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The Roles of Diethylenetriamine Pentaacetate (DTPA) and Ethylenediamine Disuccinate (EDDS) in Remediation of Selenium from Contaminated Soil by Brussels Sprouts (Brassica oleracea var. gemmifera)
2012
Esringü, Aslıhan | Turan, Metin
The objective of this study was to investigate the effects of adding different rates of diethylenetriamine pentaacetate (DTPA) at different concentrations (0, 0.5, 1, and 5 mmol kg−1) and ethylenediamine disuccinate (EDDS) at 0, 5, 7.5, and 10 mmol kg−1 on the capacity of Brussels sprouts plants to take up Se from soils contaminated with 0, 5, 10, and 15 mg kg−1 NaSeO4, under a greenhouse conditions. Results indicated that the application of DTPA and EDDS to Se-contaminated soils significantly affect plant Se concentration, Se uptake, and dry matter yield of plants. Se concentration in the plant leaves, stems, and roots increased with increase in DTPA and EDDS application doses, but total Se uptake increased from 0 to 1.0 and 7.5 mmol kg−1 DTPA and EDDS application doses, respectively, and decreased after those levels due to toxic Se concentration for plant. Most plant available fractions and the carbonate, metal oxide, and organic matter-bound fractions increased linearly with Se application. At all DTPA and EDDS application rates, the Se concentrations in the leaves were about two to three times higher than those in the roots and about three to four times higher than those in the stems. This study suggests that the above-ground organs like leaf and shoots of Brussels sprouts can effectively be used in the removal of Se from soils contaminated with Se. Under the conditions in this experiment, Brussels sprouts were capable of removing 0.9–1.8 mg Se pot−1 when harvested at maturity without any chelating agent take into consideration one growing season per year. Based on the data of present experiment, it would be necessary to approximately 57–67 growing seasons without EDDS and EDTA to remove all total Se from polluted soil. Selenium removal can be further increased 12- to 20-fold with 7.5 mmol kg−1 EDDS and 1.0 mmol kg−1 DTPA application, respectively.
显示更多 [+] 显示较少 [-]Evaluation of the Influence of Natural and Antrhopogenic Processes on Water Quality in Karstic Region
2012
Calijuri, Maria Lúcia | do Couto, Eduardo de Aguiar | Santiago, Aníbal da Fonseca | Camargo, Rodrigo de Arruda | e Silva, Marcos D. F. M.
This paper presents a comprehensive study on the quality of surface and groundwater in an environmentally sensitive karstic watershed strongly pressed by urban growth. The objective of the study was to assess the integrated effects of human activities and natural characteristics of karstic environments on the quality of surface and groundwater using multivariate statistical techniques. Data from 18 physical, chemical, and microbiological water quality variables obtained throughout a hydrological year were analyzed using principal components analysis (PCA) and cluster analysis. The PCA was carried out individually for surface water and groundwater. Our goal was to study the behavior of the water quality variables at each of these systems, as well as to infer the importance of these variables on the dynamics of the water resources in the region. Our results for surface water showed that the 18 original variables could be reduced to five principal components which together accounted for 69% of the total variation in the data, whereas for groundwater, 70% of the total variation in the data was explained by five principal components. In order to evaluate the impacts of anthropic activities on the water quality at the monitoring locations, the cluster analysis was applied to the ten sampling points. The analysis identified five clusters, two of which are formed by points with low contamination levels and three where the anthropic interference is noticeable. The results suggest the existence of specific contamination sources in many points, including in the groundwater, and highlight the natural vulnerability of the karstic environments.
显示更多 [+] 显示较少 [-]Decolorization of Azo, Triphenylmethane and Anthraquinone Dyes by Laccase of a Newly Isolated Armillaria sp. F022
2012
Hadibarata, Tony | Yusoff, Abdull Rahim Mohd | Aris, Azmi | Salmiati, | Hidayat, Topik | Kristanti, Risky Ayu
A newly isolated white-rot fungus, Armillaria sp. strain F022, was isolated from the decayed wood in a tropical rain forest. Strain F022 was capable of decolorizing a variety of synthetic dyes, including azo, triphenylmethane, and anthraquinone dyes, with an optimal efficiency of decolorization obtained when dyes added after 96 h of culture, with the exception of Brilliant Green. All of the tested dyes were decolorized by the purified laccase in the absence of any redox mediators, but only a few were completely removed, while others were not completely removed even when decolorization time was increased. The laccase, with possible contributions from unknown enzymes, played a role in the decolorization process carried out by Armillaria sp. F022 cultures, and this biosorption contributed a negligible part to the decolorization by cultures. The effect of dye to fungal growth was also investigated. When dyes were added at 0 h of culture, the maximum dry mycelium weight (DMW) values in the medium containing Brilliant Green were 1/6 of that achieved by the control group. For other dyes, the DMW was similar with control. The toxic tolerance of dye for the cell beads was excellent at least up to a concentration of 500 mg/l. The optimum conditions for decolorization of three synthetic dyes are at pH 4 and 40°C.
