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Inorganic Pollutants in Wet Atmospheric Deposition and the Trajectories of Their Possible Transport
2009
Vach, Marek | Skřivan, Petr | Rohovec, Jan | Fišák, Jaroslav | Kubínová, Petra | Burian, Miloš
This work is concerned with analysis of the transport trajectories and identification of the probable emission sources of a set of chemical elements monitored in samples of atmospheric precipitation collected in the area of Central Bohemia, Czech Republic. This is based on evaluation of the significance of transport trajectories obtained using the HYSPLIT model for specific periods of duration of the sampled precipitation episodes in dependence on the values of the corrected concentrations of the monitored elements in the individual samples. The proposed method of correction of the measured concentrations of the elements is concerned with elimination of meteorological effects that are unspecific from with respect to the direction of the transport trajectories. The results for the group of elements with higher concentration levels in the sampled precipitation agree with the assumptions on their probable most important sources. The common main source of Na, Mg and Ca is marine aerosol, while K, P and Mn are probably of biogenic origin. The common main sources of Al and Fe--probably terrigenic dust--also correspond to the assumptions. Sulfur does not exhibit a significant predominant direction to the sampling site. Zinc, Cd, Cu and also Si are transported to the greatest degree from the north-westerly direction, indicating the probable effect of large energy-production sources in the area under the Krušné Mountains in the CR or the effect of traffic in the Capital City of Prague. The predominant direction of dispersion of Pb and As is a north-easterly to easterly direction of transport.
Afficher plus [+] Moins [-]Remediation of Copper and Cadmium in Contaminated Soils using Compost with Inorganic Amendments
2009
Gadepalle, Vishnu Priya | Ouki, Sabeha K. | Hutchings, Tony
Compost enriched with inorganic amendments has been evaluated in laboratory-based experiments for its effectiveness to immobilise heavy metals in contaminated soils. This paper reports the results pertaining to copper (Cu) and cadmium (Cd) only. The inorganic amendments used were naturally occurring zeolite-Clinoptilolite and synthetic iron oxide (Fe₂O₃). A series of experiments have been performed on the amended soils and the results demonstrated that a combination of compost/iron oxide was effective in reducing the uptake of Cu in rye grass (Lolium perenne L.) whereas compost/iron oxide as well as compost/zeolite mixture was effective for reducing Cd uptake. The amended compost performed better in re-vegetating contaminated soil compared to compost or amendments alone. The sequential extraction of the control sample showed that major fraction of both Cu and Cd were associated with organic fraction indicating that the metals might be available to plants under oxidising conditions of soil. The percentage of Cu in the control sample associated with different fractions was in the following order: Organic > Residual > Reducible > Exchangeable fraction whereas for Cd it was: Organic > Reducible > Residual > Exchangeable. The sequential extraction of amended soils showed that exchangeable Cu decreased by 50% to 92% compared to the control. An increase in residual fraction of Cd (up to 40%) was observed in the amended soils. It was concluded that zeolite and/or iron oxide enriched compost can be used effectively for immobilising Cu and Cd in contaminated soils. The effect of amended compost on other metals should be taken into consideration for real field applicaitons.
Afficher plus [+] Moins [-]Anthropogenic Heavy Metal Pollution in the Surficial Sediments of the Keratsini Harbor, Saronikos Gulf, Greece
2009
Galanopoulou, Stavroula | Vgenopoulos, Andreas | Conispoliatis, Nikolaos
The contents of ten elements [Cd, Pb, W, Zn, Mn, As, Se, Cr, Cu, and organic carbon (Corg)] have been determined in the surficial sediments of Keratsini harbor, Saronikos Gulf, Greece. The contamination of the sediments was assessed on the basis of geoaccumulation index and to corresponding sediment quality guidelines (SQGs) effects range low/effects range median. The results revealed highly elevated Cd, Pb, W, Zn, As, Se, Cr, Cu, and Corg values (Cd, 190-1,763 mg kg⁻¹; Pb, 521-1,263 mg kg⁻¹; W, 38-100 mg kg⁻¹; Zn, 409-6,725 mg kg⁻¹; Mn, 95-1,101 mg kg⁻¹; As, not detectable-1,813 mg kg⁻¹; Se, not detectable-58 mg kg⁻¹; Cr, 264-860 mg kg⁻¹; Cu, 195-518 mg kg⁻¹; and Corg, 0.69-4.41%). The enrichment of metals in the sediments results from the contribution of the central Athens sewage outfall through which the waste of the Attica basin ends up in Keratsini harbor as well as from industrial and ship contaminants.
Afficher plus [+] Moins [-]Evaluation of Greenwaste Mulch to Control Runoff Quality from Landfill Sites During Frequent Storms
2009
Brodie, I. M. | Misra, R. K.
