徐金英,鄭利林,徐力剛,王曉龍*

南方丘陵區(qū)河流表層沉積物重金屬污染評(píng)價(jià)

徐金英1,2,鄭利林1,2,徐力剛1,王曉龍1*

(1.中國(guó)科學(xué)院南京地理與湖泊研究所,中國(guó)科學(xué)院流域地理學(xué)重點(diǎn)實(shí)驗(yàn)室,江蘇 南京 210008；2.中國(guó)科學(xué)院大學(xué),北京 100049)

采樣分析南方丘陵山區(qū)甌江、錢塘江、閩江、九龍江沉積物中重金屬含量,并對(duì)其來源及生態(tài)風(fēng)險(xiǎn)進(jìn)行研究.結(jié)果顯示,沉積物中Mn、Zn、As、Cd、Pb、V在九龍江有較高濃度,Ni、Cu在錢塘江濃度最高,Cr、Sb在甌江濃度最高,而Al、Co和V的最高濃度分布在閩江.但重金屬含量空間差異不顯著.SQGs、Igeo和EF評(píng)價(jià)顯示,Cd在研究區(qū)沉積物中污染最為嚴(yán)重,呈中度至重度污染,其次是Mn、Zn、Pb,其在研究區(qū)部分地區(qū)存在輕度污染,其他重金屬處于無污染狀態(tài).RI評(píng)價(jià)顯示,研究區(qū)河流沉積物存在極高重金屬潛在生態(tài)風(fēng)險(xiǎn),尤其是Cd.相關(guān)分析和PCA分析顯示,Zn、As、Cd、Pb來自于自然過程、礦業(yè)開采及農(nóng)業(yè)生產(chǎn)過程,Cr、Ni、Sb來自于工業(yè)生產(chǎn)過程產(chǎn)生廢水,Al、Co和V來自于自然過程,而Cu則來源于混合源.pH值、TP、TN和LOI是影響水體中重金屬含量的重要因子.本研究為河流生態(tài)系統(tǒng)的健康和保護(hù)提供重要依據(jù).

東南丘陵山區(qū)；河流；沉積物；重金屬；生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)；來源解析

重金屬具有毒性、持久性和生物聚集性,水生生態(tài)系統(tǒng)因其重金屬污染在全球范圍內(nèi)備受關(guān)注[1-2].水生生態(tài)系統(tǒng)重金屬可來自自然過程和人類活動(dòng).隨著社會(huì)經(jīng)濟(jì)快速發(fā)展,人類活動(dòng)取代自然過程成為水生生態(tài)系統(tǒng)重金屬污染的主要來源[3].重金屬進(jìn)入水體后,最終會(huì)通過吸附于細(xì)顆粒物等方式沉淀入表層沉積物[4].但理化環(huán)境或水文條件發(fā)生變化時(shí),沉積物會(huì)生再懸浮,從而造成二次污染[7-8].因此,有必要掌握表層沉積物中重金屬的分布及污染狀況[9],為水環(huán)境保護(hù)提供有效基礎(chǔ)和依據(jù).

河流在提供水資源、防洪、灌溉、水產(chǎn)養(yǎng)殖、氣候調(diào)節(jié)和維持生態(tài)系統(tǒng)平衡等各個(gè)方面發(fā)揮重要作用[10].但來自自然過程及人類活動(dòng)的污染物使世界各地河流遭受不同程度重金屬污染[11-13].目前關(guān)于河流表層沉積物中重金屬研究主要集中于三個(gè)方面:一是通過地累積指數(shù)(geo)、富集指數(shù)(EF)等評(píng)價(jià)指數(shù)對(duì)表層沉積物重金屬污染程度進(jìn)行評(píng)價(jià)[14];二是通過潛在風(fēng)險(xiǎn)指數(shù)(RI)對(duì)表層沉積物重金屬潛在風(fēng)險(xiǎn)進(jìn)行分析[15];三是通過相關(guān)分析、主成分分析(PCA)等[16]多元統(tǒng)計(jì)以及同位素示蹤[17]等方法對(duì)重金屬來源進(jìn)行源解析.

