No description available.

No description available.

As human populations grow worldwide, there is an increasing need to address the problems associated with the creation and disposal of wastes. Although a variety of recent technologies have been shown to be somewhat effective in the remediation of metal contaminated soils, e.g., chemical extraction and stabilization, they are often expensive and labor-intensive. Additionally, these technologies can impart detrimental effects on the chemical and physical properties of the soil under treatment. As an alternative, the less expensive, more environmentally benign use of green plants as tools for the remediation of contaminated soils (phytoremediation) has been studied in recent years.The reported research activities studied the ability of a variety of green plants to extract lead (Pb), cadmium (Ca) and barium (Ba) from metal contaminated soil. Additionally, the researcher studied the degree to which the addition of the synthetic chelate diethylenetriaminepentaacetate (DTPA) and dilute HNO3 affected: the phytoextraction of metals from contaminated soil; the translocation of these metals within study plants; and the effects that the treatments had on biomolecule production in Zea mays, Glycine max, Brassica juncea and Helianthus annuus. A growth chamber study was also conducted to determine if several species of green plants (Ipomoea leptophylla, Lycopersicon esculentum, Capsicum annuum and Tagetes minuta) were capable of hyperaccumulating any of the metals present in the contaminated soil. Additionally, a leachate study was performed to determine the effects that DTPA and HNO3 had on soil Pb mobility rates.Samples were analyzed for Pb, Ca and Ba using FAAS and the data were further analyzed to determine universal measures of variance. While no plants showed overall significant (p=0.05) differences with regard to both treatment and plant part, all species were capable of both accumulating and distributing Pb from the contaminated soil; no plants were able to extract Ba from the soil; some plants extracted trace amounts of Cd in various plant parts. Significant (p=0.05) differences were measured in chlorophyll a, chlorophyll b and carotenoid concentrations with regard to both plant and treatment. Results from the Pb mobility study showed significant (p=0.01) differences in Pb mobility with regard to both treatment and time. / Department of Natural Resources and Environmental Management

No description available.

Phytoremediation, i.e., the use of plants to clean up contaminated soil, may serve as a feasible alternative if a high-biomass crop can be found that accumulates metals to a high.degree. Two plant species, corn (Zea mays) and Indian mustard (Brassica juncea), were grown in soil from a Superfund site contaminated with Pb and Cd (PbTota, = 65,200 mg/kg and CdTotI = 52 mglkg) over two croppings. Soil treatments consisted of composted sewage sludge (CSS), ethylenediaminetetraacetic acid (EDTA), and sodium citrate at two concentrations. In most cases, the EDTA and citrate treatments were superior in terms of extracting soil Pb into root tissue, and translocation of Pb into aboveground biomass. The CSS treatment typically resulted in the lowest Pb removal efficiencies. The high pH (7.4) and high exchange capacity of the CSS may have immobilized soil Pb. Soil Cd was generally more mobile than soil Pb. The EDTA2 treatment was most effective in removing soil Pb into roots, and translocation to shoots. Lead remaining in the soil after two croppings was mainly associated with the carbonate, organic, and residual fractions, which represent the less bioavailable form of this metal. / Department of Natural Resources and Environmental Management

