环境科学研究  2020, Vol. 33 Issue (1): 163-173  DOI: 10.13198/j.issn.1001-6929.2019.05.20

引用本文  

李泽文, 王海燕, 孔秀琴, 等. 松花江表层沉积物中16种多环芳烃空间分布特征及生态风险评价[J]. 环境科学研究, 2020, 33(1): 163-173.
LI Zewen, WANG Haiyan, KONG Xiuqin, et al. Spatial Distribution Characteristics and Ecological Risk Assessment of 16 PAHs in Surface Sediment of Songhua River[J]. Research of Environmental Sciences, 2020, 33(1): 163-173.

基金项目

国家水体污染控制与治理科技重大专项(No.2015ZX07201-008-02)
National Water Pollution Control and Management Science and Technology Major Project of China (No.2015ZX07201-008-02)

责任作者

王海燕(1976-), 女, 河南南阳人, 研究员, 博士, 主要从事水(体)污染控制原理与技术研究, wanghy@craes.org.cn.

作者简介

李泽文(1994-), 男, 甘肃平凉人, lzewenjy@163.com

文章历史

收稿日期:2018-11-06
修订日期:2019-05-15
松花江表层沉积物中16种多环芳烃空间分布特征及生态风险评价
李泽文1,2,3, 王海燕2,3, 孔秀琴1, 杨艳艳2,3, 钟震1,2,3, 李莉2,3, 吴桐2,3    
1. 兰州理工大学, 甘肃 兰州 730050;
2. 中国环境科学研究院环境污染控制工程技术研究中心, 北京 100012;
3. 中国环境科学研究院, 环境基准与风险评估国家重点实验室, 北京 100012
摘要:为揭示松花江干支流表层沉积物中16种PAHs(多环芳烃)的空间分布特征及其生态风险状况,采用气相色谱-质谱联用仪分析了2017年9月松花江干支流26个表层沉积物16种PAHs质量分数特征,并采用比值法对其污染来源进行解析,运用沉积物质量基准法和质量标准法评价其生态风险状况.结果表明:①松花江干支流表层沉积物中w(∑16PAHs)为169.76~3 769.19 ng/g,以3~6环高环为主,并且支流w(∑16PAHs)(范围为169.76~3 769.19 ng/g,平均值为1 598.41 ng/g)高于干流(范围为459.92~2 092.58 ng/g,平均值为1 173.67 ng/g),呈从上游到下游逐渐降低的趋势.②松花江干支流表层沉积物中w(∑16PAHs)主要来源于生物质燃烧和石油燃烧.③松花江干支流表层沉积物中w(∑16PAHs)总体处于低生态风险水平,个别支流点位(3个)会发产生经常性生态风险.研究显示,松花江流域干支流表层沉积物中w(∑16PAHs)呈从上游到下游逐渐降低的趋势,并且支流高于干流,但总体处于低生态风险水平.
关键词松花江    16种多环芳烃    分布特征    沉积物    生态风险    
Spatial Distribution Characteristics and Ecological Risk Assessment of 16 PAHs in Surface Sediment of Songhua River
LI Zewen1,2,3, WANG Haiyan2,3, KONG Xiuqin1, YANG Yanyan2,3, ZHONG Zhen1,2,3, LI Li2,3, WU Tong2,3    
1. Lanzhou University of Technology, Lanzhou 730050, China;
2. Research Center for Environmental Pollution Control Engineering Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China;
3. State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Abstract: In order to reveal the spatial distribution characteristics and ecological risk of 16 polycyclic aromatic hydrocarbons (∑16PAHs) in surface sediment of the mainstream and tributaries in Songhua River Basin, the ∑16PAHs concentration of 26 samples collected in Sep. 2017 were analyzed using chromatography-mass spectrometry (GC-MS). The ∑16PAHs sources were determined by the ratio of feature components, and their ecological risk was assessed by the sediment quality guidelines and sediment quality standards (SQSs). The results show that:(1) The total concentration of ∑16PAHs (w(∑16PAHs) was in the range of 169.76-3769.19 ng/g, and the main components were 3-6 ring PAHs. The w(∑16PAHs) in the sediments of the tributaries (169.76-3769.19 ng/g, averaged at 1598.41 ng/g) was higher than that of the mainstream (459.92-2092.58 ng/g, averaged at 1173.67 ng/g) in Songhua River, and the w(∑16PAHs) decreased gradually from the upstream to the downstream. (2) The w(∑16PAHs) was mainly derived from the biomass fuel combustion and fossil fuel combustion. (3) The ecological risk level of sediment w(∑16PAHs) was low except for 3 sampling points in the tributaries, which had frequent ecological risks. This research showed that the sediment w(∑16PAHs) in Songhua River decreased gradually from the upstream to the downstream, the sediment w(∑16PAHs) in the tributary was higher than that in the main stream, and the ecological risk of the entire Songhua River Basin was low.
Keywords: Songhua River    16 kinds of PAHs    distribution characteristics    sediments    ecological risk    

沉积物是河流生态系统的重要组成部分,作为污染物载体时刻与河水进行着物质和能量交换[1]. PAHs(多环芳烃)主要来源于环境中有机物的不完全燃烧[2],具有低溶解性和疏水性,很容易与水体中悬浮物结合,沉降于河流沉积物中,因此沉积物是PAHs的主要聚集地,具有吸附和释放PAHs的功效[3-4]. PAHs污染具有来源广、残毒时间长、致癌性强的特点,对河流水生生物和人类健康造成了潜在威胁[5-6],尤其是Nap(萘)、Ace(苊烯)、Acp(苊)等16种PAHs(∑16PAHs)为美国[7]和我国的优先控制污染物[8],更应引起关注和研究.

