall in Being during the recent years [J]. Environmental Monitoring in China, 2006,(4):49-52.

[2] Del Vento S, Dachs J J E s. Atmospheric occurrence and deposition of polycyclic aromatic hydrocarbons in the northeast tropical and subtropical Atlantic Ocean [J]. Environmental science technology, 2007,41(16):5608-5613.

[3] Balaram V. Rare earth elements: A review of applications, occurrence, exploration, analysis, recycling, and environmental impact [J]. Geoscience Frontiers, 2019,10(4):1285-1303.

[4] Liang T, Li K,Wang L. State of rare earth elements in different environmental components in mining areas of China [J]. Environmental monitoring assessment, 2014,186(3):1499-1513.

[5] Malhotra N, Hsu H S, Liang S T, et al. An updated review of toxicity effect of the rare earth elements (REEs) on aquatic organisms [J]. Animals, 2020,10(9):1663.

[6] Rim K T. Effects of rare earth elements on the environment and human health: A literature review [J]. Toxicology Environmental Health Sciences, 2016,8(3):189-200.

[7] Gwenzi W, Mangori L, Danha C, et al. Sources, behaviour, and environmental and human health risks of high-technology rare earth elements as emerging contaminants [J]. Science of the Total Environment, 2018,636:299-313.

[8] Yan Y, Yu R l, Hu G r, et al. Characteristics and provenances of rare earth elements in the atmospheric particles of a coastal city with large-scale optoelectronic industries [J]. Atmospheric Environment, 2019,214:116836.

[9] P?ppelmeier F, Lippold J, Blaser P, et al. Neodymium isotopes as a paleo-water mass tracer: A model-data reassessment [J]. Quaternary Science Reviews, 2022,279:107404.

[10] Yang J, Li G, Rao W, et al. Isotopic evidences for provenance of East Asian Dust [J]. Atmospheric Environment, 2009,43(29):4481-4490.

[11] Stock B C, Jackson A L, Ward E J, et al. Analyzing mixing systems using a new generation of Bayesian tracer mixing models [J]. PeerJ, 2018,6:e5096.

[12] Dietrich M, Krekeler M P, Kousehlar M, et al. Quantification of Pb pollution sources in complex urban environments through a multi-source isotope mixing model based on Pb isotopes in lichens and road sediment [J]. Environmental Pollution, 2021,288:117815.

[13] Li T, Rao W, Wang S, et al. Identifying the clay-size sediment provenance of the radial sand ridges in the southwestern Yellow Sea using geochemical and SrNd isotopic tracers [J]. Marine Geology, 2023,455:106957.

[14] 陳璋琪.泉州市環(huán)境空氣質(zhì)量現(xiàn)狀、影響因素及綜合防治對(duì)策 [J]. 地球環(huán)境學(xué)報(bào), 2019,10(2):201-209. CHEN Z. Air quality, influence factors and control countermeasure in Quanzhou, southeastern coast of China [J]. Journal of Earth Environment, 2019,10(2):201-209.

[15] 魯斯唯,胡清華,吳水平,等.海峽西岸經(jīng)濟(jì)區(qū)大氣污染物排放清單的初步估算 [J]. 環(huán)境科學(xué)學(xué)報(bào), 2014,34(10):2624-2634. Lu S W, Hu Q H, Wu S P, et al. Establishment of air pollutant emission inventory in the West Coast of Taiwan Strait [J]. Acta Scientiae Circumstantiae, 2014,34(10):2624-2634.

[16] 張棕巍,于瑞蓮,胡恭任,等.泉州市大氣降塵中稀土元素地球化學(xué)特征及來(lái)源解析 [J]. 環(huán)境科學(xué), 2016,37(12):4504-4513. ZHANG Z, YU R, HU G, et al. Geochemical characteristics and S ource apportionment of rare earth elementsin the dustfall of Quanzhou City [J]. environmental sciences, 2016,37(12):4504-4513.

[17] GB/T 17672-1999 巖石中鉛、鍶、釹同位素測(cè)定方法 [S]. GB/T 17672-1999 Determinations for isotopes of lead、strontium and neodymium in rock samples [S].

[18] DePaolo D J, Wasserburg G. Nd isotopic variations and petrogenetic models [J]. Geophysical Research Letters, 1976,3(5):249-252.

[19] Hakanson L. An ecological risk index for aquatic pollution control. A sedimentological approach [J]. Water Research, 1980,14(8):975-1001.

[20] Chen H, Chen Z, Chen Z, et al. Calculation of toxicity coefficient of potential ecological risk assessment of rare earth elements [J]. Bulletin of Environmental Contamination Toxicology, 2020,104(5):582-587.

