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The leaching kinetics of chalcopyrite (CuFeS 2 ) concentrate in sulfuric acid leach media with and without the initial addition of Fe 3+ under carefully controlled solution conditions ( E h 750 mV SHE, pH 1) at various temperatures from 55 to 85 °C were measured. Kinetic analyses by (i) apparent rate (not surface area normalised), and rate dependence using (ii) a shrinking core model and (iii) a shrinking core model in conjunction with Fe 3+ activity, were performed to estimate the activation energies ( E a ) for Cu and Fe dissolution. The E a values determined for Cu and Fe leaching in the absence of added Fe 3+ are within experimental error, 80 ± 10 kJ mol −1 and 84 ± 10 kJ mol −1 , respectively (type iii analyses E a are quoted unless stated otherwise), and are indicative of a chemical reaction controlled process. On addition of Fe 3+ the initial Cu leach rate (up to 10 h) was increased and Cu was released to solution preferentially over Fe, with the E a value of 21 ± 5 kJ mol −1 (type ii analysis) suggestive of a transport controlled rate determining process. However, the rate of leaching rapidly decreased until it was consistently slower than for the equivalent leaches where Fe 3+ was not added. The resulting E a value for this leach regime of 83 ± 10 kJ mol −1 is within experimental error of that determined in the absence of added Fe 3+ . In contrast to Cu release, Fe release to solution was consistent with a chemical reaction controlled leach rate throughout. The Fe release E a of 76 ± 10 kJ mol −1 is also within experimental error of that determined in the absence of added Fe 3+ . Where type (ii) and (iii) analyses were both successfully carried out (in all cases except for Cu leaching with added Fe 3+ , E a derived are within experimental error. However, the type (iii) analyses of the leaches in the presence of added Fe 3+ (>10 h), as compared to in the absence of added Fe 3+ , returned a considerably smaller pre-exponential factors for both Cu and Fe leach analyses commensurate with the considerably slower leach rate, suggestive of a more applicable kinetic analysis. XPS examination of leached chalcopyrite showed that the surface concentration of polysulfide and sulfate was significantly increased when Fe 3+ was added to the leach liquor. Complementary SEM analysis revealed the surface features of chalcopyrite, most likely due to the nature of the polysulfide formed, are subtly different with greater surface roughness upon leaching in the absence of added Fe 3+ as compared to a continuous smooth surface layer formed in the presence of added Fe 3+ . These observations suggest that the effect of Fe 3+ addition on the rate of leaching is not due to the change in the chemical reaction controlled mechanism but due to a change in the available surface area for reaction.

The Earth’s mantle contains non-radiogenic noble gas isotopes that imply transfer of noble gases from the atmosphere into the mantle through subduction. Hydrated serpentinite rocks within subducting oceanic lithosphere are recognized as key carriers of water and chlorine, but the pathways for noble gas subduction have been poorly constrained. Here we analyse the concentration of noble gas isotopes and halogens in rocks from the Ligurian Alps, Italy and the Betic Cordillera, Spain. These rocks and the fluid inclusions trapped within them preserve a record of serpentinite dehydration during progressively deeper stages of subduction. We find that the noble gas and halogen signature of serpentinites reflects that of sea water and sediment pore fluids. The fluids released become progressively depleted in noble gases and chlorine is subducted to greater depths than bromine or iodine. After complete breakdown of the serpentinites at mantle depths of around 70 km, the dehydrated rock residues still retain a seawater-derived noble gas signature and significant chlorine. We suggest that these samples are proxies for serpentinite dehydration in cold slabs at mantle depths of 200 km or greater. We conclude that atmospheric noble gases are readily incorporated into hydrous minerals formed close to the sea floor, and incompletely removed by subduction zone metamorphism. This implies that noble gases can be subducted to great depths in the Earth’s mantle. Noble gases from the atmosphere are carried into Earth’s mantle through subduction. Geochemical analyses of rocks that record slab dehydration during progressively deeper stages of subduction indicate that noble gases incorporated into hydrous minerals close to the sea floor are efficiently transported to mantle depths of at least 200 km.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:25:58Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:47:19Z : No. of bitstreams: 1 2-s2.0-80051844148.pdf: 432012 bytes, checksum: bd3963821dd9c7c5e7a59d26db770ee6 (MD5) Made available in DSpace on 2014-05-27T11:25:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-09-01 Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1mLL -1. The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota. © 2011 Elsevier Ltd. Departamento de Química e Ciências Ambientais Universidade Estadual Paulista (IBILCE/UNESP), Rua Critóvão Colombo, 2265, CEP 15054-000 São José do Rio Preto, SP Departamento de Química e Ciências Ambientais Universidade Estadual Paulista (IBILCE/UNESP), Rua Critóvão Colombo, 2265, CEP 15054-000 São José do Rio Preto, SP

