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Pollutant Concentrations in the Rime and Fog Water at the Milesovka Observatory Texto completo
2009
Fisak, Jaroslav | Tesar, Miroslav | Fottova, Daniela
The paper summarizes results of chemical analyses of fog and rime water samples. The samples were collected at Milesovka, the Czech meteorological observatory. The input data set contains the samples acquired during 234 fogs and 14 rime events. The fog and rime samples were collected in the period of 2000-2004. Methods employed for sampling fog and rime water and differences in the pollutant concentrations are described. The following components were analyzed: conductivity, acidity (pH), cations Na⁺, K⁺, NH₄ ⁺, Mg²⁺, Ca²⁺, and anions F⁻, Cl⁻, NO₃ ⁻, SO₄ ²⁻. The attention was exclusively devoted to the precipitation originating in fogs (no falling precipitation particles were considered). Differences in the relative content of selected ions in the annual average samples of rime and fog are presented together with their absolute values. The importance of rime contributions to total precipitation amounts is demonstrated by maximum values of the rime weight detected at the Milesovka Observatory. The absolute maximum of 52.3 kg m⁻² was registered at Milesovka Mt. on December 28, 2002.
Mostrar más [+] Menos [-]Relation Between pH and Desorption of Cu, Cr, Zn, and Pb from Industrially Polluted Soils Texto completo
2009
Ottosen, Lisbeth M. | Hansen, Henrik K. | Jensen, Pernille E.
Desorption of Cu, Cr, Pb, and Zn from industrially polluted soils as a result of acidification is in focus. The eight soils of the investigation vary greatly in composition and heavy metal concentration/combination. Three soils had elevated concentrations of Cu, Pb, and Zn; regardless of pollution level, pollution origin, and soil type, the order for desorption as pH decreased was Zn > Cu > Pb. Turning to a single heavy metal in different soils, there was a huge difference in the pH at which the major desorption started. The variation was most significant for Pb where, e.g., less than 10% was desorbed at pH 2.5 from one soil, whereas in another soil 60% Pb was desorbed at this pH. Sequential extraction was made and the soils in which a high percentage of Pb was found in the residual phase (adsorbed strongest) was also the soils where less Pb was desorbed at low pH in the desorption experiments. It was evident that Cu, Pb, and Zn started to desorb at a higher pH from calcareous soils than from soils with low carbonate content. The mechanism responsible for this is co-precipitation of heavy metals in the carbonates. When the carbonates are dissolved at a relatively high pH of about 5, the co-precipitated heavy metals are released. The sequential extraction pattern for Cr differed generally much from the other heavy metals since the majority of Cr was extracted in the last two steps. Cr was also the heavy metal that desorbed the least at high acidification.
Mostrar más [+] Menos [-]Transfer of Cd, Pb, Ra and U from Phosphogypsum Amended Soils to Tomato Plants Texto completo
2009
Enamorado, S. | Abril, J. M. | Mas, J. L. | Periáñez, R. | Polvillo, O. | Delgado, A. | Quintero, J. M.
About 170 million tons of phosphogypsum (PG) are annually generated worldwide as a by-product of phosphoric acid factories. Agricultural uses of PG could become the main sink for this waste, which usually contains significant radionuclide (from the ²³⁸U-series) and toxic metals concentrations. To study PG effects on pollutant uptake by crops, a completely randomised greenhouse experiment was carried out growing Lycopersicum esculentum Mill L. on a reclaimed marsh soil amended with three PG rates (treatments), corresponding to zero (control without PG application), one, three and ten times the typical PG rates used in SW Spain (20 Mg ha⁻¹). The concentrations of Cd, Pb, U (by inductively coupled plasma mass spectroscopy) and ²²⁶Ra and ²¹⁰Po (by γ-spectrometry and α-counting, respectively) were determined in soil, vegetal tissue and draining water. Cadmium concentrations in fruit increased with PG rates, reaching 44 ± 7 μg kg⁻¹ formula weight with ten PG rates (being 50 μg kg⁻¹ the maximum allowed concentration by EC 1881/2006 regulation). Cd transfer factors in non-edible parts were as high as 4.8 ± 0.5 (dry weight (d.w.)), two orders of magnitude higher than values found for lead, lead, uranium and radium concentrations in fruit remained below the corresponding detection limits--0.5 and 0.25 mg kg⁻¹ and 0.6 mBq kg⁻¹, respectively (in a d.w. basis). ²³⁸U (up to 7 μg kg⁻¹ d.w.) and ²¹⁰Po (up to 0.74 Bq kg⁻¹ d.w.) could be measured in some fruit samples by α-spectrometry. Overall, the concentrations of these metals and radionuclides in the draining water accounted for less than 1% of the amount applied with PG.
