铅与对二氯苯复合污染对小麦和大白菜种子发芽及幼苗期生长的毒性

在草甸棕壤条件下,测定了铅(Pb2 )与对二氯苯(PDB)的单一及复合污染对小麦和大白菜种子发芽率、幼苗生物量(鲜重、干重)、芽伸长抑制率和根伸长抑制率的影响。结果表明,对外源污染物的敏感顺序为根伸长抑制率>芽伸长抑制率>幼苗鲜重>发芽率和幼苗干重。Pb2 与PDB复合污染的条件下,Pb2 的浓度为500 mg.kg-1时,Pb2 与PDB处于协同效应。Pb2 的浓度为2 000 mg.kg-1时,Pb与PDB联合毒性比较复杂。但不论对于小麦还是大白菜,Pb与PDB的联合作用更多的是依靠Pb2 的作用而不是PDB的作用。     

土壤重金属污染对蚯蚓的急性毒性效应研究

测定了草甸棕壤条件下 ,Cu、Zn、Pb、Cd单一 /复合污染对蚯蚓的急性致死及亚致死效应 .结果表明 ,Cu、Pb浓度与蚯蚓死亡率显著相关 (α=0 .0 5 ,RCu=0 .86 ,RPb=0 .87) ,Cu浓度与生长抑制率显著相关 (α=0 .0 5 ,RCu=0 .84) ,其他供试重金属浓度与蚯蚓死亡率和生长抑制率相关性不显著 .蚯蚓个体对重金属毒性的耐受程度差别较大 .其毒性阈值 (引起个体蚯蚓死亡浓度 )分别为 :Cu 30 0mg·kg-1,Zn 130 0mg·kg-1,Pb 170 0mg·kg-1,Cd 30 0mg·kg-1.LC50 分别为 :Cu 40 0～ 45 0mg·kg-1,Zn15 0 0～ 190 0mg·kg-1,Pb2 35 0～ 2 40 0mg·kg-1,Cd 90 0mg·kg-1.在Cu、Zn、Pb、Cd单一污染引起 >10 %蚯蚓死亡的浓度下 ,复合污染导致 10 0 %蚯蚓死亡 ,表明复合污染极强的协同效应 .     

重金属复合污染对小麦种子根活力的影响

应用二次回归旋转设计法,以小麦种子为材料,研究了水培条件下重金属复合污染对其根生长及活力的影响;借助回归分析建立了相应的数学模型,分析了Cu、Zn、Cd和Pb4种重金属对根活力的毒性、两两重金属问的联合作用以及各重金属的边际毒性效应．结果表明重金属对根活力的影响顺序为Pb＞Cu＞Cd＞Zn;Cu与Cd、Cu与Zn、Zn与Cd以及Cd与Pb元素间的互作效应显著;在0-20mg.L^-1浓度范围内,Cu和zn两元素在最小浓度时的边际效应值最大,Cd和Pb两元素的边际效应最大值却出现在最高浓度处．     

菲和芘对土壤中植物根伸长抑制的生态毒性效应

测定了草甸棕壤条件下 ,菲、芘对小麦、白菜、西红柿 3种植物根伸长抑制率 ,以及复合污染毒性效应。结果表明 ,菲、芘浓度与植物根伸长抑制率呈显著线性或对数相关 (P =0 0 5 )。 2种有机物对植物根伸长抑制强度为菲 >芘。这与菲、芘的水中溶解度明显相关。与土壤脱氢酶活性和蚕豆根尖微核实验结果相比 ,植物根伸长对菲、芘毒性更敏感。小麦为有机污染的最敏感指示植物。菲、芘复合污染产生明显协同作用。     

