五里河城市河道湿地汞的特征

提出了城市河道湿地——一种新湿地类型的概念,论述了辽宁省葫芦岛市市区五里河城市河道湿地的生态特征,研究了五里河城市河道湿地沉积物和植被中汞的分布特征,采用生态风险指数法评价了该城市河道湿地沉积物中汞污染程度及其生态风险。五里河属季节性河流,葫芦岛市市区段的五里河河道不同的生态位生长着不同类型的植被,具有典型的湿地特征。河道湿地表层沉积物的总汞质量比为0.037～16.07mg/kg,平均质量比为9.241mg/kg。在该城市河道湿地龙湾大桥采样点,比较3种植物的总汞含量发现,三棱草(Rhizomacy-peri)的总汞含量高于稗草(Echinochloa crusgalli),稗草的总汞含量高于芦苇(Phragmites australis)。3种植物都存在根的总汞含量大于叶,叶的总汞含量大于茎的现象。由于水文和地域等条件的差异,五里河城市河道湿地与三江平原的碟形沼泽湿地汞的分布特征明显不同。评价结果显示,五里河城市河道湿地有重度的汞污染且具有严重的潜在生态危害。     

徐闻南山镇红树林沉积物及红树植物中重金属的累积特征与迁移规律

为探究重金属在红树林沉积物及红树植物中的分布累积及迁移规律，选取了徐闻南山镇红树林为研究对象，通过测定红树林沉积物及红树植物不同部位（根、茎、叶）的重金属质量分数，运用富集因子、生物富集系数、转移系数及相关性分析等方法进行分析。结果表明：1）红树林沉积物重金属质量分数表现为铬（Cr）＞锌（Zn）＞镍（Ni）＞铜（Cu）＞铅（Pb）＞砷（As）＞汞（Hg）＞镉（Cd），为中等变异程度；除了镍（Ni）元素外，其余7种重金属未超过国家一级标准，除了铅（Pb）元素外，其余7种重金属均超过广东省土壤环境背景值，说明研究区沉积物中重金属具有一定的积累效应。2）沉积物中砷（As）、铜（Cu）、锌（Zn）、汞（Hg）、镍（Ni）、铬（Cr）富集因子值均＞1.5，说明受到轻微人为活动影响；各站位镍（Ni）富集因子值均＞5，结合研究区背景，反映了镍（Ni）受到自然和人为输入的共同影响。3）白骨壤体内重金属主要集中在根部，而红海榄体内重金属在根茎叶中分布相对均匀。白骨壤根茎叶部位的大多数重金属质量分数远高于红海榄，说明白骨壤对重金属的吸附能力比红海榄强。汞（Hg）集中分布在植物的叶片部位，且与其他重金属之间相关性不明显；推测汞（Hg）主要通过叶片吸收进入植物体内，与交通运输污染有关。4）不同红树植物对不同重金属富集能力各异，白骨壤对重金属的富集能力表现为：镉（Cd）＞砷（As）＞铜（Cu）＞锌（Zn）＞汞（Hg）＞铅（Pb）＞镍（Ni）＞铬（Cr），红海榄表现为：镉（Cd）＞铜（Cu）＞汞（Hg）＞锌（Zn）＞铅（Pb）＞砷（As）＞镍（Ni）＞铬（Cr）。白骨壤和红海榄对汞（Hg）的运移能力都较强；红海榄对镉（Cd）的富集能力和转运能力都较强，而白骨壤对镉（Cd）富集能力较强，转运能力却较弱，这说明红树植物对重金属元素的富集能力与转运能力不存在正比关系。     

澜沧江河床沉积物重金属污染评价

河床沉积物是河流水体与泥沙环境中重金属的主要积存载体,能反映水环境的重金属污染状况。本文选取澜沧江为对象,通过对澜沧江干流西藏和云南境内22个河段的河床沉积物重金属测定分析,得到了8种主要的重金属元素(Cr、Mn、Ni、Zn、As、Pb、Cu和Co)的含量,并采用沉积物富集系数法与地质积累指数法分别对所测得沉积物的重金属污染程度进行了评价。结果表明:①澜沧江干流大部分河段污染情况并不明显,但在中游的旧州和功果桥河段,因该区域的地质金属背景值和支流沘江流域铅锌矿开采,地表的重金属元素被雨水冲刷到该河段,导致沉积物重金属富集现象明显,出现了轻度到较强度污染;②澜沧江流域受人为干扰的区域集中于中游与下游,部分河段(功果桥附近)Cu、Pb和Zn等元素呈轻度或偏中度污染;③大坝对河流的阻隔效应使得干流沉积物重金属污染呈现片段化分布,河流沿岸城市化等人类活动对附近河段沉积物重金属污染状况也有较明显的影响。     