福建浙江兩省是中國(guó)東南丘陵山區(qū)重要省份.因其地理位置、資源優(yōu)勢(shì)社會(huì)經(jīng)濟(jì)得到快速發(fā)展,但同時(shí)也使得其主要河流(主要為九龍江、閩江、甌江、錢塘江)受到不同程度重金屬污染[18-21].如,已有研究顯示九龍江表層沉積物中Pb、Cd、Co、Zn、和Cu具有較高生態(tài)風(fēng)險(xiǎn)[22],而閩江、錢塘江和甌江沉積物受到Cd、Pb、Zn等重金屬污染[23,20-21].基于此,本研究綜合評(píng)價(jià)福建浙江兩省主要四條河流表層沉積物重金屬污染情況,并對(duì)其來源進(jìn)行比較分析.

1 材料與方法

1.1 研究區(qū)概況

研究區(qū)位于南嶺以南,年均溫度為18℃,年降水量為1250mm,降水主要集中在5~8月.所研究四條河流均為流域經(jīng)濟(jì)發(fā)展重要水源。閩江為福建省最大河流,全長(zhǎng)541m,流域面積60992km[20-21].九龍江是福建省第二大河流,屬于典型亞熱帶中小流域,流域面積為1.47′104km2;流域內(nèi)礦產(chǎn)資源種類多,儲(chǔ)量豐富[17-18,24].錢塘江位于浙江省西北部,是浙江省內(nèi)最大河流,流域面積達(dá)55558km2,流域內(nèi)人口約為2699.3萬人,占浙江省總?cè)丝?5.55%[25].甌江位于浙江省南部,是浙江省第二大河,長(zhǎng)達(dá)388km,流域面積18028km2,上游是重要的水電開發(fā)地區(qū),下游是浙江省主要工農(nóng)業(yè)經(jīng)濟(jì)區(qū)[21].

1.2 研究方法

1.2.1 樣品采集與處理 于2015年1月,用不銹鋼采泥器從甌江、錢塘江、九龍江和閩江4條河流上、中和下游分別采集表層沉積物(0~10cm)樣品.每個(gè)采樣點(diǎn)采集5個(gè)點(diǎn)(5m左右間距)作為混合樣,每條河流設(shè)3個(gè)樣點(diǎn)(圖1).所有樣品放置在酸洗聚乙烯塑料帶運(yùn)輸?shù)綄?shí)驗(yàn)室中,-20℃保存,待進(jìn)一步分析.

1.2.2 樣品分析與質(zhì)量控制 所有沉積物樣品理化指標(biāo)及重金屬指標(biāo)均在中科院南京地理與湖泊研究所國(guó)家重點(diǎn)實(shí)驗(yàn)室測(cè)定.用于測(cè)定重金屬的沉積樣品經(jīng)凍干、研磨和過100目篩.每個(gè)樣品稱量0.12g,在HCl-HNO3-HF-HClO4消解系統(tǒng)中消解.重金屬M(fèi)n、Zn、Cr、Co、Ni、Cu、As、Cd、Sb、Pb和V濃度用電感耦合等離子體質(zhì)譜法(ICP-MS, 7700x, NYSE: A,美國(guó))測(cè)定.重金屬最低測(cè)定值分別為0.05mg/kg, 0.2mg/kg, 0.1mg/kg, 0.01mg/kg, 0.05mg/ kg, 0.02mg/kg, 0.1mg/kg, 0.01mg/kg, 0.05mg/kg, 0.02mg/kg和0.1mg/ kg.Al采用電感耦合等離子體原子發(fā)射光譜法(ICP- AES, Prdodigy, Teledyne Leeman Labs,美國(guó))方法測(cè)定,測(cè)定最低20mg/kg.為保證測(cè)定重金屬數(shù)據(jù)的質(zhì)量,在測(cè)定過程中設(shè)置空白、重復(fù)和標(biāo)準(zhǔn)樣.每個(gè)樣品每種重金屬測(cè)定3個(gè)重復(fù),取均值.分析過程用國(guó)標(biāo)GBWO7358進(jìn)行全程質(zhì)量監(jiān)控,測(cè)定值和標(biāo)準(zhǔn)值相對(duì)標(biāo)準(zhǔn)偏差控制在10%以內(nèi).