国内外学者对沉积物PAHs污染分布特征及生态风险评价展开了大量研究,涉及河流、湖泊和近海水域等[9-14].沈小明等[9]研究长江河口沉积物中w(∑14PAHs)为83.4~5 206.9 ng/g,部分点位具有潜在生态风险;陈明华等[10]利用比值法分析太湖竺山湾湖滨带w(∑16PAHs)主要来源于化石燃料的高温燃烧;冉涛等[11]发现,渤海湾中部海域w(∑16PAHs)呈现由近岸区向深海区递减的趋势;Singare等[12]等发现,印度Mithi河沉积物中w(∑16PAHs)为1 206.0~ 3 705.0 ng/g,具有一定的生态风险;Souza等[13]等发现,巴西Poxim河w(∑16PAHs)为2.2~28.4 ng/g,主要来源于燃烧源;Guinan等[14]等发现,北爱尔兰Larne和Strangford海湾沉积物中w(∑13PAHs)为83~2 300 ng/g,主要来源于燃烧源,部分点位具有潜在生态风险;Echols等[15]曾报道,美国Missouri河下游沉积物中w(∑27PAHs)〔除2个城市点位分别为1 100和4 000 ng/g外〕为250~700 ng/g,主要来源于燃烧源;Duodu等[16]研究了澳大利亚Brisbane河表层沉积物15种PAHs的污染状况,认为其具有一定的致癌风险.综上,不同地区不同水体中PAHs污染分布特征及生态风险均有所不同,但多数来源于燃烧源.

松花江是我国七大水系之一,属国家重点流域,也是东北地区居民生产、生活的主要水源[17].松花江来自北源嫩江和南源第二松花江,在吉林省松原市的三岔河附近汇合后,称松花江干流(该研究称松花江主段干流).近年来,随着松花江流域社会经济的快速发展,松花江沉积物的污染物逐渐增多. 2015年黑龙江和吉林两省废水排放量占松花江全流域的95%左右[18-19],但目前有关松花江流域沉积物中PAHs空间分布特征的研究主要集中在第二松花江的部分河段[20]和松花江主段干流[21-22]. CUI等[21]报道2014年松花江主段干流及第二松花江干流表层沉积物中w(∑16PAHs)为34~4 456 ng/g,主要来源于煤炭燃烧;ZHAO等[22]研究松花江主干流(包括嫩江和第二松花江干流各1个点位、松花江主段干流13个点位)2007年表层沉积物中w(∑16PAHs)为68.25~654.15 ng/g,总体处于低生态风险水平.但有关松花江全流域(黑龙江省和吉林省)干流和支流表层沉积物中16种PAHs分布特征及其生态风险评价的研究尚未见报道,缺乏针对第二松花江、松花江主段干流及其典型支流沉积物中16种PAHs的污染特征揭示和风险状况评估.

因此,该研究以松花江全流域(黑龙江省和吉林省)干流和典型支流为对象,揭示了16种PAHs在松花江全流域干支流表层沉积物的空间分布特征,采用沉积物质量基准法和沉积物质量标准法对其生态风险进行了评价,并运用比值法和主成分分析法对其来源进行解析,以期为松花江水生态恢复研究提供科学基础和理论依据.

1 材料与方法 1.1 样品采集

2017年9月在松花江全流域(具体为第二松花江干流、松花江主段干流及其典型支流)进行表层沉积物样品的采集,共布设26个采样点,分布在流域上、中、下游区域(见图 1表 1).使用抓斗式采样器采集沉积物样品,每个采样点随机采集3份沉积物平行样.采集的样品用锡箔纸包好,置于不锈钢盒中,在实验室冷冻保存,备用.

图 1 松花江流域采样点分布 Fig.1 Distribution of sampling sites in Songhua River Basin

表 1 松花江流域采样点信息 Table 1 Information of Sampling sites in Songhua River Basin
1.2 仪器与试剂

仪器:冷冻干燥机(美国Labconco公司);SPE-DEX 4790全自动固相萃取仪(美国Horizon公司);ASE-350加速溶剂萃取仪(美国Dionex公司);氮吹浓缩仪(美国Caliper公司);Agilent 7890A型气相色谱-质谱仪(GC-MS)(美国Agilent公司).

主要试剂包括16种PAHs混标、代标和内标.无水硫酸钠、硅藻土(干燥剂)和石英砂,使用前马弗炉450 ℃烘烤4 h后冷却至室温.铜粉使用前先用1 mol/L硝酸氧化,去除铜粉表面的氧化物,再用甲醇冲洗3遍,氮气吹干.氦气,纯度≥99.99%.正己烷、环己烷、丙酮,均为分析纯.

1.3 样品预处理与分析

样品预处理包括样品冷冻干燥、研磨过筛、称量、加替代标准物、加速溶剂萃取、氮吹、PSA+硅胶小柱净化、氮吹、加内标、定容、GC-MS测定等步骤[23]:①将冷冻干燥后的样品研磨成粉,过0.149 mm筛后称取5 g,加2 g硅藻土后置于加速溶剂萃取仪中进行萃取,萃取溶剂为体积比为1 :1的正己烷与丙酮溶液,萃取仪载气压力为0.8 MPa,加热温度为100 ℃,萃取池压力为8.3~13.8 MPa,预加热平衡5 min,静态萃取5 min,溶剂淋洗体积为60%池体积;氮气吹扫时间为60 s;静态萃取2次. ②将萃取后的萃取液氮吹浓缩至2 mL,进行铜粉脱硫,然后采用Aglient硅胶小柱串联PSA小柱,对萃取液进行纯化,以去除腐殖酸、色素和极性杂质等.连接好固相萃取装置,在串联好的小柱上加入2 g无水硫酸钠脱水;然后加入20 mL正己烷进行柱子的活化,活化后进行上样,用40 mL体积比为1 :1的丙酮与正己烷溶液洗脱PAHs,收集洗脱液,然后再次氮吹缓慢吹至近干,用正己烷溶液定容到1 mL,用于GC-MS分析.