To better characterize the tropical aerosols in Indian region, PM10 samples collected from Chennai, India (13.04° N; 80.17° E) were analyzed for carbonaceous and water-soluble ionic components. Concentration ranges of elemental carbon (EC) and organic carbon (OC) were 2.4–14 μg m−3 (ave. 6.5 μg m−3) and 3.2–15.6 μg m−3 (ave. 9.1 μg m−3) in winter samples whereas they were 1.1–2.5 μg m−3 (ave. 1.6 μg m−3) and 4.1–17.6 μg m−3 (ave. 9.7 μg m−3) in summer samples, respectively. Concentration of secondary organic carbon (SOC) retrieved from EC-tracer method was 4.6±2.8 μg m−3 in winter and 4.3±2.8 μg m−3 in summer. OC accounted for 38.5±14 % (n = 49) of combined concentrations of carbonaceous and ionic components in PM10. We also found that OC concentrations are generally higher than those of SO42− (8.8±2.5 μg m−3 and 4.1±2.7 μg m−3 in winter and summer, respectively), which was the most abundant ionic species (57 %) followed by NH4+ (15 %) >NO3−>Cl−>K+>Na+> Ca2+>MSA−>Mg2+. The mass fractions of EC, organic matter (OM) and ionic species varied seasonally, following the air mass trajectories and corresponding source strength. Based on mass concentration ratios of selected components and relations of EC and OC to marker species, we found that biofuel/biomass burning is a major source of atmospheric aerosols in South and Southeast Asia. The high concentrations of SOC and WSOC/OC ratios (ave. 0.45; n = 49) as well as good correlations between SOC and WSOC suggest that the secondary production of organic aerosols during long-range atmospheric transport is also significant in this region. This study provides the baseline data of carbonaceous aerosols for southern part of the Indian subcontinent.

The growth of Pseudomonas sp. was studied in fed-batch process with an aim to improve the caffeine degradation rate and caffeine demethylase activity. The effects of varying initial caffeine concentrations in the batch mode, increase in the number of feeds, varying feed flow rates, and added nutrients to the feed on the fed-batch process were investigated. A maximum caffeine degradation rate of 0.82 g/L h and maximum caffeine demethylase activity of 2.6 U/mg were achieved using manual intermittent pulse feeds of caffeine with substrate concentration as feedback parameter for the fed batch started with an initial caffeine concentration of 3 g/L. A slight increase in the caffeine degradation rate (0.85 g/L h) and caffeine demethylase activity (3.4 U/mg) was observed when the additional nutrients were added along with caffeine in the feed. This is the first report showing complete degradation of large magnitudes of caffeine amounting to 237 g in 75 h. These results show that the fed-batch conditions achieved in this study using Pseudomonas sp. facilitate the development of a sustainable bioprocess to degrade the high concentrations of caffeine in industrial effluents. � 2011 Springer-Verlag.

In this work, a new separation-preconcentration method was developed for the determination of trace amounts of Cu(II), Ni(II), and Fe(III) by flame atomic absorption spectrometry (FAAS). Analytes were complexed by using zincon (2-[2-[alpha(2-hydroxy-5-sulfophenylazo) benzylidene] hydrazino] benzoic acid sodium salt). The analyte ions were quantitatively adsorbed on a Diaion HP-20 resin at pH 5. The retained metal ions on the resin were eluted by acetone. The analytical parameters such as pH of the sample, eluent type and volume, sample volume, and flow rates of the solution and the eluent were investigated. The influences of concomitant ions on the recoveries of the analytes were also examined. The instrumental detection limits for the analytes after application of the presented solid-phase extraction procedure were in the range of 0.72-1.41μg/L. The validation of the presented procedure was checked by analyzing certified reference material of SRM1515 Apple Leaves. The procedure was performed by analyzing some spice samples. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low ice crystal concentration and sustained in-cloud supersaturation, commonly found in cloud observations at low temperature, challenge our understanding of cirrus formation. Heterogeneous freezing from effloresced ammonium sulfate, glassy aerosol, dust and black carbon are proposed to cause these phenomena; this requires low updrafts for cirrus characteristics to agree with observations and is at odds with the gravity wave spectrum in the upper troposphere. Background temperature fluctuations however can establish a "dynamical equilibrium" between ice production and sedimentation loss (as opposed to ice crystal formation during the first stages of cloud evolution and subsequent slow cloud decay) that explains low temperature cirrus properties. This newly-discovered state is favored at low temperatures and does not require heterogeneous nucleation to occur (the presence of ice nuclei can however facilitate its onset). Our understanding of cirrus clouds and their role in anthropogenic climate change is reshaped, as the type of dynamical forcing will set these clouds in one of two "preferred" microphysical regimes with very different susceptibility to aerosol.

