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重金属汞(Hg)和砷(As)是环境中典型污染物,具有持久性、累积性、生物毒性和沿食物链富集等多种特性;Hg和As可通过工业废水排放、地表径流和大气沉降等途径进入湖泊水体,造成湖泊水体污染,直接或间接危害人体健康[1-4]。南四湖属淮河流域,流域资源丰富[5],工业主要以高污染的能源企业、煤化工、造纸业、冶金业为主[6],从而导致南四湖水体受到一定程度的Hg和As的污染[7]。菹草作为南四湖重要的初级生产者之一[8],已由普通优势种演变为湖区绝对优势种[9]。由于受水体的理化性质、菹草密度等多种因素的影响,菹草对不同金属(Pb、Cd、Zn和Cu)的富集能力不同[10-11],且有研究表明菹草对Hg、As具有一定的富集作用[12]。目前对南四湖重金属的研究多集中在入湖河流和上级湖重金属元素的空间分布及赋存形态等方面,而对水生植物富集重金属的相关研究较少,因此研究南四湖菹草对重金属的富集特征对进一步揭示重金属在植物体内分布和南四湖重金属的污染防治具有重要意义。
本研究通过对南四湖菹草、上覆水和沉积物进行系统同步采样,分析菹草、上覆水和沉积物中Hg和As的含量及其空间分布特征,并计算菹草及各器官(茎、叶和果实)对Hg和As的富集系数,以探究南四湖Hg和As的分布特征以及菹草不同器官对Hg和As富集能力的差异,研究结果以期为南四湖水体重金属污染防治提供基础数据和科学依据。
南四湖菹草对上覆水和表层沉积物中汞和砷的富集特征
Enrichment characteristics of mercury and arsenic by Potamogeton crispus in the overlying water and surface sediment of Nansi Lake
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摘要: 为了解南四湖菹草对水体中汞(Hg)和砷(As)的富集能力,于2019年4月在南四湖采集了49个采样点的上覆水、菹草、表层沉积物样品,测定了样品中Hg和As的含量,并采用生物富集系数法(BCF)评价了菹草茎、叶和果实对上覆水和表层沉积物中Hg和As的富集能力。结果表明,南四湖上覆水中Hg的超标率为34.7%,As浓度达到Ⅲ类水标准;表层沉积物Hg和As的平均含量分别为南四湖底泥背景值的6.23倍和2.44倍;菹草中Hg和As平均含量分别为0.14 mg∙kg−1和3.02 mg∙kg−1;Hg在叶中的含量分别是茎和果实的1.22倍和1.56倍;As在茎中的含量分别是叶和果实的1.22倍和1.47倍。上覆水、菹草和表层沉积物中的Hg、As含量的空间分布差异均较大,且出现局部的高值区。菹草各器官对Hg的富集能力表现为叶>茎>果实,对As富集能力为茎>叶>果实。菹草对上覆水和表层沉积物中Hg、As富集系数均为高度变异,空间分布差异较大,且与上覆水和表层沉积物中Hg、As含量具有相关关系,说明Hg和As在菹草-上覆水-沉积物系统中具有一定的动态迁移能力。Abstract: In order to understand the enrichment abilities of mercury (Hg) and arsenic (As) by Potamogeton crispus (P. crispus) in Nansi Lake, P. crispus, overlying water and surface sediment samples were synchronously collected in 49 sampling sites around the Nansi Lake in April, 2019. The total content of Hg and As in all the samples and in organs of P. crispus were analyzed, and the bioconcentration factors (BCFs) were calculated to assess the enrichment abilities of Hg and As by the whole plant and organs of P. crispus during its growing period. The results showed that Hg concentrations in 34.7% sampling sites exceeded the type Ⅲ standard value of the GB3838—2002 National Environment Quality Standards for Surface Water, while As concentrations were all lower than its corresponding type Ⅲ standard value. The average content of Hg and As in the surface sediment were 6.23 times and 2.44 times of the sediment background values of Nansi Lake, respectively. The average content of Hg and As in P. crispus were 0.14 mg∙kg−1 and 3.02 mg·kg−1, respectively. The average Hg content in leaves was severally 1.22 times and 1.56 times of those in stems and fruits, while the average As content in stems was 1.22 times and 1.47 times of those in leaves and fruits respectively. The spatial distribution of Hg and As content in overlying water, P. crispus and surface sediments differed greatly, and the high values of Hg and As occurred in different areas of the lake. The enrichment abilities of Hg in different organs of P. crispus were in the order of leaf > stem > fruit, while for As it was stem > leaf > fruit. The BCFs of Hg and As in overlying water and surface sediments by P. crispus were highly variable, and their spatial distribution was quite different. Moreover, the BCFs had some significant correlations with their corresponding content of Hg and As in overlying water and surface sediment, which suggested that Hg and As might have certain dynamic migration abilities in P. crispus, overlying water and sediment system.
