锌、镉复合污染对重金属蓄集植物黑麦草养分吸收及锌、镉积累的影响

采用根袋盆栽试验研究了锌、镉单一及复合污染对重金属蓄集植物黑麦草(Lolium perenne L．)生长、养分吸收及锌、镉积累的影响．结果表明,锌、镉单一及复合污染对黑麦草生物量存在不同程度的抑制作用．锌、镉单一及复合污染均明显降低了黑麦草植株N、P、K含量,以锌、镉复合污染对植株养分吸收的抑制作用最大．锌、镉污染共存下,黑麦草对锌、镉的吸收为协同效应．黑麦草吸收的锌、镉主要集中在地上部,以锌、镉复合污染植株对锌、镉的蓄集量最大,其地上部锌、镉含量分别达到3108．72、73．97 mg·kg-1．     

硅对镉、锌、铅复合污染土壤中黑麦草生理生化性质的影响

采用正交试验设计L9(34)对黑麦草(Lolium perenne L.)进行温室盆栽试验,观测Cd、Zn、Pb复合污染条件下,硅(Si)对黑麦草生物量、叶绿素含量以及保护酶系统的影响.结果表明,Cd使黑麦草根系发育受阻导致生物量下降,中等水平的Zn和Pb有利于黑麦草生物量的积累;Cd、Zn、Pb复合污染造成黑麦草叶绿体结构的破坏,使叶绿素含量减少;低水平的Cd、Zn、Pb复合污染对黑麦草CAT和POD活性起到激发作用,但随着添加水平提高,两种酶活性受到抑制.Si可以促进黑麦草根系生物量的增加,有利于根系对水分和养分的吸收,保证地上部分的养分供给,使叶片生物量增加;硅化细胞的形成有利于黑麦草叶片对光能的吸收利用,Si也使叶绿素含量增加;Si对CAT和POD有显著激活作用,从而减轻重金属复合污染对黑麦草产生的伤害.     

土壤环境中镉、锌形态转化的探讨

论述了土壤中镉、锌的形态分布,讨论了影响土壤环境中Cd、Zn形态转化的因素和物质,如pH、石灰、有机质和其它一些离子和它们的影响机制,为治理土壤重金属污染提供理论依据。     

不同土壤处理对东南景天吸取土壤中锌和镉效率的影响

通过盆栽试验，观察分析东南景天植物在未处理及若干用土壤添加剂处理的土壤介质上生长和累积锌、镉的状况。结果显示：除单独使用沸石粉外，所有土壤处理均有利于土壤改良和东南景天的生长。与对照处理相比，赤泥和城市污泥对东南景天累积锌起促进作用，而施用熟石灰却无助或甚至不利于东南景天累积锌。不过，尽管赤泥和城市污泥对东南景天累积镉的效果比熟石灰好，无论施用赤泥、城市污泥或熟石灰，东南景天植物干物质所含的镉均比对照处理高得多。总的来说，赤泥和城市污泥均为改良土壤、促使东南景天生长和超累积锌、镉的良好添加剂；而熟石灰或沸石粉单独使用则对东南景天超累积锌、镉的作用较小。在试验中，将15g污泥、15g沸石和6g赤泥与1000g土壤混和的T7处理对促使东南景天生长和超累积锌、镉最为有效。研究结果表明，在利用东南景天修复酸性锌、镉污染土壤时，通过加入合适的改良剂，调控土壤pH值和营养供给，可大大提高植物修复重金属污染的效果。     

土壤镉、锌污染对蚯蚓纤维素酶活性的影响

为了探究土壤镉、锌污染对土壤动物蚯蚓的生理毒害情况,为土壤生态环境质量评价提供数据支持,以赤子爱胜蚓(Eisennia foetida)为研究对象,采用自然土壤法进行急性毒性试验,研究了土壤外源添加镉(Cd)和锌(Zn)单一污染与复合污染对蚯蚓纤维素酶活性的毒性效应.试验结果表明,蚯蚓体内纤维素酶活性在培养过程中呈先增大后减小的变化趋势.单一污染试验,酶活性的最大值出现在第7至第9天,最小值出现在第14天;复合污染试验,同一处理不同培养时间的酶活性最小值也大多出现在第14天.土壤Cd和Zn单一及复合污染都会对蚯蚓体内纤维素酶活性产生抑制作用.单一污染在培养的前5天抑制效果明显,且随着污染物添加剂量的增加抑制效果增强.复合污染,镉和锌在土壤中的联合效应除个别测定结果表现为加和作用或协同作用外,多数处理都表现为拮抗作用,且主要是受体拮抗.相比较而言,镉对蚯蚓体内纤维素酶活性的抑制作用强于锌.     