Airborne particulate matter (PM) and associated metals were measured in a district of an industrial city in Western Turkey. We compared PM concentrations in Bursa, Turkey (Nilufer district) with international air quality standards. Turkish legislature adopted the EC Air Quality Framework in 2008, and compliance is required in the medium term. State-of-the-art reference methods were used for all measurements. A Partisol sampler measured urban background PM2.5 and PM10 between May 2007 and April 2008, and PM2.5 samples were later analysed for selected metals using ICP-MS. Average PM2.5 and PM10 mass concentrations over the year were 53 and 83 mu g/m(3), respectively. The annual mean PM2.5:PM10 ratio in Bursa was 0.64. PM2.5 and PM10 were highly correlated at the site (R=0.91 overall), especially in winter. In the cold seasons, the coarse and fine fractions were strongly correlated R=0.67 (p

cited By 7; To measure the long term retention and seasonal dynamics of an initial 4 kg addition of 133Cs into an 11.4-ha, 157,000 m3 reservoir (Pond 4, near Aiken, South Carolina, USA), the concentrations and inventories of 133Cs in the water column were measured at periodical intervals for 522 days following the 1 August, 1999 release. After rapid declines in concentrations and inventories during the first 90 days, the 133Cs concentrations in the water column declined at an average proportional rate of 0.004 d-1. However, there were periods of less rapid and more rapid rates of declines, and these were correlated with periods of increasing and decreasing K concentrations in the water column. The decline rates were less and the K concentrations greater in the winter than in the summer. In the deeper, neighboring monomictic reservoirs of Par Pond and Pond B, a yearly cycle of increasing and decreasing 137Cs concentrations in the water column is driven by anoxic remobilization of Cs from the sediments into a persistent summer hypolimnion. In Pond 4, whose mean depth of 1.6 m is too shallow to support a persistent anoxic hypolimnion, the pattern of yearly dynamics for K and Cs appear to be related to the accumulation and release of these elements from the extensive, seasonal macrophyte communities. The contrasting results between Pond 4 and Pond B suggest that a full appreciation of the relative importance of 1) anoxic remobilization and 2) accumulation and release by macrophytes in these systems remains to be established. © 2010.

In May 2008, the measurement campaign IMPACT for observation of atmospheric aerosol and cloud properties was conducted in Cabauw, The Netherlands. With a nudged version of the coupled aerosol-climate model ECHAM5-HAM we simulate the size distribution and chemical composition of the aerosol and the associated aerosol optical thickness (AOT) for the campaign period. Synoptic scale meteorology is represented realistically through nudging of the vorticity, the divergence, the temperature and the surface pressure. Simulated concentrations of aerosol sulfate and organics at the surface are generally within a factor of two from observed values. The monthly averaged AOT from the model is 0.33, about 20% larger than observed. For selected periods of the month with relatively dry and moist conditions discrepancies are approximately −30% and +15%, respectively. Discrepancies during the dry period are partly caused by inaccurate representation of boundary layer (BL) dynamics by the model affecting the simulated AOT. The model simulates too strong exchange between the BL and the free troposphere, resulting in weaker concentration gradients at the BL top than observed for aerosol and humidity, while upward mixing from the surface layers into the BL appears to be underestimated. The results indicate that beside aerosol sulfate and organics also aerosol ammonium and nitrate significantly contribute to aerosol water uptake. The simulated day-to-day variability of AOT follows synoptic scale advection of humidity rather than particle concentration. Even for relatively dry conditions AOT appears to be strongly influenced by the diurnal cycle of RH in the lower boundary layer, further enhanced by uptake and release of nitric acid and ammonia by aerosol water.

The oceans are a major source for particles that play an important role in many atmospheric processes. In Europe sea salt may contribute significantly to particulate matter concentrations. We have compiled sodium concentration data as a tracer for sea salt for 89 sites in Europe to provide more insight in the distribution of sea salt across Europe. The annual average sea salt concentrations above land were estimated to range between 0.3 and almost 13 μg m-3. Maximum concentrations are found at the Irish coast. At coastal sites along the Atlantic and North Sea coast concentrations tend to be around 5 μg m-3. More inland locations up to about 300 km away from the coast tend to show concentrations between 2 and 5 μg m-3, whereas sites further away from the coast are characterized by lower concentrations. An analysis of the representativity of the data with respect to a long term average showed that the long average is associated with a standard deviation of around 15%. The compilation of observations provides an improved overview of sea salt concentrations in Europe as well as an improved basis for model validation. Verification of the results of the LOTOS-EUROS model learned that the model represents well the spatial variability of the observed sea salt concentrations very well. However, the absolute concentrations are significantly overestimated due to large uncertainties in the emission and dry deposition parameterizations. Using the high explained variability in the gradients across Europe, the bias-corrected modelled distribution serves as a best estimate of the sea salt distribution across Europe for 2005. © 2010.

Arsenic removal from drinking water by precipitation-coprecipitation method using aluminum sulfate was investigated. The Box-Behnken statistical experiment design (BBD) and response surface methodology (RSM) were used to investigate the effects of major operating variables. Initial arsenate concentration, pH, and aluminum sulfate dose were selected as independent variables in BBD while arsenate removal was considered as the response function. The predicted values of arsenate removal obtained using the response function were in good agreement with the experimental data. Aluminum sulfate was found as effective and reliable coagulant due to required dose, residual arsenate and aluminum concentration. The optimum pH range for maximum arsenate removal was 6-8. In the low initial arsenate concentrations, the highest arsenate removal efficiency was obtained at high aluminum sulfate doses, while in the high initial arsenate concentrations, the highest arsenate removal efficiency was provided at low coagulant doses. This study showed that statistical design methodology was an efficient and feasible approach in determining the optimum conditions for arsenic removal by coagulation and flocculation. The use of all types of coagulant aids increased the removal efficiency of the treatment method but application of cationic polyelectrolyte was more effective than anionic and nonionic ones. (C) 2009 Elsevier B.V. All rights reserved.