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Key words:
- mercury /
- arsenic /
- Potamogeton crispus /
- bioconcentration /
- water body /
- Nansi Lake
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表 1 南四湖上覆水、表层沉积物和菹草Hg、As含量水平
Table 1. Concentrations of Hg and As in overlying water、surface sediments and P. crispus of Nansi Lake
参数
Parameters上覆水
Overlying water表层沉积物
Surface sediments菹草(干重)
P.crispus (dry weight)Hg/(μɡ∙L−1) As/(μɡ∙L−1) Hg/(mg∙L−1) As/(mg∙L−1) Hg/(mg∙L−1) As/(mg∙L−1) 平均值 Average 1.18 4.03 0.094 18.3 0.142 3.02 最小值 Minimum ND 1.69 ND 6.21 ND 0.31 最大值 Maximum 4.91 13.1 0.42 27.6 0.742 17.3 S.D. 1.25 1.9 0.091 5.42 0.187 2.94 CV/% 106 47 97 30 131 97 偏度系数 Coefficient of Skewness 1.66 2.59 2.15 −0.153 1.74 2.85 峰度系数 Coefficient of Kurtosis 2.57 9.87 5.06 −0.865 2.55 11.0 中国地表水Ⅲ类水质标准值[22]
The type Ⅲ standard values of Surface Water[22]0.1 50 — — — — 南四湖底泥背景值[23]
The sediment background values of Nansi Lake[23]— — 0.015 7.5 — — 洞庭湖[24] Dongting Lake[24] — — 0.155 21.4 — — 乌梁素海[25] Wuliangsuhai Lake[25] — — 0.036 7.48 — — 南四湖[26]Nansi Lake[26] — — 0.048 14.1 — — 南四湖[27]Nansi Lake[27] — — 0.092 12.2 — — 东平湖[12] Dongping Lake[12] 0.769 7.86 0.072 17.1 0.169 2.11 注:“ND”代表低于检出限,下同; “—”表示无数据.
