洞庭湖表层底泥重金属污染及其生态风险评价

对洞庭湖表层底泥样进行了Cd、Pb、Cu、Zn、As、Hg和Cr等7种元素含量分析,并采用潜在生态风险指数法和土壤环境质量标准首次对各河流入湖口和各子湖区(段)表层底泥重金属的污染状况进行了评价。结果显示,洞庭湖各子湖区(段)表层底泥中以Cd污染最为严重,所有样点Cd含量均超过国家土壤质量三级标准限值;其次为Pb、Cu和Zn,各子湖区该三种金属含量均属于国家土壤质量二级标准;再次为As和Hg,东洞庭湖和西洞庭湖等湖区As、Hg均属于国家土壤质量二级标准;而Cr对洞庭湖表层底泥的污染最轻。主要河流入湖口中,湘江和资江入湖口表层底泥的Cd、Pb、Zn和As污染最为严重,沅江入湖口表层底泥的Hg污染最为严重,资江和汨罗江表层底泥的Cu和Cr污染最为严重。潜在生态风险指数法评价结果表明:西洞庭湖表层底泥重金属污染对生态潜在危害极高,南洞庭湖、东洞庭湖、城陵矶和大通湖的重金属污染潜在生态风险指数分级为高。根据潜在生态风险综合指数(RI)值大小,洞庭湖各子湖区(段)重金属复合污染程度由重到轻次序为:西洞庭湖大通湖城陵矶东洞庭湖南洞庭湖。     

玉滩湖表层沉积物重金属污染特征及潜在生态风险评价

为了掌握重庆玉滩湖表层沉积物重金属污染情况,监测了玉滩湖表层沉积物中Cr、Cd、Pb、Cu和Zn的相对含量,并采用地质累积指数法和潜在生态风险指数法对重金属的污染程度和潜在生态风险进行评价。结果表明,玉滩湖表层沉积物中重金属Cr、Cd、Pb、Cu和Zn的平均含量分别为28.41mg/kg、0.75mg/kg、46.04mg/kg、66.98mg/kg、131.55mg/kg,Pb和Cu受人为活动影响较大;重金属污染程度为Cu(轻度)Pb(轻微)Cd(轻微)Zn(轻微)Cr(无污染);有机质含量和重金属Pb、Cd含量显著正相关,是玉滩湖流域重金属污染防治的重点因子;玉滩湖总体的生态风险程度为轻微,重金属单项潜在生态风险程度为Cd(中等)Cu(轻微)Pb(轻微)Zn(轻微)Cr(轻微),Cd是主要的生态风险因子。     

宝鸡千河底泥营养盐及重金属风险评价

对宝鸡千河河道11个监测点底泥的OM(总有机质)、TN(总氮)、TP(总磷)和重金属(Pb、Zn、Cu、Cr、Cd)含量进行了监测,评价了该河道底泥营养盐和重金属的潜在生态风险。结果表明:底泥中OM浓度为1.25~8.48g/kg,TN浓度为0.14~1.92g/kg,TP浓度为0.41~1.02g/kg;营养盐污染评价结果表明,该河段底泥有机指数总体上处于清洁水平,但部分监测点有机氮污染相对严重,应注意对外源氮的控制;重金属Pb浓度为15.1~49.1mg/kg,Zn浓度为51.1~171.9 mg/kg,Cr浓度为7.86~43.5 mg/kg,Cd浓度为0.09~0.88 mg/kg,Cu浓度为3.64~19.5mg/kg;底泥中Pb、Zn、Cd的平均含量高于陕西省土壤元素背景值;重金属污染评价结果表明,底泥潜在重金属生态风险指数(RI)平均值为146.1,存在轻微的潜在生态风险水平;底泥中Cd的潜在生态危害风险高,贡献最大。     