汉水水系水环境中稀土元素的分布特征

系统探讨了汉水水系水相（原水、滤水、悬浮物）、沉积物相中8个稀土元素的含量水平、丰度模式、悬浮物含量对水中元素含量的影响及沉积物粒度对元素的富集与分散作用等，结果表明：Eu、Lu主要以溶解态存在于水相中，而Sm主要存在于悬浮物中；汉水水中稀土元素的含量基本在世界淡水的范围内；湖库悬浮物中稀土元素含量均低于江河悬浮物，悬浮物和细粒沉积物中稀土元素含量相近，序列也基本一致；粒度对汉水沉积物中稀土元素含量的影响不明显；地表径流对水中悬浮物含量和悬浮物中稀土元素含量均有一定影响，稀土元素在汉水悬浮物、沉积物中均有一定程度的富集现象；汉水各相中均以轻稀土为主，重稀土含量较少。     

南坑河污染初步调查及河岸植物的富集能力

南坑河是新丰江的一条支流,直接汇入广东省最大的饮用水源地新丰江水库。野外调查中发现私自采矿和在河流沿岸洗矿等行为不断发生,大量洗矿废水未经处理直接注入南坑河,可能会造成污染。因此,采样初步分析了南坑河河水、河流底泥沉积物及附近优势植物的9种重金属元素含量。结果发现：与地表水II类标准相比,南坑河枯水期水体污染严重,其中连续2 a的铅、砷和汞超标,超标倍数分别为1.7~1.8、1.3~1.9和1.6~2.9倍,而底泥中铜、镉、铅、锌和砷均超标,超标倍数分别为4.8、9.0、3.9、4.3和10.9倍,镉和砷超标较为严重。另外,收集并鉴定了河岸或河漫滩中天然生长的15种植物,发现以蕨类植物和多年生禾草为主要类型。通过分析植物体内9种重金属元素含量,发现对砷吸附能力最强的当属蜈蚣草,其叶片中砷的含量（609.20 mg/kg）和茎干中砷的含量（814.77 mg/kg）均大于根部的砷含量（577.30 mg/kg）;蜈蚣草对铁、锰、铜和铅的吸附能力也远远大于其他河岸植物,可以作为良好地修复以砷为主的复合重金属污染土壤的富集植物。     

睦洞湖和古桂柳运河表层沉积物中汞和砷含量及其生态风险评价

于2018年1月18～19日,在广西会仙喀斯特湿地的睦洞湖和古桂柳运河中,设置了13个采样点,采集了表层(0～10 cm深度)的沉积物样品,采用(1+1)王水水浴消解法,消解沉积物样品,利用原子荧光形态分析仪,测定样品中的汞和砷含量;采用地累积指数法和潜在生态风险评价法,对会仙湿地睦洞湖和古桂柳运河表层沉积物中汞和砷的污染等级和潜在生态风险进行了评价。研究结果表明,表层沉积物中的汞质量比为0.29～1.81 mg/kg,平均值为0.51 mg/kg,其大于广西壮族自治区土壤汞含量背景值,表层沉积物中汞的地累积系数为0.40～1.22,表现为轻度污染或偏中度污染,并存在强潜在生态风险;表层沉积物中砷质量比为5.96～54.25 mg/kg,平均值为21.44 mg/kg,其略高于广西壮族自治区土壤砷含量背景值,表层沉积物中砷的地累积系数为-0.90～0.01,未出现明显的砷污染,但是,在部分采样点,表层沉积物中的砷含量极高,存在轻微潜在生态风险。     

