土壤中镉、铅、锌及其相互作用对作物的影响

通过作物盆栽模拟试验(砂壤质褐土、pH值8.2)揭示：土壤中分别施入镉(CdCl2)、铅[Pb(CH3COO)2]或锌(ZnSO4)其影响表现为,植物各器官镉的含量超过对照植物的数倍至500倍。土壤镉浓度<5ppm和<10ppm分别造成某些蔬菜和水稻的污染。铅主要积累在植物根部,土壤铅污染对作物的影响较小。锌主要积累在植物叶片和根部,对水稻产生生长抑制的土壤锌浓度临界值不大于200ppm,此浓度对旱作无影响。土壤中同时施入镉和铅,植物对镉的吸收增加。而土壤中镉的增加却减少了植物体内铅的含量。土壤中由于镉、锌或铅、锌相互作用的结果,水稻对它们的吸收都有增加。在旱地土壤锌浓度的增高,降低了植物对镉、铅的吸收。镉、铅、锌同时施入土壤由于相互作用的结果,除锌之外,植物对镉、铅的吸收有明显下降。评价土壤重金属污染,不仅要看它们的含量及其存在形态,而且要分析它们之间的相互作用(促进或拮抗)特点。     

重金属（铜、镉、锌和铅）对海水无机碳体系影响的模拟研究

通过室内模拟实验,研究了孔石莼和重金属(铜、镉、锌和铅)共同作用下,海水无机碳体系及碳源汇格局的变化.结果表明,t=7d时,无机碳体系各参数的变化幅度(Δ)与重金属种类和浓度有关.与对照相比,低浓度(<1μmol · L-1)的重金属添加组中,DIC、HCO-3 和PCO2的下降幅度都很明显(P<0.01* *).当铜、镉浓度大于"转折浓度"后, DIC、HCO-3和Pco2 均要大于初始值,其增幅随着重金属浓度的增加而增大.对于锌和铅,二者浓度高达50μmol · L-1时,水体中无机碳各参数与初始值相比仍呈现下降趋势.此外,当重金属浓度和种类不同时,水体中的碳源汇格局亦做不同的变化.当铜和镉浓度小于转折浓度时,水体表现为大气CO2的汇;而当铜和镉超出转折浓度时,水体会由大气CO2的汇过渡到源,并且当水体成为CO2的源后,其CO2的释放量是随着铜、镉浓度的增加而增大.在本实验设计的各浓度锌、铅添加组水体始终表现为碳汇,但当锌、铅浓度分别高于15μmol · L-1和20μmol · L-1时,其碳汇强度开始小于对照组(P<0.05*).     

大亚湾表层沉积物和底栖生物中重金属的污染特征与生物积累

通过分析2015 年5 月大亚湾海域34 个采样站位表层沉积物和底栖生物生物体中5 种重金属(铜、铅、锌、镉、汞)的综合污染程度因子、潜在生态风险因子和生物-沉积物积累因子, 评估了大亚湾海域表层沉积物重金属的污染现状、潜在生态风险水平和生物-沉积物积累程度。结果表明: 大亚湾海域表层沉积物中重金属含量上呈现锌>铅>铜>镉>汞的规律; 空间上呈带梯度带分布: 北部沿岸海域含量较高, 南部口门附近海域最低。重金属污染属于中等-比较严重污染水平, 其中锌、镉、汞是大亚湾沉积物污染的主要因子, 潜在生态风险属于中等-较高风险水平, 汞、镉是较大的潜在风险因子。底栖生物生物体重金属含量上呈现锌>铜>铅>镉>汞。铜、铅、锌、汞四种重金属除铜、锌在棒锥螺(Turritella terebra)生物体轻度积累外, 其它均无明显积累表现, 而重金属镉呈现较强的积累现象。     

