湘江衡阳段重金属在水体、悬浮颗粒物及表层沉积物中的分布特征研究

采用ICP-MS研究湘江衡阳段上覆水、悬浮颗粒物、表层沉积物及孔隙水中重金属的含量及分布特征.结果表明,湘江衡阳段主要的重金属污染元素是Cd,上覆水中Cd的平均含量为0.26μg·L-1,高于美国水质基准的持续基准浓度CCC(USEPA2009),已经对部分水生生物表现出潜在的毒性效应;悬浮颗粒物和表层沉积物中Cd的富集含量较高,分别为42.03μg·g-1和29.62μg·g-1,达到加拿大淡水沉积物保护准则最初影响水平TEL的70倍和50倍,其中,从沉积物中取得的孔隙水中Cd平均含量为3.8μg·L-1,该值是CCC的15倍甚至高于最大基准浓度(CMC),已经对部分水生生物表现出实际的急性毒性效应.湘江衡阳段重金属的空间分布特征表现为中下游污染较上游严重,在衡阳水口山地区等污染企业密集区,重金属含量较高,表明人类活动输入已经成为湘江重金属的重要来源.研究结果还表明,悬浮颗粒物及沉积物相作为水体重金属污染物的主要赋存介质,对重金属污染的迁移、沉积、转化及生物富集作用具有决定性的意义,其重要性不容忽视.     

Distribution of heavy metals in the water column, suspended particulate matters and the sediment under hydrodynamic conditions using an annular flume

Sediment resuspension plays an important role in the transport and fate of heavy metals in the aquatic environment. In the present study, the release and binding forms of Cr, Cu, Zn, Pb under hydrodynamic conditions were investigated using an annular flume. Two sediments located at YLZ and GBD from Liangshui River, Beijing were resuspended for 10 hr at 0.159 and 0.267 m/sec, respectively. The concentrations of suspended particulate matters of YLZ were higher than those of GBD during resuspension, indicating that the former sediment is more sensitive to the velocity. Cr in the dissolved phase stayed nearly constant at about 2.25 and 1.84 μg/L for YLZ and GBD, respectively, due to the high percentage of its stable binding fractions in both sediments, while Cu, Zn, and Pb showed a fast release in the initial period of time. However, their concentrations in SPM generally decreased with time and were higher at the lower velocity of 0.159 m/sec, which resulted from the entrainment and depressing effect of larger size particles with lower heavy metal content, commonly referred to as the "particle concentration effect". In addition, the binding form and heavy metal fractions were also found to vary during the resuspension event. A decrease in the sulphide/organic matters bounded form in GBD sediment was observed, whereas no visible changes were perceived in YLZ site samples. This phenomenon is due to the oxidation of heavy metal-sulphide binding forms, which originated from its high acid volatile sulphide content in GBD sediment.     

长江口南槽重金属的分布特征

利用ICP－AES测试长江口南槽水体中各重金属浓度的结果表明,水相中Mn、Zn、Cu、Al、Fe的浓度在枯水期明显大于洪水期,而悬浮物中各重金属的浓度随季节变化不明显;表层悬浮物中各重金属浓度大多比底层高,水相中各重金属浓度则是底层比表层高．近10多年来,水体中Cu、Pb、Cd的浓度变化不大,但Ｚｎ的浓度有明显的增大;Fe、Al、Mn、Cu等重金属之间具有良好的相关性,说明其化学行为具有相似性．水体中各重金属的分布受到稀释、离子交换、吸附和凝聚的影响．     

Heavy metals partitioning in the sediments of Izmir Inner Bay

Izmir Bay is known to be polluted by high concentrations of heavy metals and organic pollutants.Sediment samples taken from 7 different stations in Izmir Inner Bay were analyzed for their total organic matter content and,Cu,Cr Pb and Zn.In addition,the chemical distribution of the metals were determined by means of the BCR(Community Bureau of Reference)Extraction Procedure (developed by European Commission for Standards,Measurement and Testing) which allows the determination of metals bound as four fractions;exchangeable and acid soluble,reducible(bound to iron-manganese oxides),oxidizable(bound to organics)and residual.The results show that Izmir Inner Bay contains sediments with high metal concentrations.According to the chemical distribution of metals,Cr and Cu tend to accumulate mostly on the organic fraction of the sediment.Pb is mostly found in the reducible fraction where Zn is mobile in the sediment,and it is distributed evenly on each fraction.     