The atmospheric concentrations and dry deposition of carbazole were measured to present the temporal changes, gas/particle partitioning and magnitude of fluxes. Atmospheric samples were collected from July 2004 to May 2005 at four different sites in Bursa, Turkey. The average total (gas and particulate) carbazole concentrations were 7.6 +/- 9.9 ng m(-3) in Gulbahoe (Residential), 1.1 +/- 1.2 ng m(-3) in BUTAL (Traffic), 33 +/- 5.0 ng m(-3) in BOID (industrial), and 1.2 +/- 0.7 ng m(-3) in the Uludag University Campus (UU) (Suburban). Experimental gas/particle partition coefficient (K-P) was determined using the study results and compared with K-P values calculated from octanol-air and soot-air+octanol partitioning models. Total dry deposition fluxes of carbazole were 290 +/- 484 ng m(-2) d(-1) in BUTAL and 72 +/- 67 ng m(-2) d(-1) in the UU Campus. Particulate phase dry deposition velocities were 0.81 +/- 0.78 cm s(-1) and 0.90 +/- 1.53 cm s(-1) for BUTAL and the UU Campus, respectively. On the other hand, gas-phase mass transfer coefficients were calculated to be 0.34 +/- 0.29 cm s(-1) and 026 +/- 0.17 cm s(-1) for BUTAL and the UU Campus, respectively. (C) 2009 Elsevier B.V. All rights reserved.

A comprehensive modeling approach has been developed for use in formulating a watershed management plan to improve the water quality of Cedar Creek reservoir, one of five large water supply reservoirs in north central Texas operated by Tarrant Regional Water District. Eutrophication, or specifically the increase in concentrations of chlorophyll-a (chl'a') over the last 18 years, is a major concern for the water managers. To develop a watershed management plan, the watershed model SWAT was linked with the lake eutrophication model WASP. Several intensive field campaigns and surveys were conducted to collect extensive water quality and land management data for model setup and calibration. In addition to the streamflow, the SWAT model was well calibrated for sediment (including channel erosion) and nutrients. Further, a simple modification to the SWAT in-stream routine allowed simulation of the nutrient load due to channel erosion. The in-stream water quality parameters for SWAT were based on an independent QUAL-2E model calibration. The calibrated SWAT model showed that more than 85% of the total N and total P loading to the lake are from watershed nonpoint sources. Although cropland occupies only 6% of the watershed area, it contributed more than 43% of the sediment, 23% of total N, and 42% of total P loading from the watershed. The channel erosion contributed about 35% of the total sediment load. The watershed model identified subbasins that contribute considerable amounts of sediment and nutrients. Based on these loads, the calibrated WASP model showed that the watershed nonpoint-source nutrient load (total N and total P) should be reduced by at least 35% to see a significant reduction in chl'a' concentrations when compared to the WASP calibration levels. � 2010 American Society of Agricultural and Biological Engineers.

The purpose of this study was to predict the equilibrium soil concentrations and distributions of Σ 41 Polychlorinated Biphenyl (PCB) congeners from the air data measured at 4 sites (urban, suburban, residential, and industrial) in Bursa between 2004 and 2005. The soil–air partition coefficient ( K SA ) was used for the predictions. Predicted soil concentrations ranged from 25 pg/g to 690 pg/g, while the atmospheric concentrations fluctuated between 35 pg/m 3 and 1112 pg/m 3 . The soil concentrations were found to be in agreement with the lower range of European and global values, and below the regulatory limits. The urban and residential sites yielded higher PCB concentrations and a higher degree of heavier congeners than the sites characterized as suburban. The urban and residential sites were dominated by hexa-chlorinated biphenyls (CBs), followed by tri-CBs, while the industrial site was dominated by tri-CBs, followed by tetra-CBs. PCB congeners of 153, 180, 138, 118, and 101 were higher in all locations. The effect of the temperature changes on the concentrations was found to be insignificant, as the correlations ranged between 0.0009 and 0.22 for all sites. The K SA approach yielded reasonable results, and it is recommended to use this approach when there is limited data about the pollution levels of a certain media such as soil by using the measured levels of the other media such as air.

