牡蛎对重金属生物富集动力学特性研究

应用半静态双箱模型室内模拟了牡蛎对四种重金属 (As、Hg、Cd、Pb)的生物富集实验 ,通过非线性拟合得到了牡蛎富集重金属的吸收速率常数 k1 、排出速率常数 k2 、生物富集因子 BCF、生物学半衰期 B1 /2 等动力学参数。结果表明 :吸收速率常数 k1及生物富集因子 BCF均随着外部水体浓度的增大而减小而平衡状态下生物体内金属含量 CAmax随着外部水体浓度的增大而增大 ,且成显著正相关 ,这说明牡蛎比较理想的重金属 Hg、Cd、Pb污染的指示生物。     

斑马鱼对铜、铅和镍的生物富集动力学研究

以斑马鱼为实验对象,应用双箱动力学模型模拟了其暴露在不同浓度的3种重金属（Cu、Pb、Ni）养殖水中,考察其在富集与排出过程中的生物富集规律,利用电感耦合等离子体质谱法（ICP MS）对斑马鱼体内重金属含量进行动态监测,并对结果进行非线性拟合,得到斑马鱼富集重金属的动力学参数。对模型拟合度检验表明双箱动力学模型拟合程度良好,可用于描述Cu、Pb和Ni在斑马鱼体内的生物富集规律。结果表明：斑马鱼对水中重金属的富集能力与暴露浓度呈正相关,而其对不同重金属的富集具有选择性,对3种重金属生物富集能力由强到弱排序为Cu>Pb>Ni,其中斑马鱼对Cu的富集能力极强。此外,斑马鱼对3种重金属的排出速率系数与生物半衰期均与暴露浓度无明显相关性,不同种类的重金属在斑马鱼体内的生物半衰期按时间长短排序为Ni>Pb>Cu,但排出阶段结束后,斑马鱼体内的重金属浓度依然高于初始浓度数倍甚至数十倍。     

中华绒螯蟹对Pb和Cd的富集与释放特性

应用生物富集双箱动力学模型模拟了中华绒螯蟹(Eriocheir sinensis)分别在Pb浓度为0.25、0.50、0.75mg/L,Cd浓度为0.025、0.050、0.075mg/L的单一水环境中暴露时,蟹鳃、肝胰腺、肌肉和血淋巴对Pb和Cd的生物富集与释放实验,并通过非线性拟合得到中华绒螯蟹对Pb和Cd的富集速率常数k1、排出速率常数k2、生物富集系数BCF、生物半衰期B1/2、富集平衡时生物体内Pb和Cd含量CAmax等动力学参数。结果表明:(1)中华绒螯蟹对Pb和Cd具有明显的富集,蟹鳃、肝胰腺和肌肉中Pb和Cd的含量与富集时间和水环境中Pb和Cd暴露浓度表现出了很好的正相关,血淋巴在富集阶段没有明显的规律。理论平衡状态下鳃、肝胰腺和肌肉中Pb和Cd含量CAmax随着暴露浓度的增大而增大,且成正相关。(2)Pb和Cd在中华绒螯蟹组织器官中的富集具有选择性,开始实验前,Pb在中华绒螯蟹体内的的分布规律为:肝胰腺>鳃>肌肉>血淋巴;Cd的分布规律为:鳃>肝胰腺>血淋巴>肌肉。在实验浓度的Pb和Cd水环境中暴露16d后,Pb的分布规律为:鳃>肝胰腺>肌肉>血淋巴;Cd的分布规律为:肝胰腺>鳃>肌肉>血淋巴。(3)中华绒螯蟹对Pb和Cd的生物富集和释放都较缓慢。经过16d的生物富集,各组织器官中Pb和Cd的含量均未达到稳态平衡。Pb和Cd在组织器官中的生物富集系数(BCF)范围分别为5-51和6-3148,中华绒螯蟹对Cd的富集能力明显高于Pb(P1/2)范围分别为4-9d和8-57d,中华绒螯蟹对Cd的排出能力明显低于Pb。       