显示更多 [+] 显示较少 [-]Plant Availability and Uptake of Lead, Zinc, and Cadmium in Soils Contaminated with Anti-corrosion Paint from Pylons in Comparison to Heavy Metal Contaminated Urban Soils
2012
Brokbartold, Marcel | Wischermann, Mareike | Marschner, Bernd
Red lead (Pb3O4) has been used extensively in the past as an anti-corrosion paint for the protection of steel constructions. Prominent examples being some of the 200,000 high-voltage pylons in Germany which have been treated with red lead anti-corrosion paints until about 1970. Through weathering and maintenance work, paint compounds and particles are deposited on the soils beneath these constructions. In the present study, six such “pylon soils” were investigated in order to characterize the plant availability and plant uptake of Pb, Cd, and Zn. For comparison, three urban soils with similar levels of heavy metal contamination were included. One phase extractions with 1 M NH4NO3, sequential extractions (seven steps), and extractions at different soil pH were used to evaluate the heavy metal binding forms in the soil and availability to plants. Greenhouse experiments were conducted to determine heavy metal uptake by Lolium multiflorum and Lactuca sativa var. crispa in untreated and limed red lead paint contaminated soils. Concentrations of Pb and Zn in the pylon soils were elevated with maximum values of 783 mg Pb kg−1 and 635 Zn mg kg−1 while the soil Cd content was similar to nearby reference soils. The pylon soils were characterized by exceptionally high proportions of NH4NO3-extractable Pb reaching up to 17% of total Pb. Even if the relatively low pH of the soils is considered (pH 4.3–4.9), this appears to be a specific feature of the red lead contamination since similarly contaminated urban soils have to be acidified to pH 2.5 to achieve a similarly high Pb extractability. The Pb content in L. multiflorum shoots reached maximum values of 73 mg kg−1 after a cultivation time of 4 weeks in pylon soil. Lime amendment reduced the plant uptake of Pb and Zn significantly by up to 91%. But L. sativa var. crispa cultivated on soils limed to neutral pH still contained critical Pb concentrations (up to 0.6 mg kg−1 fresh weight). Possible mechanisms for the exceptionally high plant availability of soil Pb derived from red lead paint are discussed.
显示更多 [+] 显示较少 [-]Novel Water-Soluble Calix[4,6]arene Appended Magnetic Nanoparticles for the Removal of the Carcinogenic Aromatic Amines
2012
Aksoy, Tuba | Erdemir, Serkan | Yildiz, H Bekir | Yılmaz, Mustafa
This article describes the synthesis of p-sulfonated calix[4,6]arene derivatives and firstly their immobilization onto magnetic nanoparticles for removal of some carcinogenic aromatic amines. The prepared new water-soluble calix[4,6]arene appended magnetic nanoparticles (p-C[4]-MN and p-C[6]-MN) were characterized by a combination of Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analyses. The separation and quantification of aromatic amines were performed by high performance liquid chromatography. In batch sorption experiments, the compounds 7 and 8 were found to be effective sorbent for aromatic amines. It was observed that the percentage of aromatic amine removal was 44–97 % for compound 7 and 63–97 % for 8 when the pH of the aromatic amine solution was in the range of 3.0–8.5. The sorption of aromatic amines by p-sulfonated calix[n]arenes-based magnetic nanoparticles shows that sulfonic acid groups play a major role for the formation of hydrogen bonds and electrostatic interactions.
显示更多 [+] 显示较少 [-]Modeling 2D Multispecies Reactive Transport in Saturated/Unsaturated Porous Media with the Eulerian–Lagrangian Localized Adjoint Method
2012
Ramasomanana, F. | Younes, A. | Fahs, M.
In the present paper, the Eulerian–Lagrangian localized adjoint method (ELLAM) formulation developed by Younes et al. (Advances in Water Resources 29:1056–1074, 2006) is combined with the sequential noniterative approach to accurately simulate 2D multicomponent reactive transport in saturated/unsaturated porous media. The performance and accuracy of the developed model, named ELLAM_REACT, are compared against those of an existing numerical model based on a combination of discontinuous Galerkin and multipoint flux approximation methods (DGMPFA_REACT). Three studied test cases, dealing with reactive transport in saturated and unsaturated porous media and involving chemical reactions with only aqueous species or both fixed and aqueous species, show the superiority of the ELLAM_REACT model compared to the DGMPFA_REACT model.
显示更多 [+] 显示较少 [-]Regional Contamination of Moravia (South-Eastern Czech Republic): Temporal Shift of Pb and Zn Loading in Fluvial Sediments
2012
Matys Grygar, Tomáš | Sedláček, Jan | Bábek, Ondřej | Nováková, Tereza | Strnad, Ladislav | Mihaljevič, Martin
Regional contamination by Pb and Zn in southern Moravia (south-east part of the Czech Republic) in the twentieth century was analysed in Brno Dam lake sediments and in floodplain sediments of the Morava River near Strážnice. The age model for the Brno Dam lake sediments has been obtained by 137Cs (maxima corresponding to the nuclear tests in atmosphere and the 1986 Chernobyl accident) and the construction of the dam (1940); the time constraints for the Morava River sediments was the erection of flood defences (1930s) and 210Pb dating. In the case of floodplain sediments, profiles exhibiting post-depositional mobilisation of heavy metals by pedogenic processes (gleying) must be excluded to reconstruct the history of contamination. There was a relatively fast joint onset of Pb and Zn load since the early stages of industrialisation in the first half of the twentieth century, but then the concentrations of these two metals developed in a different manner. Pb load only slightly increased till its peak in 1960s and 1970s. The increase of Zn load was rather stepwise: Soon before 1930s (Morava River floodplain) and in 1940s and 1950s (in Brno Lake), the relative contamination by Zn was much lower than during its peak in the 1970s to the present days. The offset of Pb and Zn contamination curves could have been caused by three different artificial sources of these heavy metals. The temporal shift of Pb and Zn loads can be used for dating sediments.