Mostrar más [+] Menos [-]Adsorption of Lead and Cadmium from Aqueous Solution by Using Almond Shells Texto completo
2009
Mehrasbi, Mohammad Reza | Farahmandkia, Zohreh | Taghibeigloo, Bahareh | Taromi, Azra
The potential of almond shells was assessed for adsorption of heavy metal ions such as Pb²⁺ and Cd²⁺ from aqueous solution. Almond shells were pretreated separately with 0.4 mol/L NaOH, 0.4 mol/L HNO₃, and distilled water and their adsorption abilities were compared. Batch adsorption experiments were carried out as a function of the initial ion concentration, pH, and adsorbent dosage. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir, Freundlich, and BET models. The alkali-modified almond shells had adsorption capacities for Pb²⁺ from 2 to 9 mg/g and for Cd²⁺ from 2 to 7 mg/g, which was much higher than acid- and water-pretreated adsorbents. Experimental results showed that the best pH for adsorption was 5-6 and the adsorption values decreased with lowering pH. Isotherm models indicated the best fit for Langmuir model for alkali-modified almond shells. In comparing the parameters of the models, it was observed that the affinity of almond shells for adsorption of lead is stronger than affinity for adsorption of cadmium.
Mostrar más [+] Menos [-]The Effect of Aluminium on the Planarian Polycelis felina (Daly.) Texto completo
2009
Kovačević, Goran | Gregorović, Gordana | Kalafatić, Mirjana | Jaklinović, Ivica
The effect of aluminium on histopathological and behavioral changes in the planarian Polycelis felina (Daly.) in laboratory conditions was studied. The planarians were treated with seven concentrations of aluminium sulfate for five days and compared to three control groups of animals. Microscopical, histological and morphometric methods were used. The results showed distinguished morphological changes on the planarian body as well as behavioral changes: various depigmentations, disordered locomotion, twisting of the body parts, hardly reacting to the mechanical stimuli, body contractions, deformations and mortality. Histomorphometric analyses showed changes in the size and number of neoblasts and reticular cells. Changes in epithelial cells and segments, parenchyma and muscular layer were also noticed. Concentrations of 600 and 1100 mg/L caused most distinct changes in behavior, morphological and histological structure of planarians. The highest concentrations caused irreversible changes. Considering high LC₅₀ (1100 mg/L), the used concentrations of aluminium presented no actual environmental threat to planarian populations in nature, but showed the extent of damages in a possible concentrated aluminium environment.
Mostrar más [+] Menos [-]Ash Leaching of Forest Species Treated with Phosphate Fire Retardants Texto completo
2009
Liodakis, Stylianos | Tsoukala, Magdalini
The chemical, mineralogical, and leaching behavior of three dominant Greek forest species ashes (Pinus halepensis, Pistacia lentiscus, and Olea europaea), before and after treating forest species with diammonium phosphate (DAP) 5% and 10% weight to weight, have been studied using a new five-step shake leaching method at pH = 6. For the analysis of ashes (prior and after leaching) and leachants, the following analytical techniques were used: atomic absorption spectroscopy, X-ray diffraction, and scanning electron microscopy with energy dispersive X-ray fluorescence analysis. The presence of DAP obstructs the extraction process of some metal ions (i.e., Na, K) contained in ashes by converting the soluble carbonate salts to the less soluble phosphates (i.e., Na₂CO₃ [rightward arrow] Na₃PO₄). On the contrary, DAP enhances the mobility of some other metals (i.e., Ca) by forming more soluble compounds [i.e., CaCO₃ [rightward arrow] Ca₃(PO₄)₂]. In addition, the presence of DAP lowers the pH of leachates, causing dissolution of some toxic elements (i.e., Mn, Pb, Zn). Unexpectedly, DAP prevents the leachability of Cr from ash. The above study concerns the environmental effects (soil and ground and underground water streams) caused by the use of chemical retardants on forest fires.
