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Результаты 1221-1230 из 1,506
Occurrence of perfluorinated compounds in water and sediment of L’Albufera Natural Park (València, Spain)
2012
Picó, Yolanda | Blasco, Cristina | Farré, Marinella | Barceló, Damià
PURPOSE: Perfluorinated compounds (PFCs) are widely distributed from industrialized to remote locations throughout the world. This study demonstrates the spatial distributions of PFCs in water and sediments from the L’Albufera Natural Park (Valencia, Spain). METHODS: Grab water and sediment samples were collected. PFCs were extracted from sediments with acidified acetonitrile by ultrasonication and cleaned up by solid-phase extraction (SPE) and from water by SPE. Determination was carried out by liquid chromatography–tandem mass spectrometry. RESULTS: In 100% of the samples (both water and sediments), perfluorooctane sulfonate (PFOS) and perfluoroctanoic acid (PFOA) were the predominant PFCs. Among the 12 sampling sites, PFOS concentrations in sediments ranged from 0.10 to 4.80 ng/g dry weight and in water from 0.94 to 58.1 ng/L. PFOA concentrations in sediment were from 0.004 to 1.24 ng/g and in water from 0.99 to 120 ng/L. Other perfluorocarboxylic acids (C5, C6, C7, C9, and C10) and perfluorosulfonates (C4 and C10) were also identified in several locations. The sum of all 10 compounds (ΣPFCs) concentration range from 0.99 to 120 ng/L in water and from 0.25 to 17.4 ng/g in sediments. Sediment–water distribution coefficients (log K D) were in the range 2.31–4.51 and positively correlated with perfluoroalkyl chain length. CONCLUSIONS: PFC concentrations in water and sediment were both less than those able to cause acute toxicity; low but detectable PFCs pollution in the L’Albufera Natural Park in Valencia was demonstrated. These compounds are bioaccumulative; thus, the risk associated with these exposures requires a deeper evaluation of long-term chronic toxicity.
Показать больше [+] Меньше [-]Metal pollution does not bias offspring sex ratio in great tit (Parus major)
2012
Eeva, Tapio | Sillanpää, Saila | Lehikoinen, Esa
PURPOSE: We measured offspring sex ratios in a resident insectivorous passerine bird, the Great tit Parus major, to find out whether metal pollution around a Finnish copper smelter would bias sex ratios in this territorial forest bird species. Besides a direct effect of pollutants, we were interested in possible indirect effects of pollution-related resource limitation, i.e., changes in food quality and quantity, on sex ratio. METHODS: We manipulated the diet quantity and quality (carotenoid levels) of P. major nestlings in polluted and unpolluted environments to find out if variation in dietary resource levels has any effect on fledgling sex ratios. Faecal metal levels of nestlings were analysed to monitor the level of pollution exposure at each territory. Near the time of fledging (at the age of 15 days), feather samples were collected for molecular sex determination. RESULTS: We did not find any association between metal exposure levels and offspring sex ratio, and thus, our results do not support the hypothesis that metal pollution would have direct effects on P. major offspring sex ratio. We found that, irrespective of pollution level, high nestling mortality was associated with male-biased sex ratio, most likely due to sex-specific mortality. Our feeding treatment, however, showed no significant effects on offspring sex ratio, possibly because natural variation in food availability outweighed the effect of our food manipulation on nestling mortality. CONCLUSIONS: We conclude that metal exposure at the levels found in our study area does not bias fledgling sex ratios in this species, but biased sex ratios may follow under natural or pollution-related resource limitation.