GC-MS分析条件:进样口温度为280 ℃,不分流;进样量为1.0 μL;柱流量为1 mL/min;柱温为80 ℃保留2 min,以20 ℃/min升至180 ℃,保持5 min,再以10 ℃/min升至290 ℃,保持5 min.离子源温度为230 ℃;离子化能量为70 eV;接口温度为280 ℃;四级杆温度为150 ℃;用选择离子扫描进行定量检测.

1.4 生态风险评价方法 1.4.1 沉积物质量基准法

沉积物质量基准法常用的两个指标是ERL(effects range low, 效应范围低值)和ERM(effects range media, 效应范围中值)[24]. ERL和ERM将PAHs的生态风险分为3个等级:当有机物浓度高于ERM时,生态风险发生的概率较高(大于50%),对周边生物及生态环境会产生经常性生态风险;当污染物浓度大于ERL小于ERM时,对周边生物体及生态环境偶尔产生生态风险;当研究区域污染物浓度低于ERL时,发生生态风险的概率较低(小于10%),几乎不会对周边人类及生态环境产生危害[25].

1.4.2 沉积物质量标准法

沉积物质量标准法也是一种广泛用于评价沉积物中PAHs生态风险的方法[26].目前我国尚未颁布,一般采用2006年加拿大魁北克省颁布的沉积物质量标准法,该标准设定REL(罕见效应浓度值)、TEL(临界效应浓度值)、OEL(偶然效应浓度值)、PEL(可能效应浓度值)和FEL(频繁效应浓度值)5个阈值来评价沉积物中PAHs的污染程度和生态风险(见表 2).

表 2 加拿大魁北克省淡水沉积物中PAHs的质量评价标准 Table 2 Evaluation standard of PAHs quality in surface sediment in Quebec Province of Canada
1.5 来源分析 1.5.1 特征分子比值法

PAHs的污染来源常运用同分异构体特征比值法来判断[27],常用比值有An/(Phe+An)、Flu/(Flu+Pyr)和BaA/(BaA+Chr),其不同特征比值范围代表沉积物中PAHs的主要来源(见表 3).

表 3 同分异构比值法鉴定PAHs污染来源 Table 3 Identification of PAHs pollution sources by isomeric ratio method
1.5.2 主成分分析法

主成分分析是多元统计分析中一种非常重要的分析方法,对原始数据进行降维处理分析,将变量之间的相关性系数组合成较少的因子,通过因子之间的相关性,来确定沉积物中PAHs的污染来源[28].

2 结果与讨论 2.1 沉积物PAHs含量分布

松花江全流域26个采样点表层沉积物中16种PAHs均有检出,其质量分数(以干质量计)范围为169.76~3 769.19 ng/g,平均值为1 458.43 ng/g(见表 4).其中w(BaA)为19.80~950.06 ng/g,平均值为327.81 ng/g,明显高于其他化合物. w(Fl)、w(Acp)、w(Ace)和w(BkF)相对较低,变化范围分别为3.77~60.44、22.67~113.89、11.19~95.32、11.45~130.15 ng/g,平均值分别为12.21、55.22、38.57和62.83 ng/g.其中干流采样点w(∑16PAHs)为459.92~2 092.58 ng/g,平均值为1 173.67 ng/g,支流采样点w(∑16PAHs)为169.76~3 769.19 ng/g,平均值为1 598.41 ng/g,支流采样点w(∑16PAHs)明显高于干流,并且支流采样点每种PAHs的平均值均高于干流.

表 4 松花江表层沉积物中PAHs质量分数 Table 4 Concentrations of PAHs in the sediments of Songhua River

松花江上、中、下游采样点w(∑16PAHs)分别为478.06~3 769.19、459.92~2 522.94和169.76~1 269.82 ng/g,平均值分别为1 818.13、1 364.72和616.62 ng/g,总体呈从上游到下游逐渐降低的趋势.这可能是因为松花江上游曾集中了大量的石油化工等工业企业,而且有石油开采行业[18-19],因此上游w(∑16PAHs)相对偏高;松花江下游工业相对没有上游发达,PAHs污染主要受居民生活污染等因素影响,w(∑16PAHs)相对较低. w(∑16PAHs)的最大值出现在S8号采样点(松花江上游第二松花江支流辉发河楞场村),这可能与该采样点位于白山市(人口密集、交通发达和工业企业较多)下游有关;最小值出现在S24号采样点(松花江下游一级支流倭肯河上的安兴村),这与该采样点周围自然环境较好、远离城市和受人类活动影响较小有关.