四川马边某磷矿区土壤重金属特征及形态分析

为研究四川马边某磷矿区土壤重金属分布状况及特征,采集矿区土壤样品,用ICP-MS测定了重金属As、Cu、Zn、Cd、Pb、Cr的含量及其形态,并用潜在生态危害指数法对土壤重金属污染程度进行评价。结果表明,研究区土壤重金属中的Cd和Pb含量高于四川土壤背景值的10.00、7.14倍,高于全国土壤背景值8.14、8.48倍,其余元素均略高于各背景值,经相关性分析,As、Zn、Cd 3种重金属具有同源性。形态分析显示,Cd的形态分布以可还原态为主,易迁移释放,其余元素均以残渣态为主,Pb除残渣态外,可还原态与可氧化态占一定比例,具有一定的潜在风险。潜在生态危害指数法分析表明,重金属的单一潜在生态危害程度Er^i顺序为Cd>Pb>As>Cu>Cr>Zn,各样点重金属潜在生态危害指数RI平均值为378.87,属于强生态危害,其中又以Cd贡献率最大,为78%。     

天津市蔬菜种植地土壤重金属潜在生态风险评价

利用Hakanson潜在生态风险指数法,对天津市宁河县蔬菜种植地的土壤重金属潜在生态危害进行评价。Hg、Cd、Cu、Zn、Pb和As 6种重金属的Eir均小于40,5个研究乡镇的RI均小于150。表明该区域的潜在生态危害水平为轻度危害。虽然5个乡镇的重金属的潜在生态危害略有差异,但总体上均以Hg和Cd的污染为主,Zn和Pb的污染最小。从而也可以说明对于这种小尺度范围的重金属污染研究,若不存在显著的污染源则无需利用RI法进行详细的分区研究。     

四川省马边磷矿区水环境中典型重金属污染分析

马边磷矿区磷矿资源丰富,区内磷矿开采企业较多。在开采的过程中难免会对当地的河水造成一定的影响。为了进一步了解马边磷矿区的环境影响问题,本文通过对磷矿区采集的水体样品和同一地点的水系沉积物样品进行分析测试,共检测了Cd、As、Cu、Cr、Pb、Zn六种重金属元素的含量,采用潜在生态危害指数法对沉积物中的重金属污染程度进行了综合评价。结果如下:马边磷矿区河水中的重金属元素的浓度较低,6种重金属元素含量均低于国家标准(GB3838-2002)。水系沉积物中的重金属元素含量较高,其中:Cd、Pb、Zn分别为2. 06mg/kg、182. 39mg/kg、479. 13 mg/kg。与四川省土壤元素背景值相比:Cd元素超标25. 7倍,Pb元素超标5. 9倍,Zn元素超标5. 5倍,其余元素未超标。与马边地区1∶20万区域水系沉积物背景值相比:Cd元素超标3. 12倍,Pb元素超标3. 3倍,Zn元素超标2. 5倍,As元素超标1. 6倍,Cu、Cr元素含量在背景值以内。与“中国土壤元素背景值”相比:Cd元素超标29. 4倍,Pb元素超标7. 7倍,Zn元素超标7. 1倍。潜在生态危害指数法评价结果表明:Cd的生态危害指数最大,其次为Pb和As,其余Cu、Cr、Zn等元素属于轻微生态风险。     

长江入海口北支沿海滩涂养殖区底泥重金属污染特征及趋势评价

对长江入海口北支沿海滩涂养殖区底泥重金属污染的总体水平进行调查,结果表明,滩涂养殖区底泥重金属含量满足海洋沉积物质量一类标准要求,污染程度属于安全Ⅰ级水平,重金属潜在生态危害属轻微级别,6种重金属潜在生态危害由大到小排序依次为Cd﹥Hg﹥Cu﹥Cr﹥Pb﹥As,2005年～2011年,底泥重金属污染程度均处于安全的Ⅰ级水平。     