Notes: “ND” means not detected, the same below; “—” means no data available.表 2 Hg、As在茎、叶、果实中的含量水平
Table 2. Concentrations level of Hg and As in stem, leaf and fruit
参数 Parameters 茎 Stem 叶 Leaf 果实 Fruit Hg As Hg As Hg As 平均值 /(mg∙kg−1) 0.11 3.51 0.14 2.88 0.09 2.38 最小值 /(mg∙kg−1) ND 0.10 ND 0.03 ND 0.05 最大值/(mg∙kg−1) 0.70 30.91 0.74 13.65 0.46 12.26 S.D. 0.17 5.01 0.20 2.68 0.15 3.28 CV/% 144 142 144 92 169 137 偏度系数 Coefficient of Skewness 2.03 4.61 1.41 2.44 1.74 2.84 峰度系数 Coefficient of Kurtosis 4.17 24.2 0.842 6.33 2.13 8.67 表 3 上覆水、表层沉积物和菹草中 Hg 和 As含量的相关系数
Table 3. Correlation coefficients of concentrations of Hg and As in overlying water, surface sediments and P. crispus
参数 Parameters 上覆水 Overlying water 表层沉积物 Surface sediments 菹草 P. crispus Hg As Hg As Hg As/Overlying water −0.048 Hg/surface sediments 0.010 −0.083 As/surface sediments 0.023 −0.343 a 0.266 a Hg/P. crispus −0.163 0.108 0.204 b −0.108 As/P. crispus −0.135 −0.108 0.152 0.308 a −0.062 注:n=49;a P < 0.01;b P < 0.05. 表 4 南四湖菹草对上覆水和表层沉积物中Hg和As的富集水平
Table 4. Bioconcentration levels of Hg and As in overlying water and surface sediments by P. crispus
参数 Parameters BCFHg(w) BCFAs(w) BCFHg(s) BCFAs(s) 平均值 413 890 5.07 0.167 最小值 0 110 0 0.010 最大值 8271 4206 114 1.12 S.D. 1411 874 17.1 0.169 CV/% 342 98 337 101 表 5 菹草对上覆水、表层沉积物中 Hg 和 As 的富集系数的相关分析
Table 5. Correlation analysis of enrichment coefficients of Hg and As in overlying water and surface sediments by P. crispus
参数 Parameters Hg/(W) As/(W) Hg/(S) As/(S) BCFHg(w) BCFAs(w) BCFHg(s) BCFHg(w) −0.540 a 0.165 −0.122 −0.087 BCFAs(w) −0.062 −0.528 a 0.194 0.559 a 0.005 BCFHg(s) −0.126 0.138 −0.499 a −0.230 0.831 a −0.089 BCFAs(s) −0.281 0.024 0.047 0.063 0.264 0.708 a 0.059 注:n=49;a表示P < 0.01;W代表上覆水;S代表表层沉积物.
Notes: n=49; a Correlation is significant at the 0.01 level (two-tailed); W is for overlying water; S is for surface sediments. -
[1] 张家泉, 田倩, 许大毛, 等. 大冶湖表层水和沉积物中重金属污染特征与风险评价 [J]. 环境科学, 2017, 38(6): 2355-2363. ZHANG J Q, TIAN Q, XU D M, et al. Pollution characteristics and risk assessment of heavy metals in water and sediment from Daye Lake [J]. Environmental Science, 2017, 38(6): 2355-2363(in Chinese).
[2] 敖亮, 雷波, 王业春, 等. 三峡库区典型农村型消落带沉积物风险评价与重金属来源解析 [J]. 环境科学, 2014, 35(1): 179-185. AO L, LEI B, WANG Y C, et al. Sediment risk assessment and heavy metal source analysis in typical country water level fluctuated zone (WLFZ) of the three gorges [J]. Environmental Science, 2014, 35(1): 179-185(in Chinese).
[3] 张彦, 卢学强, 刘红磊, 等. 渤海湾天津段表层沉积物重金属分布特征及其来源解析 [J]. 环境科学研究, 2014, 27(6): 608-614. ZHANG Y, LU X Q, LIU H L, et al. Distribution characteristics and source identification of heavy metals in surface sediments of Bohai Bay near Tianjin [J]. Research of Environmental Sciences, 2014, 27(6): 608-614(in Chinese).
[4] 方明, 吴友军, 刘红, 等. 长江口沉积物重金属的分布、来源及潜在生态风险评价 [J]. 环境科学学报, 2013, 33(2): 563-569. doi: 10.13671/j.hjkxxb.2013.02.024 FANG M, WU Y J, LIU H, et al. Distribution, sources and ecological risk assessment of heavy metals in sediments of the Yangtze River estuary [J]. Acta Scientiae Circumstantiae, 2013, 33(2): 563-569(in Chinese). doi: 10.13671/j.hjkxxb.2013.02.024
[5] 李爽. 基于SWAT模型的南四湖流域非点源氮磷污染模拟及湖泊沉积的响应研究[D]. 济南: 山东师范大学, 2012. 153. LI S. Simulation of Non-Point Source pollution of Nitrogen, Phosphorus using SWAT model and response of lacustrine deposit in Nansihu Basin [D]. Jinan: Shandong Normal University, 2012. 153 (in Chinese).