从各江段w(∑16PAHs)来看,松花江主段支流(1 622.47 ng/g)>松花江主段干流(1 509.86 ng/g),第二松花江支流(2 143.01 ng/g)>第二松花江干流(928.72 ng/g),针对最大支流牡丹江,牡丹江支流(1 302.54 ng/g)>牡丹江干流(1 069.95 ng/g),总体而言,支流w(∑16PAHs)高于干流,这主要是因为支流多为城市内河,接纳的污染物相对集中,同时由于支流流量较小,PAHs等有机物更容易被积累于沉积物中,而干流流量相对较大、含沙量高、有机物易稀释扩散;并且第二松花江干支流的w(∑16PAHs)(1 651.89 ng/g)高于松花江主段干支流(1 588.68 ng/g),可能与第二松花江石化企业集中有关;松花江主段干流和第二松花江干流表层沉积物中w(∑16PAHs)与CUI等[21]研究结果接近.

研究区域沉积物中PAHs的质量分数和污染程度与当地的经济发展和人类活动密切相关,工业越发达、人口越密集,PAHs质量分数越高.与国内外其他河流相比(见表 5),松花江表层沉积物污染水平处于中低水平,其PAHs质量分数低于我国的珠江、大辽河、墨水河和印度的Mithi河,与南黄海和第二松花江接近,但高于太湖、莱州湾、渤海北部和滦河口.

表 5 松花江表层沉积物中PAHs质量分数与国内外其他水体对比 Table 5 Comparison of PAHs in sediments of Songhua River with other waterbodies at home and abroad
2.2 沉积物PAHs组成特征

PAHs根据苯环数可以分为2环、3环、4环、5环和6环PAHs.一般而言,小分子的2环和3环PAHs主要来源于石油化工污染源,而高分子的PAHs(4环以上)主要来源于燃烧过程[39].由于PAHs性质的差异,其环境行为也有所不同,表现出的毒性和致癌性也存在差异[40-41],因此研究PAHs的组成特征,对于保障河流生态系统健康具有重要意义.

松花江流域干支流26个表层沉积物中2、3、4、5、6环的PAHs分别占w(∑16PAHs)的3.77%、22.98%、45.16%、14.08%和14.01%,占比从大到小依次为4环>3环>5环>6环>2环.除了S13、S21和S24号采样点以3环为主,占比范围为26%~39%,其他采样点都是以4环为主,其中S2、S12、S14和S17号采样点4环占比均高于50%.总体而言,松花江表层沉积物4环以上PAHs占比较高,为45.16%(见图 2),可以初步判断PAHs主要来源于各种物质的燃烧过程[39].与国内其他河湖相比,研究区沉积物各环PAHs组成分布特征与长江口[42]及千岛湖[43]完全一致(4环>3环>5环>6环>2环).

图 2 松花江表层沉积物中PAHs组成特征 Fig.2 Composition characteristics of PAHs in sediments of Songhua River
2.3 PAHs的来源分析 2.3.1 特征分子比值法

松花江表层沉积物26个采样点的An/(Phe+An)范围为0.11~0.55,均大于0.1(见图 3),结合表 2可知,主要来源于燃烧源,包括生物燃烧源和石油燃烧源;26个采样点Flu/(Flu+Pyr)范围为0.09~0.58,除倭肯河上的S24号采样点(0.09 < 0.4)外,其他采样点均大于0.5,表明除S24号采样点是石油燃烧源外,其他采样点均是生物燃烧源;26个采样点BaA/(BaA+Chr)范围为0.38~0.93,其中S13和S21号采样点分别为0.48和0.38,来源于石油燃烧,其他采样点均大于0.5,均来自于生物燃烧(见图 3).结合An/(Phe+An)、Flu/(Flu+Pyr)和BaA/(BaA+Chr)综合判断,除S24号采样点来自于石油源外,其他采样点的PAHs均来自于燃烧源,并且以生物燃烧为主,其次为石油燃烧.这与东北地区是我国老工业基地和粮食生产基地有关[22],生物质、石油等资源丰富,因此导致松花江PAHs污染主要是以燃烧源为主的混合源.研究区沉积物PAHs的污染来源与陈锋等[44-45]研究结果一致.

图 3 松花江表层沉积物中PAHs来源诊断 Fig.3 Diagnosis of PAHs sources in surface sediments of Songhua River
2.3.2 主成分分析

对松花江流域26个表层沉积物进行主成分分析,提取3个主成分(PC1、PC2、PC3),计算的累计方差贡献率如表 6所示.由表 6可见,主成分PC1方差贡献率为62.22%,主要由2环~6环的PAHs构成,Nap、Ace、Acp、Fl、Phe、An、Flu、Pyr、Chr、BbF、BkF、BaP、DbA和BgP具有较大的负荷值,其中Nap、Ace、Acp、Fl和Flu主要是木材、秸秆等生物质燃烧的指示物[46],而高环Phe、Pyr、Chr、BbF与BkF主要来源于煤炭燃烧和交通污染[47],因此推断PC1是燃烧混合源. PC2方差贡献率为9.73%,InP具有较大的负荷值. Larsen等[47]发现,InP主要来自柴油燃烧源,因此PC2为柴油燃烧源. PC3方差贡献率为7.99%,BaA和InP具有较大的负荷值,BaA是天然气排放的重要指标[29],因此推断PC3为煤炭和天然气燃烧污染源.主成分分析结果表明,松花江流域沉积物中的PAHs主要受木材、煤炭、柴油和天然气等燃烧源为主的混合源影响,石油泄漏污染较少,与2.3.1节解析结果相一致.

表 6 松花江表层沉积物中PAHs主成分分析 Table 6 Principal component analysis of PAHs in surface sediments from Songhua River
2.4 沉积物PAHs的生态风险评价 2.4.1 沉积物质量基准法

沉积物质量基准法相对比较成熟[48-49],该研究采用沉积物质量基准法对松花江表层沉积物PAHs的生态风险进行评价,结果如表 7所示.

