广州市区植物叶片重金属元素含量及其大气污染评价

文章通过对广州市区植物叶片中重金属元素含量的分析,研究了植物大气环境污染指数,探讨了植物叶片重金属元素含量与城市大气环境污染之间的关系。结果表明,植物叶片中Cu,Pb,Cd,Cr元素污染都较严重,在重污染区这些元素的含量明显高于清洁对照区;用植物污染指数可以综合评价大气环境质量状况;利用植物叶片内的重金属含量变化,为大气污染生物监测和环境质量评价提供了科学依据。     

重金属对水生生物的生态毒理效应及生物耐受机制研究进展

近年来,随着国民经济的快速发展,重金属以其特有的性质而被大量的应用于生产生活当中,同时也由于各种原因造成了水体重金属污染现象。水体重金属污染不仅对水生生物的生长和繁殖造成了严重的威胁,同时也威胁到人类的健康。因此,重金属污染具有潜在的生态与健康风险。本文主要概括介绍了重金属对水生植物、动物、微生物的生态毒理效应以及水生生物对重金属的各种耐受机制,展望了重金属对水生生物生态毒理效应的未来研究重点和方向。     

Heavy metals accumulation in tree leaves from urban areas

Higher plants may be used as biomonitors for the assessment of atmospheric heavy metal pollution by means of their bioaccumulative properties. We evaluated the reliability of biomonitoring heavy metal pollution by horse chestnut and linden leaves, common species found in Belgrade city parks. The results show that the highest concentrations of heavy metals were found in horse chestnut leaves at Studentski Park site, amounting to 110.2, 20.3 and 4.9 g g^–1 dry weight for Cu, Pb and Cd, respectively, which are considered above toxic levels for plants.Selected article from the Regional Symposium on Chemistry and Environment, Krusevac, Serbia, June 2003, organised by Dr. Branimir Jovancicevic.     

土壤重金属污染对丛枝菌根真菌产孢量的影响

以沈阳附近重金属矿区自然和农田土壤为研究对象，对土壤重金属含量、植物类型、AMF种群及孢子密度进行了调查，并对污染的农田、荒地土壤进行了比较．结果表明：调查污染区土壤中球囊霉属为优势类群，无梗囊霉属为少见类群，盾巨孢囊霉属为偶见类群，无梗囊霉属和盾巨孢囊霉属对重金属污染特别是铜污染较为敏感；丛枝菌根真菌重金属污染土壤中分布广泛．在综合污染指数达到28．03的严重污染土壤中仍能生存，其孢子密度在不同污染程度的土壤中变异很大，轻、中度污染土壤中较高，随重金属污染程度的增加而锐减；矿区重金属污染土壤中土壤污染程度、土壤pH值、土壤利用情况及宿主植物都影响AMF产孢．图4表4参32     

利用废弃物煅烧水泥时重金属Pb、Cd的逸放污染

利用废弃物作为代替原料煅烧水泥已广泛应用于水泥生产,但其带来的环境污染问题不容忽视。以利用废弃物生产水泥的厂家为研究对象,采用原子吸收分光光度法检测所采集样品中重金属Pb、Cd的含量,对水泥生产过程中重金属Pb、Cd的逸放及其对周围土壤的污染进行研究。研究结果表明:利用废弃物煅烧水泥的过程中,重金属Pb、Cd的逸放率很高,其中立窑的Pb、Cd逸放率高达84%～90%,湿法回转窑的Pb、Cd逸放率达到63%～74%;在水泥厂上下风向500m、1000m和2000m处采集土壤样品,工厂周围的土壤均已受到不同程度的重金属污染,位于工厂下风向的土壤受到的污染更为严重,距离工厂500m处土壤中重金属Pb、Cd的含量均超过了国家标准的最大限量;对几家工厂员工的头发进行随机取样,头发样品中Pb含量均超过正常限量。     

