上海市桃浦垃圾填埋场封场植被的重金属吸收和积累特征

城市垃圾填埋场的生态修复问题越来越受到重视,选择合适的封场植被对生态恢复至关重要。本研究对上海市桃浦垃圾填埋场的土壤和29种优势植物的重金属含量进行检测,结果显示,该填埋埋场土壤呈现Zn和Cd的中度复合污染。在研究的优势植物中,杨树、雪松和夹竹桃吸收Zn的能力较强,杨树、紫薇、金丝桃吸收Cd的能力较强。荆芥表现为重金属Zn的富集型植物;龙葵表现为重金属Cd的富集型植物;麦冬和狗尾巴草则表现为重金属的根部囤积型植物。可综合选择这些植物用于城市垃圾填埋场的植物修复和植被恢复。     

4种茄科植物对矿区污染土壤重金属的吸收和富集

采集了湖南及江苏8个矿区或冶炼厂周边4种茄科(Solanaceae)植物及其根际土壤,分析了植物及土壤样品中Cd、Cu、Pb、Mn和Zn 5种重金属浓度.结果表明:番茄(Lycopersicon esculentum)对5种重金属可能有着较强的耐性,但不具有超积累的潜力;刺天茄(Solanum indicum)对Mn、...     

某铅锌矿坑口周围具有重金属超积累特征植物的研究

针对目前植物修复中Cd-Pb-Cu-Zn复合污染的超富集植物缺乏研究,采用野外采样系统分析方法,对青城子铅锌矿各主要坑口周围17科31种杂草植物进行其积累特性的初步研究。结果表明,全叶马兰(Kalimeris integrifolia)、蒲公英(Taraxacum mongolicum)和鬼针草(Bidens bipinnata)3种植物地上部对Cd的富集系数均>1,且地上部Cd含量大于根部Cd含量,具备了重金属超富集植物的基本特征,进一步研究的价值很大。以杂草为对象筛选超富集植物很可能获得较大突破。     

水培翅碱蓬对重金属吸收的研究

由于人类活动以及工业化的迅速发展,滩涂湿地正在遭受前所未有的污染和破坏,其中重金属污染是主要污染问题之一。生物修复技术是近年发展起来的新型环境污染治理方法,它在去除污染的同时还具有较高的环保价值,因此受到人们的广泛关注。以中国北方滩涂湿地的优势种植物翅碱蓬(Suaeda heteroptera kitag)为研究对象,通过测定翅碱蓬体内重金属的含量,分别探讨了翅碱蓬对单一Cu、Zn、Pb、Cd及Cu和Zn、Pb和Cd混合重金属的吸收规律、翅碱蓬不同部位对Cu的积累特性。实验结果表明,翅碱蓬对Cu、Zn、Pb、Cd的最大吸收速率分别为31、101、34、62mg/(kg.d);Cu的存在,促进了翅碱蓬对Zn的吸收,翅碱蓬各部位对Cu的积累量大小为根>茎>叶。     

公路周边土壤重金属污染及植物修复

随着中国公路建设迅猛发展,公路周边土壤重金属污染也日趋严重。文中结合近年来国内外的研究情况,以公路土壤污染中的铅、镉、锌、铜、铬等元素为重点,对土壤重金属污染的危害、分布特征及其影响因素,以及相应的植物修复技术等相关研究进行综述。     

类芦对铅的耐性及富集能力探讨

通过野外调查和盆栽试验,研究了类芦(Neyraudia reynaudiana)对Pb的耐性和富集能力.研究结果表明,类芦对Pb耐受的临界浓度为800 mg/kg,在此浓度以下Pb对类芦的生长基本无抑制作用.随着处理浓度的增加,类芦生长变缓慢、出现中毒症状,但仍能存活.从富集能力来看,土壤Pb为中低浓度时,类芦的富集能力较强,但Pb浓度超过1 000 mg/kg后地上部富集量增加缓慢,而根部的含量则降低.在各种Pb处理浓度下,类芦地上部Pb含量均大于根部,说明这种植物对Pb有较好的迁移能力.研究发现,类芦具有较高的生物量,因此其地上部Pb迁移总量较高,在土壤Pb浓度为800 mg/kg时类芦地上部的迁移总量可达到221.77 mg/m2.综合分析可知,类芦对中度Pb污染土壤的植物修复具有较大的潜力.     