圖1 研究區(qū)域及采樣點(diǎn)位置

沉積物TN和TP采用過硫酸鹽氧化法同時(shí)測(cè)定;沉積物pH值采用pH計(jì)現(xiàn)場(chǎng)測(cè)定;沉積物有機(jī)質(zhì)含量(LOI)通過燒失法測(cè)定.

1.2.3 污染程度評(píng)價(jià)方法

(1)用地累積指數(shù)法(geo)地累積指數(shù)評(píng)價(jià)重金屬污染程度.其計(jì)算方式如下[26]:

式中:C為重金屬的濃度;B為重金屬的地理化學(xué)背景值(BG);參數(shù)1.5為自然作用可能會(huì)對(duì)沉積物產(chǎn)生的影響(如巖石風(fēng)化或者沉積物侵蝕等).由于地理位置的差異,福建和浙江兩省河流分別用對(duì)應(yīng)省份的元素背景值,如表1所示[2].

表1 福建和浙江省重金屬元素背景值(mg/kg)

表2 Igeo,, EF和RI等級(jí)

(2)富集指數(shù)(EF)富集指數(shù)用來評(píng)估人為活動(dòng)可能會(huì)對(duì)沉積物中重金屬含量產(chǎn)生的影響.計(jì)算公式為[7]:

式中:(C/Al)沉積物為沉積物樣品中金屬濃度(C)與重金屬Al濃度(Al)的比值;(C/Al)背景值為重金屬背景濃度(C)與Al背景濃度(Al)比值.

所有評(píng)價(jià)指標(biāo)等級(jí)如表2所示.

1.3 統(tǒng)計(jì)分析方法

通過Pearson相關(guān)分析和主成分分析(PCA)分析重金屬來源.通過冗余分析(RDA)來進(jìn)一步分析沉積物重金屬含量受理化性質(zhì)的影響.通過單因素方差分析(ANOVA)分析河流之間重金屬含量的差異性.

2 結(jié)果與分析

2.1 沉積物理化性質(zhì)變化

表3為河流沉積物基本理化性質(zhì)特征.pH值均值為7.60,最大值在九龍江下游,最小值在九龍江上游.TN變化范圍為1.70~7.19mg/kg,最大值在閩江中游,最小值在甌江中游.TP濃度范圍為0.63~ 4.49mg/kg,在閩江中游濃度顯著較高,在錢塘江上游、閩江上游和甌江上游顯著較低.LOI含量范圍為2.02%~7.65%,在閩江中游含量最高,九龍江中游、甌江中下游含量最低.

表3 河流沉積物理化性質(zhì)基本特征

2.2 沉積物重金屬濃度特征

研究區(qū)沉積物Al、Mn、Zn、Cr、Co、Ni、Cu、As、Cd、Sb、Pb和V的平均濃度分別為76.65, 1470.2, 246.10, 90.64, 12.44, 35.33, 54.80, 11.83, 1.60, 1.18, 146.86, 71.07mg/kg.與國(guó)內(nèi)外規(guī)范及河流比較顯示(表4),所有重金屬濃度均高于TEL和UCC;且除Co以外,所有重金屬濃度均高于USEPA. Zn、Cd、Pb濃度略高于PEL,Zn、Cr、Cd、Pb濃度超過中國(guó)土壤環(huán)境質(zhì)量二級(jí)標(biāo)準(zhǔn).且研究區(qū)所有重金屬濃度均高于長(zhǎng)江和珠江(除As外);且除Co、Cu和As外所有重金屬濃度均高于饒河.

