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1.
螯合剂对大叶井口边草Pb、Cd、As吸收性影响研究   总被引:5,自引:0,他引:5  
用室内土培试验方法,研究在采自田间的Pb、Cd、As、Zn和Cu复合污染土壤上种植大叶井口边草条件下,外源分别添加0、1.5、3、6、12 mmol/kg乙二胺二琥珀酸(EDDS)、氨三乙酸(NTA)和乙二胺四乙酸(EDTA)对大叶井口边草吸收Pb、Cd和As的影响。结果表明,3种螯合剂处理对大叶井口边草生物量没有显著影响,说明大叶井口边草对3种螯合剂耐性较强;6、12 mmol/kg EDTA处理能极显著提高土壤Pb有效态浓度,进而促进大叶井口边草对Pb的吸收。大叶井口边草地上部Pb吸收量最高达(47.4 ± 1.7)mg/kg,是对照的3.66倍。6、12 mmol/kg EDTA处理能极显著地提高土壤中Cd的有效性,但未促进大叶井口边草地上部对Cd吸收。6 mmol/kg EDDS和3 mmol/kg NTA显著提高了土壤中As有效态浓度,进而提高大叶井口边草地上部对As的吸收,大叶井口边草地上部吸收As最高达(276 ± 10) mg/kg。6 mmol/kg EDTA和6 mmol/kg EDDS处理下大叶井口边草提取的Pb、As量最大,分别为(317 ± 53) μg/盆和(873 ± 41)μg/盆,说明6 mmol/kg EDDS处理下大叶井口边草对复合污染土壤中As的修复具有较大的潜力。  相似文献   

2.
Chelating agents are commonly used to enhance the phytoremediative ability of plants. The type of chelating agent applied and the selection of plant species are important factors to consider for successful phytoremediation. This study investigates the effects of four different rates (0, 2, 4, 8 mmol kg?1) of ethylenediaminetetraacetic acid (EDTA) on lead (Pb) dissolution, plant growth, and the ability of two spring wheat varieties (Auqab-2000 and Inqalab-91) to accumulate Pb from contaminated soils in a pot study. The results indicated that the addition of EDTA to the soil significantly increased the aqueous solubility of Pb and that wheat variety Inqalab-91 was more tolerant to Pb than Auqab-2000. Application of EDTA at 8 mmol kg?1 resulted in biomass yield, photosynthetic rate, and transpiration rate significantly lower in Auqab-2000 than in Inqalab-91. Although EDTA enhanced the uptake of Pb by both wheat varieties, Auqab-2000 accumulated significantly more Pb in the shoots than Inqalab-91. The results of the present study suggest that under the conditions used in this experiment, EDTA at the highest dose was the best amendment for enhanced phytoextraction of Pb using wheat. High concentrations of Pb were found in leachates collected from the bottom of columns treated with EDTA. Application of EDTA in the column leaching experiment increased the concentration of Pb in leachate with increasing EDTA dosage (0–8 mmol kg?1). These results suggest that EDTA addition for enhancing soil cleanup must be designed properly to minimize the uncontrolled release of metals from soils into groundwater.  相似文献   

3.
重金属超富集植物是重金属污染土壤植物修复的基础,研究了3种重金属富集植物羽叶鬼针草、美洲商陆和紫叶芥菜对重金属Cd的吸收积累规律,为植物修复Cd污染的农田和生态环境建设提供科学依据。采用盆栽方法,在不同浓度(0、20、35、50、65、80mg·kg^-1)Cd处理下,分别测定3种植物地上部与根部Cd的含量,计算了地上部Cd迁移量、根系耐性指数、富集系数,研究了土壤中Cd添加量与植物富集Cd量的相关性。结果表明,随着土壤中Cd离子浓度的升高,3种植物地上部和根系中的Cd含量也在增加,相关系数都大于0.99;综合地上部与根部Cd含量,地上部Cd迁移量,根系耐性指数和富集系数,3种植物对Cd的富集能力的相对顺序为:羽叶鬼针草〉美洲商陆〉紫叶芥菜。羽叶鬼针草、美洲商陆种植在Cd处理浓度为65mg·kg^-1的土壤中和紫叶芥菜种植在Cd处理浓度为80mg·kg^-1的土壤中栽培时,3种植物地上部与根部的Cd含量均超过了100mg·kg^-1,达到了Cd超富集量的标准。羽叶鬼针草、美洲商陆和紫叶芥菜对Cd有很强的耐受性和富集性,可以作为先锋植物去修复被Cd污染的土壤。  相似文献   

