金华地区11种杂草对4种重金属的吸收与富集作用研究

定量测定了分布于浙江师大校园（地处金华）及金华某冶炼厂的 11种杂草对 4种重金属的吸收与富集能力。结果表明，对 Cu吸收和富集能力较强的有早熟禾（ Poa annua）、裸柱菊（ Soliva anthemifolia）、北美独行菜 (Lepidium virginicum)、北美鬼针草（ Bidens frondosa）；对 Cd富集能力较强的是北美车前 (Plantago virginica)、早熟禾、裸柱菊和蚊母草（ Veronica peregrina）；对 Pb的吸收富集能力以早熟禾、蚊母草和裸柱菊等为强；对 Cr吸收富集能力较强的是蚊母草、早熟禾和北美车前。     

Response of microbial communities to phytoremediation of nickel contaminated soils

Through pot experiment, effects of phytoremediation on microbial communities in soils at different nickel treatment levels were studied. Two Ni hyperaccumulating and one Ni tolerant species were planted in paddy soils different in Ni concentration, ranging from 100 to 1 600 mg/kg. After 110 days of incubation, soil microbial activities were analyzed. Results showed that populations of bacteria, fungus, and actinomycetes and biomass of the microorganisms were stimulated when nickel was added at a rate of 100 mg/kg in non-rhizospheric soil. When the rate was over 100 mg/kg in the soil, adverse effects on the soil microbial communities were observed. The plantation of Ni hyperaccumulating species could increase both the population and biomass of soil microorganisms, because, by absorbing nickel from the soil and excreting root exudates, the plants reduced nickel toxicity and improved the living environment of the microbes. However, different plant species had different effects on microorganisms in soil. Randomly Amplified Polymorphic DNA (RAPD) with five primers was used in this study in 25 soil samples of four types of soils. A total of 947 amplified bands were obtained, including 888 polymorphic bands and 59 non-polymorphic bands. The results indicated that the composition of microbial DNA sequences had changed because of the addition of nickel to the treated soils. Shannon-Weaver index of soil microbial DNA sequences reduced in the nickel contaminated soils with increasing nickel concentration. The changes in Shannon-Weaver index in the four types of soils ranged from 1.65 to 2.32 for Alyssum corsicum, 1.37 to 2.27 for Alyssum murale, 1.37 to 1.96 for Brassica juncea, and 1.19 to 1.85 for nonrhizospheric soil. With the same amount of nickel added to soils, the Shannon-Weaver index in rhizospheric soil with plants was higher than that in non-rhizospheric soil. Translated from Acta Pedologica Sinica, 2006, 43(6): 919–925 [译自: 土壤学报]     

植物清除环境污染物的策略及应用

综述了无机污染物和有机污染物的植物修复策略及应用。指出植物具有许多内在的遗传和生化生理特性,利用植物抽提、隔离、解除污染物毒性来清除土壤和水体环境污染物已取得明显进展,相对于机械去污法,植物修复已被广泛地认为是一种生态可靠的替代方法。     

氮肥形态和螯合剂对印度芥菜和高积累镉油菜吸收镉的影响

用Cd污染的土壤做盆栽试验，研究了氮肥形态和螯合剂对印度芥菜和高积累Cd油菜吸收Cd的影响。结果表明，生长后期浇入EDTA可增加植株地上部的吸Cd量和对土壤的净化率，而浇入柠檬酸的作用相反。在施氮量相同的条件下，施用不同形态氮肥对印度芥菜和油菜川油Ⅱ-10地上部和根吸Cd量有显著影响，施用硫酸铵的处理印度芥菜和高积累Cd油菜吸Cd量高于施用硝酸铵和硝酸钙的处理。     

黑麦草对复合污染河道疏浚底泥修复的研究

采用室温盆栽试验,研究了黑麦草(LoliummultiflorumLam)对排污河道疏浚底泥中的重金属(Zn、Pb、Cu、Cd、Ni)-有机物复合污染的修复情况。结果表明,第2次收获(剪切)的黑麦草地上部分积累的重金属Zn、Pb、Cu、Cd的数量均小于第1次收获(剪切),且第2次连根收获发现黑麦草的根部积累了大量的重金属;两次收获地上部分积累的重金属数量和重金属的离子交换态数量有很好的相关性,而与底泥中重金属总量的相关性较差;种植黑麦草后的底泥中重金属的存在形态和晶格结构发生了变化。黑麦草对底泥中的有机污染物有很好的修复作用;在两次收获后的底泥中的有机污染物的降解率达到72.6%,大部分有机物被炭化为CO2和H2O,其中部分难降解的大分子量有机污染物也被植物降解为小分子量的易于被植物吸收的形态,种植黑麦草后底泥的多酚氧化酶和脲酶活性均得到提高。证明黑麦草是修复重金属-有机物复合污染的良好植株。     

Heavy‐metal displacement in chelate‐treated soil with sludge during phytoremediation