表4 研究區(qū)河流沉積物重金屬含量與規(guī)范及其他研究的對(duì)比(mg/kg)

注:TEL表示高于此濃度重金屬不利影響可能會(huì)發(fā)生;PEL表示高于此濃度重金屬不利影響會(huì)頻繁發(fā)生;UCC表示陸地地殼重金屬濃度值;USEPA表示美國(guó)淡水系統(tǒng)水體重金屬濃度毒性限值.

2.3 沉積物重金屬空間分布特征

如圖2所示, Mn、Zn、As、Cd、Pb在九龍江濃度較高,分別為2684.28, 372.74, 17.79, 3.03, 296.42mg/kg,且在九龍江上游濃度最高,分別為5617.12, 678.88, 28.20, 7.17, 724.65mg/kg. Ni、Cu在錢塘江濃度最高,分別為44.11, 69.13mg/kg,且在錢塘江中游明顯濃度最高,分別為89.88, 160.63mg/kg. Cr、Sb在甌江濃度最高,分別為125.03, 1.63mg/kg,且Cr在甌江下游濃度最高,為146.45mg/kg,而Sb在上游濃度最高,濃度為3.55mg/kg.Al、Co和V的最高濃度分布在閩江,濃度分別為84.26, 16.46mg/kg和91.51mg/kg.

圖2 重金屬在河流沉積物中的分布

2.4 沉積物重金屬污染評(píng)價(jià)

2.4.1geo評(píng)價(jià)Cd在4條河流沉積物中g(shù)eo值排序?yàn)榫琵埥?4.02)>錢塘江(3.20)>閩江(3.18)>甌江(2.70)(圖3).其他重金屬geo值均<1.

2.4.2 EF評(píng)價(jià) Cd在4條河流中EF順序?yàn)?九龍江(31.62)>錢塘江(14.47)>閩江(11.58)>甌江(7.40)(圖4).Mn和Zn在九龍江EF值分別為5.23和3.26.Pb在九龍江和甌江EF在3~5之間.一些河流重金屬EF值在1~3之間:如甌江、閩江和錢塘江重金屬M(fèi)n和Zn、閩江和錢塘江重金屬Pb等.重金屬在其他河流中重金屬EF值均小于1.

圖3 重金屬在河流沉積物中的Igeo值

圖4 重金屬在河流沉積物中的EF值

2.5 沉積物重金屬潛在生態(tài)風(fēng)險(xiǎn)評(píng)價(jià)

2.6 沉積物重金屬來源分析

2.6.1 相關(guān)分析 相關(guān)分析顯示，Mn、Zn、As、Cd、Pb之間顯著相關(guān);Cr、Ni、Sb之間顯著相關(guān);Co和V顯著相關(guān);而Cu和Zn, Co, Ni, Cd, V顯著相關(guān);而Al不和任何重金屬的相關(guān)性顯著.

2.6.2 PCA分析 PCA分析將重金屬分為3個(gè)主成分,解釋總方差的87.05%.第一主成分解釋總方差的48.25%,與Mn、Zn、As、Cd、Pb顯著相關(guān).第二主成分解釋總方差的24.52%,與Cr、Ni、Cu、Sb顯著相關(guān).第三主成分解釋總方差的14.29%,與Al、Co、V顯著相關(guān).

表5 河流沉積物重金屬含量相關(guān)性分析

注:* 在0.05水平(雙側(cè))上顯著相關(guān).** 在0.01水平(雙側(cè))上顯著相關(guān).