Effect of substrate concentration on the bioleaching of heavy metals from sewage sludge

IntroductionTheproductionofexcesssewagesludgeisincreasingrapidlywiththewidespreadofwastewatertreatment,whichcausesseriousproblemtothedisposalofsewagesludge .Landapplicationofsewagesludgeisthemostcost effectiveandfeasibleutilizationapproachatpresent.Howeve…     

黄河下游水体悬浮颗粒物中金属元素的地球化学行为

为调查黄河下游颗粒物的风化状况以及重金属变化规律及其污染程度,于2009年6~7月调水调沙期间(每日)及2010年4月至2011年11月(每月中旬)对垦利浮桥水体颗粒物进行采样调查.样品经消解后采用ICP-AES测定其中Al、Na、K、Ca、Fe、Mn、Cu、Zn、Cr、Ni、V的含量.采用化学风化指数(CIA)来衡量硅酸盐的化学风化程度,结果表明,黄河流域颗粒物化学风化程度为中等,近30年来颗粒物化学风化程度没有明显变化.黄河下游颗粒物中重金属(Cu、Zn、Cr、Ni、V)浓度呈现出冬季高夏季低的变化规律,调水调沙期间重金属浓度降低后期略有回升,这一变化规律主要是受泥沙的稀释及颗粒物粒径等因素影响.重金属富集因子(EF)的计算表明,黄河下游Zn具有中等程度的污染,其他元素无明显污染.提取3个因子对黄河下游颗粒物的化学组成因素进行分析,颗粒物主要受风化的影响,同时也受径流量以及人类活动的影响.     

The chemical stability of heavy metals in a natural water system

A comprehensive investigation of heavy metal pollutants in Xiangjiang river was accomplished to evaluate their chemical stability through three different ways: (1) Chemical speciation by direct measurements; (2) Chemical equilibrium model simulation; (3) Sediment extraction experiments. All the results demonstrated that the directly bioavailable fraction was in a very limited amount. The metal bound to organic ligands, adsorbed particles and precipitated species presented a buffer for solution species. The majority of metals occured in the residues as solid particulates. It was inferred that the heavy metal pollutants in this aquatic system exhibited a high chemical stability. The critical limits of discharging load and pH values were suggested.     

Speciation and distribution characteristics of heavy metals in the Changjiang River water

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人工湿地在重金属废水处理中的应用

文章论述了人工湿地处理技术处理重金属废水的机理和优点.人工湿地利用基质、植物、微生物这个复合生态系统的物理化学及微生物的作用,通过过滤、吸附、共沉淀、植物吸收、离子交换和微生物分解来实现对重金属废水的高效净化;人工湿地污水处理系统具有较高的净化效率和相对较低的基建投资与处理成本,该技术已被许多国家广泛应用.根据人工湿地在重金属污水处理中的研究和应用现状,指出了人工湿地处理重金属废水的前景及今后的研究方向.     

成都市东区TSP及其重金属污染分析

采用TSP大流量采样器对成都市东区进行连续采样,对该区域大气总悬浮颗粒物的污染情况以及其中的重金属铅、镉、铜、锰、砷、汞的含量进行了分析。结果表明,成都市东区总悬浮颗粒物的超标率达到37.5%,存在中度的大气污染;TSP中重金属元素平均浓度的大小顺序为:As>Mn>Pb>Hg>Cu>Cd;TSP中重金属的含量虽未超过工作场所空气中有毒物质容许浓度值,但随着人类活动及机动车数量的增加,其排放量仍不容忽视。     

重金属在水体中的化学状态、危害及其防治对策

本文对目前研究最多的汞、铬、镉、铅和砷等重金属,详细分析了它们在水体中的迁移转化、价态变化、吸附与解吸附作用、吸附和共沉淀作用等动态过程;简要地阐述五种重金属对水体的污染给人体带来的危害;重点讨论了对水体重金属污染采取控制与消除土壤污染源、含重金属工业废水的排放和生物修复技术等防治对策。     

