水环境中腐殖质对重金属吸附行为的影响

水环境中金属离子-腐殖质-矿物（或细菌）之间的相互作用能够显影响金属离子在地质体中的迁移和归宿。本综述了水环境中腐殖质对金属离子在矿物、微生物等表面只附行为影响的研究现状，分析讨论了复合型表面的基本特点、腐殖质对金属吸附到矿物表面的影响因素、腐殖质影响细菌表面吸附金属离子的机理，以及对三相体系不同研究的研究思路与结论等。     

土壤对氟离子的吸附和释放实验研究

实验研究了土壤中的粘土矿物对氟离子有良好的交换吸附作用,用饱水动态土柱法对氟离子进行交换吸附处理可使含氟1.6mg/l的饮用水降到0.2mg/l,并且水的各项指标均达到国家饮用水标准,是降氟的很好材料,在水环境治理中发挥了很大作用.     

包气带土壤组成对三氯乙烯的吸附影响研究

有机质和矿物质是包气带土壤中的主要吸附介质,其吸附特性直接影响有机污染物在环境中的迁移、转化等过程。分别采用分析纯石英砂和典型粘土矿物高岭石模拟土壤的原生矿物和粘土矿物,利用批实验的方法研究土壤中各组成部分对三氯乙烯(TCE)的吸附行为。土壤有机质的吸附行为通过全土样和矿物质的对比得出。结果表明,粘土矿物是吸附氯代烃的主要矿物质,原生矿物对氯代烃的吸附量很小;土壤有机质含量和土壤吸附量之间有很好的正相关性;土壤有机碳含量与土壤粘土矿物含量的比值是影响吸附行为的另一重要因素,比值越小,Koc值越大,土壤对TCE的亲和力就越强。由于自然界中的土壤有机质大都与矿物质形成有机质-粘土矿物结合体,据此推测有机质-矿物质结合体会影响有机质的组成和形态,从而对其吸附行为有重要作用。     

长寿地区土壤重金属元素污染特征及评价

为查明长寿城区及周边区域表层土壤中As、Cd、Hg等8个重金属元素的污染情况,进行土壤测量结果显示,区内Cr、Hg、Ni等大部分元素的平均含量高于三峡库区深层土壤背景值,Hg、Pb的后期叠加作用最为强烈;除Hg外,其余7个元素含量间存在显著正相关,其中Cr、Ni最为显著;随着p H值增加,Ni、Cr、Cd、Cu含量显著增加;单因子污染指数评价和内梅罗综合指数评价均显示研究区内土壤环境质量总体较好,污染区域较少,以轻度污染-中度污染为主,重污染约占全区面积的0.3%,Hg元素为研究区内最主要的污染元素。     

粘土矿物对金属镉的吸附与解吸研究

通过以2:1型膨润土、1:1型高岭土为代表的粘土矿物吸附金属元素Cd和以醋酸、草酸和柠檬酸为代表的有机酸对粘土矿物吸附金属Cd的解吸作用研究,得出结果:粘土矿物对镉离子的吸附率随Cd浓度增大而下降;2:1型膨润土的吸附能力大于1:1型高岭土;三种弱酸对粘土矿物吸附的镉离子具有一定的解吸附能力,其中柠檬酸>草酸>醋酸,且对膨润土的解吸效率低于对高岭土的解吸效率.     

兰州地区土壤重金属污染元素的组合特征

通过对区域化探中的面金属量(Ps)与环境评价中的污染指数(Pi)之间的数学关系式进一步推演,建立了元素污染量(W)这一命题。以各元素污染总量排序来评价兰州地区土壤污染元素组合,其特征是1极易污染量最大元素为Hg,其污染量值占了全部污染量的37%以上;2常见污染元素为Pb、Zn、Cu,其3元素的污染异常出现率在80%以上;3Hg与Pb、Zn、Cu总量之比约4∶1;4排在Hg、Pb、Zn、Cu之后的各元素大多是一种特征指示元素,代表了某种工业类型三废排放的污染突出元素,如F代表重金属冶炼、轻金属冶炼,Cd代表了机械工业,Cu、Cd代表了仪器仪表工业等。这种元素污染量的组合特征对研究区域环境污染对人体健康的危害,以及研究在人类社会工业化过程时期冰川、深海、黄土、河湖沉积地层中重金属含量特征具有一定的参考意义。     