This paper describes a preliminary evaluation of two types of greenwaste (fresh and aged) used as a mulch layer to control runoff from disturbed landfill areas. Fresh greenwaste refers to woody and herbaceous garden waste that has been recently collected, chopped and shredded. Aged greenwaste is greenwaste which has been stockpiled for 18 months. We used rainfall simulator tests to investigate two aspects: (1) the performance of greenwaste mulch in reducing runoff during designed storm events with a high frequency of occurrence and (2) the release of pollutants via runoff as total suspended solids (TSS) and total organic carbon (TOC) during rain. Rainfall of <5-year average recurrence interval (ARI) was generally applied, consistent with stormwater compliance requirements for many Australian landfills. TOC released from fresh greenwaste material was higher in concentration than from aged greenwaste. However, when used as a 10-cm-deep mulch layer, fresh greenwaste was able to completely prevent runoff, even when tested under rainfalls of up to 50-year ARI duration. An equivalent mulch layer of aged greenwaste was also effective in reducing runoff volume and TSS concentration compared with the bare soil during a 3.5-year ARI rainfall, but mean TOC concentration was higher. Based on these preliminary results, fresh greenwaste mulching of bare soils is an attractive option to control runoff and erosion from areas subject to intermittent landfill operations and worthy of further investigations.
Afficher plus [+] Moins [-]A Study of Diffusive Gradients in Thin Films for the Chemical Speciation of Zn(II), Cd(II), Pb(II), and Cu(II): The Role of Kinetics
2009
Gaabass, Ibraheem | Murimboh, John D. | Hassan, Nouri M.
The lability and mobility of Zn(II)-, Cd(II)-, Pb(II)-, and Cu(II)-humic acid complexes were studied using diffusive gradients in thin films (DGT). A unique feature of this research was (1) the use of DGTs with diffusive layer thicknesses ranging from 0.4 to 2.0 mm to study lability and mobility of Zn(II)-, Cd(II)-, Pb(II)-, and Cu(II)-humic acid complexes, combined with (2) the application of a competing ligand exchange (CLE) method using Chelex 100, the same chelating resin that is used in DGT, to study the kinetic speciation. The CLE experiments were run immediately after the completion of the DGT experiments, thereby allowing effects of the competing ligand to be separated from the effects introduced by the use of the polyacrylamide gel that is used in DGT. The results indicate that Zn(II) and Cd(II) tend to form more labile and more mobile complexes with humic acid than Pb(II) or Cu(II). The dissociation rate constants of Zn(II), Cd(II), and Pb(II) were found to increase with the ionic potential of the metal, suggesting that the binding between some trace metals and humic acid has a significant covalent component. Furthermore, the results suggest that the Eigen mechanism may not be strictly obeyed for metals such as Cu(II) which have high rate constants of water exchange, k w. Consequently, the markedly slow kinetics of Cu(II)-HA species suggests that the usual equilibrium assumption may not be valid in freshwaters.
Afficher plus [+] Moins [-]Nickel Uptake and its Effect on Some Nutrient Levels, Amino Acid Contents and Oxidative Status in Matricaria chamomilla Plants
2009
Kováčik, Jozef | Klejdus, Bořivoj | Hedbavny, Josef | Bačkor, Martin
The effect of nickel (Ni) excess on selected aspects of chamomile (Matricaria chamomilla L.) metabolism was studied. Water-soluble Ni represented 27%, 46%, and 47%, and the methanol-soluble fraction 54%, 70%, and 88% of total shoot Ni content after 10 days of treatments with 3, 60, and 120 μM Ni, respectively. “Intra-root” Ni content represented 72% (3 μM), 96% (60 μM), and 78% (120 μM) of total root Ni. Leaf rosettes treated with 120 μM contained 137 μg Ni g⁻¹ DW after 10 days of treatment. The highest Ni concentration particularly affected the content of mineral nutrients (e.g., decrease of K and increase of Fe) and activity of selected antioxidative enzymes (increase of ascorbate peroxidase and guaiacol peroxidase activities). Malondialdehyde accumulation was not influenced (measured in methanol extracts). Among 17 detected free amino acids, accumulation of histidine, proline, methionine, and cysteine was most distinct in the leaf rosettes and/or roots, indicating their involvement in Ni detoxification. Lower Ni toxicity in comparison to previously tested metals is also discussed.
Afficher plus [+] Moins [-]Effect of Multiple Stressors on Water Quality and Macroinvertebrate Assemblages in an Effluent-Dominated Stream
2009
Canobbio, Sergio | Mezzanotte, Valeria | Sanfilippo, Umberto | Benvenuto, Federica
Lura stream flows in the populated and industrialized conurbation North of Milan, Italy. The area suffers a sprawling urbanization which is leading to major alterations in water quality, hydrology and morphology of streams. These water bodies are known as effluent-dominated streams, because most of the baseflow is given by Wastewater Treatment Plant (WWTP) discharges. In this paper, a 5 year long assessment of Lura stream is presented and the collected data is discussed to understand overall ecological quality. Multivariate analysis carried out on macroinvertebrate assemblages and environmental variables suggests that invertebrate communities suffer severe alteration both upstream and downstream WWTP discharges. Results indicate that the high polluting loads coming from WWTP discharges affect seriously the stream water quality, but the most important cause of impairment are pulse perturbations related to the modified hydrology, causing droughts and flash floods, and to the spills of untreated sewage from overflows during rain events.