单一与复合污染条件下两种敏感性植物对Cd、Zn、Pb的吸收效应

为了进一步研究镉、锌、铅 3种重金属元素间的相互作用以及对植物吸收重金属能力的影响 ,在模拟单一重金属污染试验研究的基础上 ,采用正交回归设计方案 ,研究了 Cd、Zn、Pb复合污染情况下紫花苜蓿和披碱草两种敏感性植物对 3种重金属的吸收效应。结果表明 ,在单一污染条件下 ,镉元素对紫花苜蓿生长的影响大于锌、铅 ,铅元素对披碱草生长的影响大于锌、镉 ;紫花苜蓿对于镉的吸收累积显著高于披碱草 ,植物内镉元素浓度最高达到 1 0 88.5 mg/kg,而披碱草对于铅元素的吸收则高于紫花苜蓿 ,植物内铅元素浓度最高达到 1 3 4 5 .5 mg/kg。在复合污染条件下 ,两种植物对铅、锌和铅、镉的吸收在不同浓度范围内分别存在存在着协同效应和拮抗效应 ;同时两种植物对锌、镉元素在实验涉及浓度范围内都存在着拮抗效应。这对于深入研究复合污染条件下重金属的土壤环境化学行为 ,对植物的综合毒性以及不同植物对重金属的吸收累积效应等 ,具有一定的参考意义     

蜈蚣草耐铅、铜、锌毒性和修复能力的研究

重金属复合污染是主要土壤污染类型之一。为了探明蜈蚣草修复土壤重金属复合污染的能力,土培试验研究了分别添加不同浓度铅、铜、锌条件下蜈蚣草生物量变化,结果表明,不同浓度铅和较低浓度锌处理下蜈蚣草生物量呈显著性地增加,土壤Pb、Zn添加浓度分别为1750mg／kg和1350mg／kg,蜈蚣草生物量最大。说明蜈蚣草有极强的耐Pb、Zn毒性能力,能在较高有效态Pb或Zn污染土壤上正常生长。蜈蚣草具有一定的耐Cu毒性能力,在Cu耐性方面,蜈蚣草可能存在生态型的差异。以上结果说明,利用蜈蚣草修复萃取Pb—As,Zn—As,Cu-As等复合污染土壤上As有重要的意义。     

Cd2+对绿球藻生长及生理特性的影响研究

重金属对水环境的危害是人们日益关注的问题。随着经济的迅猛发展,工农业生产过程中排出的有害重金属离子日益增加,如：汞、镉、铅、铜、锌、铬、镍等,造成水体受到不同程度的污染。过量的重金属离子如铜、锌、镉等对生物体具有毒性,并可通过食物链进入人体而引起各种疾病。这些污染物不仅直接危害人体健康,破坏自然环境,而且还会给国民经济造成重大损失。     

单一与复合污染条件下两种敏感性植物对Cd、Zn、Pb的吸收

为了进一步研究镉、锌、铅3种重金属元素间的相互作用以及对植物吸收重金属能力的影响,在模拟单一重金属污染试验研究的基础上,采用正交回归设计方案．研究了Cd、Zn、Pb复合污染情况下紫花苜蓿和披碱草两种敏感性植物对3种重金属的吸收效应。结果表明,在单一污染条件下．银元素对紫花苜蓿生长的影响大于锌、镉、铅元素对披碱草生长的影响大于锌、镉,紫花苜蓿对于镉的吸收累积显著高于：披碱草,植物内银元素浓度最高达到1088．5mg/kg。而披碱草对于铅元素的吸收则高于紫花苜蓿。植物内铅元素浓度最高达到1345．5mg/kg。在复合污染条件下．两种植物对铅、锌和铅、镉的吸收在不同浓度范围内分别存在存在着协同效应和桔抗效应;同时两种植物对锌、银元素在实验涉及浓度范围内都存在着拮抗效应。这对于深入研究复合污染条件下重金属的土壤环境化学行为,对植物的综合毒性以及不同植物对重金属的吸收累积效应等,具有一定的参考意义。     