利用废弃物煅烧水泥时重金属Pb、Cd的逸放污染

利用废弃物作为代替原料煅烧水泥已广泛应用于水泥生产,但其带来的环境污染问题不容忽视。以利用废弃物生产水泥的厂家为研究对象,采用原子吸收分光光度法检测所采集样品中重金属Pb、Cd的含量,对水泥生产过程中重金属Pb、Cd的逸放及其对周围土壤的污染进行研究。研究结果表明：利用废弃物煅烧水泥的过程中,重金属Pb、Cd的逸放率很高,其中立窑的Pb、Cd逸放率高达84％～90％。湿法回转窑的Pb、Cd逸放率达到63％～74％;在水泥厂上下风向500m、1000m和2000m处采集土壤样品,工厂周围的土壤均已受到不同程度的重金属污染,位于工厂下风向的土壤受到的污染更为严重,距离工厂500m处土壤中重金属Pb、Cd的含量均超过了国家标准的最大限量;对几家工厂员工的头发进行随机取样,头发样品中Pb含量均超过正常限量：     

Research of usability of tree leaves and soil in determining the contribution of industry and traffic to air pollution in Bozüyük (Turkey) region

In industrialized regions like Bozüyük, generally density of settlement and traffic is also observed. As a result of this density, the metal pollution that results from either industrial activities or traffic shall affect the air quality negatively. In determining this effect and sources thereof inspection of the depositing of heavy metals, which cause pollution, on the tree leaves and in the soil, and making comments by comparing with the values in the same kinds of plants and soil in the clean region has been aimed. For this purpose, zinc, copper, chromium, cadmium, iron, nickel, lead analysis have been carried out in order to determine the accumulation of pollution in plants and soils resulting from heavy industry and vehicles around Bozüyük (Turkey) region which is close to highway. These analyses have been carried out on washed and unwashed tree leave samples and surface soil from ten locations. Data used in the results were the average values of a series of data obtained from the experimental studies.     

铅迫胁下黄瓜幼苗期叶片内源激素的变化

土壤中的重金属污染会对植物造成伤害,在细胞内重金属离子会通过不同途径干扰和破坏细胞的正常代谢。植物激素能调节和控制植物的生长和发育。以黄瓜(Cucumis sativus L.)为材料,通过人工模拟重金属污染环境,对不同质量浓度铅胁迫下黄瓜幼苗的叶片,采用高效液相色谱法进行生长素(IAA)、细胞分裂素(Z)、赤霉素(GA3)、脱落酸(ABA)的分离、纯化和测定。探讨重金属污染对植物内源激素水平方面的变化的影响,进一步了解重金属污染对植物产生伤害的机制及抵御胁迫所发生的变化,从而采取有效措施解决重金属污染的问题。结果发现:所测的几种激素均表现出明显的变化规律:GA3、ABA升高,IAA、Z含量先上升后下降;同时经比较分析得出,随着铅质量浓度的增大,IAA/ABA、Z/ABA及GA3/ABA之比下降,Z/IAA升高。结果表明黄瓜幼苗期抵抗重金属污染的能力与内源激素水平及内源激素平衡有关。     

Correlation between levels of some heavy metals in plants and sediments from a segment of Calabar River and associated creeks in Cross River state of Nigeria

Plants and sediments were collected at three sites along Calabar River (CR), Upper Town Creek (UCC) and Lower Town Creek (LCC). The CR is a major tributary of Cross River, Nigeria. The concentrations of 10 heavy metals were determined and results for Fe, Mn and Zn at almost all the sites showed that the levels of these metals exceeded the amounts present in non-polluted areas. Fe was found in the highest concentration at all three sites in both plants and sediments. Correlation analysis between levels of heavy metals in plants and sediments were also determined. The occurrence of higher concentrations of heavy metals in plants and coastal sediments at CR, UCC and LCC is an indication of anthropogenically induced pollution rather than contributions from natural sources.     