7种树木的叶片微形态与空气悬浮颗粒吸附及重金属累积特征

为揭示树木叶片微形态与吸附空气悬浮颗粒及累积重金属的关系,在淮南市交通繁忙点选择银杏等7种树木进行实验.分析了:①叶片吸附不同粒径空气悬浮颗粒的百分率;②单位叶面积吸附不同粒径颗粒的质量与叶片微形态的关系;③单位叶面积不同粒径颗粒吸附量与重金属累积量的相关性.结果表明,叶片面积小、表皮角质丰富和细胞壁凸凹不平、无表皮毛阻挡、气孔密、气孔口大的树木,属气孔吸附主导型,主要吸附细颗粒物;表皮毛多的树木,属表皮吸附主导型,主要吸附粗颗粒物.7种树木叶片累积重金属除铅外都具显著差异,其中银杏、女贞、香樟对重金属的累积能力较强;7种树木叶片对Cd、Cr、Ni、Zn、Cu这5种重金属及总含量的累积与单位面积吸附的可吸入颗粒量呈正相关,d10与d2.5、d10与d1.0、d2.5与d1.0的相关系数分别是0.987、0.971、0.996,达到极显著水平,d2.5/d10、d1.0/d10、d1.0/d2.5的值分别是0.844、0.763、0.822,表明由交通污染产生的颗粒物主要是细颗粒物.     

开封城市河流底泥重金属积累生态风险评价及同位素源解析

分析了开封市不同区位3条代表性河流底泥样品中重金属总量及形态.采用改进的Hakanson潜在生态风险指数法评价了不同区位河流底泥的污染情况.使用MC-ICP-MS分析了Pb、Zn和Cu的稳定同位素组成,并基于此尝试解析底泥中重金属污染来源.结果表明：①开封城市河流底泥各重金属含量均超过环境背景值,重金属污染以Cd最为严重,其次为Zn、Cu、Pb、As、Cr和Ni.位于老工业区的化肥河底泥中重金属的平均含量明显高于老城区和新开发区.②从形态分布来看,开封城市河流底泥重金属Cd和Zn的生物有效态含量最高,具有较高的潜在风险.老工业区河流底泥中重金属的生物有效态含量高于老城区及新开发区.③潜在生态风险评价结果表明,位于老工业区的化肥河底泥重金属污染表现为很强生态风险程度的V等级,位于老城区的黄汴河和新开发区的马家河则均表现为强生态风险程度.④基于Pb-Zn-Cu同位素组成表明,老工业区底泥重金属主要来自工业活动,老城区黄汴河和新开发区马家河重金属主要来自生活污水的排放及城市地表径流.     

邢台市区道路可悬浮灰尘重金属污染特征及来源识别

为探究工业企业转型城市的道路可悬浮灰尘中重金属的来源特征,在邢台市区采集50份道路灰尘样品,利用X-Ray荧光光谱仪测定可悬浮灰尘中Cr、 Mn、 Co、 Ni、 Cu、 Zn、 As和Pb的含量,采用富集因子法评价重金属的污染水平,利用相关分析、主成分分析和聚类分析判别重金属之间的关系,识别其可能来源.结果表明,Co、 Cu、 Zn和Pb的平均含量是其相应河北省土壤背景值的2倍以上.富集因子评价结果显示,邢台市道路可悬浮灰尘中Co、 Cu、 Zn和Pb整体呈现中度富集,Ni、 As、 Cr和Mn无富集或轻微富集.综合样品中各重金属元素的含量特征与多元统计分析结果,邢台市区道路可悬浮灰尘中Cr、 Mn和Ni主要来源于自然和工业混合源,Zn、 Pb和Cu来源于交通和燃煤源,As来源于自然源,Co主要受工业活动的影响.     