The nature of the main selenium (Se) carrier phases in soil is in debate, with some authors emphasizing the role of minerals, and others the role of organic material. In this study, we address the role of the different soil components in Se sorption by determining its interaction with easily separable and workable fractions of bulk soil. Thus four separated fractions (two organic and two mineral) isolated by size density fractionation from a grassland soil were taken as models for soil Se carrier phases. Two concentrations of selenite were used to estimate its reactivity during experiments. In addition, SEM-TEM analyses (coupled with EDS) were used to determine the chemical environment of Se sorbed onto the different fractions. The results showed that for the smaller selenite concentration nearly all the fractions gave the same selenite sorption (approximately 99%). For the larger concentration, selenite sorption ranged between 44% (mineral fractions) and 93% (organic fractions), indicating that the sorption capacities of organic fractions were greater than those of mineral fractions. In all soil fractions, elementary analyses and SEM/EDS and TEM/EDS observations revealed that Se sorption and the detection of Se hot spots on the soil particles correlated with the presence of Fe and Al. Although a direct association between Se and organic material could not be excluded, we suggest that Se sorption on organic particles is indirect, mainly resulting from association with surface Fe oxides or clays. These findings question the current view of a direct correlation between organic carbon and Se in natural soil samples. © 2009 British Society of Soil Science.

The absence of species in polluted sediments does not necessarily imply exclusion due to toxicity. Other factors, like for instance food availability and oxygen content, could also partly cause their absence. Hence, knowledge of the (combinations of) factors acting on individual organisms is essential in order to understand how populations can persist in polluted sediments. In this study species-specific responses of two benthic invertebrate species, the mayfly Ephoron virgo and the midge Chironomus riparius, to environmental variables were compared. It was assessed how these responses determine the distribution of these species in polluted sediments. Subsequently, it was discussed how these results can assist in the formulation and implementation of policies with respect to the ecological risks of pollution to benthic invertebrates. The present study showed that sediment pollution is likely to act only occasionally as a single selective force reducing the persistence of sensitive species. Yet, it was shown in our studies that the pollution level in some tested sediments limits the persistence of insects with the sensitivity of E. virgo. In other cases, however, a combination of conditions is likely to determine their persistence. As shown here for C. riparius, sediment pollution drives this species close to intoxication, but a high availability of food enables them to persist very well. The present study provides evidence that pollution levels exceeding current Dutch Negligible Concentrations may pose a detectable ecological effect at least for sensitive benthic invertebrates. © 2008 Elsevier B.V. All rights reserved.

Interannual variability (IAV) in tropospheric species concentrations can be driven by variability in emissions, chemistry, transport and UV radiation. In a 3D CTM study we have found good agreement between the IAV of NO2 columns observed by the GOME satellite instrument and model simulations over Western Europe from 1996 to 2000. We find that meteorological variability is an important factor during this period. Averaged 10 m wind speeds from the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis are a good proxy for the overall meteorology driving the IAV during the studied period of 1996-2000. Copyright © 2008 Royal Meteorological Society.

A simple, economic and sensitive method for selective determination of As(III) and As(V) in water samples is described. The method is based on selective coprecipitation of As(III) with Ce(IV) hydroxide in presence of an ammonia/ammonium buffer at pH 9. The coprecipitant was collected on a 0.45 µm membrane filter, dissolved with 0.5 mL of conc. nitric acid and the solution was completed to 2 or 5 mL with distilled water. As(III) in the final solutions was determined by graphite furnace atomic absorption spectrometry (GFAAS). Under the working condition, As(V) was not coprecipitated. Total inorganic arsenic was determined after the reduction of As(V) to As(III) with NaI. The concentration of As(V) was calculated by the difference of the concentrations obtained by the above determinations. Both the determination of arsenic with GF-AAS in presence of cerium and the coprecipitation of arsenic with Ce(IV) hydroxide were optimised. The suitability of the method for determining inorganic arsenic species was checked by analysis of water samples spiked with 4-20 µg L-1 each of As(III) and As(V). The preconcentration factor was found to be 75 with quantitative recovery (?95%). The accuracy of the present method was controlled with a reference method based on TXRF. The relative error was under 5%. The relative standard deviations for the replicate analysis (n = 5) ranged from 4.3 to 8.0% for both As(III) and As(V) in the water samples. The limit of detection (3?) for both As (III) and As(V) were 0.05 µg L-1. The proposed method produced satisfactory results for the analysis of inorganic arsenic species in drinking water, wastewater and hot spring water samples. © 2008 Taylor & Francis.

The ability of secondary organic aerosol (SOA) produced from the ozonolysis of α-pinene and monoterpene mixtures (α-pinene, β-pinene, limonene and 3-carene) to become cloud droplets was investigated. A static CCN counter and a Scanning Mobility CCN Analyser (a Scanning Mobility Particle Sizer coupled with a Continuous Flow counter) were used for the CCN measurements. Consistent with previous studies monoterpene SOA is quite active and would likely be a good source of cloud condensation nuclei (CCN) in the atmosphere. A decrease in CCN activation diameter for α-pinene SOA of approximately 3 nm hr−1 was observed as the aerosol continued to react with oxidants. Hydroxyl radicals further oxidize the SOA particles thereby enhancing the particle CCN activity with time. The initial concentrations of ozone and monoterpene precursor (for concentrations lower than 40 ppb) do not appear to affect the activity of the resulting SOA. Köhler Theory Analysis (KTA) is used to infer the molar mass of the SOA sampled online and offline from atomized filter samples. The estimated average molar mass of online SOA was determined to be 180±55 g mol−1 (consistent with existing SOA speciation studies) assuming complete solubility. KTA suggests that the aged aerosol (both from α-pinene and the mixed monoterpene oxidation) is primarily water-soluble (around 65%). CCN activity measurements of the SOA mixed with (NH4)2SO4 suggest that the organic can depress surface tension by as much as 10 N m−1 (with respect to pure water). The droplet growth kinetics of SOA samples are similar to (NH4)2SO4, except at low supersaturation, where SOA tends to grow more slowly. The CCN activation diameter of α-pinene and mixed monoterpene SOA can be modelled to within 10–15% of experiments by a simple implementation of Köhler theory, assuming complete dissolution of the particles, no dissociation into ions, a molecular weight of 180 g mol−1, a density of 1.5 g cm−3, and the surface tension of water.