中性环境中铝盐絮凝剂对典型作物的生态毒性效应

采用种子发芽和根伸长抑制的陆生生态毒理方法,在中性条件(pH=7.0)下对铝盐絮凝剂(AlCl₃)的生态毒性效应进行了研究.结果表明,AlCl₃溶液在pH=7.0时,与其酸性条件(pH=4.0)相比对萝卜、白菜和小麦等受试作物种子发芽和根伸长均表现出抑制作用,且发芽抑制率和根伸长抑制率与铝浓度均呈极显著相关(P＜0.01).尽管在酸性条件下AlCl₃对白菜和小麦根伸长抑制效应比相同浓度中性条件更为强烈,但对萝卜根伸长的抑制程度在相同铝浓度条件下则是pH=7.0时明显大于pH=4.0时,在低浓度时萝卜发芽抑制率也是中性条件明显高于酸性条件.同时,铝盐在中性条件下对萝卜、白菜的发芽和根伸长产生明显抑制效应的起始浓度低于酸性条件(＜2.0 mg·L^-1).     

重金属胁迫对毛竹种子萌发及其富集效应的影响

以毛竹种子为供试材料,研究4种重金属(Pb2+、Zn2+、Cu2+、Cd2+)胁迫对毛竹种子萌发的影响,并考察重金属在毛竹幼苗各组织部分的富集情况。结果表明:(1)Pb2+和Cd2+对毛竹种子的发芽率、发芽势、发芽指数及活力指数有抑制作用,低浓度下Cu2+和Zn2+对毛竹种子的发芽势、发芽率、发芽指数等指标有促进作用,高浓度则显著抑制;当浓度达到1600μmol/L时Cd2+对种子萌发的抑制效果明显强于其他3种元素;(2)选取根尖数、根表面积、根体积、根系总长4个根系形态指标发现,低浓度处理下Pb2+、Zn2+对根系生长有促进作用,而Cu2+和Cd2+起到明显的抑制作用;(3)处理10d后,种子萌发幼苗地上部对Pb2+、Zn2+、Cu2+、Cd2+的含量最高可达6810.51、1387.77、951.77、429.33 mg/kg,转移系数Zn2+Cd2+Pb2+Cu2+。综上,系统揭示了毛竹种子在重金属胁迫下的萌发和富集情况,为今后的土培、大田试验提供了有益的参考,也为将毛竹作为植物修复材料加以研究开启了新的研究视角,具有重要的研究价值。     

香根草和鹅观草对Cu、Pb、Zn及其复合重金属的耐性研究

采用根伸长实验研究了香根草和鹅观草对重金属的耐性随着溶度的升高,耐性指数下降,当香根草和鹅观草受Cu2+、Pb2+、Zn2+单一污染时,三元素的危害作用依次为Cu2+>Pb2+>Zn2+;在Cu、Pb、Zn混合溶液中,其两种植物耐性指数的大小及变化与单一元素Cu溶液最为相似,Cu在溶液中起到主导因子作用;香根草与鹅观草相比,不论是受Cu、Pb、Zn单一污染还是三者的复合污染,香根草比鹅观草都具有较强抵制重金属的胁迫能力,其耐性指数大都大于0 5。因此香根草具有对重金属较强的耐性,在重金属污染土壤的植物修复及尾矿废弃地的植被重建中,可优先作为选择的材料。     

不同工艺阶段味精废水对作物种子发芽和根伸长的毒性效应

为了对味精废水的污染进行全面的评价,针对不同工艺阶段排放的味精废水,采用小麦、白菜和西红柿等作物种子,以污水为环境介质,进行了种子发芽和根伸长的污染暴露实验,并结合污染现场,进行了相应的定量分析.结果表明,在高浓度原味精废母液中, 小麦种子的发芽抑制率和根伸长的抑制率与废水的浓度呈显著正相关.味精废水对3种作物种子的发芽和根伸长的毒性强弱顺序为：西红柿＞白菜＞小麦西红柿对味精废水毒性响应最为敏感,可以认为是一种较为理想的生物毒性指示作物.味精生产不同工艺阶段所排放的污水对这3种作物种子的发芽半抑制浓度(IC₅₀)为22.0～32432 mg·L^-1,对根伸长的半抑制浓度(IC₅₀)为17.3～3320 mg·L^-1.     