Afficher plus [+] Moins [-]Environmental Characterization of a Eutrophicated Semi-Enclosed System: Nutrient Budget (Encerrada Bay, Tierra del Fuego Island, Patagonia, Argentina)
2009
Torres, A. I. | Gil, M. N. | Amín, O. A. | Esteves, J. L.
Encerrada Bay (EB) is located in the far south of Argentina, on the north coast of the Beagle Channel and is artificially connected with Ushuaia Bay (UB). This study was carried out between 2004 and 2005; and assesses the impact of Ushuaia city to the nutrient dynamics in EB. It was focused on physical and chemical characterization of discharges, water and sediment quality, nutrient benthic fluxes, and water exchange with UB. The average ammonium, nitrate, phosphate and silicate concentrations in the water bay were 99.5 ± 30.7; 10.0 ± 4.2; 2.0 ± 0.7; 23.5 ± 2.9 µM, respectively. Benthic fluxes showed a consumption of oxygen (50-450 mg m⁻² h⁻¹) and nitrate (20-416 µmol m⁻² h⁻¹) by sediment and release of ammonium (79−4,772 µmol m⁻² h⁻¹) and phosphate (27-36 µmol m⁻² h⁻¹) into the water column. The daily contributions of nitrogen and phosphate from the effluents to EB were between 102 and 517 kg day⁻¹ and between 4 and 22 kg day⁻¹ respectively, while the net average export fluxes to UB were 41.7 kg day⁻¹ of nitrogen and 15.7 kg day⁻¹ of phosphate. The difference between received and exported nutrients is consumed in EB by primary producers, partially buffering the impact of wastewater in UB at its own eutrophication risk.
Afficher plus [+] Moins [-]Nutrient Pollution in Laucala Bay, Fiji Islands
2009
Singh, Sarabjeet | Aalbersberg, W. G. L. | Morrison, R. J.
The Laucala Bay coastal system was investigated from 2003 to 2005 to evaluate the changes in water quality (nutrients) after improvements in sewage effluent quality from Kinoya sewage treatment plant (KSTP), whose output is discharged into the bay. The oxidized nitrogen (NO x -N) values averaged 1.31 µM, but varied from 0.76 to 3.77 µM, and the filterable reactive phosphate or orthophosphate (FRP) averaged 0.77 µM, ranging from 0.24 to 2.37 µM. The mean concentrations of NO x -N and FRP, respectively, were two and ten times higher than concentrations found in unpolluted sites in Fiji. Based on these values and NH₃ concentrations from parallel studies, Redfield ratio estimates suggest that primary productivity of the bay is N limited. No significant decrease in concentration of both NO x -N and FRP was found in Laucala Bay waters during the present investigation compared to concentrations found in two previous studies. This indicates that KSTP effluent may be only a minor source of nutrients into the bay, and to protect the Laucala Bay ecosystem from increasing nutrient pollution, there is a need to control nutrient input from other major point and nonpoint sources.
Afficher plus [+] Moins [-]Biomass District Energy Trigeneration Systems: Emissions Reduction and Financial Impact
2009
Rentizelas, A | Tolis, A | Tatsiopoulos, I
Biomass cogeneration is widely used for district heating applications in central and northern Europe. Biomass trigeneration on the other hand, constitutes an innovative renewable energy application. In this work, an approved United Nations Framework Convention on Climate Change baseline methodology has been extended to allow the examination of biomass trigeneration applications. The methodology is applied to a case study in Greece to investigate various environmental and financial aspects of this type of applications. The results suggest that trigeneration may lead to significant emissions reduction compared to using fossil fuels or even biomass cogeneration and electricity generation. The emissions reduction achieved may be materialized into a considerable revenue stream for the project, if traded through a trading mechanism such as the European Union Greenhouse Gas Emission Trading Scheme. A sensitivity analysis has been performed to compensate for the high volatility of the emission allowances' value and the immaturity of the EU Trading Scheme, which prevent a reliable estimation of the related revenue. The work concludes that emission allowances trading may develop into one of the major revenue streams of biomass trigeneration projects, significantly increasing their financial yield and attractiveness. The impact on the yield is significant even for low future values of emission allowances and could become the main income revenue source of such projects, if emission allowances increase their value substantially. The application of trigeneration for district energy proves to lead to increased environmental and financial benefits compared to the cogeneration or electricity generation cases.
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