Atmospheric PAH concentrations were determined in Gulbahce district of Bursa, Turkey between August 2004 and April 2005. Measured PAH concentrations were classified as heating and non-heating season samples. The concentrations of total PAHs in heating season were almost ten times higher than those in non-heating season. Diagnostic ratios and factor analysis results show that in the heating season traffic along with residential heating emissions heavily influence PAH concentrations. The plot of logKp versus logPL0 for all the data set of heating and non-heating season samples gave significantly different slopes. The slope for the heating season samples (− 0.92) was steeper than the one for the non-heating season samples (− 0.78). The partitioning results for individual samples further indicated that slope values varied depending on air parcel trajectories. Air parcels traveled over water (either over the Black Sea or Aegean Sea) prior to arriving at the sampling site had less steep slopes. Partitioning of PAHs was also investigated by comparing experimentally determined Kp values with the results obtained both from octanol-based model (Kp(Oct.)) and soot and octanol-based model (Kp (Soot + Oct.)). Both models were useful in predicting the experimental Kp values. However, they did not explain the observed variability in the experimental Kp values.

In order to better evaluate the consequences of an accidental release of heavy gas, such as uranium hexafluoride (UF6), in some installations in the nuclear fuel cycle, an experimental and numerical study was conducted by IRSN on heavy gas dispersion in a ventilated room. This study was based on about 20 injection configurations of a large quantity of a heavy tracer gas, sulphur hexafluoride (SF6), inside two ventilated rooms of different sizes. Stratification of the tracer gas was detected in all the configurations studied, even at low concentrations. Numerical simulations performed with the multidimensional CFX code enabled the stratification and the concentration levels reached in the rooms to be predicted overall, and the higher the air flow rate, the more satisfactory the comparison between simulation and experiment. © 2007 Elsevier B.V. All rights reserved.

Fog samples were collected in two population centers of the US Gulf Coast (Houston, Texas and Baton Rouge, Louisiana) using Caltech active strand cloud collectors. A total of 32 fogwater samples were collected in Baton Rouge (November 2004-February 2005) and Houston (February 2006). These samples were analyzed for pH, total and dissolved organic carbon, major inorganic ions, and a variety of organic compounds including organic acids, aromatics, carbonyls, and linear alkanes. Fogs in both environments were of moderate density, with typical fog liquid water contents

A group of Roman glass objects from the Bocholtz burial in the SW of Limburg (The Netherlands) was found to have been subject to varying degrees of degradation. Many of the 25 colourless glass objects were fragmented to pieces

Pool boiling heat transfer using nanofluids (which are suspensions of nano-sized particles in a base fluid) has been a subject of many investigations and incoherent results have been reported in literature regarding the same. In the past, experiments were conducted in nucleate pool boiling with varying parameters such as particle size, concentration, surface roughness etc. and all sort of results ranging from heat transfer enhancement, deterioration and no effect were reported. This work tries to segregate a survey on pool boiling of nanofluids with respect to particle concentration. This is due to the fact that a major drift in heat transfer behavior is observed at higher and lower particle concentration. But upon deep perusal it has been found that deterioration in heat transfer coefficient are mainly observed at higher particle concentrations (4-16% by weight) and enhancements mainly at lower particle concentrations (0.32-1.25% by weight). Moreover, the relative size of the particle with respect to the surface roughness of the heating surface seems to play an important role in understanding the boiling behaviour. Also, recent works have reported that change in 'surface wetting' of the heating surface due to nanofluids and the formation of a porous layer modifiying nucleation site density can be of importance in predicting nucleate pool boiling characteristics of nanofluids. In the present paper, attempts are made to make systematic analysis of results in literature and try to bring out a common understanding of the results in literature. � 2008 Springer Science+Business Media B.V.