刺楸年轮中重金属含量动态变化及富集特性

为探索刺楸对受污染土壤重金属的富集和修复效应, 以南京栖霞山的乡土树种刺楸及其根际周边土壤为研究对象, 截取其根基部年轮盘及根际土壤样本, 采用ICP-AES法测定年轮及土壤样本中重金属(Cu、Cd、Cr、Mn、Ni、Pb、Zn)元素含量。结果表明: 栖霞山样地中的土壤受Mn、Pb和Zn污染最为严重, 存在Cu、Cd、Mn、Pb、Zn元素的高度复合污染, Cd、Cr、Cu、Ni、Zn在土壤和年轮中存在相关性, Mn和Pb则没有表现出明显的相关性; 刺楸修复受Cd、Mn、Pb、Zn污染的土壤效果并不显著, 更适用于Cr、Cu、Ni污染的土壤修复; 鉴于Cu元素含量变化特征, 刺楸也可以作为反映当地污染历史的记录载体; 刺楸年轮中的重金属元素之间存在交互作用, 其中Cd与Zn元素含量高度相关(r=0.984, p<0.01), 在刺楸年轮吸收重金属元素的过程中, Cu与Cd、Cr、Mn、Zn元素具有协同作用, Mn元素对其他元素有一定的拮抗作用。     

小麦不同生育时期Cd、Cr、Pb污染监测指标体系

以小麦为供试材料,分别采用发芽试验、溶液培养、土柱栽培等毒理试验方法,研究了小麦萌芽期、幼苗期及成株期受重金属污染毒害的指标体系。结果表明,①小麦根伸长抑制率可作为萌芽期重金属污染评价的一项生物指标;Cd、Cr、Pb对小麦根生长的7d半效应浓度(EC50)值分别为1.39、0.20mmo.lL-1和2.75mmol.L-1,据此得到3种重金属对小麦同一性状的毒性次序为CrCdPb;此外各性状抑制率与胁迫浓度的关系可用双曲线模型y=x/(a+x/100)或指数曲线模型y=a(1-exp(-bx))较好模拟。②Cd、Cr、Pb单一污染胁迫对小麦幼苗性状的毒性次序均以影响叶面积和冠部干重为主,表明叶面积和冠部干重为幼苗期污染监测的敏感指标;重金属对除根干重外所有性状的毒性次序:CrCdPb,该毒性次序是根据引起50%抑制的临界浓度即EC50值确定的;各性状抑制率与胁迫浓度的关系可用直线模型、或双曲线模型、或指数曲线模型较好模拟。③重金属单一污染胁迫造成小麦籽粒产量下降幅度是CdCrPb;二元互作对产量影响的重要性次序为CdCrCdPbCrPb;在Cd、Cr、Pb复合污染胁迫条件下,穗数可以作为成株期重金属污染监测的首选指标。以上指标可为农田小麦重金属污染的监测和综合治理提供一些理论依据。     

重金属对土壤中萝卜种子发芽与根伸长抑制的生态毒性

高等植物是生态系统中的基本组成部分。一个平衡、稳定的生态系统生产健康、优良的高等植物。反之 ,一个不稳定或受到外来污染的生态系统 ,对高等植物的生长可带来不利和可见的负面影响。因此 ,利用高等植物的生长状况监测土壤污染程度 ,是从生态学角度衡量土壤健康状况 ,评价土壤质量的重要方法之一[4 ,6] 1) 。土壤生态毒理学评价方法是对化学分析方法的重要补充。目前已建立的高等植物毒理试验有三种方法 ,即 1根伸长试验 ;2种子发芽试验 ;3早期植物幼苗生长试验[3 ,5,6,10 ] 。最初 ,这类试验主要用于纯化学品的毒性检验 ,但随着对土壤…     

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.     