鸟类在湿地汞循环和汞监测中的作用

湿地被称为汞的活性库,鸟类在汞的生物富集和搬运过程中发挥了重要作用。鸟类汞富集程度与营养级及年龄呈正相关,在其组织器官中,羽毛、肝和肾中的汞富集含量高。食鱼鸟类是湿地生态系统的顶级消费者,汞富集程度最高,鸥类、鹭类等常见食鱼鸟是推荐的指示生物。在极地等偏远地区,生物富集和生物搬运的协同作用对汞迁移的影响大于大气沉降,粪便、羽毛是鸟体排出汞的主要方式。由于鸟类的周期性迁徙,以及对不同生境的利用强度不同,鸟类对汞的生物搬运呈现出明显的规律性和方向性,影响其生物搬运汞的因素主要有新陈代谢、迁徙、栖息地景观特征和气候变化等。鸟类的组织器官乃至种群参数已经被广泛用于汞污染监测中,鸟的羽毛和卵因具有汞富集程度高、易于获取、无损伤性、可以长期保存等优点,所以是推荐的可以采集的样品材料。未来加强鸟类食物链结构分析、室内控制毒理实验、鸟类迁徙生态等基础研究,可提高鸟类作为汞污染指示生物的科学性和准确性。     

兰州市城区河道表层沉积物地球化学元素分布特征

通过对兰州市河道表层沉积物地球化学元素分析发现,兰州市河道表层沉积物41种地球化学元素富集因子多小于1,Cl、S、P、Bi、Cr、Cu、Pb、Sn、U、W、Zn富集因子值均大于2,显示了较高的污染水平。对单个采样点总富集因子的分析研究发现,R值均大于2,显示出较多的富集。其中水磨沟下游和鱼儿沟下游富集因子出现高值,显示出严重污染。元素来源研究结果显示,兰州市河道表层沉积物地球化学元素的来源可分为3类:①生活污水排放以及雨水对地面或街道的冲刷作用;②工业污染,包括冶金、电镀、农药和化肥等污水的排放;③本地土壤类型灰钙土中元素的贡献。通过粒度与元素相关性分析可知,元素P、Cl主要分布于细颗粒物质中,反映了兰州市河道表层沉积物污染物质在细颗粒中有较大量的富集。     

西安高陵近代河漫滩沉积与洪水变化

 根据高陵渭河河漫滩沉积剖面中105个样品的颗粒与有机质分析,Hg与CaCO3含量测定和史书记载的年代资料,研究了西安高陵渭河距今约120 a来河漫滩沉积指示的洪水变化。结果表明,高陵渭河约120 a来至少发生了16次大洪水, 洪水规模存在一定差别, 各次洪水一般代表了当年降水量的明显增加; 高陵渭河河漫滩沉积中有机碳浓度、金属汞的含量、CaCO3含量变化显著,它们与颗粒大小之间有明显的相关性,沉积物粒度越细,其有机碳和重金属汞的含量越高,CaCO3含量越少。有机碳和重金属汞的含量变化能够间接指示洪水动力强弱变化和短暂降水量增加。汞含量变化表明,渭河汞污染发生时间相当晚。     

沅江下游入湖段河床沉积物重金属污染特征北大核心CSCDCSSCI

对沅江入湖沉积物进行钻探取样,利用等离子质谱仪(ICP-MS)对沉积物重金属进行分析。结果表明:重金属Ba、Sc、V、Th、U、Cu、Co、Ni、Cr等在沉积物中含量变化相对稳定,分布相对均匀;而Mn、Zn、Pb、Mo、Cd、Tl、Bi等重金属的含量变化大,分布不均匀。重金属含量柱状剖面变化特征及富集系数(EF值)的计算结果显示:沉积物中Cd达显著富集,而Sc、V、Mn、Pb、Bi等为中等富集程度。沉积物中存在3个重金属富集层,即中下部Pb、Tl、Bi富集层;中上部Pb、Cr、Ni、Cu富集层;浅表部V、Cr、Mn、Ni、Cu、Zn、Pb、Cd、Tl、Bi等多种重金属富集层。地累积指数(Igeo)和综合富集指数(EI)评价结果显示:沅江入湖沉积物重金属污染程度自河床深部向浅部,污染程度趋于增强,污染元素组合趋于由Pb-Bi的单一元素组合向由V-Cr-Mn-Ni-Cu-ZnPb-Cd-Bi组成的复合元素组合变化。且自上游向下游,沉积物重金属污染程度趋于降低。这种重金属污染空间变化特征与区域人为活动有关,值得进一步研究。     

Assessing the Influence of the Mining Operations on the State of Streams in the Northern Part of the Red River Basin (Viet Nam)