矿区周围土壤中重金属危害性评估研究

分别用总量法和连续萃取法对广东大宝山矿周围土壤、植物和沉积物中重金属的总量和化学形态进行了详细分析。结果发现，矿山废水流入的横石河沉积物中Pb、Zn、Cu和Cd的质量分数分别为1841．02、2326．28、1522．61和10.33mg／kg；经此河水灌溉的稻田中重金属(Cu、Cd、Pb和Zn)的质量分数也远远超出了土壤环境二级标准值，其中Cu、Cd超标倍数分别为14．01和4．17倍。结果还表明，生长在矿区周围的植物也受到不同程度重金属的污染且不同植物吸收和积累重金属的能力相差很大。用Tessier连续法对土壤中重金属进行萃取发现，虽然重金属主要存在于残余态中，但在Fe-Mn氧化态、有机结合态中的质量分数也很高．说明这些土壤确实受到了有毒有害重金属元素的严重污染。     

含铅、镉重金属细颗粒物对几种陆生植物的暴露危害

大气重金属细颗粒物复合污染对陆生植物早期发育及幼苗生长的影响研究近年来成为大气科学与生态毒理学交叉领域研究的热点和难点。通过搭建合理的暴露场景,模拟严重大气污染浓度条件下,含Pb、Cd细颗粒物对黄瓜、小麦、西红柿和玉米4种受试植物出苗、幼苗生长期内茎高和鲜重等生物量的影响。结果显示,暴露处理组4种受试植物陆上部分对Cd元素的吸收增量变化范围为0~0.025 mg·kg-1;对Pb元素的吸收增量变化范围为0.020~0.292 mg·kg-1。暴露处理组4种受试植物出苗抑制率变化范围为0%~30%;茎高抑制率变化范围为-3%~14%;鲜重抑制率变化范围为-12%~3%。由此可见,在试验周期内,含Pb、Cd重金属细颗粒物复合污染对几种植物的陆上部分生物量的抑制作用不明显,甚至有积极的刺激作用。与空白对照组相比,暴露处理仅对小麦出苗抑制产生显著性差异,并显现协同效应。说明几种受试植物在现有暴露环境下,对设定浓度的污染物敏感性较低,受危害程度不大。     

SO2污染对农业害虫的间接影响

用开顶式熏气罩研究了SO2污染对粘虫、黄地老虎、小菜蛾、桃蚜、萝卜蚜和豆蚜等农业害虫的影响．结果表明，适度SO2污染显著地促进了这些昆虫的生长和／或繁殖，但高浓度SO2污染对它们有明显的不良影响，这种作用是通过食料植物间接发生的．这些昆虫对适度SO2污染的反应因种类而异：3种鳞翅目昆虫表现为幼虫的平均相对生长速率（MRGR）明显加快，成虫繁殖力变化不大；3种蚜虫主要表现为成蚜的繁殖力大幅度提高．若蚜（除豆蚜外）的MRGR也显著增加．对被处理食料植物营养成分的分析表明，SO2污染诱导的蛋氨酸相对含量变化可能是它产生这些间接影响的重要原因．     

不同来源重金属污染的土壤对水稻的影响

采用人工污染土壤、尾矿砂、污泥等不同载体的污染源来模拟土壤污染 ,研究其对水稻生长、吸收养分和吸收重金属的影响。结果表明 ,不同污染载体对水稻生长的影响不同 ,其影响的大小顺序为人工污染土壤 >尾矿砂 >污泥 >尾矿砂 +污泥。不同污染载体对水稻吸收重金属的影响亦不同 ,以纯化学试剂的形式添加到土壤中的重金属最易被提取出来 ,植物从中吸收的Cu、Zn、Pb、Cd最多 ,而从以污泥为污染载体的土壤中吸收的Zn、Pb、Cd最少。研究表明 ,用添加纯化学试剂的方法来模拟污染土壤对生态与环境的影响是可行的 ,确定土壤负载容量是安全的 ,因为在实验条件下它对供试植物的影响最明显     