上海市中小型河道沉积物和水生植物中重金属累积特征研究

采用野外调查和室内分析相结合的方法,以上海市8个区县25条中小型河道为研究对象,调查研究重金属在沉积物和水生植物中累积特征,采用潜在生态风险指数评价法对沉积物重金属污染进行了评价,采用生物富集系数(BCF)方法评价不同水生植物对重金属的富集特性,对水生植物与沉积物中的重金属含量进行相关性分析。分析表明,与土壤环境质量国家二级标准(GB15618-1995)相比,As、Ni和Zn平均含量是标准的6.7倍、1.5倍和1.4倍,Cd、Pb、Cu、Cr平均含量不超标。参照上海市土壤环境背景值,上海市中小型河道沉积物中7种重金属的潜在生态风险依次为:CdAsPbNiCuZnCr,其中Cd、As生态风险严重,7种潜在生态风险Ri平均值为431.43,有强生态风险。植物体内累积最高的重金属为Cu,累积最低的重金属为Cd,沉水植物体内重金属Cd、As、Cr、Pb、Ni、Cu的含量均大于挺水植物,沉水植物苦草和水盾草对多种重金属的富集能力大于1,在重金属复合污染水体修复中具有较大潜力。根据植物体与沉积物中重金属的含量关系,发现黑藻与沉积物中重金属Cu、Ni、Pb的含量显著正相关;水盾草与沉积物中重金属Cu含量显著正相关,芦苇与沉积物中重金属Cr的含量显著正相关,上述3种植物可作为上海市河道重金属污染监测植物的选择对象。     

上海市中小型河道沉积物和水生植物中重金属累积特征研究

采用野外调查和室内分析相结合的方法,以上海市8个区县25条中小型河道为研究对象,调查研究重金属在沉积物和水生植物中累积特征,采用潜在生态风险指数评价法对沉积物重金属污染进行了评价,采用生物富集系数(BCF)方法评价不同水生植物对重金属的富集特性,对水生植物与沉积物中的重金属含量进行相关性分析。分析表明,与土壤环境质量国家二级标准(GB15618-1995)相比,As、Ni和Zn平均含量是标准的6.7倍、1.5倍和1.4倍,Cd、Pb、Cu、Cr平均含量不超标。参照上海市土壤环境背景值,上海市中小型河道沉积物中7种重金属的潜在生态风险依次为：Cdgt;Asgt;Pbgt;Nigt;Cugt;Zngt;Cr,其中Cd、As生态风险严重,7种潜在生态风险Ri平均值为431.43,有强生态风险。植物体内累积最高的重金属为Cu,累积最低的重金属为Cd,沉水植物体内重金属Cd、As、Cr、Pb、Ni、Cu的含量均大于挺水植物,沉水植物苦草和水盾草对多种重金属的富集能力大于1,在重金属复合污染水体修复中具有较大潜力。根据植物体与沉积物中重金属的含量关系,发现黑藻与沉积物中重金属Cu、Ni、Pb的含量显著正相关;水盾草与沉积物中重金属Cu含量显著正相关,芦苇与沉积物中重金属Cr的含量显著正相关,上述3种植物可作为上海市河道重金属污染监测植物的选择对象。     

乐安河—鄱阳湖湿地植物群落特征及其优势植物对重金属Cu、Pb、Cd的富集

选择乐安河—鄱阳湖湿地典型植物群落,采用重要值方法评价各样点植物群落特征并筛选出典型优势植物,通过室内理化测试分析不同生境中优势植物植株及其根区土壤中重金属Cu、Pb、Cd的含量;采用生物富集系数(BCF)方法评价不同优势植物对重金属Cu、Pb、Cd的富集特性。结果表明:研究区湿地植物以草本为主,在各样点共发现124种物种,包括蕨类植物2科2属2种,种子植物40科97属122种,并从中筛选出羊蹄、红蓼、鼠曲草、紫云英、苎麻等5种富集能力较强的优势植物;植物根区土壤中的Cu、Cd含量均超过土壤环境质量三级标准,而且Cu、Cd的最高含量分别为824.03、5.03 mg·kg-1;不同优势植物对Cu、Pb、Cd等3种重金属元素中的1种或2种表现出较强的富集能力,其中优势物种红蓼对Cu具有较强的富集能力,含Cu量最高为148.80 mg·kg-1,另一种优势物种鼠曲草对三种元素的生物富集系数均较高,且对Cd的最高富集含量为15.17 mg·kg-1,对Cd的生物富集系数最高值为19.14,高于其他植物10倍以上,鼠曲草对重金属Cd具有富集植物的基本特征,且对Cu和Cd具有共富集特征并具有较高的耐性,紫云英、羊蹄等对Cd的富集能力也较强。上述5种优势植物种群对鄱阳湖湿地Cu、Pb、Cd等重金属污染物的生态修复具有一定参考价值,可作为鄱阳湖湿地重金属污染修复植物的选择对象。     