表面活性剂对长柔毛委陵菜(Potentilla griffithii var. velutina)修复重金属污染的促进作用

研究了十二烷基苯磺酸钠(SDBS)、十六烷基三甲基溴化铵(CTAB)、聚乙二醇辛基苯基醚(TritonX-100)等不同离子类型的表面活性剂对水稻土中重金属的解吸效果,并采用盆栽实验研究了上述3种表面活性剂对Zn超富集植物长柔毛委陵菜(Potentilla griffithii var. velutina)的生物量、吸收和富集重金属的影响.结果表明:CTAB对水稻土中Zn、Pb、Cd和Cu的解吸效果好于SDBS和TritonX-100,而且3种表面活性剂对各重金属的解吸率大小都为Cd>Zn>Cu>Pb.3种表面活性剂促进长柔毛委陵菜叶、柄和根的生物量增加了0.2～2.5倍,并且长柔毛委陵菜各部位的生物量大小为叶>柄>根.3种表面活性剂都增加了长柔毛委陵菜各部位对Zn、Cd吸收及其叶和柄对Pb、Cu的吸收,同时显著促进Zn、Pb、Cd和Cu从植物根部向地上部转运,从而增加了Zn、Pb、Cd和Cu在长柔毛委陵菜地上部的提取量和分布以及长柔毛委陵菜对Zn、Pb、Cd和Cu的富集能力;因此3种表面活性剂都提高了长柔毛委陵菜修复重金属污染土壤的效率.     

Distribution of Heavy Metals and Arsenic in Greenbelt Roadside Soils of Pudong New District in Shanghai

We studied the distribution of seven heavy metals and As in typical municipal greenbelt roadside soils in Pudong New District, Shanghai, China. As and Ni showed no significant accumulation compared with the background values of the local soils, but there was strong evidence of accumulation of Cd, Cr, Cu, Hg, Pb and Zn in the roadside soils. However, only Zn and Cd contents were higher than the pollution thresholds of the Chinese National Soil Quality standard. The concentrations of heavy metal(loid)s in the soils were significantly affected by the length of time since the roads were constructed. Soils from areas adjacent to an older road had higher levels of Cu, Pb, Cd and Zn. In terms of spatial distribution, more Cd, Cu, Pb and Zn were found in the soil from the green areas of median between carriageways than from those of the roadside verges. Vertical distribution analysis shows that the contents of Pb, Cd, Cu and Zn had maximum values in the topsoil and were substantially lower in the deeper layers of the soil profile. Moreover, correlation analysis reveals that these four heavy metals originated from the same pollution sources and their contents were directly associated with the traffic density.     

公路源重金属对青藏高原高寒草甸土壤线虫群落的影响

为了解重金属对青藏高原高寒草甸土壤线虫群落的影响,在邦杰塘草原利用公路源重金属含量差异,采用高通量测序技术,分析重金属对高寒草甸土壤线虫群落多样性及群落组成的影响。结果表明：在重金属含量较低样本中,土壤线虫群落Shannon指数、Ace指数、Chao指数比重金属含量较高样本均要小,且整体上Shannon指数、Ace指数、Chao指数与重金属含量较高样本差异显著（P<0.05）。重金属含量升高改变了高寒草甸土壤线虫纲水平和目水平的群落结构,使近自然状况下的色矛纲（Chromadorea）、小杆目（Rhabdtida）优势土壤线虫群落转变为一类未分类线虫纲（unclassified_p_Nematoda）、一类未分类线虫目（unclassified_p_Nematoda）的优势土壤线虫群落。重金属Cu、Pb、Zn、Cd与线虫门（Nematoda）和刺嘴纲（Enoplea）正相关,但与色矛纲（Chromadorea）负相关,且对土壤线虫Chao指数的变异解释比例依次减小。研究表明土壤重金属含量对青藏高原高寒草甸土壤线虫群落多样性及组成产生很大影响,但仍需对高寒草甸区域进行系统的土壤线虫调查,并丰富土壤线虫生物信息数据库。     