不同钝化剂对水稻小麦籽粒镉吸收的影响

在土壤镉污染日趋加重的背景下,镉污染农田生产安全性备受关注,进行土壤镉污染修复和降低农产品镉污染风险成为相关领域的研究重点。该研究通过田间试验揭示不同钝化剂处理（海泡石、秸秆生物炭、石灰、石灰+腐殖酸、石灰+海泡石、石灰+偏硅酸钠+硫酸镁）对土壤镉及小麦和水稻吸收镉的影响,并比较钝化剂对降低小麦和水稻镉污染风险效果的差异。结果表明,石灰+腐殖酸（施用质量比为2:1）能使小麦田土壤p H提升16.8%,单施石灰使水稻田土壤p H提升3.7%;石灰+偏硅酸钠+硫酸镁（施用质量比为20:4:1）使小麦籽粒镉含量降低25.8%;单施秸秆生物炭能够使小麦秸秆镉含量降低18.3%;石灰+海泡石（施用质量比为2:15）能使水稻籽粒镉含量降低72.8%,水稻秸秆镉含量降低28.0%。从不同钝化材料对小麦和水稻镉转移系数的影响来看,石灰+腐殖酸（施用质量比为2:1）能够同时降低小麦和水稻对镉的转移系数,降幅分别为39.7%和28.0%,对两种作物而言是降低镉转移系数的最佳钝化材料。经过对小麦、水稻籽粒和秸秆镉含量的相关性分析可知,小麦籽粒镉含量与秸秆镉含量呈幂函数关系,籽粒镉含量随秸秆镉含量的升高而缓慢...     

磷对褐土中锌镉次级吸附和解吸影响

通过吸附和解吸试验,研究了不同磷吸附量石灰性褐土对锌镉次级吸附和解吸的影响。结果表明,次级吸附锌和镉对不同吸附量磷土壤的磷解吸量随磷吸附量的增加而增加,而磷解吸量随次级吸附后锌、镉浓度的增加而降低,即随锌镉添加量的增加,磷的有效性有所降低。土壤对锌的次级吸附量和吸附率随磷吸附量的增加先降低后升高,并随添加镉浓度的增加而降低,解吸量和解吸率随磷吸附量的增加而增加,说明在正常施磷范围内,增加磷的施用量能提高土壤中锌的有效性,同时,土壤对高浓度锌的次级吸附率小于低浓度锌的次级吸附率,而土壤对高浓度锌的解吸量和解吸率要远大于对浓度锌的解吸量和解吸率;土壤对镉的次级吸附量、吸附率和解吸量、解吸率都随着磷吸附量的增加而增加,且吸附量随添加镉的量增加而增加,但镉次级吸附量和吸附率随添加锌浓度的增加而减小,解吸量和解吸率却增大,说明在磷吸附量相同的条件下,添加锌促进了镉的有效性。     

外源亚精胺对镉胁迫下黑麦草的生理调控效应

为解决植物修复重金属污染时遇到的耐性受损和低生长量等问题,研究了外源亚精胺(spermidine, Spd)对黑麦草镉(cadmium, Cd)胁迫的缓解效应。采用水培试验,在0、5和10 mg·L^-1 Cd处理的基础上,添加0.1 mmol·L^-1 Spd,定量考察分析了Spd对黑麦草生长发育、抗氧化能力和Cd积累特征的影响。结果显示,Cd处理显著抑制了黑麦草的生长和生理耐性。Cd浓度为10 mg·L^-1时,添加Spd使黑麦草生物量与耐性指数(tolerance index, TI)分别显著提高了20.90%和20.89%,叶绿素(a、b和a+b)含量显著提高了24.05%～46.11%。Spd还可抑制叶片内氧化产物丙二醛(malondialdehyde,MDA)和过氧化氢(hydrogen peroxide,H₂O₂)的积累,使其含量分别降低16.73%和16.45%;对抗氧化系统指标的影响则不一致,其中过氧化氢酶(catalase,CAT)、超氧化物歧化酶(superox...     