圖5 河流表層沉積物重金屬Eri和RI值

每個(gè)點(diǎn)位RI值為所有重金屬E值之和

圖6 河流沉積物重金屬與理化性質(zhì)RDA分析

2.6.3 RDA分析 RDA前兩軸的特征值分別為0.267和0.056,解釋總方差的32.4% (圖6).第一軸解釋總方差的26.7%,主要載荷重金屬為Mn、Pb、As、Cd、Zn、Co、V、Cu,與pH值存在顯著正相關(guān)(=0.624),與TP存在負(fù)相關(guān)(-0.20).第二軸解釋總方差的5.7%,主要載荷重金屬為Sb、Ni、Al、Cr,與TN(=0.27)和LOI(=0.38)存在正相關(guān).

表6 河流沉積物重金屬主成分分析

3 討論

重金屬污染是福建浙江河流面臨的重要問題,其可能來源于自然過程,如巖石風(fēng)化、水文侵蝕等,也可能來源于人類活動(dòng),如農(nóng)業(yè)活動(dòng)、工業(yè)生產(chǎn)、城市建設(shè)與發(fā)展及日常生活.本研究中,某些重金屬在沉積物中濃度較高,如Mn、Zn、As、Cd、Pb、V在九龍江,Cu、Ni在錢塘江,Cr、Sb在甌江,Al、Co和V在閩江濃度較高.由于區(qū)域氣候和地形環(huán)境具有相似性,人類活動(dòng)可能在重金屬空間分布方面起著重要作用.福建和浙江兩省均為東部省份,自然條件相似,相對(duì)于中西部省份,第二、三產(chǎn)業(yè)是其優(yōu)勢(shì)產(chǎn)業(yè),因此工業(yè)發(fā)展、服務(wù)業(yè)發(fā)展可能是導(dǎo)致其重金屬污染的主要原因[2,25].錢塘江流域分布有大量電鍍、化工等工業(yè)制造業(yè)[25],這可能是Cu和Ni在此流域濃度較高的原因.九龍江流域經(jīng)濟(jì)發(fā)展較好,其覆蓋的主要城市工業(yè)產(chǎn)業(yè)比值均在50%左右[35].九龍江上游礦產(chǎn)資源豐富,如龍巖新羅區(qū)馬坑和潘洛鐵礦區(qū),龍巖竹子板錳礦區(qū)等[24],這些礦產(chǎn)資源伴有大量Zn、Pb、Cd、As等金屬[36].近年來的礦業(yè)開采和工業(yè)廢水排放可能是造成這些重金屬污染的重要原因.閩江流域經(jīng)濟(jì)總量達(dá)到全省的40%,流域中上游化工煤炭等重工業(yè),下游機(jī)械、電子等產(chǎn)業(yè)以及中下游農(nóng)業(yè)發(fā)展可能是重金屬Co、V等重金屬濃度較高的原因[35].而甌江下游工業(yè)城市如溫州的快速發(fā)展,可能導(dǎo)致其個(gè)別重金屬濃度較高[21].

與國(guó)內(nèi)外標(biāo)準(zhǔn)比較及污染評(píng)價(jià)結(jié)果顯示,Cd在研究區(qū)域污染最為嚴(yán)重,九龍江受到Cd極嚴(yán)重污染,錢塘江和閩江均受到Cd非常嚴(yán)重污染,甌江受到Cd中等嚴(yán)重程度污染,這與其他研究結(jié)果相一致[22]. Cd普遍存在于工業(yè)廢水及農(nóng)業(yè)生產(chǎn)活動(dòng)中[37-39],研究河流中下游農(nóng)業(yè)發(fā)展及機(jī)械、電子、化工等涉及重金屬的工業(yè)發(fā)展可能是造成Cd污染的重要原因.同時(shí),RI健康風(fēng)險(xiǎn)評(píng)價(jià)顯示,Cd在所有河流中生態(tài)風(fēng)險(xiǎn)極高,這與已有研究一致[23].Cd濃度很低,生態(tài)風(fēng)險(xiǎn)卻極高,這一方面是因?yàn)镃d本身毒性比較高,另一方面可能是因?yàn)镃d主要以溶解態(tài)為主[40].研究區(qū)Cd的高生態(tài)風(fēng)險(xiǎn)機(jī)制有待進(jìn)一步研究.