ICP-MS测量土壤中重金属元素的方法研究

采用改进后的电热板湿法消解,混合酸(硝酸+氢氟酸+高氯酸+硫酸)分解土壤试样,使土壤中重金属元素以离子形式进入溶液,用ICP-MS测其含量。试验结果表明方法的检出限和定量限均低于规范要求的检出限和定量限,工作曲线相关系数为0. 999,加标回收率为87. 8%～111. 0%。测量结果经土壤标准物质验证精密度、准确度均满足全国土壤污染状况详查技术规范的要求,方法适合于大批量土壤样品中重金属元素的同时测定,快速、高效。     

合肥市土壤重金属元素异常及其生态效应

通过对合肥市及其周边地区表层土壤重金属元素异常空间分布特征的分析，查明了生活和工业排污是形成Hg、Cd、Pb、Zn异常的主要原因；相对于深层土壤，表层土壤具有明显的富集特征，自地表向下重金属元素含量呈迅速下降趋势。探讨了土壤重金属元素全量与有效量、土壤pH值的关系，土壤重金属元素有效度大小排序为：Cd〉Pb〉Zn〉Hg，Cd、Pb有效量与全量相关性显著，且与pH值呈负相关，随着土壤cd、Pb元素全量的增加以及土壤不断酸化，其生态风险将显著增大。异常区土壤重金属的累积已造成部分蔬菜重金属超标，进而影响到蔬菜食用安全性，因此，加强土壤环境质量保护，对保证合肥市社会经济可持续发展具有重要意义。     

氟在土壤中的富集与淋滤

土壤中的氟处于淋失和富集两种地球化学作用过程的平衡之中.淋失过程占优势的条件下,在干旱半干旱地区内的特定区域形成地带性的高氟地面水和地下水,这是饮水型地方性氟中毒发生的物质基础.在氟的富集占优势的条件下,湿润气候地区将形成富氟土壤,并与其它条件结合则产生燃煤型地方性氟中毒.在决定风化壳中氟平衡状态的诸因素中,粘土矿物对氟的吸附与解吸附性质是最关键的因素.     

Study on soil heavy metals contamination of a lead refinery

The contents of Pb, Cd, Cr, As, and Hg was investigated in the neighboring areas of a lead smelting enterprise and the metals contamination of soil was evaluated with the methodologies of the single factor index and Nemerow integrated index. It is found that the content of heavy metals in the neighboring areas has no obvious difference from the reference points. And the soil contamination of heavy metals varies by elements, the contamination index follows the pollution order： Cd〉Hg〉Cr〉As〉Pb. The pollution degree of Cd is at high level and Hg at low level, but Cr and As reached the warning level. Therefore, the lead smelting enterprises should not only control lead but also other heavy metals as Cd.     

A study on the characteristics of heavy metals in orange ecosystem

An investigation was conducted to identify the characteristics of heavy metals in orange ecosystem in three areas in the Three Gorge Reservoir Region by using the modified Tessier sequential extraction procedure. The contents of Cu and Pb in different speciation fractions of the soils can be ordered as the Residual (F6)>Reducible (F4)>Oxidable (F5)>Water soluble (F1)>Carbonate (F3)>Exchangeable (F2), and the contents of Zn and Ni follow the order of the Residual (F6)>Oxidable (F5)>Reducible (F4)>Water soluble (F1)>Carbonate (F3)> Exchangeable (F2), and those of Cd follow the order of the Reducible (F4)>Oxidable (F5)>Exchangeable (F2)>Carbonate (F3)>Residual (F6)>Water soluble (F1). The concentrations of Cu in the different organs of oranges follow the increasing sequence of pulp>leaf>pericarp, those of Zn and Ni following the increasing sequence of leaf>pulp>pericarp, and those of Pb and Cd follow the increasing sequence of leaf>pericarp>pulp. Correlation degrees of different forms of same heavy metals in soils are according to the order of Cu>Zn>Cd>Pb>Ni. Correlation degrees of different heavy metals in same forms are according to the order that the forms of Reducible (F4), Oxidable (F5) and Residual (F6) are higher than the forms of Water soluble (F1), Exchangeable (F2) and Carbonate (F3). There are either positive or negative correlations between heavy metals in leaves and in pulp, while there are all positive correlations between heavy mentals in leaves and in pericarp. There are significant correlations between the concentrations of some heavy metals in leaves, pericarp or pulp, and those in speciation fractions in the soils.     