土壤重金属的植物污染化学研究进展

针对中国土壤重金属污染加剧的趋势,为改善土壤环境质量和保障农产品安全,提出了土壤重金属的植物污染化学研究领域.结合多年的研究工作,从土壤重金属的植物根际化学行为、土壤重金属的植物吸收与解毒机制和重金属污染土壤的植物-微生物交互作用等方面简要阐述了土壤-植物系统中重金属的分布、存在形态、迁移转化、累积及生物学效应和控制规律的研究进展,并对将来的植物污染化学理论研究提出了展望.     

重金属污染土壤植物修复及进展

土壤污染是当今面临的一个重要环境问题。常规的土壤污染物化学治理技术，如客土换土法、冲洗法、热处理、固化、玻璃化、动电修复法等，由于其技术要求高或经济成本高昂，对土壤结构的扰动破碎较严重，因而，大规模推广应用存在较大问题。重金属超累积植物的不断发现，使人们认识到有可能利用植物于土壤污染的治理修复。自20世纪90年代起，植物修复成为环境污染治理研究领域的一个前沿性课题。研究表明，通过植物的吸收、挥发、根滤、稳定等作用，可以净化土壤或水体中金属污染物，达到净化环境的目的。近10年来，在超累积植物的找寻培育、植物根际微生物共存体系研究、植物对重金属的耐忍性、超量吸收及其解毒机制以及植物修复的工艺技术方面已有不少研究，并取得长 的进展，现代分子生物学的发展以及基因工程技术的应用有可能使植物修复技术取得根本性的突破。     

硫酸盐还原菌对重金属污染土壤的处理研究

讨论了不同重金属污染物和浓度、反应时间、温度条件对硫酸盐还原菌(SRB)去除土壤中Cu2+和Cd2+的影响.结果表明:(1)SRB代谢SO2-4的能力受重金属离子抑制,当Cu2+从5 mg/L提高至10 mg/L时,SO2-4去除率从90％ 以上明显降低至59.2％,Cd2+的抑制作用更强.(2)SRB对中低强度污染土...     

能源植物皇草对重金属的耐性及修复潜力

重金属污染及生态修复是环境和生态领域研究的热点和难点。皇草是重要的纤维素生物燃料和电力植物。选用皇草作为重金属污染土壤的修复植物,探讨皇草对重金属的耐性机理和对重金属污染土壤的修复效果。结果表明：皇草的株高和干重在Ni、As、Zn、Pb处理中显著高于对照处理或者与对照处理没有显著差异,但在Cr处理中显著低于对照处理。皇草在Ni、As、Zn、Pb和低浓度Cr污染土壤均能生产大量的生物质,每季产25.55~28.51 t·hm-2鲜草和8.23~9.12 t·hm-2干草。皇草叶片中MDA和POD的含量随着Cr、Ni、As和Pb浓度的升高有所增加,但CAT和SOD的活性表现出相反的趋势。在Zn的2个浓度梯度下,皇草叶片中的CAT、POD和SOD的活性均随着Zn浓度升高而下降。从重金属在皇草各器官分布来看,Cr、As和Pb的浓度为根 > 叶 > 茎;Ni和Zn为根 > 茎 > 叶。从重金属在植物叶片中的形态来看,Cr、Ni、Zn和Pb的盐酸提取态的含量较高。从重金属在亚细胞分布来看,Cr、As和Pb在皇草叶片亚细胞组分分布为细胞质 > 细胞壁 > 细胞器,Ni和Zn在皇草叶片亚细胞组分分布为细胞器 > 细胞质 > 细胞壁。皇草对重金属的富集系数和转运系数均小于1,对重金属的提取量较低,但其耐性强、生物量大,适合应用于土壤重金属污染的植物稳定技术。     