[6] 刘恩峰, 沈吉, 杨丽原, 等. 南四湖及主要入湖河流表层沉积物重金属形态组成及污染研究 [J]. 环境科学, 2007, 28(6): 1377-1383. doi: 10.3321/j.issn:0250-3301.2007.06.037 LIU E F, SHAN J, YANG L Y, et al. Chemical fractionation and pollution characteristics of heavy metals in the sediment of Nansihu Lake and its main inflow rivers, China [J]. Environmental Science, 2007, 28(6): 1377-1383(in Chinese). doi: 10.3321/j.issn:0250-3301.2007.06.037
[7] 王龙凤. 南四湖表层沉积物中典型重金属污染研究[D]. 济南: 济南大学, 2014. 55. WANG LONG FENG. Study on typical heavy metals pollution in the surface sediments of Nansi Lake [D]. Jinan: University of Jinan, 2014. 55 (in Chinese).
[8] 张桂斋. 两类持久性有机污染物和重金属在南四湖食物链中的分布和生物积累[D]. 济南: 山东大学, 2014. 119 ZHANG G Z. Distribution and bioaccumulation of two types of persistent organic pollutions and heavy metals in food web of Nansi Lake, China [D]. Jinan: Shandong University, 2014. 119(in Chinese).
[9] 焦银合, 于泉洲, 刘恩峰, 等. 基于遥感的南四湖菹草群落时空演变特征及其原因分析 [J]. 林业资源管理, 2020(1): 72-80, 93. JIAO Y H, YU Q Z, LIU E F, et al. The characteristics of and causes to spatiotemporal evolution Potamogeton crispus L. Community in Nansi Lake based on remote sensing data [J]. Forest Resources Management, 2020(1): 72-80, 93(in Chinese).
[10] 高海荣, 陈秀丽, 赵爱娟, 等. 5种沉水植物对重金属富集能力的对比研究 [J]. 环境保护科学, 2016, 42(4): 101-105. doi: 10.16803/j.cnki.issn.1004-6216.2016.04.021 GAO H R, CHEN X L, ZHAO A J, et al. Comparison of heavy metal accumulation by five submerged macrophytes [J]. Environmental Protection Science, 2016, 42(4): 101-105(in Chinese). doi: 10.16803/j.cnki.issn.1004-6216.2016.04.021
[11] 张伟. 南四湖水体中汞的分布特征及风险评价研究[D]. 济南: 济南大学, 2018. 53. ZHANG W. Distribution characteristics and risk assessment of mercury in water of Nansi Lake [D]. Jinan: University of Jinan, 2018. 53(in Chinese).
[12] 殷山红, 张智博, 肖燕, 等. 东平湖菹草-上覆水-沉积物系统中汞、砷的赋存特征 [J]. 环境化学, 2019, 38(3): 635-643. doi: 10.7524/j.issn.0254-6108.2018051203 YIN S H, ZHANG Z B, XIAO Y, et al. Distribution characteristic of mercury and arsenic in the Potamogeton crispus-overlying water- sediment system of Dongping Lake [J]. Environmental Chemistry, 2019, 38(3): 635-643(in Chinese). doi: 10.7524/j.issn.0254-6108.2018051203
[13] 赵群群, 杨凯. 南四湖污染物排放对南水北调东线水质的影响及治理措施 [J]. 价值工程, 2010, 29(8): 105-106. doi: 10.3969/j.issn.1006-4311.2010.08.064 ZHAO Q Q, YANG K. Influence and governance of Nansi Lake pollutants on water quality of south-north diversion project eastern route [J]. Value Engineering, 2010, 29(8): 105-106(in Chinese). doi: 10.3969/j.issn.1006-4311.2010.08.064
[14] 郭森. 南四湖沉积物中重金属含量特征及历史反演[D]. 石家庄: 河北科技大学, 2019. 58. GUO S. Characteristics and history of heavy metal content in sediments of the Nansi Lake [D]. Shijiazhuang: Hebei University of Science and Technology, 2019. 58(in Chinese).