重金属胁迫条件下空心莲子草的生长和营养特征分析

空心莲子草是一种常见的水生植物,并能在重金属污染的水体或附近土壤中生长.本研究发现,空心莲子草能富集6种常见的重金属元素,其富集能力为:Zn2+>Mn2+>Pb2+>Cu2+>Cd2+>Cr3+.高浓度(1 mmol/L) Cu2+、Mn2+、Zn2+和Cr3+ 等重金属胁迫处理条件下,空心莲子草的根冠比增加,生物干重、总根长和总根表面积都相应降低.此外,高浓度(1 mmol/L) Pb2+、Cd2+、Cu2+或Zn2+分别胁迫处理条件下,空心莲子草的K+、Ca+和Mg+等元素的含量变化差异显著(P＜0.05).以上研究表明,空心莲子草通过改变体内钾钙镁等重要生长元素营养情况来适应重金属污染的胁迫,有很强的富集重金属元素的能力,进而降低污染、净化水体.空心莲子草对重金属污染的生长响应及体内重要矿物元素营养特性之间的相互关系,可能为重金属污染的水土生物修复提供理论依据.     

泉州湾河口红树林湿地重金属的分布与迁移

通过测定泉州湾河口湿地2种红树植物(桐花树和秋茄)不同部位(根、枝和叶)及其根际沉积物中重金属酸可提取态含量,探讨该区域重金属元素的分布、在植物不同部位富集和迁移的情况。结果表明:2种红树植物根际沉积物中酸可提取态重金属含量顺序均为FeMnZnPbCuCrNi;秋茄根际沉积物中Cu、Zn、Pb、Ni和Cr两两之间呈正相关,桐花树根际沉积物中Cu与Zn呈正相关,Pb与其他重金属的相关性不显著;2种红树植物根中大多数重金属含量与根际沉积物中重金属酸可提取态含量之间呈正相关,而枝中的相关性不显著;2种红树植物重金属富集的情况较接近,Mn富集系数最大,其次是Cu和Zn;Mn、Cu、Zn、Cr主要富集在叶中,而Pb、Fe、Ni主要富集在根部;2种植物中Mn的迁移能力最强,易于从根部运输到叶中。     

混合暴露条件下近江牡蛎对重金属的积累与释放特征

选择近江牡蛎作为试验生物,研究了混合暴露条件下8种重金属在近江牡蛎体内的积累和释放特征.结果表明: 近江牡蛎对重金属Pb、Cu、Ni、Cd、Cr和Hg有很强的累积能力,可较好地指示溶液中的重金属浓度水平,但对重金属Zn和As的积累能力很小,不能真实反映溶液中重金属Zn和As含量的变化水平.在随后35 d的释放阶段,8种重金属在近江牡蛎体内的含量没有明显变化,表明近江牡蛎对重金属的释放能力较差.双箱动力学模型可较好地反映混合暴露条件下近江牡蛎对重金属的积累特征,但不适合对其释放特征进行描述.     