两株镉抗性奇异变形杆菌对龙葵修复镉污染土壤的强化作用

以广东省大宝山尾矿区植物根际土壤为分离样品,人工制备镉污染LB培养基,从中分离筛选出2株具有较强镉耐受能力的细菌,分别为TL3和DBS2,最高镉耐受浓度达300mg／L。结合其形态学特征、生理生化特性及16SrDNA序列分析,初步确定2株菌均为奇异变形杆菌（Proteusmirabilis）。随后以龙葵为实验植株,分别接种TL3、DBS2及TL3与DBS2混菌的培养液,通过盆栽实验检验2株菌对龙葵吸收土壤中镉的强化作用。结果显示,2株菌对龙葵吸收镉具有显著的提升作用,且能够促进植株的生长,3个实验组龙葵根部镉含量分别比对照组（122．7mg／kg）增加了17．2％、85．6％和130．1％。     

Strategies for enhancing the phytoremediation of cadmium-contaminated agricultural soils by Solanum nigrum L

Field trials contribute practical information towards the development of phytoremediation strategies that cannot be provided by laboratory tests. We conducted field experiments utilizing the Cd hyperaccumulator plant Solanum nigrum L., on farmland contaminated with 1.91 mg kg⁻¹ Cd in the soil. Our study showed that S. nigrum has a relatively high biomass. Planting density had a significant effect on the plant biomass and thus on overall Cd accumulation. For double harvesting, an optimal cutting position influenced the amount of Cd extracted from soils. Double cropping was found to significantly increase the amount of Cd extracted by S. nigrum. Fertilizing had no significant effect on plant biomass or on the Cd remediation of the soil over the short-term period. Our study indicates that S. nigrum can accumulate Cd from soils where the concentrations are relatively low, and thus has application for use in decontamination of slightly to moderately Cd-contaminated soil.     

不同质量浓度黄莒蒲和狭叶香蒲对铜绿微囊藻的化感作用

分别采用黄菖蒲（IrispseudacorusL．）、狭叶香蒲（TyphaangustifoliaL．）和铜绿微囊藻（Microcystisaeruginosa）共生培养的实验方法研究了不同质量浓度黄菖蒲、狭叶香蒲对铜绿微囊藻的化感作用。结果表明,黄菖蒲在质量浓度大于10g／L时对初始密度为1．0×10^7ind／mL的铜绿微囊藻具有较好的抑制作用,表现为黄菖蒲质量浓度为10、20和40g／L时,第15天对铜绿微囊藻的抑制率分别为30．1％、51．8％和84．0％;狭叶香蒲在质量浓度大于20g／L时对铜绿微囊藻有明显的抑制作用,表现为狭叶香蒲质量浓度为20g／L和40g／L时,第15天对铜绿微囊藻的抑制率分别为34．2％和77．7％,实验过程中,铜绿微囊藻叶绿素a含量逐渐减少,而藻密度、SOD活性及MDA含量先增加后逐渐降低,表明经过一段时间持续地化感胁迫,黄菖蒲和狭叶香蒲可以诱导铜绿微囊藻产生氧化胁迫,导致细胞结构严重损伤和叶绿素大量分解,从而强烈抑制铜绿微囊藻的生长。     

Heavy metals uptake and its impact on the growth dynamics of the riparian shrub Ricinus communis L. along Egyptian heterogenic habitats

Environmental Science and Pollution Research - Heavy metals are well known for their toxicity and become significant environmental pollution with a continually rising technology and public outcry...     

Tolerance, uptake and removal of nitrobenzene by a newly-found remediation species Mirabilis jalapa L

The growth, photosynthesis rate, and ultrastructure of Mirabilis jalapa L. as a newly-found remediation species under stress of nitrobenzene (NB) and its uptake and removal of NB by the plants were investigated. The results showed that M. jalapa plants could endure contaminated soils by lower than 10.0 mg NB kg⁻¹ because there was no decrease in the total length of the plant roots, the maximum length of the hypocotyle, the length of the first seminal root, the height of the shoots and the dry biomass of the seedlings as well as the photosynthesis rate of the plants compared with those in the control. In particular, the growth of the plants could be significantly (P < 0.01) enhanced by 0.1 mg NB kg⁻¹ under unautoclaved and autoclaved soils. Ultrastructural observations on leaf cells of the plants found that these cells had smooth, clean and continuous cell membranes and cell walls, indicating that there was no obvious damage by NB in comparison with those in the control. Although the absorption of NB in shoots and roots of M. jalapa was weak, plant-promoted biodegradation of NB was considerable and the dominant contribution in the removal of NB from contaminated soils, suggesting the feasibility of M. jalapa applied to phytoremediation of NB contaminated soils.     