Показать больше [+] Меньше [-]Isolation and characterization of Bacillus cereus IST105 from electroplating effluent for detoxification of hexavalent chromium
2012
Naik, Umesh Chandra | Srivastava, Shaili | Thakur, Indu Shekhar
PURPOSE: Electroplating industries are the main sources of heavy metals, chromium, nickel, lead, zinc, cadmium and copper. The highest concentrations of chromium (VI) in the effluent cause a direct hazards to human and animals. Therefore, there is a need of an effective and affordable biotechnological solution for removal of chromium from electroplating effluent. METHODS: Bacterial strains were isolated from electroplating effluent to find out higher tolerant isolate against chromate. The isolate was identified by 16S rDNA sequence analysis. Absorbed chromium level of bacterium was determined by inductively coupled plasma-atomic emission spectrometer (ICP-AES), atomic absorption spectrophotometer (AAS), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray analysis (EDX). Removal of metals by bacterium from the electroplating effluent eventually led to the detoxification of effluent confirmed by MTT assay. Conformational changes of functional groups of bacterial cell surface were studied through Fourier transform infrared spectroscopy. RESULTS: The chromate tolerant isolate was identified as Bacillus cereus. Bacterium has potency to remove more than 75% of chromium as measured by ICP-AES and AAS. The study indicated the accumulation of chromium (VI) on bacterial cell surface which was confirmed by the SEM-EDX and TEM analysis. The biosorption of metals from the electroplating effluent eventually led to the detoxification of effluent. The increased survivability of Huh7 cells cultured with treated effluent also confirmed the detoxification as examined by MTT assay. CONCLUSION: Isolated strain B. cereus was able to remove and detoxify chromium (VI). It would be an efficient tool of the biotechnological approach in mitigating the heavy metal pollutants.
Показать больше [+] Меньше [-]Investment threshold and management reflection for industrial system cleaning: a case for China
2012
Fang, Yiping
INTRODUCTION: The recognition that industrial activity plays an essential role in a sustainable society is now widespread. To understand the causal relationship between industrial pollution abatement expenditure and industrial system cleaning level in China is of considerable importance, especially under extremely rapid industrial growth and serious pressure of industrial pollutants abatement context. STUDY METHODS: We use composite index assessment method and regression analysis in this paper. We establish the mathematical model between composite industrial cleaner index and investment intensity for industrial pollutants abatement, and analyze the effects of industrial pollutants treatment and discharge indicators on composite industrial cleaner index in China. RESULTS AND DISCUSSION: Results show that: (1) There is significant nonlinear relationship between composite industrial cleaner index and investment intensity for industrial pollutants abatement. (2) From single indicator perspective, the effect of investment intensity on pollutants treatment indicators is positively, on the contrary, the effect of investment intensity on pollutants discharge indicators is negatively; (3) From decomposition cleaner index perspective, the effect of pollutants discharge level (process control) is higher than pollutants treatment capacity (end-of-pipe) on composite industrial cleaner index; (4) There is threshold between investment intensity and composite cleaner industrial index, it is a crucial reference scale for industrial environmental management in selected period.
Показать больше [+] Меньше [-]Equilibrium, kinetic and thermodynamic studies on the biosorption of reactive acid dye on Enteromorpha flexuosa and Gracilaria corticata
2012
Sivasamy, A. | Nethaji, S. | Nisha, L. L Josmin Lalli
PURPOSE: Biosorption is an emerging, eco-friendly and economical method for treating the wastewater effluents. Compared to many other biological materials, algae biomass proved to be the better biosorbent due to the presence of cell wall polymers in them. METHODS: Algal biomasses namely Enteromorpha flexuosa and Gracilaria corticata were dried, crushed and used as biosorbents. Ponceau S, a diazo dye was used as a model adsorbate for the biosorption studies. The biosorbents were characterized by Scanning Electron Microscopy, FT-IR and zero point charge. Batch studies were performed by varying pH, biosorbent dosage and initial dye concentrations. Adsorption isotherms, kinetic and thermodynamic analyses were carried out. The effect of electrolytes was also studied. Batch desorption studies were also carried out using various reagents. RESULTS: Isotherm data were tested with Langmuir and Freundlich isotherm models and the results suggested that the Freundlich isotherm fitted the data well. Kinetic studies were performed with varying initial dye concentrations and the data were incorporated with pseudo first-order and pseudo second-order kinetic equations and was found that the studied biosorption processes followed pseudo second-order kinetic equation. Thermodynamic parameters were evaluated at three different temperatures 293 K, 300 K and 313 K. About 95% of the dye could be desorbed from both the biosorbents. CONCLUSION: Both the algal biomasses had heterogeneous surfaces and followed pseudo second-order chemical kinetics. Thermodynamic parameters proved that the biosorption by both the biomasses were spontaneous, feasible and endothermic processes. Desorption studies proved the worth of the algal biomasses as biosorbents in industrial level.