[21] 曹 劼,閆 鈺,于瑞蓮,等.稻田垂直剖面土壤稀土元素來(lái)源解析及生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)——基于鍶釹同位素示蹤結(jié)合MixSIAR模型 [J]. 中國(guó)環(huán)境科學(xué), 2023,46(6):3002-3012. Cao J, Yan Y, Yu R L, et al. Source apportionment and ecological risk assessment of rare earth elements in vertical profiles of paddy soils — Based on Strontium and neodymium isotope tracing combined with MixSIAR model [J]. China Environmental Science, 2023,43(6):3002- 3012.

[22] 中國(guó)環(huán)境監(jiān)測(cè)總站.中國(guó)土壤元素背景值 [M]. 北京:中國(guó)環(huán)境科學(xué)出版社, 1990:418-444. China Environmental Monitoring Station. Background values of soil elements in China [M]. Beijing: China Environmental Science Press, 1990:418-444.

[23] Liu Z, Gu X, Lian M, et al. Occurrence, geochemical characteristics, enrichment, and ecological risks of rare earth elements in sediments of “the Yellow river? Estuary? bay”system [J]. Environmental Pollution, 2023,319:121025.

[24] Tang Y, Han G. Investigation of sources of atmospheric dust in Guiyang City, southwest China using rare earth element patterns [J]. Journal of Earth System Science, 2020,129(1):1-11.

[25] Huang R J, Zhang Y, Bozzetti C, et al. High secondary aerosol contribution to particulate pollution during haze events in China [J]. Nature, 2014,514(7521):218-222.

The ecological risks and sources of rare earth elements in the dustfall in typical cities of West China Strait—Based on neodymium isotope tracing combined with MixSIAR model.

LI Yi-hong1, YU Rui-lian1, ZHANG Rui-qi1, HU Gong-ren1*, YAN Yan2

(1.Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China；2.Center of Analysis, Beijing Research Institute of Uranium Geology, Beijing 100029, China)., 2023,43(11)：5663～5670

Rare earth elements as a kind of emerging contaminants (ECs) began to be widely concerned by scholars. In order to investigate the ecological risk and source contribution of rare earth elements in atmospheric dust in typical cities on the west coast of the China Straits, 15 sampling sites were set up in different functional areas of Quanzhou City to collect and analyze atmospheric dust samples and main potential pollution sources. The potential ecological risk index was used to evaluate the risk of rare earth elements, and the Nd isotope MixSIAR model was used for qualitative analysis and quantitative calculation. On the whole, the potential ecological risk index of rare earth elements in the dustfall in typical cities on the west coast of the Taiwan Strait was at low risk level. While Lu element was at medium risk at some sampling points, and the potential risk index of individual sampling points in industrial areas, commercial areas and heavy traffic areas was relatively high. The Plot of εNd(0) vs Eu/Eu* and εNd(0) vsΣREEs show that rare earth elements in atmospheric dust samples were greatly affected by natural sources and local anthropogenic emissions such as gasoline exhaust dust, coal burning dust and cement dust. The relative contribution rate of each potential source was calculated by using the (143Nd/144Nd) MixSIAR model. The influence of rare earth elements in atmospheric dusfall in Quanzhou City was greatly influenced by the background soil(24.0%～40.9%), followed by gasoline exhaust dust (20.7%～33.3%) and coal burning dust (21.1%～29.0%). The impact of cement dust (13.7%～20.0%) was relatively low.

atmospheric dustfall；rare earth elements；ecological risk；Nd isotope tracing；MixSIAR model

X513;X142

A

1000-6923(2023)11-5663-08

李依鴻(1999-),女,福建龍巖人,華僑大學(xué)碩士研究生,主要研究方向?yàn)榄h(huán)境污染化學(xué)與環(huán)境監(jiān)測(cè)評(píng)價(jià).發(fā)表論文2篇. 1609982145@qq.com.

李依鴻,于瑞蓮,張瑞琦,等.海峽西岸典型城市大氣降塵稀土元素生態(tài)風(fēng)險(xiǎn)及來(lái)源——基于釹同位素MixSIAR模型解析 [J]. 中國(guó)環(huán)境科學(xué), 2023,43(11):5663-5670.

Li Y H, Yu R L, Zhang R Q, et al. The ecological risks and sources of rare earth elements in the dustfall in typical cities of West Taiwan Strait —Based on. Neodymium isotope tracing combined with MixSIAR model [J]. China Environmental Science, 2023,43(11):5663-5670.

2023-03-29

國(guó)家自然科學(xué)基金資助項(xiàng)目(42377244);福建省自然科學(xué)基金資助項(xiàng)目(2022J01313);海洋大氣化學(xué)與全球變化重點(diǎn)實(shí)驗(yàn)室開(kāi)放基金(GCMAC2009)

* 責(zé)任作者, 教授, grhu@hqu.edu.cn