一株耐铅、锌、铬菌株的分离鉴定及其吸附能力

【背景】采矿带来的土壤重金属污染问题对生态环境和人类健康产生了极大的危害,因此矿区重金属污染问题亟待解决。生物修复法成本低、资源广、没有二次污染,是修复土壤重金属污染的有效途径。【目的】以山东省曲阜市某煤矸石山周围土壤为材料,采用平板划线法分离筛选一株同时对铅、锌、铬有高耐性且吸附能力强的菌株。【方法】通过形态学特征、生理生化鉴定、分子生物学方法鉴定菌种;采用原子吸收分光光度计测量各重金属的浓度。【结果】鉴定菌株为蜡状芽孢杆菌(Bacillus cereus),命名为Bacillus cereus MZ-11。菌株MZ-11在pH为5.5?8.5、温度为15?45 °C、NaCl质量分数为2%?8%时可正常生长。菌株MZ-11最高耐铅、锌、铬浓度高达1 000、1 200、1 600 mg/L。在培养基中铅、锌、铬3种重金属浓度分别为初始浓度(含Pb2+、Zn2+、Cr6+浓度分别为50、60、80 mg/L)、初始浓度的5倍、10倍、20倍的条件下,MZ-11对Cr6+和Zn2+的吸附比例则随浓度的提高逐渐增大,吸附百分比均在98%?99%以上。对Pb2+的吸附比例有一个最高值,并且Pb2+的浓度为初始浓度的5倍时,MZ-11对Pb2+的吸附比例达最大值97.01%。【结论】菌株MZ-11对铅、锌、铬有高耐性和较好的吸附能力,为生物法修复矿区复合重金属污染和矿区生态环境提供了有力的理论支持。     

潮间带耐铅菌与铅等重金属有机质关系初析

胶州湾潮间带有较多铅、铜、镉、锌及有机碳、氢、氮等污染物,因而也有较多耐铅菌(Lead-Tolerant Bacteria缩写作LTB,下同)等相应的微生物。LTB等微生物参与这些污染物的价态,类型变化和迁移活动。潮间带LTB量的时空变化曾有过报道,但对LTB与环境因子间的关系未探讨过,而LTB的利用则有赖于环境因子,因此探索LTB与铅等重金属、有机质的关系,对阐明污染物归宿,生态变化和污染治理     

二氧化硫剂量与植物急性伤害关系

应用大气污染植物动态反应模拟装置系统测定了菜豆和苜蓿的SO_2剂量-反应关系。这2种植物对SO_2有类似的敏感性,0.5ppmSO_2×4小时产生可见伤害症状。苜蓿在2.0ppm×4小时出现50％的叶片可见伤害;菜豆在1.0ppm×8小时显示出50％的叶片可见伤害,2.0ppmSO_2×12小时引起100％的叶片可见伤害。 剂量-反应表面图的形状表明,菜豆和苜蓿出现可见伤害症状需要一定的暴露间隔。SO_2剂量和可见伤害率之间不成线性关系。SO_2浓度和暴露时间对叶片可见伤害率都有影响,两者相比,就菜豆而言,浓度是更重要的因素,但是对苜蓿,浓度和时间是同等重要的。     

Characteristics of Phytogeochemistry in Copper Mine Area of Hongtou Shan,Liaoning Province

The contents of copper, zinc, lead nickel and cadmium for 322 samples of 44 species growing on copper mine area of Hongtou Shoo were determined. The results showed that the average contents of zinc, nickel, lead, cadmium in dry matter are 51.313 ppm, 1.536 ppm, 0.361 ppm and 0.058 ppm respectively. The variable range of zinc and cad- mium contents is larger, difference between minimum and maximum value is about 30–40 times. Zinc, lead and nickel contents in leaves of xylophyta in dry matter are mostly higher than in branches, but cadmium content of branches in dry matter is higher than leaves. The contents of lead and zinc in plants of minerelization areas are higher than that in non-minerelization areas. The results of correlative analysis showed that the linear regression between the metal contents in plants and soils are significant, for example, Lespedeza bicolor Thalictrum thumbergii, Arundinella hirta et al. It is important in phytogeochemical methods of prospecting for mineral. However, the correlative coefficients between the elements contents in leaves and branches of Quercus liaotungensis and in soils are not obvious. The correlative coefficient of nickel in plants and zinc, lead, cadmium and organic matter contents in soils are mostly negative value, without significant correlation. The results of the principal component analysis showed that the correlation of cadmium and zinc is significant among five elements in the plants. The contributive rate of first principal component is 33.94%, the positive target of the main target constitute is cadmium and zinc.     