Показать больше [+] Меньше [-]Phytoremediation of phenol using Vicia sativa L. plants and its antioxidative response
2012
Ibáñez, Sabrina G. | Alderete, Lucas G Sosa | Medina, María I. | Agostini, Elizabeth
Common vetch (Vicia sativa L.) is a legume species with an extensive agricultural use. However, the phytoremediation potentiality of this species has not been sufficiently explored because little is known about its resistance to inorganic and organic pollutants. In the present work, phenol tolerance of common vetch was assayed at different stages of growth. Germination index and germination rate decreased only at high phenol concentrations (250 and 500 mg L − 1), whereas 30-day-old plants were able to tolerate this pollutant, with high removal efficiencies. The activities of antioxidative enzymes, such as peroxidase (POD) and ascorbate peroxidase, increased significantly with the highest phenol concentration, whereas superoxide dismutase activity, malondialdehyde, and H2O2 levels remained unaltered. Besides, an increase in two basic isoforms of POD was observed in plants treated with phenol. The results suggested that common vetch has an efficient protection mechanism against phenol-induced oxidative damage. Moreover, it could tolerate and remove high phenol concentrations, avoiding serious phytotoxic effects. Thus, V. sativa could be considered an interesting tool in the field of phytoremediation.
Показать больше [+] Меньше [-]Combined biodegradation and ozonation for removal of tannins and dyes for the reduction of pollution loads
2012
Kanagaraj, James | Mandal, A. B. (Asit Baran)
PURPOSE: Tannins and dyes pose major threat to the environment by generating huge pollution problem. Biodegradation of wattle extract, chrome tannin and dye compounds using suitable fungal culture namely Aspergillus niger, Penicillium sp. were carried out. In addition to these, ozone treatment was carried out to get higher degradation rate. RESULTS: The results were monitored by carrying out chemical oxygen demand (COD), total organic carbon (TOC), and UV–Vis analysis. The results showed that wattle extract (vegetable tannin) gave better biodegradation rate than dye and chromium compounds. Biodegradation plus ozone showed degradation rates of 92–95%, 94–95%, and 85–87% for the wattle extract, dyes, chromium compounds, respectively. UV–Vis showed that there were no peaks observed for biodegraded samples indicating better degradation rates as compared to the control samples. FT-IR spectra analysis suggested that the formation of flavanoid derivatives, chromic oxide and NH2 compounds during degradation of wattle extract, chromium and dye compounds, respectively, at the peaks of 1,601–1,629 cm−1, 1,647 cm−1, and 1,610–1,680 cm−1. CONCLUSION: The present investigation shows that combination of biodegradation with ozone is the effective method for the removal of dyes and tannins. The biodegradation of the said compounds in combination with ozonation showed better rate of degradation than by chemical methods. The combination of biodegradation with ozone helps to reduce pollution problems in terms of COD, TOC, total dissolved solids and total suspended solids.
Показать больше [+] Меньше [-]Chemical and morphological characterization of aerosol particles at Mt. Krvavec, Slovenia, during the Eyjafjallajökull Icelandic volcanic eruption
2012
Beeston, Michael | Grgić, Irena | van Elteren, Johannes T. | Iskra, Ivan | Kapun, Gregor | Močnik, Griša
OBJECTIVE: In this work, continuous and size-segregated aerosol measurements at Mt. Krvavec, Slovenia, during the Eyjafjallajökull volcanic eruption were performed. Based on chemical and morphological characteristics of size-segregated particles, the presence of the volcanic aerosols after long-range transport to Slovenia was to be confirmed. RESULTS AND CONCLUSIONS: Continuous measurements with the aethalometer and SMPS indicated the suspected volcanic ash plume passing over the sampling site. The aerosols collected by discrete sampling showed a chemical signature similar to the known elemental signature of the Icelandic volcanic ash. Coarse particles showed a composition typical for silicates rich in metals; in many cases also S was present. Morphological analysis showed particles with features indicative of an explosive volcanic eruption, e.g., pumice and pumice shards, glass shards, minerals, evidence of steam condensation, etc. The high sulfate concentration associated with the fine particles resulted in sulfate crystallization within the cascade impactor leading to the formation of large structures resembling a “fern”. Mass size distributions for Fe, Ti, Mn, Ca, Na, and Mg showed one primary peak (for Fe, Mn, and Ti at 2.8 μm; for Ca, Na, and Mg at ca. 4 μm), which supports the fact that most of the particles in the coarse sizes were silicates rich in metals. The size distribution of the water-soluble SO 4 2− showed a maximum peak at 0.75 μm, which also confirms the high sulfate concentration in the fine particles. Chemical and morphological characterization of aerosols collected at Mt. Krvavec indeed confirmed that volcanic ash plume passed over Slovenia.