珠江口桂山岛表层沉积物中重金属的分布特征及潜在生态危害评价

于2011年8月采集了珠江口桂山岛海域12个站点的表层沉积物, 对沉积物中重金属的含量进行了测定。结果表明, 桂山岛沉积物中重金属含量与国内外港湾相比属于中等水平, Pb、Cr、Ni、Cu、Zn、Mn平均含量分别为40.06、31.29、14.17、30.67、100.18、599.76 mg/kg。富集系数法和 Hakanson潜在生态风险指数法评价表明:桂山岛沉积物各重金属元素的富集顺序为Cu﹥Pb﹥Zn﹥Mn﹥Cr﹥Ni, 其中Cu、Pb、Zn和Mn富集系数大于1;该海域重金属潜在生态风险总体上处于低水平, 从空间上看, S11危害最为严重。进一步通过主成分分析研究沉积物中重金属的来源, 发现前2个主成分贡献率分别为44.38%、42.61%, 表明重金属主要有2个来源:工业和生活污水排放、岩石的自然风化与侵蚀过程。     

金毛狗对重金属的富集特性的研究

为探讨金毛狗[Cibotium barometz(L.) J. Sm.]对重金属的富集能力,在广东省选取6个样点(南岭、南昆山、白云山、大岭山、梧桐山、西樵山)采集金毛狗的叶片、根状茎和根际土壤,采用ICP-MS测定9种重金属元素(Cr、Mn、Ni、Cu、Zn、As、Cd、Hg、Pb)的含量。结果表明,样地土壤已受到不同程度的重金属污染,土壤中Cd和Hg含量均高于广东省土壤背景值,分别为背景值的1.61~4.82倍和4.74~11.79倍。西樵山土壤中Cd含量最大,南岭土壤中Hg含量最大。在9种元素中,金毛狗对Hg的转运系数最高,达4.8,对Cd的富集系数最高,达2.2,Cu和Cd元素的转运系数和富集系数均大于1。这说明金毛狗对重金属元素的富集能力较弱而转运能力较强。     

两种农业种植模式对重金属土壤的修复潜力

植物修复农田土壤重金属污染需要经历一个长期的过程,而大部分用来修复的植物都不具备利用价值,不能给当地农民带来经济收入。因此,一些农作物由于其较大的生物量和一定的经济价值,在植物修复土壤重金属污染的应用中受到广泛关注。是在重金属(Cu、Zn、Pb、Cd、As、Hg)复合污染的郴州矿区废弃农田种植油菜、玉米和油葵,研究油菜-玉米和油-油葵两种种植模式对土壤重金属污染的修复潜力。实验结果表明:三种作物在复合污染土壤中对重金属都表现出一定的耐性及吸收积累能力。向日葵的根和叶中重金属Cd、Cu的含量都很高,其中Cd在向日葵的各个部位的富集系数(BCF)及Cu在向日葵的根和叶的富集系数(BCF)都大于1。两种轮作模式对作物的产量没有明显的影响,收获得到的干物质量都很高,每年每公顷分别为油菜16.6t、玉米25.29t、油葵22.5t。两种种植模式都可以对土壤中的重金属进行有效的提取,油菜-油葵种植模式下提取重金属Cu、Pb、Cd、As的量较高,分别为:Cu 2408g hm~(-2)a~(-1),Pb 2027g hm~(-2)a~(-1),Cd 658.5g hm~(-2)a~(-1),As 250g hm~(-2)a~(-1),油菜-玉米模式下Zn和Hg的提取量较高,分别为Zn 4987g hm~(-2)a~(-1)和Hg 7.92g hm~(-2)a~(-1);对于多种重金属复合污染的土壤来说,油菜-油葵的种植模式要优于油菜-玉米的种植模式。总的来说,利用3种作物两两轮作的种植模式,在不影响作物产量的前提下大大的提高了作物对重金属的提取总量。3种作物在收获以后又可以用做工业原料,这就使得当地农民充分利用矿区废弃农田修复污染的同时又能从中获得一定经济效益。     

Evaluation of bioconcentration factors of metals and non-metals in crops and soil from abandoned mines in Korea

Hazard evaluation of different heavy metal exposure on the crops cultivated around two abandoned metal mine sites was conducted. Bioconcentration Factor (BCF) of nine heavy metals including Cu, Cd, Hg, As, Cr, Zn, Pb, Mn, and Al in the samples of brown rice cultivated at exposed soil were measured. Soil-plant BCF was measured and compared with Korean and US EPA standards. BCF values of analyzed heavy metals except Hg and As were below the limits. BCF of Hg was over 5 times higher than the standard limit. Excess cancer risk (ECR) and hazard quotient (HQ) values of As was higher than the limit and suggested to have carcinogenic as well as non-carcinogenic threat to the public exposed to the sites. The data presented could be utilized in prioritizing abandoned metal mine sites for health effect survey.     