显示更多 [+] 显示较少 [-]Assessing the Effect of Saltwater Intrusion on Petroleum Hydrocarbons Plumes Via Numerical Modelling
2012
Mastrocicco, M. | Colombani, N. | Sbarbati, C. | Petitta, M.
A contamination by petroleum hydrocarbons was detected in a sandy aquifer below a petrochemical plant in Southern Italy. The site is located near the coastline and bordered by canals which, together with pumping wells, control submarine groundwater discharge toward the sea and seawater intrusion (SWI) inland. In this study, a three-dimensional flow and transport model was developed using SEAWAT-4.0 to simulate the density-dependent groundwater flow system. Equivalent freshwater heads from 246 piezometers were employed to calibrate the flow simulation, while salinity in 193 piezometers was used to calibrate the conservative transport. A second dissolved species, total petroleum hydrocarbons (TPH), was included in the numerical model to simulate the plumes originating from light non-aqueous-phase liquid. A detailed field investigation was performed in order to determine the fate of dissolved hydrocarbons. Fifteen depth profiles obtained from multilevel samplers (MLS) were used to improve the conceptual model, originally built using a standard monitoring technique with integrated depth sampling (IDS) of salinity and TPH concentrations. The calibrated simulation emphasises that density-dependent flow has a great influence on the migration pattern of the hydrocarbons plume. This study confirms that calibration of density-dependent models in sites affected by SWI can be successfully reached only with MLS data, while standard IDS data can lead to misleading results. Thus, it is recommended to include MLS in the characterization protocols of contaminated sites affected by SWI, in order to properly manage environmental pollution problems of coastal zones.
显示更多 [+] 显示较少 [-]Ethanol Addition for Enhancing Denitrification at the Uranium Mill Tailing Site in Monument Valley, AZ
2012
Borden, Andrew K. | Brusseau, Mark L. | Carroll, K. C. | McMillan, Andrew | Akyol, Nihat H. | Berkompas, Justin | Miao, Ziheng | Jordan, Fiona | Tick, Geoff | Waugh, W Jody | Glenn, Ed P.
Past mining and processing of uranium ore at a former uranium mining site near Monument Valley, AZ has resulted in nitrate contamination of groundwater. The objective of this study was to investigate the potential of ethanol addition for enhancing the reduction of nitrate in groundwater. The results of two pilot-scale field tests showed that the concentration of nitrate decreased, while the concentration of nitrous oxide (a product of denitrification) increased. In addition, changes in aqueous concentrations of sulfate, iron, and manganese indicated that the ethanol amendment caused a change in prevailing redox conditions. The results of compound-specific stable isotope analysis for nitrate–nitrogen indicated that the nitrate concentration reductions were biologically mediated. Denitrification rate coefficients estimated for the pilot tests were approximately 50 times larger than resident-condition (non-enhanced) values obtained from prior characterization studies conducted at the site. The nitrate concentrations in the injection zone have remained at levels three orders of magnitude below the initial values for many months, indicating that the ethanol amendments had a long-term impact on the local subsurface environment.
显示更多 [+] 显示较少 [-]Effectiveness of Conventional and Low-Cost Wastewater Treatments in the Removal of Pharmaceutically Active Compounds
2012
Camacho-Muñoz, D. | Martin, J. | Santos, J. L. | Aparicio, I. | Alonso, E.
In the present work, the effectiveness of conventional wastewater treatments (activated sludge and oxidation ditches) and low-cost wastewater treatments (trickling filter beds, anaerobic lagooning and constructed wetlands) in the removal of pharmaceutically active compounds has been studied. To evaluate the efficiency of removal, 16 pharmaceutically active compounds belonging to seven therapeutic groups (anti-inflammatory drugs, antibiotics, antiepileptic drugs, β-blockers, nervous stimulants, estrogens and lipid regulators) have been monitored during 1-year period in influent and effluent wastewater from 11 wastewater treatment plants of Spain. Mean removal rates of pharmaceutically active compounds achieved in conventional wastewater treatments were slightly higher than those achieved in low-cost treatments, being 64% and 55%, respectively. Ibuprofen, naproxen, salicylic acid and caffeine were the pharmaceutical compounds most efficiently removed, regardless the wastewater treatment applied, with removal rates up to 99%. Anaerobic lagooning was the less effective treatment for the removal of the most persistent compounds: carbamazepine and propranolol.
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