[15] 张祖陆, 孙庆义, 彭利民, 等. 南四湖地区水环境问题探析 [J]. 湖泊科学, 1999, 11(1): 86-90. doi: 10.18307/1999.0114 ZHANG Z L, SUN Q Y, PENG L M, et al. Water environment problem in the Nansihu Lake [J]. Journal of Lake Sciences, 1999, 11(1): 86-90(in Chinese). doi: 10.18307/1999.0114
[16] 于泉洲, 张祖陆, 高宾, 等. 基于RS和FRAGSTATS的南四湖湿地景观格局演变研究 [J]. 林业资源管理, 2013(1): 108-115. doi: 10.3969/j.issn.1002-6622.2013.01.022 YU Q Z, ZHNAG Z L, GAO B, et al. Study on the changes of landscape pattern in Nansihu wetland based on RS and FRAGSTATS [J]. Forest Resources Management, 2013(1): 108-115(in Chinese). doi: 10.3969/j.issn.1002-6622.2013.01.022
[17] 李印霞, 刘碧波, 曹志林, 等. 菹草对巢湖底泥及上覆水环境影响的研究 [J]. 海洋湖沼通报, 2020(3): 127-132. doi: 10.13984/j.cnki.cn37-1141.2020.03.017 LI Y X, LIU B B, CAO Z L, et al. Study on environmental impact of Potamogeton crispus on sediment and overburden water of Chaohu Lake [J]. Transactions of Oceanology and Limnology, 2020(3): 127-132(in Chinese). doi: 10.13984/j.cnki.cn37-1141.2020.03.017
[18] 马迎丽, 吴广州, 孟娟, 等. 菹草疯长对南四湖水质的影响 [J]. 河北渔业, 2016(11): 14-17. doi: 10.3969/j.issn.1004-6755.2016.11.005 MANG Y L, WU G Z, MEMG J, et al. Influence of Potamogeton crispus growth on water quality of Nansi Lake [J]. Hebei Fisheries, 2016(11): 14-17(in Chinese). doi: 10.3969/j.issn.1004-6755.2016.11.005
[19] GRANEL T, ROBINSON B, MILLS T, et al. Cadmium accumulation by willow clones used for soil conservation, stock fodder, and phytoremediation [J]. Australian Journal of Soil Research, 2002, 40(8): 1331-1337. doi: 10.1071/SR02031 [20] LAFABRIE C, MAJOR K M, MAJOR C S, et al. Trace metal contamination of the aquatic plant Hydrilla verticillate and associated sediment in a coastal Alabama creek (Gulf of Mexico – USA) [J]. Marine Pollution Bulletin, 2013, 68: 147-151. doi: 10.1016/j.marpolbul.2012.11.045 [21] 李庚飞. 某矿区附近不同作物对3种重金属富集能力的研究 [J]. 中国农学通报, 2012(26): 263-267. doi: 10.3969/j.issn.1000-6850.2012.26.052 LI G F. Study on the concentration capacity to three kinds of heavy metals for different crops around the gold area [J]. Chinese Agricultural Science Bulletin, 2012(26): 263-267(in Chinese). doi: 10.3969/j.issn.1000-6850.2012.26.052
[22] 国家环境保护总局, 国家质量监督检验检疫总局. GB3838—2002, 地表水环境质量标准[S]. 北京: 中国环境科学出版社, 2002. State Environmental Protection Administration of China, State Administration for Quality Supervision and Inspection and Quarantine of China. Environmental quality standards for surface water: GB 3838—2002 [S], 2002(in Chinese).