湘南4个矿区稻田As污染状况的初步调查

通过实地调查以及土壤和水稻样品分析,研究了湘南郴州柿竹园铅锌矿、郴州界牌岭锡多金属矿、衡阳水口山有色金属矿、衡阳龙王山金矿4个矿区稻田的As污染状况.结果表明:4个矿区的稻田土壤和水稻植株均已受到严重的As污染.矿区稻田土壤As含量范围为30.0～225.7mg·kg-1,超过国家土壤环境质量3级标准;水稻根系、秸秆、谷壳、糙米As含量范围分别为115.6～588.2、4.19～20.88、1.388～5.374、0.214～0.892mg·kg-1,除部分糙米样品外,均超过我国食品中As限量卫生标准.矿区稻田土壤同时受到As和重金属的复合污染,综合污染指数(P)范围为0.76～13.12.矿区稻田的As污染主要由矿产的开采和冶炼造成,其中,水口山有色金属矿区和龙王山金矿区As污染以及As和重金属复合污染最为严重,柿竹园铅锌矿区污染面积较大,界牌岭锡多金属矿区由于发生过地质灾害改变了地表面貌,污染情况更为复杂.     

Sustainability of agricultural and wild cereals to aerotechnogenic exposure

In recent decades, the problem of the constantly increasin level of anthropogenic load on the environment is becoming more and more acute. Some of the most dangerous pollutants entering the environment from industrial emissions are heavy metals. These pollutants are not susceptible to biodegradation over time, which leads to their accumulation in the environment in dangerous concentrations. The purpose of this work is to study the sustainability of cultivated and wild plants of the Poaceae family to aerotechnogenic pollution in the soil. The content of heavy metals in couch grass (Elytrigia repens (L.) Nevski), meadow bluegrass (Poa pratensis L.) and soft wheat (Triticum aestivum) plants grown in the impact zone of Novocherkassk Power Station has been analyzed. Contamination of cultivated and wild cereals with Pb, Zn, Ni and Cd has been established. It has been shown that the accumulation of heavy metals is individual for each plant species. An average and close correlation have been established between the total HM content and the content of their mobile forms in the soil and their content in plants. For the plants studied, the translocation factor (TF) and the distribution coefficient (DC) of HM have been calculated. The TF is formed by the ratio of the concentration of an element in the root plant dry weight to the content of its mobile compounds in the soil. The DC value makes it possible to estimate the capacity of the aboveground parts of plants to absorb and accumulate elements under soil pollution conditions and is determined as the ratio of the metal content in the aboveground biomass to its concentration in the roots. TF and DC values have shown a significant accumulation of elements by plants from the soil, as well as their translocation from the root system to the aboveground part. It has been revealed that even within the same Poaceae family, cultural species are more sensitive to man-made pollution than wild-growing ones.

     

植物修复土壤重金属污染中外源物质的影响机制和应用研究进展

重金属进入土壤后难以被降解,并通过食物链在生物体内富集,长此以往会导致中毒、癌症、畸形、突变,严重影响了人类生产活动及地球生态系统的稳定。植物修复技术是一种经济有效的重金属污染修复技术,其依靠超富集植物强大的自身抗性机制,从土壤中提取或稳定重金属,达到污染治理的目的。然而修复土壤重金属污染的超富集植物通常生长缓慢、生物量低,其抗性机制也会受到植物本身对重金属胁迫的阈值限制,当胁迫超过这个阈值,植物修复的效率就会大大降低甚至失去修复功能。文章在解析植物重金属相互作用机制的基础上,综述了添加外源物质对重金属毒害植物的缓解效应以及其在强化植物修复土壤重金属污染中的应用研究进展;介绍了应用外源物质调控植物吸收转运重金属的3种途径,分别为提高土壤重金属生物利用度、促进植物生长以及增强植物耐性。提出了应用外源物质作为强化植物修复措施的潜力及今后的研究方向,其未来的研究应着重于以下方面:明确外源物质的应用浓度、时期、方式与植物吸收转运重金属之间的关系;从植物内源激素及信号分子间的互作、抗逆基因表达、内生及根际微生物等不同层面上揭示外源物质对植物积累重金属的调控机理;开展外源物质与其他植物修复强化技术的联合应用研究。这些研究可为土壤重金属污染的植物修复技术及其强化措施研究提供科学依据,同时也对植物修复工程技术的发展实践具有一定的指导意义。     