The electro-optical properties of thin films of electron donor-acceptor blends of a fluorene copolymer (PF10TBT) and a fullerene derivative (PCBM) were studied. Transmission electron microscopy shows that in these films nanocrystalline PCBM clusters are formed at high PCBM content. For all concentrations, a charge transfer (CT) transition is observed with absorption spectroscopy, photoluminescence, and electroluminescence. The CT emission is used as a probe to investigate the dissociation of CT excited states at the donor-acceptor interface in photovoltaic devices, as a function of an applied external electric field and PCBM concentration. We find that the maximum of the CT emission shifts to lower energy and decreases in intensity with higher PCBM content. We explain the red shift of the emission and the lowering of the open-circuit voltage (VOC) of photovoltaic devices prepared from these blends with the higher relative permittivity of PCBM (εr = 4.0) compared to that of the polymer (εr = 3.4), stabilizing the energy (ECT) of CT states and of the free charge carriers in blends with higher PCBM concentration. We show that the CT state has a short decay time (τ = ca. 4 ns) that is reduced by the application of an external electric field or with increasing PCBM content. The field-induced quenching can be explained quantitatively with the Onsager-Braun model for the dissociation of the CT states when including a high electron mobility in nanocrystalline PCBM clusters. Furthermore, photoinduced absorption spectroscopy shows that increasing the PCBM concentration reduces the yield of neutral triplet excitons forming via electron-hole recombination, and increases the lifetime of radical cations. The presence of nanocrystalline domains with high local carrier mobility of at least one of the two components in an organic heterojunction may explain efficient dissociation of CT states into free charge carriers. © 2008 American Chemical Society.

Huge amounts of radionuclides, especially 137Cs, were released into the western North Pacific Ocean after the Fukushima nuclear power plant (FNPP) accident that occurred on 11 March 2011, resulting in contamination of the marine biota. In this study we developed a radioecological model to estimate 137Cs concentrations in phytoplankton and zooplankton populations representing the lower levels of the pelagic trophic chain. We coupled this model to a lower trophic level ecosystem model and an ocean circulation model to take into account the site-specific environmental conditions in the area. The different radioecological parameters of the model were estimated by calibration, and a sensitivity analysis to parameter uncertainties was carried out, showing a high sensitivity of the model results, especially to the 137Cs concentration in seawater, to the rates of accumulation from water and to the radionuclide assimilation efficiency for zooplankton. The results of the 137Cs concentrations in planktonic populations simulated in this study were then validated through comparison with the data available in the region after the accident. The model results have shown that the maximum concentrations in plankton after the accident were about 2 to 4 orders of magnitude higher than those observed before the accident, depending on the distance from FNPP. Finally, the maximum 137Cs absorbed dose rate for phyto- and zooplankton populations was estimated to be about 5 × 10−2 µGy h−1, and was, therefore, lower than the predicted no-effect dose rate (PNEDR) value of 10 µGy h−1 defined in the ERICA assessment approach.

In this study, poly (hydroxyethyl methacrylate) (PHEMA) nanobeads with an average size of 115 nm were prepared by emulsion polymerization. The nanobeads were characterized with infrared spectroscopy, scanning electron microscopy, and zeta size analysis. The surface area of the PHEMA nanobeads was calculated as 541.4 m2/g. Then, diethyl phthalate (DEP) removal efficiency of the PHEMA nanobeads from aqueous media was investigated. At a fixed adsorbent/solution ratio, various factors affecting the adsorption of DEP from aqueous solution such as pH, initial concentration, contact time, temperature, and adsorbent dosage were analyzed. The maximum DEP adsorption capacity of the PHEMA nanobeads was determined as 265.1 mg/g at pH 4.0, 25°C. The Sips isotherm model fits the experimental data in the wide range of DEP concentration tested (1–300 mg/L). The pseudo-first-order, pseudo-second-order, modified Ritchie’s-second-order kinetic models were used to test the adsorption kinetics. The DEP adsorption capacity of the nanobeads did not change after five batch successive usages. DEP removal efficiency of the PHEMA nanobeads from different water media such as saliva, sweat, and tap water was also evaluated. The removal efficiencies in the range from 82.4 to 100.0% demonstrate the usability of PHEMA nanobeads for DEP removal from real samples.

Fluoroquinolones (FQs) have been reported in trace amounts in different environmental matrices. The biosorption of three most prescribed FQs, ofloxacin (OFL), norfloxacin (NOR) and ciprofloxacin (CPF) by activated sludge (AS) and aerobic granular sludge (AGS) was investigated. Biosorption assays were conducted with FQs concentrations within the range of 100-700 ng mL-1, to mimic environmental conditions. At neutral pH and at the end of 48 h, AS showed higher biosorption capacity than AGS. For AS, a maximum biosorption of 1.50 ± 0.03, 3.24 ± 0.05 and 3.39 ± 0.06 mg gTSS -1 was observed for OFL, NOR and CPF respectively, whereas for AGS the maximum amount of FQs biosorbed was 1.18 ± 0.03, 2.73 ± 0.02 and 2.94 ± 0.03 mg gTSS -1. Langmuir isotherm was more applicable for describing FQs biosorption equilibrium by AS while for AGS, the Freundlich isotherm was more adequate. Given the AGS technology innovative character, the effect of change of pH on the biosorbed FQs was evaluated. FQs could be desorbed from AGS at pH 3, pH 8 and pH 9 but at pH 4 the biosorption process was promoted. This study allows a better understanding of the FQs biosorption processes. Moreover, the data from biosorption/desorption from AGS may be useful for management and operation of AGS bioreactors. © 2016 Elsevier. This work was supported by National Funds from FCT—Fundação para a Ciência e a Tecnologia through projects PTDC/EBB-EBI/111699/2009, UID/Multi/04423/2013 and UID/Multi/50016/2013. C.L. Amorim wishes to acknowledge the research grant from FCT (Ref. SFRH/BPD/96481/2013). The authors also thank to COST Action ES1202: Conceiving Wastewater Treatment in 2020 - Energetic, environmental and economic challenges.