表 7 松花江表层沉积物中PAHs质量分数与ERL和ERM的比较 Table 7 Comparison of PAHs concentration with ERL and ERM values in surface sediments of Songhua River  

表 7可见,只有w(Acp)、w(BaA)和w(DbA)超过了ERL,位于ERL和ERM之间,表明其对周边生物体及生态环境会偶尔产生生态风险[24],但BaA和DbA是化学强致癌物,未来应重点研究该污染物在松花江流域的来源和途径,并提出相应的管控措施;其余PAHs组分的平均浓度均在ERL之下,表明这些PAHs组分具有较低的生态风险水平,发生生态风险的概率较低(小于10%).

Nap、Ace、Acp、An、Fl、Phe、BaA和DbA这8种PAHs组分质量分数的最大值均超过了ERL,位于ERL和ERM之间,说明研究区内有个别采样点对周边生物体及生态环境会偶尔产生生态风险.由图 4可见,S1、S2、S3、S7、S8、S14、S15和S21号采样点的8种PAHs组分质量分数较高,其中S1、S2、S3、S7和S8号采样点位于松花江上游,表明松花江上游PAHs质量分数较高.这些地区曾聚集大量的石化企业,可能是PAHs污染的主要来源之一,建议未来应控制流域周边的石化企业的数量,同时加强对上述企业PAHs等有毒有机物的管控,从源头上减少PAHs的排放.倭肯河上的S24号采样点的PAHs质量分数最低,为138.53 ng/g,表明受到人类活动影响较小. Flu、Pyr、Chr和Bap组分质量分数的最大值均低于ERL,表明研究区内26个采样点的Flu、Pyr、Chr和Bap组分具有较低的生态风险水平,发生生态风险的概率较低. BbF、BkF、InP和BgP这4种PAHs组分没有规定最低安全值,需加以重视对其来源的管控.

图 4 松花江表层沉积物中PAHs组分的质量分数 Fig.4 Concentrations of PAHs in surface sediments of Songhua River
2.4.2 沉积物质量标准法

根据沉积物质量标准法,对松花江流域26个表层沉积物的12种PAHs生态风险状况进行评价,把26个采样点中至少有一种PAHs组分质量分数大于FEL的采样点列于表 8第一行,至少有一种PAHs组分质量分数介于PEL和FEL之间的采样点列于表 8第二行,依次类推,将各采样点的污染程度区分在各阈值之间(见表 8).

表 8 松花江表层沉积物中PAHs的污染程度分析 Table 8 Pollution Levels of PAHs in surface sediments of Songhua River

表 8可见,松花江流域26个表层沉积物中,有3个采样点(S2、S14和S15)存在高生态风险,其分别位于松花江流域中上游的拉林河和蚂蚁河支流上,其中S2号采样点位于哈尔滨市双城区周边,S14和S15号采样点位于哈尔滨市下游的通河县附近,均处于人类活动密集、交通发达的城市段,PAHs的污染来源广,因此沉积物中PAHs污染程度较高,相关部门应该予以重视,采取一定的措施,减少S2、S14和S15号采样点PAHs污染物的排放.有6个采样点(S1、S3、S5、S8、S17和S21)表层沉积物(23.07%)至少有一种PAHs的平均浓度介于PEL和FEL之间,潜在风险几率较高;有10个采样点(S4、S7、S9、S10、S13、S18、S19、S20、S23和S25)表层沉积物(38.46%)至少有一种PAHs的平均浓度介于OEL和PEL之间,潜在风险几率中等.剩余7个采样点介于TEL和OEL之间,潜在风险几率较低.研究区沉积物PAHs生态风险污染程度与长江口[50]基本持平,略高于太湖地区[51],潜在风险水平中等.总体而言,松花江流域有部分采样点存在一定的生态风险,相关部门应该采取相应的措施减少上述采样点PAHs的排放和治理.

3 结论

a) 松花江干支流表层沉积物中w(∑16PAHs)范围为169.76~3 769.19 ng/g,平均值为1 458.43 ng/g,以3~6环高环为主;并且支流w(∑16PAHs)(范围为169.76~3 769.19 ng/g,平均值为1 598.41 ng/g)高于干流(范围为459.92~2 092.58 ng/g,平均值为1 173.67 ng/g),与国内外其他河流相比,处于中低污染水平.沉积物中w(∑16PAHs)总体呈现从上游到下游逐渐降低趋势,并且支流的含量大于干流.

b) 松花江流域表层沉积物PAHs主要来源于生物质燃烧和石油燃烧,这与研究区域内产业布局和能源结构一致.

c) 松花江流域表层沉积物PAHs整体风险水平为低生态风险,位于中上游支流的3个采样点至少一种PAHs组分质量分数存在高生态风险,可能与石油化工企业等的排放及燃烧源相关,应采取相应的管控措施.