环草隆与重金属复合污染对黄瓜及小麦的毒性效应评估

为探究草坪除草剂与重金属复合污染对高等植物的生态毒性效应,以小麦与黄瓜为敏感受试植物,采用滤纸发芽试验法,研究了典型草坪除草剂环草隆与4种重金属(Cu/Zn/Pb/Cd)单一及复合污染条件下,对2种植物种子萌发与幼苗生长的毒性效应并进行评估。在此基础上采用评估因子法外推环草隆在土壤中的预测无效应浓度(PNECsoil)。结果表明,2种植物的根长及小麦的芽长对环草隆与重金属非常敏感(P<0.01),且存在明显的剂量-效应关系。黄瓜根长对环草隆最敏感,根长半抑制浓度(RI50)为0.281 mg·L-1。小麦根长对Cu、Pb、Cd比黄瓜根长更敏感。环草隆与重金属复合污染时,黄瓜根长表现得最为敏感,可作为敏感生物标记物。环草隆与重金属复合污染对小麦及黄瓜根长抑制具有协同作用,并且随着重金属浓度的增大,黄瓜和小麦根生长对环草隆的敏感性增加。环草隆与重金属复合污染对小麦芽长的联合效应主要与重金属种类及其暴露浓度有关。以黄瓜的根伸长抑制率为急性毒性终点,利用外推法计算得环草隆在土壤中的PNECsoil为1.90μg·kg~(-1),远远低于环草隆田间推荐使用量1.5~9 mg·kg~(-1)。与重金属复合污染时,环草隆的PNECsoil明显降低,导致其生态风险提高。上述研究结果能够为草坪除草剂环草隆与重金属复合污染的生态风险评价提供数据支持。     

Heavy metals,occurrence and toxicity for plants: a review

Metal contamination issues are becoming increasingly common in India and elsewhere, with many documented cases of metal toxicity in mining industries, foundries, smelters, coal-burning power plants and agriculture. Heavy metals, such as cadmium, copper, lead, chromium and mercury are major environmental pollutants, particularly in areas with high anthropogenic pressure. Heavy metal accumulation in soils is of concern in agricultural production due to the adverse effects on food safety and marketability, crop growth due to phytotoxicity, and environmental health of soil organisms. The influence of plants and their metabolic activities affects the geological and biological redistribution of heavy metals through pollution of the air, water and soil. This article details the range of heavy metals, their occurrence and toxicity for plants. Metal toxicity has high impact and relevance to plants and consequently it affects the ecosystem, where the plants form an integral component. Plants growing in metal-polluted sites exhibit altered metabolism, growth reduction, lower biomass production and metal accumulation. Various physiological and biochemical processes in plants are affected by metals. The contemporary investigations into toxicity and tolerance in metal-stressed plants are prompted by the growing metal pollution in the environment. A few metals, including copper, manganese, cobalt, zinc and chromium are, however, essential to plant metabolism in trace amounts. It is only when metals are present in bioavailable forms and at excessive levels, they have the potential to become toxic to plants. This review focuses mainly on zinc, cadmium, copper, mercury, chromium, lead, arsenic, cobalt, nickel, manganese and iron.     

Co-pyrolysis of sewage sludge and biomass for stabilizing heavy metals and reducing biochar toxicity: A review

The huge amounts of sewage sludge produced by municipal wastewater treatment plants induce major environmental and economical issues, calling for advanced disposal methods. Traditional methods for sewage sludge disposal increase greenhouse gas emissions and pollution. Moreover, biochar created from sewage sludge often cannot be used directly in soil applications due to elevated levels of heavy metals and other toxic compounds, which alter soil biota and earthworms. This has limited the application of sewage sludge-derived biochar as a fertilizer. Here, we review biomass and sewage sludge co-pyrolysis with a focus on the stabilization of heavy metals and toxicity reduction of the sludge-derived biochar. We observed that co-pyrolyzing sewage sludge with biomass materials reduced heavy metal concentrations and decreased the environmental risk of sludge-derived biochar by up to 93%. Biochar produced from sewage sludge and biomass co-pyrolysis could enhance the reproduction stimulation of soil biota by 20‒98%. Heavy metals immobilization and transformation are controlled by the co-feed material mixing ratio, pyrolysis temperature, and pyrolysis atmosphere.