There is an ever-increasing need to address problems associated with the creation and disposal of wastes which result from human activities. Pb and Cd contamination is a common problem at many abandoned and uncontrolled commercial and industrial sites. Phytoremediation is one technology that can be employed to remove metals such as Pb from the soil. This study investigated the effectiveness of several plant and soil treatments on the uptake and retention of Pb and Cd by vegetation from contaminated soil at a Superfund site. Field plots were established and plant treatments included a mixture of grasses including Festuca, Poa. and Phleum; red clover (Trifolium Pratense); and sunflower (Helianthus annuus). Soil treatments included a common NPK fertilizer, ethylenediaminetetraacetic acid (EDTA), dilute sulfuric acid (H2SO4), and a mixture of EDTA and H2SO4 (EDTA+H2SO4). Trifolium tissue contained a greater quantity of Pb (182 mg Pb/kg tissue) than that of Poa (65 mg Pb/kg tissue). Cadmium concentration was similar in Poa and Trifolium tissue. ranging from 7.2 to 10.6 mg/kg tissue. Different soil treatments affected Pb levels found in plant tissue in order of effectiveness: H2SO4>EDTA>NPK>EDTA+H2SO4 The effects of soil treatments on Cd levels were similar to those for Pb with a difference of 0.1 mg Cd/kg tissue between EDTA and NPK treatments. Soil amendments differentially influenced Pb bioavailability and uptake, with H2SO4 exhibiting the greatest positive influence on Pb and Cd concentration in tissue. There was no correlation between the quantity of Pb and Cd up taken by vegetation at the site. The current study demonstrated the capability of common native plant species to grow on toxic and infertile soils, and the ability to uptake Pb and Cd to a limited degree. Regardless of tissue concentrations of Pb or Cd, Poa coverage at the site was generally dense. demonstrating the ability of Poa to become established on toxic soils and prevent soil erosion. / Department of Natural Resources and Environmental Management

Extractive processes can permanently and significantly reduce the volume, toxicity and mobility of contaminated materials at affected sites. Ethylenediaminetetraacetic acid (EDTA), N-2 (acetamido)iminodiacetic acid (ADA), pyridine2,6-dicarboxylic acid (PDA), and hydrochloric acid (HC1) were evaluated in batch studies for their ability to remove lead (Pb) and cadmium (Cd) from a Superfund soil. The extraction of Pb as a function of time was limited and the order of Pb removal was EDTA > ADA > PDA > HC1. Repeated extractions did not treat the soil below the Pb regulatory limit (1,000 mg/kg); however, the Pb remaining occurs in an immobile form. All extractants treated the soil below the proposed Cd regulatory limit (40 mg/kg) within 1 h. Lead recovery from solution was accomplished by hydroxide precipitation in the presence of excess calcium, and recovery at pH 11 was 70%, 98%, and 97% from the EDTA, ADA, and PDA complexes, respectively. / Department of Natural Resources and Environmental Management

Evaluation of heavy metal accumulation in soils and plants is of environmental importance due to their health effects on humans and other biota. Phytoremediation is an emerging technology that can stabilize or remove heavy metals in soil utilizing metal tolerant plant species (metallophytes). The objectives of this study were to: (1) assess a Superfund site, and a lead-acid battery dump for concentrations of soil lead (Pb) and cadmium (Cd); (2) assess the various chemical fractions of Pb and Cd at both sites; (3) identify native herbaceous vegetation surviving in the contaminated soils; and (4) evaluate plant uptake of Pb and Cd. Soil Pb and Cd concentrations at the Superfund site averaged 55,480 and 8.5 mg/kg, respectively. Soil Pb at the Superfund site occurred primarily in the carbonate, sulfide/residual, and organic chemical fractions (41.6, 28.6, and 26.7, respectively). Soil Pb and Cd concentrations at the dump site averaged 29,400 and 3.9 mg/kg, respectively. Soil Pb occurred mostly in the organic and carbonate fractions as 48.5 and 42.5% respectively. Plant uptake of Pb at both sites ranged from non-detectable (Agrostemma githago, Plantago rugeli, Alliaria officinalis shoots), to 1800 mg/kg (Agrostemma githago root). Cd uptake was maximal in Taraxacum officinale at 15.4 mg/kg (Superfund site). In the majority of plants studied, root Pb and Cd content was higher than for shoots (>_65%). Tissue and soil fractions yielded r2 of 0.61 and 0.57 for the soluble and carbonate-Pb fractions, respectively. The plants with the greatest tissue concentrations of Pb and Cd were predominantly herbaceous species, some of which produce sufficient biomass to be practical for phytoremediation technologies. / Department of Natural Resources and Environmental Management

No description available.