江西德兴铜矿大坞河土壤重金属累积特征与成因

江西德兴铜矿是中国超大型斑岩铜矿,随着矿业活动的增加,德兴铜矿区重金属污染问题日益严重。查明德兴铜矿土壤重金属累积作用及原因,可为政府机构、矿山开展环境整冶提供科学依据。在大坞河上游、中游、下游选定3个剖面,采集50件土壤样品,得出其基于地球化学基线的累积特征。整体来讲,Cu、Mo累积作用最为显著,Cr、As累积作用明显,同时发现一级、二级阶地上累积显著,并从矿石组合、地化背景、河流阶地、元素形态、矿山生产等角度开展累积作用的原因分析。     

江西德兴铜矿大坞河土壤重金属累积特征与成因

江西德兴铜矿是中国超大型斑岩铜矿,随着矿业活动的增加,德兴铜矿区重金属污染问题日益严重。查明德兴铜矿土壤重金属累积作用及原因,可为政府机构、矿山开展环境整冶提供科学依据。在大坞河上游、中游、下游选定3个剖面,采集50件土壤样品,得出其基于地球化学基线的累积特征。整体来讲,Cu、Mo累积作用最为显著,Cr、As累积作用明显,同时发现一级、二级阶地上累积显著,并从矿石组合、地化背景、河流阶地、元素形态、矿山生产等角度开展累积作用的原因分析。     

几种氧化锰矿物的合成及其对重金属的吸附和氧化特性

以改进或优化的方法合成土壤中常见的几种氧化锰矿物,对其形貌、结构、组成和表面性质进行表征,研究其对几种重金属的吸附和对Cr(Ⅲ)的氧化特性及与其结构和表面性质的关系。结果表明,合成的水钠锰矿、钙锰矿、锰钾矿和黑锰矿均为单相矿物,具有典型的形貌特征。水钠锰矿、钙锰矿和锰钾矿的PZC较低,分别为1.75、3.50和2.10,其表面可变负电荷量的大小顺序为水钠锰矿≥锰钾矿>钙锰矿;黑锰矿的PZC较高,表面可变负电荷量远低于其他3种矿物。供试矿物中,水钠锰矿对Pb2 、Cu2 、Co2 、Cd2 和Zn2 等重金属的吸附能力最强,黑锰矿的吸附能力最弱,除黑锰矿吸附更多的Cu2 外,供试氧化锰矿物对Pb2 的吸附量最大。氧化锰矿物对重金属的吸附受重金属的水解常数和矿物的表面负电荷的影响较大,它们均影响氧化锰矿物表面诱导水解作用及吸附离子形态。供试氧化锰矿物对Cr(Ⅲ)氧化能力和氧化过程中Mn2 释放量不同,受矿物结构、氧化度、表面性质以及结晶度等因素影响,氧化能力顺序为水钠锰矿>锰钾矿>钙锰矿>黑锰矿,最大氧化量分别为1330.0、422.6、59.7和36.6mmol/kg。     

Assessment of heavy metals contamination in soils of Dexing region, Jiangxi Province, China

Heavy metal contamination has attracted huge concern due to its toxicity, abundance and persistence in the environment, and subsequent accumulation in soil, sediment and water. Mining is one of the most important sources of heavy metals in the environment. Mining-milling operations and disposal of tailings （the finely ground remains of milled ores） in addition to smelting and metal refining provide significant sources of pollution. Mining and mineral processing in the Dexing region of China have been carried out for over forty years and have contaminated the soils with heavy metals, Many studies were conducted to assess and establish the extent of heavy metal contamination in the soils due to mining. The aim of this work was to assess the environmental impact of mining on soils in the Dexing region and to identify the main factors involved in heavy metals dispersion. A 4800 km^2 study area was assessed with respect to its heavy metals on the basis of the current guideline values. In order to assess the extent of heavy metals contamination resulting from past mining activities in the Dexing region, 919 soil samples were collected and analyzed for As, Hg, Cd, Cr, Zn, Cu and Pb, Heavy metals levels were determined using inductively couple plasma-atomic emission spectrometry and X-ray fluorescence spectrometry. Results of soil samples reported concentrations between 1.790-899 mg/kg for As, 0.034-4.980 mg/kg for Hg, 0.043-8.330 mg/kg for Cd, 10-666 mg/kg for Cr, 25-18500 mg/kg for Zn, 6-1825 mg/kg for Cu, and 16-1312 mg/kg for Pb, respectively. The maximum values of As, Hg, Cd, Cr, Zn, Cu and Pb concentration in soils were up to 60, 33, 41, 7, 185, 52 and 37 times higher than the tolerable level, respectively. Meanwhile, the single-factor pollution index and Nemerow pollution index were used to assess the environment quality of heavy metals contamination.     