通過PCA分析結(jié)果顯示,第一主成分主要包括Mn、Zn、As、Cd、Pb 5種重金屬,相關(guān)分析顯示此5種重金屬具有顯著相關(guān)性,說明其有共同來源.Mn是自然界中廣泛存在的重金屬,說明其可能存在于自然源;而I和EF評(píng)價(jià)顯示,河流中Mn也可能來自于人類活動(dòng),研究區(qū)有大量Mn礦產(chǎn)資源分布,如九江上游Mn礦[24],且這些礦產(chǎn)資源中伴有Zn、As、Cd、Pb等重金屬,因此礦產(chǎn)資源開采及相關(guān)工業(yè)活動(dòng)可能是這些重金屬的主要來源.同時(shí)研究顯示, Cd,Cu和Pb是當(dāng)?shù)剞r(nóng)業(yè)生產(chǎn)過程中使用農(nóng)藥化肥的重要組成部分[41].故第一主成份代表重金屬來源可能為自然過程、礦產(chǎn)資源開采和農(nóng)業(yè)生產(chǎn)活動(dòng).第二主成分包括Cr、Ni、Cu和Sb,但相關(guān)分析顯示只有Cr、Ni和Sb是相互顯著相關(guān),而Cu和Zn, Co, Ni, Cd, V顯著相關(guān),說明Cu具有多元性.4種重金屬在浙江錢塘江和甌江河流濃度相對(duì)福建河流閩江和九龍江濃度高.Cr,Ni廣泛用于電鍍、化工、機(jī)械等制造工業(yè)發(fā)展過程中,這與閩江、九龍江沿江工業(yè)分布具有一致性.第二主成份重金屬可能來源于工業(yè)生產(chǎn)過程中產(chǎn)生廢水.第三主成分主要包括Al、Co、V 3種元素.I、EF污染評(píng)價(jià)結(jié)果顯示Al、Co和V處于無污染狀態(tài),故3元素應(yīng)該主要來自于自然源.Al廣泛存在于自然界中,研究區(qū)以紅壤為主,富含F(xiàn)e和Al,但是缺乏有機(jī)質(zhì),這導(dǎo)致土壤很容易被侵蝕進(jìn)入河流,造成河流沉積物中Al含量比較多[2],故Al可能來自于土壤侵蝕等自然過程.而Co、V和Al無顯著相關(guān)性,Co和V可能來源于巖石風(fēng)化等其他自然過程.Cu與三主成分各重金屬的相關(guān)性,說明Cu是來自于混合源.

RDA分析顯示,pH、TN與沉積物重金屬含量呈正相關(guān),TP與沉積物重金屬含量呈負(fù)相關(guān),與已有研究相一致[42-43].研究顯示,在富營(yíng)養(yǎng)化湖泊中,重金屬以低價(jià)態(tài)存在,在貧營(yíng)養(yǎng)化湖泊中以高價(jià)態(tài)存在[4].也有研究顯示營(yíng)養(yǎng)鹽對(duì)重金屬的影響與季節(jié)等其他因子也有關(guān)系[44].故營(yíng)養(yǎng)物質(zhì)對(duì)研究區(qū)重金屬的影響有待進(jìn)一步研究.也有研究顯示pH值是影響水體沉積物重金屬含量的重要因子,與Cd含量存在顯著正相關(guān)[42-43].有機(jī)質(zhì)含量與重金屬含量也呈正相關(guān)[45].但是具體機(jī)制有待進(jìn)行研究.