蔬菜对土壤镉铜锌富集能力的研究

调查了福建部分污染严重地区不同蔬菜对镉、锌、铜的富集能力。结果表明蔬菜对镉的平均富集系数为0.017,锌的平均富集系数为0.116.铜的平均富集系数为0.014。蔬菜对镉的富集系数的品种间差异最大,达315倍,远高于锌和铜的富集系数的品种间差异。茭白、豇豆和莲藕对镉的富集能力较低,可作为镉污染土壤优先选种的蔬菜品种,而青包菜、白包菜、芥菜、空心菜、芋头等对镉的富集系数较高,不宜在镉污染土壤上栽培。     

石灰性土壤中磷锌对小麦生长及锌吸收分配的影响

针对磷锌在土壤-植物系统中复杂的交互作用,文章采用盆栽试验,研究了石灰性土壤中施磷肥对小麦生长及吸收锌的影响,结果表明,施锌明显增加了土壤中DTPA提取态锌的质量分数,且土壤中wDTPA提取态锌随着施磷质量分数的提高逐渐增加;不同施磷质量分数背景下,随施锌质量分数的提高小麦茎 叶 籽粒壳的干重有所降低,却增加了小麦籽粒的干重;在各质量分数锌背景下施不同质量分数水平磷,明显地降低了小麦茎叶中锌的质量分数,但提高了籽粒中锌的质量分数,并增加了锌累积量;小麦地上部锌质量分数和锌累积量均随施锌水平的增加而增加.因此,石灰性土壤中施磷肥提高了土壤中锌的有效性,促进了小麦生长,降低了小麦茎叶中锌的质量分数,促进了锌元素从植株向籽粒的运输,增加了小麦籽粒中锌的质量分数,促进了小麦地上部分对锌元素的总吸收量.     

The role of root organic acids in the tolerance of Festuca rubra to zinc,lead and cadmium

Abstract

Festuca rubra L. plants are pseudometallophytes colonizing abandoned Pb/Zn mine areas, successfully employed in phytostabilization. To study the contribution of low-molecular weight organic acids to metal tolerance, F. rubra plants were grown for three months in hydroponics with Cd (1.8, 18 and 36 µmol?L^?1), Pb (50, 250 and 500?µmol?L^?1) and Zn (0.3, 3 and 6?mmol?L^?1), separately, and in ternary combination (18?µmol?L^?1 Cd + 250?µmol?L^?1 Pb + 0.3?mmol?L^?1 Zn). The roots retained most of the metals but their distribution from shoot to root was altered when the plants were treated with the ternary combination. The main organic acids in roots were citrate and malate. At the lowest concentrations, the metals caused small reductions in biomass, had no effects on photosynthetic pigments nor on malondialdehyde, but led to increases in root organic acids. At higher concentrations, phytotoxic responses were observed, associated with a decline of citrate and malate in the roots.     

Hematoxicity and hepatoxicity attributed to zinc and cadmium in the Norwegian rat

This study was carried out to determine changes in the blood and liver of rats given oral doses of cadmium (Cd) and zinc (Zn). Thirty 3 month old rats were kept six to a compartment in a well-demarcated five compartment cage labeled A, B, C, D, and E. After 2 weeks of acclimatization, and with ad libitum administration of water and feed, group A and B rats were, respectively, exposed to 100 mg CdSO₄ and 2200 mg ZnSO₄, respectively, mixed with their feed. Group C rats were fed with a combination of 100 mg CdSO₄ and 2200 mg ZnSO₄ mixed with their feed, while group D rats were exposed to 100 mg CdSO₄ mixed with their feed for 48 h, and after they were given 2200 mg ZnSO₄ for 96 h. Group E rats served as control and were fed a normal diet. Analysis of blood samples after 5 days showed that in rats of groups A, B, C, and D, WBC count increased from 6800 to 12,400 mm^?3 and platelets from 26,000 to 88,000 mm^?3. Reduction in blood counts were found for RBC from 13.8 to 4.7 × 10⁶ mm^?3, hemoglobin from 15.6 to 11.4 dL^?1, and PCV from 47 to 34%. ESR was the same 1.0 mm h^?1 in all groups. Severe damage to the liver was also shown by severe degeneration of hepatocytes and increase in Kuppfer cells. The above observations were mildest in the liver of group C rats. A reduction of body weight was observed in all treatment groups. Cd and Zn were found to be hematoxic and hepatotoxic in the Norwegian rat with Cd exhibiting greater toxicity than Zn. Toxicity of Cd was suppressed by Zn only when both metals were admistered at the same time, but a delay in intake of Zn (after 48 h) had little effect on Cd toxicity.     