4.
Cadmium and arsenic are two of the most important and toxic pollutants ubiquitous in the environment. The occurrence of numerous polluted areas as the affected by the accident of Aznalcóllar pyrite mine has promoted the employment of the phytoremediation as a feasible technology able to control and reduce the risk of this contamination at low cost. White lupin plant is proposed as a candidate for phytoremediation. This work aims to study if it is possible to use white lupin in phytoremediation of soils affected by acid pyrite sludge, with simultaneous As and Cd pollution. Pot and field experiments with sludge-affected soil were carried out. The pot trial showed that the NTA treatment increased Cd and As concentrations in lixiviates, exceeding the maximum permissible levels, so that its use in field experiments was avoided. In the field experiment, phytoextraction of Cd and As by lupin plants was very low, suggesting that it was not recommended for phytoextraction. However, lupin culture in the field produced several benefits as: increase of acid soil pH probably by citrate excretion, decrease in soluble As and Cd fractions in soil, high concentration of As and Cd in roots with accumulation of heavy metals in root nodules. All these results support the use of Lupinus albus for phytostabilization and revegetation of the spill polluted soils.  相似文献   

5.
Owing to their potential advantages such as waste reduction, recycling, and economic attributes, fast-growing bioenergy crops have the capacity to effectively phytoremediate heavy metal-contaminated soils. However, little is known about the role of microbial and chemical amendments in phytoremediation using bioenergy crops. Here, we studied the contributions of inoculation with the arbuscular mycorrhizal fungus (AMF) Acaulospora mellea ZZ and three soil amendments, i.e., hydroxyapatite (HAP), manure, and biochar, at doses of 0.1% and 1% (weight:weight) to heavy metal phytoremediation using sweet sorghum grown on an abandoned agricultural soil, with environmentally realistic contamination (2.6 mg kg-1 Cd, 1 796 mg kg-1 Pb, and 1 603 mg kg-1 Zn), in a plant growth chamber. Mycorrhizal colonization, plant biomass and metal accumulation, metal availability, and soil pH were determined in harvested seedlings 12 weeks after sowing. The results showed that root colonization by indigenous AMF decreased by 28%-46% with HAP, but increased after manure and biochar applications as compared to the no amendment control (CK). The AMF inoculation increased root colonization rates by 16%-128% and in particular, alleviated the inhibition of HAP. The remediation effects were highly dependent on the amendment type and dose. Among the three soil amendments, HAP was the most effective in promoting plant growth and phytostabilization of Cd, Pb, and Zn and phytoextraction of Cd, particularly at a dose of 1%. Compared to CK, 1% HAP decreased DTPA-extractable Cd, Pb, and Zn concentrations in soil by 31%-43%, 30%-38%, and 22%-23%, respectively. Manure and biochar also exerted positive effects on heavy metal immobilization, as indicated by lower DTPA extractability, but only the 1% manure treatment showed plant growth-promoting effect. The AMF inoculation did not affect plant growth, but increased soil pH and induced synergistic interactions with amendments on the immobilization of Cd and Pb. In conclusion, soil amendments, particularly HAP, produced positive impacts and synergistic interactions with AMF on the phytostabilization of heavy metals using sweet sorghum. Accordingly, sweet sorghum combined with soil amendments and AMF may be an effective strategy for heavy metal phytoremediation.  相似文献   

6.
用室内土培试验方法,在采自田间的Pb、Cd和As复合污染土壤中单作或间作龙葵和大叶井口边草条件下,筛选出修复Pb-Cd-As复合污染土壤较好的种植方式为间作。进一步在间作方式下,研究了外源添加不同浓度EDDS(乙二胺二琥珀酸)、NTA(氨三乙酸)和EDTA(乙二胺四乙酸)对植物吸收Pb、Cd和As的影响。结果表明,间作显著促进了龙葵地上部对Cd的吸收量和大叶井口边草地上部对As的吸收量,间作龙葵地上部吸收Cd和大叶井口边草地上部吸收As含量分别是单作龙葵和大叶井口边草的1.3倍和1.4倍,说明间作龙葵和大叶井口边草比单作更有利于修复Pb-Cd-As复合污染土壤。间作条件下,大叶井口边草对螯合剂的耐性比龙葵更强。3、6、12mmol.kg-1EDTA能极显著增加土壤中Pb、Cd有效态含量,从而促进龙葵地上部对Pb吸收和大叶井口边草地上部对Pb、Cd吸收。EDTA比NTA具有更强的提高土壤Pb、Cd有效态的能力,但对土壤As有效态促进作用与EDTA相比,NTA效果极显著,1.5、3mmol.kg-1NTA处理极显著提高土壤As有效态含量及促进龙葵和大叶井口边草地上部对As吸收。  相似文献   