徐州云龙湖底泥重金属污染评价

本文测定了云龙湖底泥中铅(Pb)、锌(Zn)、铜(Cu)、锰(Mn)4种重金属元素含量。运用了累积指数法和潜在生态风险指数法对其污染程度和潜在生态风险进行评价:4种重金属中Cu为中度污染,Pb为轻度污染,其余2种均未构成污染。云龙湖底泥中重金属污染的潜在生态风险表现为轻微的程度,生态风险顺序是Mn>Cu>Pb>Zn。     

重庆市某工业遗留地土壤重金属污染状况分析与评价

为研究土壤重金属的污染状况,从重庆市某铬污染场地土壤中采集54份样本检测分析了其Cr、Cu、Zn和Pb元素含量。结果表明:表层土壤样品中的重金属Cr、Cu、Zn、Pb的平均含量分别为3 370.8,58.0,36.1,112.4 mg/kg。该场地土壤属于重度重金属污染,潜在生态危害处于很强危害程度,各重金属的潜在生态风险指数大小顺序为:CrPbCuZn。其中,Cr的影响占绝对主导地位。研究结果可为该废弃场地的治理修复和再利用提供理论依据。     

宝山区农用土壤中重金属的监测与评价

在研究的8种重金属元素中,Cd、Cr、Cu、Pb、Zn、Ni的平均值都超过上海市土壤背景值,但均低于国家土壤环境二级标准。与上海优质农产地环境标准相比较,重金属含量平均值超过标准的有Cr、Pb、Zn,但研究区土壤中8种重金属含量的平均值均低于绿色食品产地环境技术条件和无公害食品产地环境技术条件。宝山区7个城镇农业土壤按多因子潜在生态危害指数评价,庙行镇的生态风险指数最高,月浦镇的生态风险指数最低。从宝山区农田土壤重金属含量的整体情况来看:多因子潜在生态评价值为119.08,宝山区农田土壤达到轻微生态危害。     

西湖和东苕溪沉积物重金属化学形态分析

不同赋存形态重金属的环境行为和生态效应不同,水体沉积物中重金属的迁移转化及其潜在环境危害更大程度上取决于其赋存形态.本研究在西湖和东苕溪设置12个采样点采集沉积物样品,采用改进BCR分步提取法,提取了重金属污染物的4种化学形态,分别为弱酸提取态、可还原态、可氧化态及残渣态.结果表明:沉积物中Cd以弱酸提取态为主,对外界...     

Assessment of the Effectiveness of Environmental Dredging in South Lake,China

Environmental dredging is a primary remedial option for removal of the contaminated material from aquatic environment. Of primary concern in environmental dredging is the effectiveness of the intended sediment removal. A 5-year field monitoring study was conducted to assess the effectiveness of the environmental dredging in South Lake, China. The concentrations of total nitrogen (TN), total phosphors, and heavy metals (Zn, Pb, Cd, Cu, Cr, Ni, Hg, and As) before and after dredging in sediment were determined and compared. Multiple ecological risk indices were employed to assess the contamination of heavy metals before and after dredging. Our results showed that the total phosphorus levels reduced 42% after dredging. Similar changes for Hg, Zn, As Pb, Cd, Cu, Cr, and Ni were observed, with reduction percentages of 97.0, 93.1, 82.6, 63.9, 52.7, 50.1, 32.0, and 23.6, respectively, and the quality of sediment improved based on the criterion of Sediment Quality Guidelines by USEPA and contamination degree values (C_d) decreased significantly (paired t-test, p < 0.05). Unexpectedly, the TN increased 49% after dredging compared to before dredging. Findings from the study demonstrated that the environmental dredging was an effective mechanism for removal of total phosphorus and heavy metals from South Lake. Nevertheless, the dredging was ineffective to remove total nitrogen from sediment. We conclude that the reason for the observed increase in TN after dredging was likely ammonia release from the sediment impairing the dredging effectiveness.     