Factors affecting heavy metal uptake in plant selection for phytoremediation

The heavy metal uptake of ten plant species was studied under different soil and climatic conditions. Effects of soil pH, temperature, plant species and phenophase on the heavy metal content of stems and leaves were determined in pot experiments. Plants and soil samples were collected from a lead/zinc mine ore (Gy?ngy?soroszi, Hungary) and characterised by high contents of Pb, Zn, As, Cd, Cu. The possibility of an adapted phytoremediation technology was indicated by different bioconcentration factors (BCF). The BCF depended markedly (10- to 100-fold) on plant species and environmental conditions. Based on our results a "season-adapted" phytoextraction technology with different plant species (utilising their different temperature requirements and/or harvest time) is suggested.     

三峡水库蓄水后铜鱼和圆口铜鱼肌肉和肝脏中重金属水平

为了解三峡水库蓄水后鱼体重金属富集现状及其潜在的生态风险和食品安全, 测定了三峡水库上、中、下游不同年龄组铜鱼(Coreius heterodon)和圆口铜鱼(C. guichenoti)肌肉和肝脏中重金属含量。利用等离子吸收光谱法、石墨炉原子吸收光谱法、原子荧光光谱法检测样品中Cu、Zn、Cr、Pb、Cd、Hg、As 等 7种重金属含量。结果表明: 7 种重金属在铜鱼和圆口铜鱼体内的含量水平基本一致, 重金属在铜鱼和圆口铜鱼肌肉中含量大小均为Zn Cu Cr Hg AsPb Cd, 在铜鱼肝脏中含量大小为Zn Cu Pb Cd Cr As Hg, 而在圆口铜鱼肝脏中含量大小为Zn Cu Pb Cr Cd Hg As。铜鱼和圆口铜鱼肝脏中重金属含量显著高于肌肉(P0.05)。两种鱼类间大部分重金属在库区上、中、下游无显著差异(P 0.05)。铜鱼和圆口铜鱼肌肉(可食用部分)中7 种重金属含量均未超过国家食品安全卫生标准, 属于安全食用范围;肝脏中除Cd 和Pb 外的其他元素含量均未超过国家标准。相关结果反映了三峡水库175 m 蓄水后底栖土著经济鱼类重金属的污染状况, 对了解该地区水产品质量安全状况及水产品安全评价提供了参考依据。       

Phytoremediation potential of vetiver grass irrigated with wastewater for treatment of metal contaminated soil

A field experiment was conducted to understand the potential of vetiver grass (Vetiveria zizanioides) in heavy metal uptake from the soil and wastewater. Four main irrigation treatments including T₁ (treated industrial wastewater), T₂ (1:1 ratio of municipal:industrial wastewater), T₃ (treated municipal wastewater) and T₄ (fresh water) were applied. Moreover, the effect of arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on plant growth and heavy metal concentration was evaluated. Three main criteria including bioconcentration factor (BCF), translocation factor (TF) and heavy metal uptake were applied to assess the potential of vetiver grass in accumulation and translocation of heavy metals to aerial parts. The highest concentration of heavy metals was found in plant and soil irrigated with T₁ treatment followed by T₂, T₃ and the lowest concentrations were found in T₄ treatment. Irrigation with treated municipal wastewater led to a significant increase in plant biomass and heavy metal uptake compared to other treatments. In T₁ treatment (industrial wastewater), vetiver grass caused a significant decrease in Zn, Fe, Cu, Cd and Pb concentrations in soil as compared to no-plant treatment (without planting vetiver grass). Therefore, vetiver grass, irrigated with treated industrial wastewater, is a promising method for the development of urban and industrial green space.     