咸水浸泡对珠江口滩涂围垦土壤重金属的去除效果

利用浸泡离心的方法,通过室内模拟实验,研究了浸泡时间、NaCl溶液浓度对土壤中6种重金属去除效果的影响,同时测定了NaCl浸泡前后土壤中重金属的形态变化.结果表明,浸泡时间为60d时达到最大去除率,分别为Cd30.3%、Zn22.0%、Pb9.4%、Cu8.0%、Cr12.6%、Ni9.9%;NaCl浓度为16 g/L时达到最大去除率,分别为Cd41.9%、Zn19.9%、Pb9.3%、Cu6.3%、Cr14.8%、Ni16.8%.重金属形态分析显示,NaCl浸泡能有效去除交换态、碳酸盐结合态和氧化物结合态的重金属,而对有机态和残渣态的重金属作用效果不明显.     

珠江河口悬浮颗粒的磁学特征及其对重金属污染的指示意义

以珠江河口2017年洪季16个站位和2016年枯季8个站位的悬浮颗粒的磁性测量数据为基础,结合同步的水文调查资料及样品重金属测量数据,探讨了珠江河口悬浮颗粒磁性的时空分布特征及与重金属污染的相互联系.结果表明,珠江口悬浮颗粒的磁化率平均值为61.1×10^-8 m³·kg^-1,亚铁磁性矿物是珠江口悬浮颗粒磁化率的主要贡献者.整体而言,远口段悬浮颗粒磁性高于河口段,枯季悬浮颗粒磁性高于洪季.珠江口磁性颗粒多畴、单畴和超顺磁同时存在,洪季以准单畴和多畴颗粒为主,枯季以单畴和准单畴颗粒为主.悬浮颗粒磁性的时空分布主要受母岩性质、流量等自然因素及重金属污染的影响.重金属污染和磁学参数的相关性系数多在0.4~0.7之间,且与χ、SIRM、χ_ARM、S_-100、S_-300、SOFT呈现显著的正相关关系（r≥0.5,p<0.05,n=24）,可以用来指示珠江河口悬浮颗粒不同的重金属污染程度.     

Heavy metals removal from aqueous solution using carbonaceous K_2S-impregnated adsorbent

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K_2S. Raw coal was mixed with K_2S powder and then heated at 800℃ for 30 min in nitrogen to produce K_2S char. The sulfur content and form in K_2S char were determined, and the ability of K_2S char to adsorb Zn~(2+), Cd~(2+) and Pb~(2+) was examined. The K_2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K_2S char was higher than those of raw coal and pyrolysis char. The Zn~(2+) removal in 2.4 mmol/L of Zn~(2+) solution by K_2S char was higher than raw coal with the removal rate of 100%. K_2S char adsorbed Pb~(2+) and Cd~(2+) in 24 mmol/L of Pb~(2+) and Cd~(2+) solution with the removal rate of 97 % and 35 %, respectively. The elution extents of adsorbed Pb~(2+) and Cd~(2+) were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K_2S sulfur impregnation, and that the adsorbed metals were strongly retained in K_2S char.     

我国水环境重金属污染现状及检测技术进展

阐述了重金属的危害,我国水环境重金属污染现状。详细介绍了水环境中重金属检测方法：原子吸收光谱法、原子荧光光谱法、电感耦合等离子法、溶出伏安法、激光诱导击穿光谱法的最近应用。并对酶抑制法、免疫分析法、生物传感器等新的重金属检测方法进行了概述。     

高浊度河口颗粒态重金属分布特性

根据1994年6月长江口，杭州湾的水质调查资料，分析了这类高浊度河口颗粒重金属的分布规律。研究表明，在长江口和杭州湾内，悬沙中，Cu,Pb,Cd和表层沉积物中Cu,Pb,Cd分布特征相似，尤其在杭州湾中部水域，二者重金属含量呈趋同的趋势。细颗粒物质是颗粒态重 主要载体。在高浊度河口，动力沉积过程为控制颗粒态重金属分布和输移的主要因子，悬沙中重金属的分布对泥沙运动具有指示作用。     

Bioaccumulation of heavy metals by Phragmites australis cultivated in synthesized substrates

Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order: Al(OH)3 > Al2O3 > Fe3O4 > MnO2 > FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.