基于地积累指数法和潜在生态风险指数法评价广西某蔗田土壤重金属污染

采用地积累指数法和潜在生态风险指数法对广西某蔗田土壤中重金属污染进行评价。结果表明：4种重金属元素的地积累指数污染程度由强到弱依次为：Cd〉Zn〉Pb〉Cu,潜在生态危害指数污染程度由强到弱依次为：Cd〉Pb〉Cu〉Zn,其中zn的影响程度发生了变化。2种评价方法的结果存在差异,蔗田土壤的地积累指数污染程度处于无污染情况,而潜在生态危害指数污染程度处于低度危害程度。潜在生态危害指数考虑外源重金属的富集程度和不同重金属的生物毒性的影响,使其评价结果更准确。     

Characteristics of heavy metals and Pb isotopic signatures in sediment cores collected from typical urban shallow lakes in Nanjing, China

To investigate the contamination levels and sources for heavy metals that have occurred during the development of cities, sediment cores collected from typical urban shallow lakes (Xuanwu Lake and Mochou Lake) in Nanjing, China were analyzed for Cu, Pb, Zn, Cd, Cr, Ni, and for Pb stable isotopic ratios. No significant differences were found in the concentrations of Cu, Ni and Cd among sediment layers from Xuanwu or in the levels of Cr and Ni among sediment layers from Mochou. However, there were significant differences among the layers in the concentrations of Cr, Zn and Pb in Xuanwu and Cu, Zn, Cd and Pb in Mochou. Based on geoaccumulation indexes and enrichment factors, Cd was the primary pollutant at all depths in the sediment cores. The ratios of (206)Pb/(207)Pb and (208)Pb/(206)Pb differ significantly among sediment layers in Xuanwu. No significant differences were found on the ratios of (208)Pb/(206)Pb in Mochou, but the ratios of (206)Pb/(207)Pb differ significantly among some of the sediment layers in Mochou. The range of (208)Pb/(206)Pb and (206)Pb/(207)Pb ratios was found to be 2.098-2.106 and 1.170-1.176, respectively, for sediment cores from Mochou Lake and 2.091-2.104 and 1.168-1.183, respectively, for cores from Xuanwu Lake. The differences in heavy metal concentrations and the Pb isotopic ratios with depth for the cores from Xuanwu and Mochou confirmed that the contamination sources changed during the formation of the different sediment layers. Furthermore, the ratios of (206)Pb/(207)Pb demonstrated that gasoline and vehicular Pb were not the primary sources of Pb contamination at different depths in the sediment cores in Xuanwu Lake and Mochou Lake.     

滇池沉积物重金属污染状况评估

本文通过多年滇池底泥的采样监测数据,采用地积累指数法和对数衰减模型评估滇池的底泥质量状况,希望摸清底泥中重金属污染状况,并分析评价其对水生生物的风险,为底泥疏浚、截污护岸的滇池治理工程提供一定的科学依据。研究表明:以地积累指数法评价,(1)滇池监测断面底泥质量呈现轻度污染,镉出现一定程度富集,汞在个别监测断面也出现富集情况;(2)6种重金属污染排序为镉>汞>铅>铜>铬>砷;(3)从监测断面来看,海口西污染程度较重,滇池南底泥质量较好。采用对数衰减模型评价,(1)滇池监测断面沉积物重金属污染存在潜在生物风险,应引起重视;(2)从产生可以观察到毒性效果的可能性大小看,6种重金属潜在危害可能性排序为砷>铅>铜>铬>镉>汞;(3)从监测断面来看,白鱼口和观音山中潜在危害可能性大。从富集污染程度分析,海口西监测断面的底泥污染最重,可考虑在海口西监测断面附近进行一定的底泥疏浚工程。从而达到治标治本的目的。滇池监测断面沉积物重金属污染存在潜在生物风险,应引起重视,但在可控范围。     

杭州城区河道底泥重金属污染及潜在生态风险评价

对杭州城区34条河道45个点位河道底泥进行采样,分析了pH及汞、砷、铅、铬、镉、铜、锌、镍等重金属含量,并进行污染及潜在生态风险评价。结果表明,监测点位的底泥为中性偏碱性,重金属含量分布不均,且范围波动很大,部分河道底泥重金属中汞、铅、镉、铬、锌、镍等有不同程度的超标,少数河道镉、铬、锌污染严重;按《农用污泥中污染物控...     