An assessment of copper,zinc and cadmium contamination and their ecotoxicological effects in O. mediterranea Costa, 1853 (Amphipoda,Talitridae)

This study was conducted to compare metals bioaccumulation in the Talitrid O. mediterranea collected from the banks of Bizerte lagoon. Individuals were exposed to a series of contaminated soil with different concentrations of cadmium, copper, and zinc. Biological and physiological responses were highlighted. Body metals concentrations were measured in the talitrid using flame atomic emission spectrometry. Results showed that after the second week, the mortality increased especially with cadmium exposure, and a mass gain was obtained between weeks for copper and zinc. Furthermore, the concentration factor indicated that O. mediterranea could be considered as a macroconcentrator of copper and zinc. Histopathological analysis showed that the different metals concentrations induced significant changes in the morphology and in the ultrastructural organisation of hepatopancreatic cells. Significant alterations obtained after metals exposure were the increase in the number of the majority cell organelles. Also, heavy metals were present in the form of numerous granules with different size in the cell surface. Furthermore, metals exposure affected the brush border causing the disruption of microvilli filament. Through these results, O. mediterranea could be a good indicator providing measurable responses. It could be an attractive candidate for the biochemical study of heavy metals toxicity in coastal ecosystems.     

Hyperaccumulator Thlaspi caerulescens (Ganges ecotype) response to increasing levels of dissolved cadmium and zinc

Hyperaccumulation of metals by plants involves at least three processes: efficient absorption by roots, efficient root-to-shoot translocation and hypertolerance through internal detoxification. In this study, Thlaspi caerulescens was separately exposed to Cd and Zn at 0, 50, 100 and 200 μ M for 7 d to monitor plant responses in hydroponics. Significant dose-dependent accumulation was observed for both metals, mainly in roots (up to 3.2 and 9.2 mg g ^?1 for Cd and Zn, respectively). However, Cd was more phytotoxic in terms of plant growth and photosynthesis. This higher toxicity was also evidenced by MetPLATE bioassay. Root exudation was significantly correlated to Cd and Zn translocation (r>0.85) proving its involvement in facilitating metal uptake. As for antioxidative responses, plants reacted to Cd and Zn by broadly exhibiting an elevation of glutathione reductase activity before declining at 200 μ M due to higher phytotoxicity. By contrast, superoxide dismutase activity was unlikely to be affected by both metals. Root-to-shoot apoplastic flow was traced using a fluorescent dye (trisodium-8-hydroxy-1,3,6-pyrenetrisulfonic acid; PTS), whose concentration in leaves increased to a certain extent with Cd and Zn accumulation, indicating that heavy metals have a comparable effect to drought or salinity in promoting the passive diffusion of water and solutes. Nevertheless, Cd at 200 μ M hindered the diffusion of PTS and consequently affected the apoplastic transport in plants.     

旱地长期施用锌肥对小麦吸锌及产量的影响

以17年的微量元素肥料定位试验为背景，研究了长期施用锌肥条件下小麦的需锌特点和增产效应。施人锌肥后，小麦对微量元素锌的吸收明显增加，籽粒中含锌量增加率为18．8％，秸秆含锌量增加率为41．1％。小麦吸锌量在收获期达最大值，收获期籽粒多吸收13．99g/hm^2，秸秆多吸收23．67g/hm^2，常态年锌肥增产率为4．3％。干旱年增产率为3．7％，丰水年增产率为4．1％。应根据小麦需锌特点和效应，合理施用锌肥。     

Bioaccumulation of cadmium,lead and zinc in liver and kidney of red fox (Vulpes vulpes) from NW Spain: influence of gender and age

Cd, Pb, and Zn were quantified in liver and kidney of red foxes (Vulpes vulpes) which were hunted during the 2003–2011 hunting seasons in Galicia (NW Spain). The effects of age and gender were evaluated to determine whether these variables should be included in future biomonitoring studies. The concentrations of hepatic and renal Cd (average 0.6 and 1.3 µg/g) and Pb (0.8 and 0.06 µg/g, respectively) were similar to background levels, with no known toxicological relevance. Similarly, the average levels of Zn in liver and kidney (77 and 17 µg/g) were in the range of physiological levels for canids. Although no significant gender-dependent variations were observed, the effect of aging was evident: the levels of hepatic Pb and both hepatic and renal Cd were higher in adults than in juveniles. Age should be included as a parameter during future biomonitoring programs focusing on trace metal bioaccumulation in red foxes.     