Made available in DSpace on 2015-06-17T19:34:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-17. Added 1 bitstream(s) on 2015-06-18T12:47:15Z : No. of bitstreams: 1 000830368.pdf: 921700 bytes, checksum: 66c7904c4e1a786a22301a7deeeac858 (MD5) / No presente trabalho foram empregados métodos para a determinação de chumbo em vidros provenientes de tubos de raios catódicos (CRT) e solo contaminado por este tipo de resíduo. Para as análises foram utilizadas pequenas partes dos componentes do CRT (televisão e computador) de diferentes fabricantes e desmontadas manualmente. Após a moagem, as amostras vítreas foram analisadas por MEV, EDS e DRX para determinar o tamanho de partículas e a composição elementar do material investigado. Para este estudo foi utilizada uma mistura de proporção de 1:1:1:4 em peso (canhão de elétrons, pescoço, funil e tela). Para as análises por GFAAS as amostras foram digeridas em meio ácido (2,4 mL de HCl, 1,2 mL HNO 3 , 2,4 mL de HF e 2,0 mL de H 2 O), onde cerca 125mg da amostra vítrea foram adicionados em frasco de PTFE. A concentração total de chumbo nos CRTs foi determinada por GFAAS e os valores encontrados para duas misturas provenientes de diferentes amostras foram (735,52 ± 6,12) mg kg -1 e (886,61 ± 5,49) mg kg -1 . A toxicidade da amostra foi avaliada utilizando a norma ABNT NBR 10004:2004 para resíduos sólidos. A mistura foi submetida a ensaios de lixiviação e o extrato lixiviado foi analisado por espectrometria de absorção atômica em chama (FAAS) e espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Os resultados indicaram que cerca de 85% do Pb presente no resíduo foi lixiviado. Os testes lixiviação realizados para os resíduos de CRTs atingiram os valores de Classe I (resíduo perigoso) de acordo com a norma ABNT NBR 10004:2004, devido à alta concentração de chumbo presente em sua composição. Os resíduos dos CRTs foram utilizados na simulação de descarte inadequado no solo e cultivo de alface em ambiente contaminado, após a colheita foram coletadas amostras de solo e a alface. Foi realizada uma avaliação biométrica da alface para ... / In this paper methods for the determination of lead in glass from cathode ray tube (CRT) and soil pipes contaminated by this type of waste were employed. Small parts of components CRT (television and computer) from different manufacturers were used and dismantled manually for analysis. After grinding, the vitreous samples were analyzed by SEM, EDS and XRD to determine the particle size and the elemental composition of the investigated material. For this study a mixture ratio of 1:1:1:4 by weight (electron gun, neck, funnel and screen) was used. For the analyzes by atomic absorption spectrometry in graphite furnace (GFAAS) samples were digested in acid medium ( HCl 2,4 mL, 1,2 mL HNO 3 , 2,4 mL HF and 2,0 mL of H 2 O) where about 125 mg of the glassy sample was added in PTFE bottle from the quantification was performed using the method of addition of analyte. . The total concentration of lead in CRTs was determined by GFAAS and the value for two mixtures from different samples were 735, 52 ± 6, 12 mg.kg -1 and 886.61 ± 5, 49 mg.kg -1 . The toxicity of the sample was assessed using the norm ABNT NBR 10004:2004 solid waste. The mixture was subjected to leaching tests and the leaching extract was analyzed by optical emission spectrometry with inductively coupled plasma (ICP OES) and atomic absorption spectrometry in flames (FAAS). The results indicated that about 85% of Pb present in the leach residue. The leaching tests performed for waste CRTs reached values of Class I (hazardous waste) in compliance with norm ABNT NBR 10004:2004, due to the high concentration of lead present in their composition. The danger of the glass was determined using Toxicity Characteristic leashing Procedure ( TCLP ) ( SW- 846 Method 1311 , USEPA 2003) , which determines the toxicity of waste by leaching . Waste CRTs were used in the simulation of improper disposal in soil and lettuce cultivation in contaminated ...