Geochemical properties and pollution assessment of heavy metals in the sediments of Daechung Lake,Korea

In order to examine the forms, sources, and pollution of heavy metals—arsenic (As), aluminum (Al), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)—in Daechung Lake, Korea, sediment samples were collected in November 2014. Daechung Lake was constructed to supply water for human consumption, agricultural use, and industrial use as well as to generate electric power. The lake is stratified in the summer and surrounded mostly by agricultural and mining areas. Our results indicate that the heavy metals (except As and Cd) displayed similar concentrations at all of the sampling stations. As and Cd were high in locations where fine sediments had built up. Based on the enrichment factor of the metals, the sediments collected from all of the sampling stations were highly polluted by As and Cd. Therefore, deposition of heavy metals in Daechung Lake is possibly controlled by grain size and anthropogenic activity, such as drainage from abandoned mines, agricultural activities, and/or the release of wastewater. The most dominant forms for all of the metals were oxide and silicate forms. This suggests that the sediments of Daechung Lake are not highly sulfidic. However, the sediment samples were collected after the collapse of seasonal stratification. Therefore, future studies should include elucidation of major sources for As and Cd and the collection of sediments during months of stratification.     

Heavy metal content and distribution in surface sediments of the Seyhan River, Turkey

Chemical fractionation of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) was studied using a modified three-step sequential procedure to assess their impacts in the sediments of the Seyhan River, Turkey. Samples were collected from six representative stations in two campaigns in October 2009 and June 2010, which correspond to the wet and dry seasons, respectively. The total metal concentrations in the sediments demonstrated different distribution patterns at the various stations. Cadmium was the only metal that was below detection at all stations during both sampling periods. Metal fractionation showed that, except for Mn and Pb, the majority of metals were found in the residual fraction regardless of sampling time, indicating that these metals were strongly bound to the sediments. The potential mobility of the metals (non-residual fractions) is reflected in the following ranking: Pb > Mn > Zn > Cu > Ni > Cr in October 2009 and Mn > Pb > Zn > Cu > Ni > Cr in June 2010. The second highest proportion of metals was bound to organic matter/sulfides, originating primarily from anthropogenic activities. Non-residual metal fractions for all stations were highest in June 2010, which may be linked to higher organic matter concentrations in the sediment samples with 1.40% and 15.1% in October 2009 and June 2010, respectively. Potential sediment toxicity was evaluated using the Risk Assessment Code (RAC). Based on RAC classification, Cd and Cr pose no risk, Cu and Ni pose low risk, Pb and Zn were classified as medium risk metals, while the environmental risk from Mn was high. In addition, based on the sediment quality guidelines (SQG), the Seyhan River can be classified as a river with no, to moderate, toxicological risks, based on total metal concentrations.     

河流底泥重金属污染及潜在生态风险评价——以湘江株洲段为例

通过对湘江株洲段6个监测断面左右两岸共32个底泥样品重金属Pb,Zn,Cd,As,Hg和Cr质量比进行分析研究,并进行潜在生态风险评价。结果表明：霞湾断面是重金属富集最严重的断面;Cd,Hg和As的含量均超过GB15618—1995三级标准和长沙-湘潭-株洲3市土壤背景值;重金属含量大部分分布特征为右岸高于左岸;从重金属污染的潜在生态风险看,湘江株洲段各监测断面潜在生态风险都很高;各重金属元素对生态风险影响程度从大到小的顺序为：Hg〉Cd〉As〉Pb〉Zn〉Cr。