7.
以雄安新区安新县重金属污染农田土壤为供试土壤,以Cd超积累植物红叶菾菜(Beta vulgaris var. cicla L.)为供试植物,设置不同浓度EDTA和柠檬酸(0,2.5,5,7.5,10 mmol kg?1)处理进行盆栽试验,探究螯合诱导-红叶菾菜修复Cd、Pb污染土壤的可行性。结果表明:(1)与对照相比,添加EDTA螯合剂使红叶菾菜生长及生物量均受到抑制,一定浓度柠檬酸处理能显著促进植物生长,5 mmol kg?1柠檬酸处理对植物株高、茎粗及生物量与对照相比的上升比例分别为4.52%、44.07%和50%;(2)添加EDTA螯合剂后土壤中Cd、Pb有效态含量相比对照分别提高了108.61% ~ 235.39%、67.98% ~ 224.16%,柠檬酸处理后土壤Cd、Pb有效态含量最大提高了180.07%、186.01%,EDTA对土壤重金属的活化效率显著高于柠檬酸;(3)通过对红叶菾菜地上部Cd、Pb含量及富集系数比较发现,EDTA更能促进红叶菾菜对Pb的吸收,柠檬酸更能促进红叶菾菜对Cd的吸收;(4)螯合剂处理后土壤中铵态氮、有效磷、速效钾含量显著增加。就本文试验条件、供试材料而言,螯合诱导-红叶菾菜修复铅镉复合污染土壤是可行的。  相似文献   

8.
铅镉高污染土壤的钝化材料筛选及其修复效果初探   总被引:8,自引:1,他引:7       下载免费PDF全文
郝金才  李柱  吴龙华  倪才英  骆永明 《土壤》2019,51(4):752-759
本研究以重金属高污染农田土壤(全Pb含量为1 277 mg/kg,全Cd含量为39.0 mg/kg)为研究对象,通过土培试验和玉米苗期盆栽试验,探讨海泡石、石灰、腐植酸、钙镁磷肥、磷矿粉、生物质炭等常用稳定材料不同剂量及复配组合对高污染土壤重金属的钝化修复效应。土培试验结果表明,石灰对Pb和Cd钝化效果最好,其次是海泡石,但两者表现为较高添加量处理间没有显著差异;而低剂量生物质炭和腐植酸显著增加土壤有效态Pb和Cd含量,高剂量生物质炭具有较好的钝化效果。盆栽试验表明,海泡石与石灰配施钝化效果较好,与对照相比,土壤氯化钙提取态Pb、Cd含量分别降低了97.5%、81.4%;玉米根和地上部Cd含量分别降低48.5%、34.0%,Pb含量分别降低35.6%、29.6%;但海泡石与磷材料配施显著增加玉米根Pb含量,对玉米Cd吸收没有显著影响。以上结果表明,重金属高污染农田土壤添加合适的改良剂,可较大幅度降低土壤重金属有效性和植物重金属吸收性。  相似文献   

9.
Laboratory batch and greenhouse pot experiments were conducted to determine the extraction efficiency of ethylenediaminetetraacetic acid (EDTA) for solubilizing lead (Pb) and cadmium (Cd) and to explore the natural and chemically induced Pb and Cd phytoextraction efficiencies of spinach and mustard after EDTA application. The EDTA was applied at 0, 1.25, 2.5, and 5.0 mM kg?1 soil in three replicates. Addition of EDTA increased significantly the soluble fraction Pb and Cd over the control and maximum increases for Pb (1.42- and 1.96-fold) and Cd (1.45- and 1.38-fold) were observed with the addition of 5.0 mM EDTA kg?1 in Gujranwala and Pacca soils, respectively. Similarly, addition of EDTA increased significantly the Pb and Cd concentrations in the plant shoots, soil solution, bioconcentration factor, and phytoextraction rate. Mustard exhibited better results than spinach when extracting Pb and Cd from both contaminated soils.  相似文献   

10.
刈割对六种牧草吸收重金属和修复污染土壤潜力的研究   总被引:1,自引:0,他引:1  
The pollution of soils by heavy metals has dramatically increased in recent decades. Phytoextraction is a technology that extracts elements from polluted soils using hyperaccumulator plants. The selection of appropriate plant materials is an important factor for successful phytoextraction in field. A field study was conducted to compare the efficiency of six high-biomass forage species in their phytoextraction of heavy metals (Cd, Pb and Zn) from contaminated soil under two harvesting strategies (double harvesting or single harvesting). Among the tested plants, amaranth accumulated the greatest amounts of Cd and Zn, whereas Rumex K-1 had the highest amount of Pb in the shoot under both double and single harvesting. Furthermore, double harvesting significantly increased the shoot biomass of amaranth, sweet sorghum and sudangrass and resulted in higher heavy metal contents in the shoot. Under double harvesting, the total amounts of extracted Cd, Pb and Zn (i.e., in the first plus second crops) for amaranth were 945, 2 650 and 12 400 g ha-1, respectively, the highest recorded among the six plant species. These results indicate that amaranth has great potential for the phytoextraction of Cd from contaminated soils. In addition, the double harvesting method is likely to increase phytoextraction efficiency in practice.  相似文献   

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