木本植物对大气重金属污染物——铅、镉、铜、锌吸收积累作用的研究

对环境污染除必须采取人工治理措施外,还必须充分发挥自然净化作用,才能取得经济合理和维护生态系统动态平衡的目的。 绿色高等植物特别是树木,对环境污染起着明显的净化和改善作用。因为它们的生物产量高,占有很大的空间,有巨大的根、茎、叶面积作用于环境,并对污染物具有一定的吸收积累或降解作用;生活周期长,有较长的时间与周围环境相互作用与影响,同时吸收积累的污染物质不会在短期内转移释放到环境中;此外,大部分树木是以保护环境或生产木材为主要目的,因而吸收积累的污染物不进入食物链对人产生危害。所以树木在保持和维护生态系     

Using tree leaves and barks collected from contaminated and uncontaminated areas as indicators of air metallic pollution

Abstract

The aim of this study was to show the usefulness of woody species in assessing air pollution by cadmium, copper, lead, and zinc. For this, washed leaves, unwashed leaves, and barks of a coniferous species (Cupressus sempervirens var. fastigiata) and a broadleaved one (Eucalyptus cladocalyx F. Muell) were analyzed for cadmium, copper, lead and zinc contents. A transect sampling approach was carried out during spring 2016. Fifty stations were selected along an intensive traffic road, and three in a control area. The results showed that the highest concentrations were recorded in barks for copper (21.86?µg/g, 23.33?µg/g) and lead (14.53?µg/g, 63.33?µg/g), and in unwashed leaves for cadmium (0.57?µg/g, 1.19?µg/g) and zinc (48.94?µg/g, 47.6?µg/g) for E. cladocalyx F. Muell, and C. sempervirens var. fastigiata, respectively. Lead and zinc are the most accumulated metals compared to cadmium and copper in all samples. The studied metal contents in urban area were significantly higher than that of the control one. This represents that traffic road has influenced the metals contamination of the surrounding area. Results of the bioconcentration factor (BCF) for both species indicate that the studied species could be used as biomonitors to identify ecological problems and to predict effect on wildlife habitats. The highest values of metal accumulation index (MAI) indicate the effectiveness of these trees for controlling the air metals in the polluted areas. Result shows too that the studied species could be used for phytoextraction of heavy metals from the polluted soils and/or air.     

Toxicity of heavy metals to Egyptian soil fungi

Changes in the composition of the soil mycoflora after soil treatment with 500, 2000 and 5000 ppm of mercury, zinc, lead, copper, nickel and cadmium, were determined on Czapek's glucose agar at intervals up to 15 weeks. Treatment of soil with mercuric chloride and lead nitrate significantly reduced the fungal population counts for soil treated with zinc or copper sulphate, and with nickel or cadmium chloride counts were increased on some treatments and reduced on others. When heavy metals were incorporated into the isolation medium, they depressed the total count of fungi, as well as affecting individual species.     

Uptake of six heavy metals by oat as influenced by soil type and additions of cadmium,lead, zinc and copper