Genotypic Differences in Effects of Cadmium Exposure on Plant Growth and Contents of Cadmium and Elements in 14 Cultivars of Bai Cai

Abstract

Fourteen cultivars of bai cai (Brassica campestris L. ssp. chinensis var. communis) were grown in the nutrient solutions containing 0–0.5 μg mL^?1 of cadmium (Cd) to investigate genotypic differences in the effects of Cd exposure on the plant growth and uptake and distribution of Cd in bai cai plants. The Cd exposure significantly reduced the dry and fresh weights of roots and shoots, the dry weight ratio of shoot/root (S/R), total biomass, and chlorophyll content (SPAD value). Cd concentrations in bai cai ranged from 13.3 to 74.9 μg g^?1 DW in shoots and from 163.1 to 574.7 μg g^?1 DW in roots under Cd exposure, respectively. The considerable genotypic differences of Cd concentrations and accumulations in both shoots and roots were observed among 14 bai cai cultivars. Moreover, Cd mainly accumulated in the roots. Cd also caused the changes of uptake and distribution of nutrients in bai cai and under the influence of cadmium, the concentration of potassium (K) decreased in shoot and increased in root. However, the concentrations of magnesium (Mg), phosphorus (P), manganese (Mn), boron (B), and iron (Fe) increased in shoots and decreased in roots. In addition, Cd exposure resulted in an increase in calcium (Ca), sulphur (S), and zinc (Zn) concentrations in both shoots and roots but had no significant effects on the whole uptake of the examined mineral nutrients except for S.     

Analysis and characterization of cultivable heavy metal-resistant bacterial endophytes isolated from Cd-hyperaccumulator Solanum nigrum L. and their potential use for phytoremediation

This study investigates the heavy metal-resistant bacterial endophytes of Cd-hyperaccumulator Solanum nigrum L. grown on a mine tailing by using cultivation-dependent technique. Thirty Cd-tolerant bacterial endophytes were isolated from roots, stems, and leaves of S. nigrum L. and classified by amplified ribosomal DNA-restriction analysis into 18 different types. Phylogenetic analysis based on 16S rDNA sequences showed that these isolates belonged to four groups: Actinobacteria (43%), Proteobacteria (23%), Bacteroidetes (27%) and Firmicutes (7%). All the isolates were then characterized for their plant growth promoting traits as well as their resistances to different heavy metals; and the actual plant growth promotion and colonization ability were also assessed. Four isolates were re-introduced into S. nigrum L. under Cd stress and resulted in Cd phytotoxicity decrease, as dry weights of roots increased from 55% to 143% and dry weights of above-ground from 64% to 100% compared to the uninoculated ones. The total Cd accumulation of inoculated plants increased from 66% to 135% (roots) and from 22% to 64% (above-ground) compared to the uninoculated ones. Our research suggests that bacterial endophytes are a most promising resource and may be the excellent candidates of bio-inoculants for enhancing the phytoremediation efficiency.     

Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site

This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly α-, β-, γ- and δ-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The β-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil → root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil → air → shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles → shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere.     

Dissipation of pendimethalin in the soil of field pea (Pisum sativum L.) and detection of terminal residues in plants

Dissipation of pendimethalin in the soil of field peas (Pisum sativum L.) at 0 to 110 days, and terminal residues in green and mature pea were studied under field conditions. Pendimethalin was applied as pre-emergence herbicide at 750, to 185 g a.i. ha^?1 in winter, in field peas. Dissipation of pendimethalin in the soil at 0 to 110 days followed first-order kinetics showing a half-life of 19.83 days averaged over all doses. Low pendimethalin residues were found in mature pea grain (0.004, 0.003, <0.001 μg g^?1), and straw (0.007, 0.002, <0.001 μg g^?1) at 750, 350 and 185 g a.i. ha^?1 treatments, respectively. The study indicated that residues of pendimethalin in green and mature pea were within the prescribed MRL limits.