参考文献
[1]
GONG Xionghu, XIAO Liping, ZHAO Zhonghua, et al. Spatial variation of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from rivers in hilly regions of southern China in the wet and dry seasons[J]. Ecotoxicology and Environmental Safety, 2018, 156: 322-329. (0)
[2]
YANG Wei, LANG Yinhai, LI Guoliang. Cancer risk of polycyclic aromatic hydrocarbons (PAHs)in the soils from Jiaozhou Bay Wetland[J]. Chemosphere, 2014, 112(10): 289-295. (0)
[3]
吴义国, 方冰芯, 李玉成, 等. 杭埠-丰乐河表层沉积物中多环芳烃的污染特征、来源分析及生态风险评价[J]. 环境化学, 2017, 36(6): 420-429.
WU Yiguo, FANG Bingxin, LI Yucheng, et al. Occurrence of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Hangbu-Fengle River:pollution characteristics, potential source and risk assessment[J]. Environmental Chemistry, 2017, 36(6): 420-429. (0)
[4]
ADELEYE A, JIN Hanyan, DI Yanan, et al. Distribution and ecological risk of organic pollutants in the sediments and seafood of Yangtze Estuary and Hangzhou Bay, East China Sea[J]. Science of the Total Environment, 2016, 541(3): 1540-1549. (0)
[5]
李艳静, 汪光, 李开明, 等. 潭江表层沉积物中多环芳烃分布特征及其生态风险评价[J]. 环境科学与技术, 2014, 37(5): 167-173.
LI Yanjing, WANG Guang, LI Kaiming, et al. Distribution characteristics and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from Tanjiang River[J]. Environmental Science & Technology (China), 2014, 37(5): 167-173. (0)
[6]
MITRA S, CORSOLINI S, POZO K, et al. Characterization, source identification and risk associated with polyaromatic and chlorinated organic contaminants (PAHs, PCBs, PCBzs and OCPs) in the surface sediments of Hooghly Estuary, India[J]. Chemosphere, 2018, 221: 154. (0)
[7]
CARNEIRON D S R C, VIEIRA S L G G, EWERTON S, et al. Polycyclic aromatic hydrocarbons in sediments of the Amazon River Estuary(Amapá, Northern Brazil):distribution, sources and potential ecological risk[J]. Marine Pollution Bulletin, 2018, 135: 769-775. (0)
[8]
程家丽, 黄启飞, 魏世强, 等. 我国环境介质中多环芳烃的分布及其生态风险[J]. 环境工程学报, 2007, 1(4): 138-144.
CHENG Jiali, HUANG Qifei, WEI Shiqiang, et al. Review on distribution and risks of pollution from polycyclic aromatic hydrocarbons (PAHs) in China[J]. Journal of Environmental Engineering, 2007, 1(4): 138-144. (0)
[9]
沈小明, 吕爱娟, 沈加林, 等. 长江口启东-崇明岛航道沉积物中多环芳烃分布来源及生态风险评价[J]. 岩矿测试, 2014, 42(10): 374-380.
SHEN Xiaoming, LV Aijuan, SHEN Jialin, et al. Distribution characteristics, sources and ecological risk assessment of polycyclic aromatic hydrocarbons in waterway sediments from Qidong and Chongming Island of Yangtze River Estuary[J]. Rock and Mineral Analysis, 2014, 42(10): 374-380. (0)
[10]
陈明华, 李春华, 叶春, 等. 太湖竺山湾湖滨带沉积物中多环芳烃分布、来源及风险评价[J]. 环境工程技术学报, 2014, 4(10): 199-204.
CHEN Minghua, LI Chunhua, YE Chun, et al. Istribution sources and risk assessment of polycyclic aromatic hydrocarbons in sediments from Zhushan Bay Littoral Zone, Lake Taihu[J]. Journal of Environmental Engineering Technology, 2014, 4(10): 199-204. (0)
[11]
冉涛, 李双林, 张敏, 等. 渤海湾中部表层沉积物中多环芳烃分布及其来源[J]. 海洋地质前沿, 2014, 30(5): 30-35.
RAN Tao, LI Shuanglin, ZHANG Ming, et al. Distribution and source identification of polycyclic aromatic hydrocarbon of surface sediments form the center part of Bohai Sea, China[J]. Marine Geology Frontiers, 2014, 30(5): 30-35. (0)
[12]
SINGARE P U. Studies on polycyclic aromatic hydrocarbons in surface sediments of Mithi River Near Mumbai, India:assessment of sources, toxicity risk and biological impact[J]. Marine Pollution Bulletin, 2015, 101(1): 232-242. (0)
[13]
SOUZA M R R, SANTOS E, SUZARTE J S, et al. Concentration, distribution and source apportionment of polycyclic aromatic hydrocarbons (PAH) in Poxim River sediments, Brazil[J]. Marine Pollution Bulletin, 2018, 127: 478-483. (0)
[14]
GUINAN J, CHARLESWORTH M, SERVICE M, et al. Sources and geochemical constraints of polycyclic aromatic hydrocarbons (PAHs) in sediments and mussels of two northern Irish Sea-loughs[J]. Marine Pollution Bulletin, 2001, 42(11): 1073-1081. (0)
[15]
ECHOLS K R, BRUMBAUGH W G, ORAZIO C E, et al. Distribution of Pesticides, PAHs, PCBs, and bioavailable metals in depositional sediments of the Lower Missouri River, USA[J]. Archives of Environmental Contamination and Toxicology, 2008, 55(2): 161-172. (0)
[16]
DUODU G O, OGOGO K N, MUMMULLAGE S, et al. Source apportionment and risk assessment of PAHs in Brisbane River sediment, Australia[J]. Ecological Indicators, 2017, 73: 784-799. (0)