A study was made of the influence of extraction of lead and zinc ores in the northern part of Vietnam (the Red river basin, Chodon district of Bac Can Province, and the basins of the Dai, Ban Thi, Ta Dieng and Cau rivers). Background concentrations of macro- and microelements and biogenic elements are determined in the river waters and water extracts from bottom sediments of small streams of the study area. A significance exceedance of background concentrations was revealed in stretches of the headwaters of the Ban Thi and Dai rivers caused by a combination of natural and anthropogenic factors. It is established that the river waters near the pollution sources contain increased (compared with the geochemical background) concentrations of Zn, Pb, Fe, Ni, Co, As, Bi, Cd, Cs, Sb, Ag,NO₂^? and SO₄^2?. The waters are estimated as moderately and heavily polluted, and at the other points as minimally polluted. It is determined that the level of accumulation of matter in water extracts from bottom sediments with respect to the geochemical background in the vicinity of the ore dressing factories corresponds to weakly and heavily polluted bottom sediments, and further downstream, to thy minimum level of pollution. It is shown that the influence of extraction of lead and zinc ores on the state of small streams is observed in stretches as long as 11–12 km (with a maximum in stretches of up to 4.5 km). The mathematical model of Pb and Zn distribution in the river waters of the study area has been developed and tested.     

淮河(安徽段)南岸诸河流水质标识指数评价

2010年夏季,对淮河(安徽段)南岸诸河流水质进行调查,共设置采样点160个,选取总氮、总磷、氨氮和化学需氧量4项水质指标,利用综合水质标识指数评价法(WQI)对淮河(安徽段)南岸诸河流水质进行评价。结果表明,淮河(安徽段)南岸诸河流水质达标率77%,超标的评价因子为氮营养盐和化学需氧量。污染物主要来自农业面源和生产、生活废水;水流流速、沉积物性质和周围环境对水质产生一定影响。     

A 17,300-year record of mercury accumulation in a pristine lake in southern Chile

Anthropogenic mercury accumulation in lake sediments has been studied extensively, but natural processes that controlled mercury accumulation in the past are still poorly understood. We present a 17,300-year record of mercury accumulation in the sediments of Lake Hambre, southernmost Patagonia, Chile (53°S, 70°W), in combination with an investigation of environmental changes in the region. Mercury accumulation in the remote pristine lake varied appreciably, as much as 16×, exceeding the anthropogenic forcing of atmospheric mercury fluxes by a factor of 3–5. Principal Component Analysis revealed that short-term variations were not related to changes in atmospheric mercury deposition or to fluxes of mineral soil into the lake. Instead, there was significant covariation between short-term changes in mercury and catchment-derived trace elements, e.g. copper and yttrium, throughout the past 17,000 years. Covariation between mercury and carbon concentration in some parts of the record suggests that fluxes of particulate and dissolved organic matter from the catchment to the lake account for short-term variations in mercury accumulation. Nevertheless, over the long term, there is no common trend for mercury accumulation and organic matter flux. The median mercury accumulation rate was rather constant (29 μg m^?2 a^?1), whereas the flux of terrestrial organic matter into the lake increased through time. We hypothesize that this was a consequence of a progressive decrease in the input of terrestrial organic matter-bound mercury through time. Whereas production of terrestrial organic matter increased over the long term because of development of catchment vegetation and soils, following glacier retreat, amounts of mercury, copper and yttrium provided by atmospheric deposition and bedrock weathering remained relatively constant. As a consequence, despite increased fluxes of terrestrial organic matter to the lake, fluxes of mercury remained constant.     

黑河下游地区柽柳沙丘的气候与环境记录

对黑河下游地区柽柳沙丘沉积剖面进行AMS¹⁴C定年及沉积物粒度和Hg含量的综合分析,探讨了该区域从18世纪中期到21世纪初的气候与环境变化。结果表明:沙丘沉积物以细沙为主,粒度频率分布曲线呈明显的单峰形态,反映了单一的风力沉积作用;>100 μm的粗颗粒含量变化很好地指示了该区域冬季风的强弱变化,并记录了小冰期末期以来气候转暖的过程以及现代暖期中两个相对寒冷时期——20世纪10-20年代和50-60年代。沙丘沉积物中Hg主要来源于人类的工业活动,剖面Hg含量存在3个峰值,分别对应18世纪末的西班牙美洲地区银矿开采、19世纪中后期的北美淘金热、二次世界大战及战后经济复苏。此外,剖面中有两个样品Hg含量异常升高,其原因可能是1815年和1883年印尼的两次大规模火山喷发而引起的全球Hg沉降增加。     