Показать больше [+] Меньше [-]Suitability of Scirpus maritimus for petroleum hydrocarbons remediation in a refinery environment
2012
Couto, M. Nazaré P. F. S. | Basto, M. Clara P. | Vasconcelos, M. Teresa S. D.
PURPOSE: In the ambit of a project searching for appropriate biological approaches for recovering a refinery soil contaminated with petroleum hydrocarbons (PHC), we compared results obtained in the absence and in the presence of the salt marsh plant Scirpus maritimus or Juncus maritimus or an association of these two plants, which were tested in the refinery environment. Synergistic effects caused by addition of a non-ionic surfactant and/or a bioaugmentation product were also investigated. Major challenges of this study were: field conditions and weathered contamination. METHODS: Transplants of the plants were carried out in individual containers filled with a weathered contaminated soil, which was recontaminated with turbine oil with two purposes: for increasing PHC level and allowing a comparison of the potential of plants for remediation of ancient and recent contamination. RESULTS: Analysis of total PHC led to the conclusion that, after 24-month exposure, neither J. maritimus nor the association caused any improvement in remediation. In contrast, S. maritimus revealed potential for PHC remediation, favoring degradation of both recent and older contamination (which was refractory to natural attenuation). About 15% of remediation improvement was found in the soil layer with higher root density (5–10 cm). A more marked improvement in that layer (28%) was observed when non-ionic surfactant amendment and bioaugmentation were used jointly. CONCLUSIONS: The fact that S. maritimus has demonstrated capability for PHC remediation, leads to admit that it has potential to be also used for recovering sediments that have suffered accidental oil spills.
Показать больше [+] Меньше [-]Measurement of pollution levels of organochlorine and organophosphorus pesticides in water, soil, sediment, and shrimp to identify possible impacts on shrimp production at Jiquilisco Bay
2012
Nomen, Rosa | Sempere, Julià | Chávez, Francisco | de López, Nelly Amaya | Rovira, MaDolores
This study aims to identify levels of several organochlorine and organophosphorus compounds in shrimp-raising areas of coastal El Salvador, to assess potential impacts on shrimp growth and survival that hamper the sustainability of aquaculture in the region. The paper reports the current levels of γ-HCH, 4,4′-DDT, 4,4′-DDE, 4,4′-DDD, endrin, dieldrin, heptachlor, parathion, methyl parathion, and etoprophos in soils (depth 20 cm), sediments (depth 5 cm), shrimp (Penaeus sp.), and water of three rearing ponds and also in the sediment (depth 5 cm) and water surrounding those ponds in Jiquilisco Bay. Sampling was carried out during the dry (January–March) and rainy (June–August) seasons of 2008. The presence of pesticides in the samples of water, shrimp, and sediment at shrimp ponds was not detected in either season; however, in soil samples (depth 20 cm) taken from these ponds, heptachlor, endrin, dieldrin, 4,4′-DDD, and 4,4′-DDT were identified at concentrations below the method limit of quantification (LOQ), and 4,4′-DDE was found in a concentration falling in the range from 3.85 to 19.61 ng/g. In samples of water taken at the bay water intakes to the rearing ponds, we observed dieldrin concentrations in the range between 0.085 ng/mL and 0.182 ng/mL during the dry season. In the samples of sediments taken in the surrounding areas of shrimp ponds, we found—for both seasons—that in 60 % of the samples, 4,4′-DDE was present in concentrations ranging from 3.75 ng/g to 30.97 ng/g. Additionally, in the rainy season, we observed heptachlor in sediment at concentrations below the method quantification limit. It was concluded that organochlorine compounds from pesticides are still present in Jiquilisco Bay, trapped in deep sediment, even though they have been banned since the 1980s. These were not detected in shrimp tissue, surface water, and shallow sediment in rearing ponds, and hence, we do not believe their presence has any major impact on shrimp production in sampled areas.
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