[17]
DONG Deming, LIU Xiaoxue, HUA Xiuyi. Sedimentary record of polycyclic aromatic hydrocarbons in Songhua River[J]. Environmental Earth Sciences, 2016, 16(5): 508-512. (0)
[18]
陆继龙, 蔡波, 郝立波, 等. 第二松花江中下游河段底泥中多环芳烃的初步研究[J]. 岩矿测试, 2007, 26(4): 325-327.
LU Jilong, CAI Bo, HAO Libo, et al. Preliminary study on polycyclic aromatic hydrocar bonsin bottom mudfrom the Middle and Lower Reaches of the Second Songhua River[J]. Rock and Mineral Analysis, 2007, 26(4): 325-327. (0)
[19]
刘宝林, 董德明, 花修艺, 等. 第二松花江流域水体表层沉积物多环芳烃的污染特征与暴露风险评价[J]. 吉林大学学报(理学版), 2014, 52(6): 151-157.
LIU Baolin, DONG Deming, HUA Xiuyi, et al. Pollution characteristics and exposure risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments of Second Songhua River Basin[J]. Journal of Jilin University(Science Edition), 2014, 52(6): 151-157. (0)
[20]
董德明. 松花江吉林市段江水与沉积物中多环芳烃的分布、来源和生态风险[J]. 吉林大学学报(理学版), 2014, 52(3): 623-630.
DONG Deming. Distribution, source and ecological risk of polycyclic aromatic hydrocarbons in the waters and sediments form Jilin City Section of Songhua River[J]. Journal of Jilin University(Science Edition), 2014, 52(3): 623-630. (0)
[21]
CUI Song, LI Kunyang, FU Qiang, et al. Levels, spatial variations, and possible sources of polycyclic aromatic hydrocarbons in sediment from Songhua River, China[J]. Arabian Journal of Geosciences, 2018, 11: 445. (0)
[22]
ZHAO Xuesong, DING Jing, YOU Hong. Spatial distribution and temporal trends of polycyclic aromatic hydrocarbons (PAHs) in water and sediment from Songhua River, China[J]. Environmental Geochemistry and Health, 2014, 36(1): 131-143. (0)
[23]
MA W L, LIU L Y, QI H, et al. Polycyclic aromatic hydrocarbons in water, sediment and soil of the Songhua River Basin, China[J]. Environmental Monitoring Assessment, 2013, 185(10): 8399-8409. (0)
[24]
DENG Wei, LI Xianguo. Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mud areas in the East China Sea using diagnostic ratios and factor analysis[J]. Marine Pollution Bulletin, 2013, 70(1/2): 266-273. (0)
[25]
SALVE D, VLADIMIR M. Savinov polycyclic aromatic hydrocarbons (PAHs)in bottom sediments of the Kara Sea shelf, Gulf of Ob and Yenisei Bay[J]. Science of the Total Environment, 2003, 306(3): 57-71. (0)
[26]
GU Yangguang, LI Huabing, LU Huibin. Polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the largest deep plateau lake in China:occurrence, sources and biological risk[J]. Ecological Engineering, 2017, 101(2): 179-184. (0)
[27]
MARTI N, MARTA S. Levels of PAHs in soil and vegetation samples from Tarragona County, Spain[J]. Environmental Pollution, 2014, 132(5): 1-11. (0)
[28]
IQBAL J, OVERTON E B, GISCLAIR D. Sources of polycyclic aromatic hydrocarbons in Louisiana rivers and coastal environments:principal components analysis[J]. Environmental Forensics, 2008, 9(4): 310-319. (0)
[29]
刘宗峰, 郎印海, 曹正梅, 等. 黄河口表层沉积物多环芳烃污染源解析研究[J]. 环境科学研究, 2008, 21(5): 79-84.
LIU Zongfeng, LANG Yinhai, CAO Zhengmei, et al. Source apportionment of PAHs in estuarine sediments from the Yellow River[J]. Research of Environmental Sciences, 2008, 21(5): 79-84. (0)
[30]
余云龙, 李圆圆, 林田, 等. 太湖表层沉积物中多环芳烃的污染现状及来源分析[J]. 环境化学, 2013, 22(5): 2336-2341.
YU Yunlong, LI Yuanyuan, LIN Tian, et al. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments from Taihu Lake[J]. Environmental Chemistry, 2013, 22(5): 2336-2341. (0)
[31]
罗孝俊, 陈社军, 麦碧娴, 等. 珠江及南海北部海域表层沉积物中多环芳烃分布及来源[J]. 环境科学, 2005, 26(5): 129-134.
LUO Xiaojun, CHEN Shejun, MAI Bixian, et al. Distribution and sources of polycyclic aromatic hydrocarbons in sediments from Rivers of Pearl River Delta and its nearby South China Sea[J]. Environmental Chemistry, 2005, 26(5): 129-134. (0)
[32]
张明亮, 黎慧, 徐英江, 等. 莱州湾表层沉积物中多环芳烃(PAHs)来源及生态风险评价[J]. 海洋环境科学, 2015, 34(10): 6-11.
ZHANG Mingliang, LI Hui, XU Yinjiang, et al. The source and ecological risk assessment of polycyclic aromatic hydrocarbons(PAHs)of surficial sediment in Laizhou Bay[J]. Marine Environmental Science, 2015, 34(10): 6-11. (0)
[33]
邓伟.南黄海、东海表层沉积物中脂肪烃与多环芳烃的分布特征及来源初步研究[D].青岛: 中国海洋大学, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10423-1013348246.htm (0)
[34]
GUO Wei, HE Mengchang, YANG Zhifeng, et al. Distribution of polycyclic aromatic hydrocarbons in water, suspended particulate matter and sediment from Daliao River Watershed, China[J]. Chemosphere, 2007, 68(7): 93-98. (0)
[35]