铜尾矿库区土壤与植物中重金属形态分析

对铜陵铜尾矿区土壤和植物中重金属形态进行了研究.结果表明,尾矿库区种植地极端贫瘠,有机质含量仅2.6～.8 g·kg^-1,而土壤Cu、Cd、Pb、Zn含量皆高于对照土壤,其中Cu含量达809.30～1 39.4 mg·kg^-1,Cd含量达3.2～6.3 mg·kg^-1,达到对照土壤30～60倍.结缕草和三叶草体内重金属含量与土壤重金属交换态及有机结合态含量成正相关,与碳酸盐结合态、铁锰氧化物结合态成显著或极显著负相关,与矿物态含量相关性不显著.在两种优势植物中,Cu、Zn、Pb均以活性较低的醋酸提取态、盐酸提取态和残渣态为主;Zn在根系和茎叶中,NaCl提取态占有较大比例,而Cd均以NaCl提取态为主.     

芜湖钢铁厂周边土壤及油菜籽中镉、铜、锌、铅含量和形态分布研究

研究了污染土壤、油菜籽中Cd、Cu、Zn、Pb含量、形态分布特征和重金属富集状况及可能存在的生物毒性.结果表明,土壤中Cd、Zn、Pb以铁锰氧化物结合态、Cu以残留态占5种形态最高比例,分别为31.1%、39.3%、53.79%、46.24%;Cd、Pb交换态比例较高,为23.47%、16.32%,Cu、Zn的交换态比例较小,为3.14%、0.54%;土壤中不同重金属与各重金属形态相关关系有差别,5种重金属形态转化为有效态重金属难易程度不同;油菜籽和油菜籽壳中不同重金属累积趋势有差异,Cu易在油菜籽壳中累积,Cd、Zn、Pb易在油菜籽中累积;油菜籽中不同重金属累积率不同,Cd累积率最高,为0.56.油菜籽中重金属累积率与土壤中重金属总量呈显著负相关关系(P＜0.05),土壤中重金属的形态、转化差异是此种负相关关系的主要原因;油菜籽中Cd、Cu、Pb以氯化钠态为主,分别为32.50%、22.94%、34.69%,Zn以EDTA态为主,为45.97%.油菜籽中重金属形态可能影响其毒性,但其毒性的人类膳食风险还需进一步研究证实.油菜籽中重金属形态与油菜中重金属总量相关性不好.     

Analysis of Spatial Variations and Sources of Heavy Metals in Farmland Soils of Beijing Suburbs

To understand the effect of intense human activities in suburbs on environmental quality, we obtained 758 measurements of the heavy metals in certain farmland soils of the Beijing suburbs. Multivariate statistical analysis and geostatistical analysis were used to conduct a basic analysis of the heavy metal concentrations, the distribution characteristics and the sources of pollution of the farmland soils in these suburbs. The results showed the presence of eight heavy metals in the agricultural soils at levels exceeding the background values for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. In particular, all the measured Cr concentrations exceeded the background value, while As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were present at 1.13, 1.68, 1.95, 1.43, 1.63, 0.79, 0.92 and 1.36 times their background values, respectively. The results of correlation, factor and spatial structure analyses showed that Cd, Cu, Pb and Zn were strongly homologous, whereas Cr and Hg showed a degree of heterogeneity. The analysis further indicated that in addition to natural factors, Cd, Cu, Pb and Zn in the soil were mainly associated with distribution from road traffic and land use status. Different agricultural production measures in the various areas were also important factors that affected the spatial distribution of the soil Cr concentration. The major sources of Hg pollution were landfills for industrial waste and urban domestic garbage, while the spatial distribution of As was more likely to be a result of composite pollution. The regional distribution of the heavy metals indicated that except for Cr and Hg, the high heavy metal levels occurred in districts and counties with higher organic matter concentrations, such as the northwestern and southeastern suburbs of Beijing. There was no significant Ni pollution in the agricultural soils of the Beijing suburbs.