4 結(jié)論

4.1 沉積物中, Mn、Zn、As、Cd、Pb在九龍江濃度較高,Ni、Cu在錢塘江濃度最高,Cr、Sb在甌江濃度最高,而Al、Co和V的最高濃度分布在閩江,重金屬含量空間差異不顯著.

4.2 SQGs, Igeo和EF評(píng)價(jià)顯示,Cd在研究區(qū)沉積物中污染最為嚴(yán)重,呈中度至重度污染,其次是Mn、Zn、Pb,其在研究區(qū)部分地區(qū)存在輕度污染,其他重金屬處于無污染狀態(tài).

4.3 RI評(píng)價(jià)顯示,研究區(qū)河流沉積物存在極高重金屬潛在生態(tài)風(fēng)險(xiǎn),尤其是Cd.

4.4 相關(guān)分析和PCA分析顯示,Mn、Zn、As、Cd、Pb來自于自然過程、礦業(yè)開采及農(nóng)業(yè)生產(chǎn)活動(dòng),Cr, Ni,Sb來自于工業(yè)廢水,Al,Co和V來自于自然過程,而Cu則來源于混合源.pH、TP、TN和LOI是影響水體中重金屬含量的重要因子.

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Ecological risk assessment and source analysis of heavy metals in surface sediments of rivers located in the hilly area of southern China.

XU Jin-ying1,2, ZHENG Li-lin1,2, XU Li-gang1, WANG Xiao-long1*

(1.Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China；2.University of Chinese Academy of Science, Beijing 100049, China)., 2019,39(8)：3420~3429

Heavy metals are characterized with toxicity, persistence and bioaccumulation, can exert significant adverse effect on the health of human beings and other organisms through food chain. In aquatic ecosystem, sediment is both the sink and the source of heavy metals. Thus, it’s of great importance to study heavy metals in surface sediment to keep the aquatic ecosystem in good condition. In this study, the spatial distribution, source analysis, and corresponding ecological risk of heavy metals in surface sediments of four main rivers (Minjiang River, Qiantangjiang River, Oujiang River and Jiulongjiang River) in the hilly area of southern China was analyzed. Our results showed that the relative higher values of metal group of Mn-Zn-As-Cd-Pb were observed in Jiulongjiang River. Moreover, the highest values of metal group of Ni-Cu, Cr-Sb, Al-Co-V were found in Qiantangjiang River, Oujiang River and Minjiang River, respectively. However, no significant difference of the heavy mental contents were tested among the four rivers (>0.05). Pollution assessment based on SQGs, Igeo and EF exhibited that sediments were moderately or seriously polluted by Cd and some sites were slightly polluted by Mn, Zn, and Pb. In addition, the RI assessment showed that heavy metals in sediments of our studied rivers posed extreme high potential of ecological risks. Multivariate analysis indicated that Mn, Zn, As, Cd and Pb mainly came from natural process, agricultural and mining activities; Cr, Ni and Sb may mainly come from instrial wastewater While industrial wastewater and Al, Co, V may mainly derived from natural process. And Cu derived from multiple sources above. By RDA analysis, the pH, TP, TN and LOI were the main environmental factors influencing heavy metal concentrations in the sediments. This study can provide important information for the protection of river ecosystem.

southeastern China；rivers；sediments；heavy metals；potential ecological risk；source apportionment

X522

A

1000-6923(2019)08-3420-10

徐金英(1991-),女,河南商丘人,中國(guó)科學(xué)院南京地理與湖泊研究所博士研究生,研究方向?yàn)槲廴旧鷳B(tài)學(xué).

2019-01-07

科技服務(wù)網(wǎng)絡(luò)計(jì)劃項(xiàng)目(KFJ-STS-ZDTP-011);中國(guó)科學(xué)院戰(zhàn)略優(yōu)先研究項(xiàng)目(XDA19050502)

* 責(zé)任作者, 副研究員, wangxl@niglas.ac.cn