张玉凤, 吴金浩, 李楠, 等. 渤海北部表层沉积物中多环芳烃分布与来源分析[J]. 海洋环境科学, 2016(5): 88-94.
ZHANG Yufeng, WU Jinghao, LI Nan, et al. Distribution and source identification of polycyclic aromatic hydrocarbon of surface sediments from the North Bohai Sea[J]. Marine Environmental Science, 2016(5): 88-94. (0)
[36]
ZHANG Daolai, LIU Jinqing, JIANG Xuejun, et al. Distribution, sources and ecological risk assessment of PAHs in surface sediments from the Luan River Estuary, China[J]. Marine Pollution Bulletin, 2016, 102(6): 223-229. (0)
[37]
刘少鹏, 李先国, 张大海, 等. 墨水河表层沉积物中多环芳烃(PAHs)的分布特征、来源解析及生态风险评价[J]. 环境化学, 2018, 37(4): 843-850.
LIU Shaopeng, LI Xianguo, ZHANG Dahai, et al. Distribution, source and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Moshui River[J]. Environmental Chemistry, 2018, 37(4): 843-850. (0)
[38]
SINGARE P U. Studies on polycyclic aromatic hydrocarbons in surface sediments of Mithi River Near Mumbai, India:assessment of sources, toxicity risk and biological impact[J]. Marine Pollution Bulletin, 2015, 101(1): 232-242. (0)
[39]
DENG Wei, LI Xianguo, LI Shengyong, et al. Source apportionment of polycyclic aromatic hydrocarbons in surface sediment of mudareas in the East China Sea using diagnostic ratios and factor analysis[J]. Marine Pollution Bulletin, 2013, 70(1/2): 266-273. (0)
[40]
PING L F, LUO Y M, LI Q B, et al. Distribution of polycyclic aromatic hydrocarbons in thirty typical soil profiles in the Yangtze River Delta Region, East China[J]. Environmental Pollution, 2007, 147(2): 357-365. (0)
[41]
SUN Shaojing, JIA Linran, LI Bo, et al. The occurrence and fate of PAHs over multiple years in a wastewater treatment plant of Harbin, northeast China[J]. Science of the Total Environment, 2018, 624: 491-498. (0)
[42]
母清林, 方杰, 邵君波, 等. 长江口及浙江近岸海域表层沉积物中多环芳烃分布、来源与风险评价[J]. 环境科学, 2015, 36(3): 839-846.
MU Qingling, FANG Jie, SHAO Junbo, et al. Distribution, sources and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Yangtze Estuary and Zhejiang Coastal Areas[J]. Environmental Science, 2015, 36(3): 839-846. (0)
[43]
张明, 唐访良, 吴志旭, 等. 千岛湖表层沉积物中多环芳烃污染特征及生态风险评价[J]. 中国环境科学, 2014, 34(4): 253-258.
ZHANG Ming, TANG Fangliang, WU Zhixu, et al. Pollution characteristics and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Xin'anjiang Reservoir[J]. China Environmental Science, 2014, 34(4): 253-258. (0)
[44]
陈锋, 孟凡生, 王业耀, 等. 松花江水体中多环芳烃污染源解析因子分析研究[J]. 环境科学与技术, 2016, 39(3): 105-110.
CHEN Feng, MENG Fansheng, WANG Yeyao, et al. Source apportionment of water pollution in Songhua River Basin[J]. Environmental Science & Technology (China), 2016, 39(3): 105-110. (0)
[45]
马万里, 刘丽艳, 齐虹, 等. 松花江水环境中多环芳烃的污染及致癌风险[J]. 哈尔滨工业大学学报, 2014, 46(6): 44-49.
MA Wanli, LIU Liyan, QI Hong, et al. Pollution and cancer risk of PAHs in water environmentof the Songhua River, China[J]. Journal of Harbin Institute of Technology, 2014, 46(6): 44-49. (0)
[46]
JAVED I, OVERTON E, DAVID G. Sources of polycyclic aromatic hydrocarbons in Louisiana rivers and coastal environments:principal components analysis[J]. Environmental Forensics, 2008, 9(4): 310-319. (0)
[47]
LARSEN R K, BAKER J E. Source apportionment of polycyclic aromatic hydrocarbons in the urban atmosphere:a comparison of three methods[J]. Environmental Science & Technology, 2003, 37(9): 1873-1881. (0)
[48]
SOUZA M R R, SANTOS E, SUZARTE J S, et al. Concentration, distribution and source apportionment of polycyclic aromatic hydrocarbons (PAH) in Poxim River sediments, Brazil[J]. Marine Pollution Bulletin, 2018, 127: 478-483. (0)
[49]
SAJAD A, ZEINAB R, IRAJ F, et al. Contamination levels and spatial distributions of heavy metals and PAHs in surface sediment of Imam Khomeini Port, Persian Gulf, Iran[J]. Marine Pollution Bulletin, 2013, 71(5): 336-345. (0)
[50]
张晨晨, 高建华, 郭俊丽, 等. 长江口及废黄河口海域表层沉积物中多环芳烃分布特征和生态风险评价[J]. 海洋通报, 2018, 37(1): 38-44.
ZHANG Chengcheng, GAO Jianhua, GUO Junli, et al. Distribution and ecological risk assessment of PAHs in surface sediments from the Yangtze Estuary and the Old Yellow River Estuary[J]. Marine Science Bulletin, 2018, 37(1): 38-44. (0)
[51]
康杰, 胡健, 朱兆洲, 等. 太湖及周边河流表层沉积物中PAHs的分布、来源与风险评价[J]. 中国环境科学, 2017, 37(3): 1162-1170.
KANG Jie, HU Jian, ZHU Zhaozhou, et al. Distribution, source and risk assessment of PAHs in surface sediments from Taihu Lake and its surrounding rivers[J]. China Environmental Science, 2017, 37(3): 1162-1170. (0)