介微孔复合沸石分子筛对重金属离子吸附性能的实验研究

以介微孔复合沸石分子筛MCM-41／ZSM-3为吸附剂，采用静态吸附方法初步研究了其对重金属离子Cu^2 、Zn^2 、Pb^2 、Cd^2 的吸附性能。结果表明：对于配置的60mg／dm^3重金属离子溶液，使用分子筛用量为10g／dm^3时，在较宽的pH范围内MCM-41／ZSM-3对Cu^2 、Zn^2 、Pb^2 、Cd^2 的吸附率可达90％以上；对等温吸附曲线的回归分析得出Cu^2 、Zn^2 、Pb^2 、Cd^2 在实验浓度范围内符合Langmuir单吸附位吸附曲线且具有较大的吸附容量。     

土壤中重金属元素Pb、Cd地球化学行为影响因素研究

通过研究湖南洞庭湖地区水稻土中Pb、Cd与土壤有机质、粘粒和pH值的关系,结果表明,(1)土壤中有机质含量与Cd、Pb有着显著的正相关性,土壤中有机质含量增加可明显降低Cd和Pb的离子态和可交换态含量。(2)随着粘粒含量增加,Pb和Cd离子可交换态占全量的比值略有增加,这说明粘粒表面吸附的Pb和Cd容易进入植物体中,对生态系统安全具有危害的组分。(3)Cd离子交换态与土壤pH值呈显著相关关系,土壤酸化使Cd的离子交换态比例上升,可直接导致农作物中Cd含量增加,防止土壤酸化是控制Cd对生态系统危害的有效途径;Pb的离子交换态与全量的比值与pH值具有显著的相关性,对于Pb污染严重的土壤,保持土壤pH值在弱酸性至弱碱性范围,防止土壤酸化和盐碱化,可以降低Pb危害。土壤有机质含量、pH值等是控制重金属元素地球化学行为的重要因素之一。     

Adsorption of heavy metals in glacial till soil

The charged sites on soil particles are important for the retention/adsorption of metals. Metallic counterions can neutralize the intrinsic charges on the surfaces of soil particles by forming complexes. In this study, efforts have been made to determine the effect of surface potential, pH, and ionic strength on the adsorption of four metal ions, hexavalent chromium Cr(VI), trivalent chromium Cr(III), nickel Ni(II) and cadmium Cd(II), in glacial till soil. Batch tests were performed to determine the effect of pH (2–12) and ionic strength (0.001–0.1 M KCl) on zeta potential of the glacial till soil. The point of zero charge (pH _PZC ) of glacial till was found to be 7.0±2.5. Surface charge experiments revealed the high buffering capacity of the glacial till. Batch adsorption experiments were conducted at natural pH (8.2) using various concentrations of selected metals. The adsorption data was described by the Freundlich adsorption model. Overall glacial till shows lower adsorption affinity to Cr(VI) as compared to cationic metals, Cr(III), Ni(II) and Cd(II).     

青藏高原典型金属矿山河流重金属污染对比

为研究青藏高原金属矿山勘探、开采、闭坑阶段不同开发阶段河流重金属污染的严重程度,通过野外调查,室内测试分析,对比5个金属矿山河流重金属元素含量、污染指数沿程变化,得出以下结果:(1)勘探阶段和闭坑后河流水质污染较小,开采阶段矿业活动对河水水质污染较大。(2)As、Pb、Cd、Cu和Zn五种元素是金属矿山的特征污染物。开采矿区中德尔尼铜矿区、下柳沟铅锌矿、甲玛矿区河流均有重金属元素污染,微碱性环境中德尔尼铜矿区,主要污染物为As,单项污染指数为0～10.6;下柳沟铅锌矿Pb、Cd、Cu和Zn元素单项污染指数分别为0.2～2.1、0～55、0.4～24、0.3～1550;偏酸性环境中甲玛矿区的特征污染物主要为Cu、Cd。其中Cu、Cd单项污染指数为0～4174、0～4;勘探矿区大场金矿、闭坑矿区罗布莎铬铁矿区河流未出现污染元素。(3)青藏高原5处典型的高海拔山地矿山河流由于稀释作用重金属流经2km后达到安全水平,研究结果可为青藏高原矿山开采中河流水环境保护提供参考依据。