Bioavailability and Concentration of Heavy Metals in the Sediments and Leaves of Grey Mangrove, <Emphasis Type="BoldItalic">Avicennia marina</Emphasis> (Forsk.) Vierh,in Sirik Azini Creek,Iran

The concentration and bioavailability of Ni, Cu, Cd, Zn, and Pb in the sediments and leaves of grey mangrove, Avicennia marina, were studied throughout Sirik Azini creek (Iran) with a view to determine heavy metals bioavailability, and two methods were used. Results show that Zn and Ni had the highest concentrations in the sediments, while Cd and Cu were found to have the lowest concentrations in the sediments. Compared to the mean concentrations of heavy metals in sedimentary rock (shales), Zn and Cu showed lower concentration, possibly indicating that the origin of these heavy metals is natural. A geo-accumulation index (I _geo) was used to determine the degree of contamination in the sediments. I _geo values for Zn, Cu, Pb, and Ni showed that there is no pollution from these metals in the study area. As heavy metal concentrations in leaves were higher than the bioavailable fraction of metals in sediments, it follows that bioconcentration factors (leaf/bioavailable sediment) for some metals were higher than 1.     

Bioaccumulation of trace metals by the live macroalga Gracilaria lemaneiformis

The macroalga Gracilaria lemaneiformis is an important and commercially valuable renewable resource. It is distributed widely in shallow marine waters but grows mostly on tropical or subtropical coasts. We investigated the accumulation of Cd, Cu, and Pb by live G. lemaneiformis under low concentrations. There was a positive correlation between the organisms’ metal concentrations and exposure concentrations. When exposed to both Cu and Cd, the concentrations of Cu and Cd in G. lemaneiformis were higher than those exposed to solutions of Cu and Cd alone. However, the concentrations of heavy metals in G. lemaneiformis were not markedly different (p?<?0.05) between the treatment groups and the control groups. We analyzed the results with nonlinear curve fitting and employed a two-compartment model to study the accumulation kinetics of heavy metals by G. lemaneiformis. The uptake rate constants and bioconcentration factors (BCFs) of the metals decreased with increased exposure concentration. The theoretical equilibrium concentrations increased significantly with the exposure concentrations. Our results suggested that G. lemaneiformis obviously accumulated heavy metals from seawater. As an important resource for food and pharmaceuticals, G. lemaneiformis should be cultivated in clear seawater.     

Phytoavailability of Heavy Metals and Metalloids in Soils Irrigated with Wastewater,Akaki, Ethiopia: A Greenhouse Study

Irrigation with untreated wastewater from several industrial, commercial, and domestic discharges for decades caused accumulation of various heavy metals and metalloids in soils along the Akaki River in Ethiopia. Assessment of environmental threats and the potential phytoremediation of the soils require understanding of the toxic elements’ uptake and distribution in plant parts. Hence, a greenhouse study was performed to examine the phytoavailability and distribution of Cr, Ni, Co, Cu, Zn, Cd, Pb, Hg, Se, V, and As in forage grasses: Oat (Avena sativa), Rhodes grass (Chloris gayana), Setaria (Setaria sphacelata), and the legumes Alfalfa (Medicago sativa) and Desmodium (Desmodium unicinatum). The average contents of Cr, Ni, Co, Cu, Zn, Pb, Hg, Se, and V in the plants were generally higher than the background levels for forage grasses/legumes, and some of these elements were in the phytotoxic range. Root bioconcentration factor (BCF = root to soil concentration ratio) > 1 was observed for Cu (Oat, Rhodes, Desmodium, and Setaria: Fluvisol), Zn (Setaria: Fluvisol), Cd (Rhodes: Fluvisol; Setaria from both soils) and Hg (Oat and Alfalfa: Fluvisol). Alfalfa and Desmodium displayed translocation factor > 1 (TF = shoot to root concentration ratio) for most heavy metals. Most heavy metals/metalloids may pose a health threat to humans and stock via introduction to the food chain. The plant factors (species and plant part), soil factors (soil type, soil fractions, pH, and CEC), and their interactions significantly (p < 0.05) influenced plant heavy metal and metalloid levels. However, the role of plant part and species emerged as the most important on heavy metal uptake, translocation, sequestration, and ultimately transfer to the food chain. Accordingly, the uptake and distribution of heavy metals/metalloids in the plants reflect the potential environmental and health hazards attributable to the use of fodder grasses, legumes, and cultivation of vegetables in soils with polymetallic and metalloid contamination.