Uptake of zinc, cadmium and phosphorus by arbuscular mycorrhizal maize (Zea mays L.) from a low available phosphorus calcareous soil spiked with zinc and cadmium

In a multifactorial pot experiment, maize (Zea mays L.) with or without inoculation with the arbuscular mycorrhizal (AM) fungus Glomus mosseae BEG167 was grown in a sterilized soil spiked with three levels of zinc (0, 300 and 900 mg Zn kg⁻¹ soil) and three levels of cadmium (0, 25 and 100 mg Cd kg⁻¹ soil). At harvest after 8 weeks of growth, the proportion of root length of inoculated plants colonized decreased with increasing Zn or Cd additon, and was 56% in the absence of both metals and was reduced significantly to 27% in the presence of the higher levels of both metals. Mycorrhizal plants had higher biomass than non-mycorrhizal controls except at the highest soil level of Cd. Cadmium had more pronounced effects on plant biomass than did Zn at the levels studied and the two metals showed a significant interaction. The data suggest that mycorrhizal inoculation increased plant growth with enchancement of P nutrition, perhaps increasing plant tolerance to Zn and Cd by a dilution effect. AM inoculation also led to higher soil solution pH after harvest, possibly reducing the availability of the metals for plant uptake, and lowered the concentrations of soluble Zn and Cd in the soil solution, perhaps by adsorption onto the extrametrical mycelium.     

施用石灰对Pb、Cd、Zn在土壤中的形态及大白菜中累积的影响

重金属的不同形态对于作物吸收重金属及受害具有十分密切的关系,通过施用石灰改变重金属的形态、毒性以及对作物的影响具有重要的意义。以大白菜(Brassica pekinensis)为研究对象,通过盆栽试验,探讨了在铅、镉和锌污染土壤上,施用石灰对土壤中不同形态镉、铅和锌含量及在大白菜中累积的影响。结果表明,施用石灰后,土壤中碳酸盐结合态Pb、Cd和Zn含量明显减少,铁、锰氧化物结合态和有机物结合态Pb、Cd和Zn含量明显增加;对大白菜吸收Pb、Cd和Zn均起到较好的抑制作用,石灰用量为5g·kg-1土时,对大白菜吸收Pb、Cd和Zn的抑制效果最好。     

Cadmium,copper, and zinc in carrots in Japan

Cadmium (Cd), copper (Cu), and zinc (Zn) in carrots obtained from different regions throughout Japan were assessed in a baseline study on the contents of trace metals in foods. These three metals were measured by flameless atomic absorption spectrophotometry. The geometric mean contents (with one geometric standard deviation indicated in parentheses) of Cd, Cu, and Zn were 0.02 (2.2), 0.7 (2.1), and 2.4 (1.6) mg?kg^?1 wet weight in carrots obtained in Japan. While there was a close relationship among the contents of the three metals in the carrots grown in Cambisols and Gleysols, a significant relationship was recognized only between the contents of Cd and Zn in those grown in Andosols and Fluvic Gleysols. Cd and Zn are classified as 2B metals in the periodic table of elements, and the authors speculate that the similarity of the metal characteristics between Cd and Zn may be responsible for the close relationship in the contents of the two metals, with no relation to the soil type.     

镉与除草剂草甘磷的交互作用对小麦的毒性

种子发芽试验、根伸长抑制试验及植物早期生长试验是目前所建立的3种高等植物毒性试验，这些试验通过研究植物在污染条件下根系发育状况、生物量减少程度或植物耐污特性等方面而对污染物的环境效应进行诊断。文章研究了镉与草甘磷交互作用对小麦发芽率以及发芽后小麦的根长和芽长的影响。结果发现，镉对小麦发芽率没有明显影响，而草甘磷对小麦发芽率、根长和芽长有明显抑制效应。镉在一定程度上降低了草甘磷对小麦发芽的毒性，但对小麦生长仍有明显毒害。当镉与草甘磷共同作用于小麦时，镉的存在增加了低浓度草甘磷的生物毒性，而降低了高浓度草甘磷的生物毒性或没有影响。但是，随着镉浓度增加它们的联合毒件又逐渐增加。