Retention of mercury in sediments of the Baltic Sea near Oulu,Finland

Several cores were compared to elucidate the grade of mercury retention in sediments of the Baltic Sea near Oulu, Finland. The known history of the mercury discharge to waste water from a chlor-alkali plant, the primary pollution source, was compared to that in the sedimentary record. One core was dated by lead-210 and varve counts. During the past thirty years, the rate of sedimentation was up to 10 mm per year corresponding to a dry matter accumulation rate of about 3 kg m^–2a^–1. Under these conditions, most of the mercury reaching the sediment was retained. Correspondingly, the mercury levels in fish were considerably lower, with a delay of some five years.The present mercury content of the upper layers is some 1/4 or 1/5 that of the late 1970's, but it is still some twentyfold compared to levels at the beginning of the century. The extent to which the present mercury level in the sediment represents the various phases of industrial emission remains unsolved due to the origin of mercury in this sea area from several other sources and due to difficulties in exact core correlations from different years.     

Untangling the influence of in-lake productivity and terrestrial organic matter flux on 4,250 years of mercury accumulation in Lake Hambre, Southern Chile

There is ongoing debate about the relative influence of aquatic production, flux, and sedimentation of aquatic and terrestrial organic matter on mercury accumulation in lake sediments. In this study, lake sediments spanning the past 4,250 years, were collected from remote, organic-rich Lake Hambre, Patagonia (53° S) and investigated for changes in the accumulation of pre-anthropogenic mercury and organic matter of aquatic and terrestrial origin. Natural mercury accumulation varied by up to a factor of four, comparable to the recent anthropogenic forcing of the mercury cycle (factor 3–5). Hydrogen and Oxygen indices (HI and OI, Rock–Eval©) and nitrogen/carbon ratios of the organic matter, combined with multi-element sediment data, reveal intense changes in aquatic productivity as well as influx of terrestrial organic matter into the lake. Evaluation of the multi-element dataset using Principal Component Analysis shows clear covariation of mercury with other soil-derived elements such as copper and yttrium. This covariance reflects a common transport mechanism, i.e. leaching of trace-element-bearing organic matter complexes from catchment soils. Correlation between changes in aquatic productivity and mercury concentrations occurs in some sections of the record, but we do not suggest they are linked by a direct causal relationship. Mass balance approaches suggest that mercury scavenging and accumulation in this organic-rich lake is controlled by the supply of mercury from catchment soils rather than the amount of organic material produced within the water column. A common controlling mechanism, i.e. changing climate, however, is thought to independently drive variations in both the flux of terrestrial organic matter mercury complexes and aquatic productivity.     

Seasonal and spatial distribution of heavy metals in the Selenga River Delta

In order to estimate the present-day pollution levels in the ecosystem of the Se-lenga River Delta and to monitor the changes caused by the discharge of household refuse and industrial wastes, as well as the functioning of the agricultural and stock farming, a comprehensive study of the water and bottom sediments in the main branches of the Selenga River Delta was carried out. This study has determined the concentrations of heavy metals in river water and bottom sediments in its delta.     

色楞格河三角洲重金属季节和空间分布

In order to estimate the present-day pollution levels in the ecosystem of the Selenga River Delta and to monitor the changes caused by the discharge of household refuse and industrial wastes,as well as the functioning of the agricultural and stock farming,a comprehensive study of the water and bottom sediments in the main branches of the Selenga River Delta was carried out.This study has determined the concentrations of heavy metals in river water and bottom sediments in its delta.     

澜沧江-湄公河重金属污染评价及大坝影响(英文)

The resource development and changes of hydrological regime,sediment and water quality in the Mekong River basin have attracted great attentions.This research aimed to enhance the study on transboundary pollution of heavy metals in this international river.In this study,eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River.In addition,the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed.The geoaccumulation index(I geo) and potential ecological risk analysis were employed to assess heavy metal pollution status in the mainstream of the Mekong River.The results show that the average content of the heavy metal elements Zn is 91.43 mg/kg,Pb is 41.85 mg/kg,and As is 21.84 mg/kg in the bed sands of the Upper Mekong River,which are higher than those(Zn 68.17 mg/kg,Pb 28.22 mg/kg,As 14.97 mg/kg) in the Lower Mekong.The average content of Cr in the Lower Mekong is 418.86 mg/kg,higher than that in the Upper Mekong(42.19 mg/kg).Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg.The concentration of Cu in all of the 8 sampling sites is similar,except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg.The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong.Cr is the primary pollutant in the Lower Mekong,especially at Luang Prabang and Pakse.Slight pollution with As also occurs in Pakse.The potential ecological risk index indicates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low.We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and dilution along the river.