Heavy metals (HMs) in domestic sewage sludge, applied to land, contaminate soils. Phytoremediation is the use of plants to clean‐up toxic HMs from soil. Chelating agents are added to soil to solubilize the metals for enhanced uptake. Yet no studies report the displacement of HMs in soil with sludge following solubilization with chelates. The objective of this work was to determine the uptake or leaching of HMs due to a chelate added to a soil from a sludge farm that had received sludge for 25 y. The soil was placed in long columns (105 cm long; ?? 39 cm) in a greenhouse. Columns either had a plant (hybrid poplar; Populus deltoides Marsh. × P. nigra L.) or no plant. After the poplar seedlings had grown for 144 d, the tetrasodium salt of the chelating agent EDTA was irrigated onto the surface of the soil at a rate of 1 g per kg of soil. Drainage water, soil, and plants were analyzed for three toxic HMs (Cd, Ni, Pb) and four essential HMs (Cu, Fe, Mn, Zn). At harvest, extractable and total concentrations of each HM in the soil with EDTA were similar to those in soil without EDTA. The chelate did not affect the concentrations of HMs in the roots or leaves. With or without plants, EDTA mobilized all seven HMs and increased their concentrations in drainage water. Lower concentrations of Cd, Cu, Fe, Ni, and Zn in leachate from columns with EDTA and plants compared to columns with EDTA and no plants showed that poplars can reduce groundwater contamination by intercepting these HMs in the soil. But the poplar plants did not reduce Pb and Mn in the leachate from columns with EDTA. Concentrations of Cd and Pb in the leachate mobilized by EDTA remained above drinking‐water standards with or without plants. The results showed that a chelate (EDTA) should not be added to a soil at a sludge farm to enhance phytoremediation. The chelate mobilized HMs that leached to drainage water and contaminated it.     

向日葵幼苗对Pb、Cu富集能力与耐受性研究

采用室内培养技术研究了向日葵幼苗对Cu、Pb的富集能力与耐受性。结果表明：向日葵幼苗对Pb、Cu具有很强的富集能力,根是主要的富集器官,Cu由根向茎叶运输能力大于Pb。低浓度Pb、Cu刺激了幼苗营养生长;在高浓度条件下,除Pb组外,其它处理均抑制向日葵幼苗的营养生长。Pb、Cu抑制了幼苗根系活力,刺激了幼苗茎叶脯氨酸的生成,改变幼苗茎叶、根蛋白质含量分配水平。Pb与Cu交互作用对幼苗营养生长和生理生化反应具有协同作用。向日葵属于重金属富集植物,对Pb具有很强的耐受性,可以用于修复被Pb污染的土壤。     

镉在两种菊芋品种中的吸收与转移特性研究

Jerusalem artichoke(Helianthus tuberosus L.) not just can be used for bioethanol production but may be potentially used in phytoremediation for the removal of heavy metal pollutants.Two Jerusalem artichoke cultivars,N2 and N5,were subjected to six cadmium(Cd) concentrations(0,5,25,50,100 and 200 mg L1) to investigate Cd tolerance and accumulation.After 21 days of growth,the effects of Cd on growth,chlorophyll content,net photosynthetic rate,intercellular CO2 concentration and malondialdehyde content were evaluated.Most growth parameters were reduced under Cd stress.The two Jerusalem artichoke cultivars had relatively high Cd tolerance and accumulation capacity(> 100 mg kg1),with N5 being more tolerant and having higher Cd accumulation than N2.Roots accumulated more Cd than stems and leaves.The bioconcentration factors(far higher than 1) and translocation factors(lower than 1) decreased with an increase in Cd applied.The results suggested that Jerusalem artichoke could be grown at relatively high Cd loads,and N5 could be an excellent candidate for phytoremediation of Cd-contaminated soils.     

紫湖溪流域重金属污染风险与植物富集特征

土壤重金属污染已成为当今农业与环境领域关注的热点。为揭示紫湖溪流域重金属(As、Cd、Cr、Cu、Mn、Ni、Pb和Zn)污染状况,该研究测定与分析了紫湖溪水体、河底淤泥和河岸土壤以及9种河岸植物的重金属含量,利用污染指数法系统评估其污染状况,进而筛选出具有富集与修复重金属污染潜力的植物。结果表明,紫湖溪水体中Cd与Mn严重超标;河底淤泥中Cd、Zn和Cu污染严重,重金属潜在生态风险:ZnCdCuPbAsNiCrMn;河岸土壤受污水与底泥泛滥影响,土壤重金属间呈显著正相关性,其中,Cd、Zn和Cu重度污染;9种优势植物对重金属的选择性吸收导致其对Cd、Cr和Pb的富集系数(BCF,bioconcentration factor)偏低,转移系数(TF,translocation factor)均小于1,表现出根部囤积型特征。早熟禾、灰绿藜和枸杞对重金属的吸收具有抵抗性,湿地生态型植物水花生与猫爪草对富集重金属具有独特优势,构树对多种重金属较强的富集与转移能力暗示了该木本植物在重金属修复技术领域的巨大应用前景。