Mostrar más [+] Menos [-]Trends of Livestock-related NH₃, CH₄, N₂O and PM Emissions in Greece Texto completo
2009
Sidiropoulos, Christos | Tsilingiridis, George
It is well established that the livestock sector is a major contributor to greenhouse gases (GHG) and ammonia (NH₃) emissions. In this paper, the evolution of livestock NH₃, methane (CH₄), nitrous oxide (N₂O) and particulate matter (PM) emissions is presented for the period 1960-2005 in Greece and the factors influencing the emission fluxes (such as livestock population changes, manure management systems in use) are examined and analyzed. Emission estimates are based on the updated EMEP/CORINAIR methodology together with the revised IPCC guidelines; newly published, Greece-specific emission factors are used. The emissions level from livestock is evaluated and compared with the corresponding emissions from other anthropogenic sources in Greece. Geographical analysis concerning the distribution of animals and the subsequent NH₃ emissions is performed. Main results indicate high levels of emissions from 1960 to 1995, while emissions from 1995 to 2005 show a stabilizing trend.
Mostrar más [+] Menos [-]Anaerobic Bioremediation of a Soil With Mixed Contaminants: Explosives Degradation and Influence on Heavy Metal Distribution, Monitored as Changes in Concentration and Toxicity Texto completo
2009
Elgh Dalgren, Kristin | Waara, Sylvia | Düker, Anders | Kronhelm, Thomas von | Hees, Patrick A. W van
Two soils with explosives and metals were evaluated for the degradation efficiency of explosives by native microorganisms under anaerobic conditions. The commercially available method Daramend®, amended with zero-valent iron (ZVI), was compared with a horse-manure-amended compost and a treatment with ZVI alone. In a moderately contaminated soil, Daramend® and ZVI treatment gave significantly higher removal rates compared to compost and control treatments (Tukey's test, P < 0.05). The largest overall decrease in ecotoxicity, measured with bioluminescent bacteria (Vibrio fischeri), was achieved with ZVI treatment. In a more contaminated soil, no degradation of contaminants and no decline in soil toxicity could be distinguished after the same time period. Problems with establishment of anaerobic conditions during parts of the remediation process and low microbial activity due to acute toxicity of contaminants are plausible explanations. Redistribution that could potentially lead to mobilization of the co-contaminant Pb was not observed in either of the soils during the biological treatments.
Mostrar más [+] Menos [-]Response of Leafy Vegetable Kalmi (Water Spinach; Ipomoea aquatica L.) at Elevated Concentrations of Arsenic in Hydroponic Culture Texto completo
2009
Shaibur, Molla Rahman | Islam, Tamanna | Kawai, Shigenao
Effects of elevated arsenic (As) concentrations on hydroponic Kalmi (Ipomoea aquatica L.) were investigated. Plants were treated with 0, 10, 25, and 50 μM As in the greenhouse for 14 days. Arsenic was added from sodium meta-arsenite (NaAsO₂). Visible toxicity symptom could not easily be recognized without visible growth reduction. Little brown spots on the leaf blade were found at 50 μM As treatment. Dry matter yields decreased by 18.8%, 43.2%, and 78.2% in leaves; 23.6%, 56.4%, and 81.8% in stems; and 11.0%, 28.6%, and 63.7% in roots in the 10-, 25-, and 50-μM As treatments, respectively. Arsenic concentrations increased in leaves (except in 50 μM As treatment), stems, and roots with increasing As concentrations in the medium. Roots contained 12.7, 11.3, and 10.5 times higher As concentrations as compared to stems and 15.5, 15.9, and 52.8 times higher as compared to leaves in the 10-, 25-, and 50-μM As treatments, respectively. Arsenic concentration followed the trend of roots > stems > leaves. Kalmi concentrated unaccepted levels of As in leaf and stem tissues for human consumption in the As-treated plants. Based on 10% dry weight (DW) reduction, the critical toxicity level (CTL) of As in the leaves was 7.02 and 23.6 μg g⁻¹ DW in stems.
Mostrar más [+] Menos [-]Developing Measures for Assessing the Causality of Safety Culture in a Petrochemical Industry Texto completo
2009
Wu, Tsung-Chih | Lin, Chia-Hung | Shiau, Sen-Yu
This paper discusses safety culture in the petrochemical sector and the causes and consequences of safety culture. A sample of 520 responses selected by simple random sampling completed questionnaires for this survey, the return rate was 86.75%. The research instrument comprises four sections: basic information, the safety leadership scale (SLS), the safety climate scale (SCS), and the safety performance scale (SPS). SPSS 12.0, a statistical software package, was used for item analysis, validity analysis, and reliability analysis. Exploratory factor analysis indicated that (1) SLS abstracted three factors such as safety caring, safety controlling, and safety coaching; (2) SCS comprised three factors such as emergency response, safety commitment, and risk perception; and (3) SPS was composed of accident investigation, safety training, safety inspections, and safety motivation. We conclude that the SLS, SCS, and SPS developed in this paper have good construct validity and internal consistency and can serve as the basis for future research.
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