[23] 杨丽原, 沈吉, 张祖陆, 等. 南四湖表层底泥重金属和营养元素的多元分析 [J]. 中国环境科学, 2003(2): 95-98. doi: 10.3321/j.issn:1000-6923.2003.02.022 YANG L Y, SHEN J, ZHANG Z L, et al. Multivariate analysis of heavy metal and nutrient in surface sediments of Nansihu Lake [J]. China Environmental Science, 2003(2): 95-98(in Chinese). doi: 10.3321/j.issn:1000-6923.2003.02.022
[24] 石雪芳, 张海涛, 张宇, 等. 洞庭湖表层沉积物中重金属污染评价与分析 [J]. 环境科学与技术, 2017, 40(12): 267-277. SHI X F, ZHANG H T, ZHANG Y, et al. Analysis and pollution assessment of heavy metals in surface sediments of Dongting Lake [J]. Environmental Science & Technology, 2017, 40(12): 267-277(in Chinese).
[25] 马红. 乌梁素海沉积物中汞砷的分布特征及环境风险评价[D]. 内蒙古: 内蒙古农业大学, 2016. 61. MA H. Distribution characteristics and environmental risk assessment of Hg and As in sediments of Wuliangsuhai Lake [D]. Inner Mongolia: Inner Mongolia Agricultural University, 2016. 61(in Chinese).
[26] 刘良, 张祖陆. 南四湖表层沉积物重金属的空间分布、来源及污染评价 [J]. 水生态学杂志, 2013, 34(6): 7-15. doi: 10.3969/j.issn.1674-3075.2013.06.002 LIU L, ZHANG Z L. Spatial distribution, sources and pollution assessment of heavy metals in the surface sediments of Nansihu Lake [J]. Journal of Hydroecology, 2013, 34(6): 7-15(in Chinese). doi: 10.3969/j.issn.1674-3075.2013.06.002
[27] 杨丽原, 沈吉, 张祖陆, 等. 南四湖表层底泥重金属污染及其风险性评价 [J]. 湖泊科学, 2003, 15(3): 252-256. doi: 10.3321/j.issn:1003-5427.2003.03.009 YANG L Y, SHEN J, ZHANG Z L, et al. Distribution and ecological risk assessment for heavy metals in superficial sediments of Nansihu Lake [J]. Journal of Lake Sciences, 2003, 15(3): 252-256(in Chinese). doi: 10.3321/j.issn:1003-5427.2003.03.009
[28] WILDING L P. Spatial variability: Its documentation, accommodation and implication to soil surveys [M]. Spatial Variations, 1985. [29] 曲晓华, 郭敬, 闫先名, 等. 南四湖沉积物重金属的季节性分布特征及评价 [J]. 山东农业科学, 2018, 50(9): 72-77. QU X H, GUO J, YAN X M, et al. Seasonal distribution characteristics and evaluation of heavy metals in sediments of Nansihu Lake [J]. Shandong Agricultural Sciences, 2018, 50(9): 72-77(in Chinese).
[30] 李爽, 张祖陆. 南四湖表层底泥重金属空间分布及污染程度评价 [J]. 水资源保护, 2012, 28(4): 6-11. doi: 10.3969/j.issn.1004-6933.2012.04.002 LI S, ZHNAG Z L. Spatial distribution and pollution assessment of heavy metals in surface sediments of Nansihu Lake [J]. Water Resources Protection, 2012, 28(4): 6-11(in Chinese). doi: 10.3969/j.issn.1004-6933.2012.04.002
[31] LIANG P P, XING Y X, WEI C L, et al. Distribution and assessment of heavy metals in the overlying water-sediment-plant-fish system in the Wuliangsuhai Lake by using inductively coupled plasma mass spectrometry [J]. Spectroscopy and Spectral Analysis, 2019, 39(2): 652-658. [32] 潘义宏, 王宏镔, 谷兆萍, 等. 大型水生植物对重金属的富集与转移 [J]. 生态学报, 2010,30(23): 6430-6441. PAN Y H, WANG H B, GU Z P, et al. Accumulation and translocation of heavy metals by macrophytes [J]. Acta Ecologica Sinica, 2010,30(23): 6430-6441(in Chinese).
[33] DENG H G, ZHANG J, CHEN S Y, et al. Metal release/accumulation during the decomposition of Potamogeton crispus in a shallow macrophytic lake [J]. Journal of Environmental Sciences, 2016, 42(4): 71-78.