Summary The influence of heavy metal additions on availability and uptake of cadmium, lead, zinc, copper, manganese and iron by oat was studied. The experiments were carried out as pot experiments using sandy loam, sandy soil and organic soil. Selective extractants were used to remove metals held in different soil fractions.Lead and copper were preferently bound by organics and oxides, zinc by oxides and inorganics, and cadmium by inorganics and organics.Addition of cadmium to the soils resulted in higher cadmium concentrations in all plant parts but lower concentrations of lead, zinc, copper, manganese and iron, and the accumulation indexes of these metals were also lower when cadmium was added to the soil.Addition of cadmium plus lead, zinc and copper resulted in higher cadmium concentrations in leaves and straw of plants grown in sandy loam and sandy soil, but lower concentrations when plants were grown in organic soil as compared with the results when cadmium was added separately. The transfer of cadmium, lead, zinc and copper from soil to plant was greatest from sandy soil, and zinc and cadmium were more mobile in the plant than were lead and copper.Cadmium concentrations in leaves correlated significantly with CaCl₂ and CH₃COOH extractions in sandy loam and sandy soil and with CH₃COOH extractions in organic soil.Generally, the total metal uptake was lowest from organic soil.     

Phytoextraction capacity of trees growing on a metal contaminated soil

Phytoremediation is an innovative biological technique to reclaim land contaminated by heavy metals or organic pollutants. In the present work, we studied the ability of five woody species to extract heavy metal (copper, zinc or cadmium) from a polluted soil to their above-ground tissues. Metal content in leaves and twigs was determined. Salix and Betula transferred zinc and cadmium to leaves and twigs, but Alnus, Fraxinus and Sorbus excluded them from their above-ground tissues. None of the species considered transferred copper to the shoots.     

Emergence of the midge chironomus tentans when exposed to heavy metal contaminated sediment

This experiment tested the effects of heavy metal contaminated sediment on emergence of chironomids. The number of adults emerging from test chambers containing an uncontaminated sediment and ones with sediment containing 1030 ppm cadmium (Cd), 17,300 ppm zinc (Zn), and 1640 ppm chromium (Cr) were observed for 14 days. It was found that emergence was reduced by over three times and delayed for two days in the heavy metal contaminated sediment.     

A Study of Air Pollution with Heavy Metals in Athens City and Attica Basin Using Evergreen Trees as Biological Indicators

Concentrations of five metals (cadmium, chromium, copper, nickel and lead) were determined in tree leaves collected from 13 areas of the Attica basin and Athens city, Greece. Geographical distribution patterns were investigated, and factors affecting toxic element accumulation in trees were discussed. The mean heavy metal content in the tree leaves is described in the descending order of copper>lead>nickel>chromium>cadmium. Generally, the most damaged areas have been proved to be those near the city center and in the vicinity of the Attica highway. The geomorphological relief of the area plays an important role in the dispersion of airborne particles from pollution sources to the surrounding area. Areas on the NE region are also polluted mainly due to wind directions. In Citrus aurantium leaves, with relatively impermeable cuticle, high chromium, copper and nickel concentration would be possibly caused only by significant stomatal uptake. The conifer tree Pinus brutia providing a rough leaf surface also showed elevated concentrations, especially of cadmium and lead. The thick waxy cuticle of the sclerophyllous broad-leaved Olea europaea forms a smooth sheet increasing the barrier properties of the leaf epidermis and causing a reduction in leaf permeability. The dense trichomes of the abaxial epidermis of Olea europaea also act as a pollution screen keeping away the air particles from the epidermis stomata. The presence of a certain metal within the leaf cells could reduce the uptake or toxicity of some others.     

Avoidance response of Midge Larvae (Chironomus Tentans) to sediments containing heavy metals

Avoidance reactions of chironomid larvae to contaminated sediment taken from a heavy metal impacted lake were studied. Heavy metal levels in the test sediment ranged from background of 0.6 parts per million (ppm) cadmium, 77 ppm zinc and 17 ppm chromium to a maximum of 1,029 ppm cadmium, 17,262 ppm zinc and 2,106 ppm chromium. A linear relationship was established between cadmium and zinc levels in the sediment and avoidance by chironomids.An approximate threshold avoidance of metals in the sediment was determined to be between 213–422 ppm cadmium, 4385–8330 ppm zinc and 799–1513 ppm chromium.Supported by NIH Training Grant Number 5T01-ES00071 from National Institute of Environmental Health Sciences and in part by an NSF (RANN) Grant Number GI-35106.Purdue University Agricultural Experiment Station, Jour. No. 6474.