The first extensive set of measurements of methane concentrations and fluxes for the Negro River and its major tributaries combined with complementary data for the Solimões and Madeira rivers and several tributaries are presented and their temporal and spatial variations examined. Fluxes were measured using floating chambers, and dissolved CH4 concentrations were measured by the headspace technique. In the Solimões basin, tributaries had higher fluxes when water levels were low; no statistical difference among periods for lakes and the main stem river was observed. In the Negro basin, rivers had higher fluxes with greater variations among rivers during high water than during low water based on fluxes calculated from the concentration gradient and modelled gas transfer coefficients. We estimate a regional methane emission of 0.31 Tg C yr−1 for large river channels in the lowland Amazon basin. © 2016 Association for the Sciences of Limnology and Oceanography

We investigate the potential of polarization lidar to provide vertical profiles of aerosol parameters from which cloud condensation nucleus (CCN) and ice nucleating particle (INP) number concentrations can be estimated. We show that height profiles of particle number concentrations n50, dry considering dry aerosol particles with radius > 50 nm (reservoir of CCN in the case of marine and continental non-desert aerosols), n100, dry (particles with dry radius > 100 nm, reservoir of desert dust CCN), and of n250, dry (particles with dry radius > 250 nm, reservoir of favorable INP), as well as profiles of the particle surface area concentration sdry (used in INP parameterizations) can be retrieved from lidar-derived aerosol extinction coefficients σ with relative uncertainties of a factor of 1.5–2 in the case of n50, dry and n100, dry and of about 25–50 % in the case of n250, dry and sdry. Of key importance is the potential of polarization lidar to distinguish and separate the optical properties of desert aerosols from non-desert aerosol such as continental and marine particles. We investigate the relationship between σ, measured at ambient atmospheric conditions, and n50, dry for marine and continental aerosols, n100, dry for desert dust particles, and n250, dry and sdry for three aerosol types (desert, non-desert continental, marine) and for the main lidar wavelengths of 355, 532, and 1064 nm. Our study is based on multiyear Aerosol Robotic Network (AERONET) photometer observations of aerosol optical thickness and column-integrated particle size distribution at Leipzig, Germany, and Limassol, Cyprus, which cover all realistic aerosol mixtures. We further include AERONET data from field campaigns in Morocco, Cabo Verde, and Barbados, which provide pure dust and pure marine aerosol scenarios. By means of a simple CCN parameterization (with n50, dry or n100, dry as input) and available INP parameterization schemes (with n250, dry and sdry as input) we finally compute profiles of the CCN-relevant particle number concentration nCCN and the INP number concentration nINP. We apply the method to a lidar observation of a heavy dust outbreak crossing Cyprus and a case dominated by continental aerosol pollution.

The different two series/associations as Upper Cretaceous Karakoç plutonics and Paleocene felsic plutonic rocks belonging to Central Anatolian Plutonics are present in the Yıldızeli area. Karakoç plutonics consist of ultramafic and mafic rocks and are of transition into each other. Phlogopite mineralizations related to Karakoç plutonics are surrounded by Yıldızeli metamorphic rocks and cut by felsic plutonic and vein rocks. Garnet-scapolite-epidote-phlogopitic pyrometasomatic occurrences are seen within the zones intruded by dikes. Packages of phlogopite plates (1-5 cm) are surrounded by a zone (10-15 cm) with pyroxene and/or hornblendes in which garnet, epidote and scapolite layers and/or lenses are found in places. Phyllosilicates are formed of smectite, C-S (chlorite-smectite), chlorite and P-V/I-V (phlogopite-vermiculite/illite-vermiculite) in the Karakoç plutonics, smectite, chlorite and I-S (illite-smectite) in the mafic plutonic rocks, smectite in the felsic plutonic rocks, and 1M Fe-Al phlogopite, smectite, I-V/P-V and S-V (smectite-vermiculite) in the pyrometasomatic rocks. Phlogopite components as Mg/(Mg+Fe) are 0.74 for phlogopite and 0.67 for P-V. Hornblende, scapolite and garnet from the other silicate minerals are Ca-Na-K magnesian hastingsite, mizzonite and grossular in compositions, respectively. Total trace element concentrations decrease phlogopite-P-V-garnet-hornblende-scapolite trend. The distributions of chondrite-normalized trace and rare earth elements (REE) were clearly decreased from garnet-hornblende-scapolite–phlogopite towards P-V and mineral patterns distinguish from each other and also show a clear differentiation/fractionation. δ18O values of phlogopite and P-V have lower than those of mantle and MORB; whereas they are similar to those of continental originated magmatic rocks. δ18O and δD concentrations of phyllosilicate minerals suggested that the phlogopite and P-V have respectively hypogene and supergene origins. The decreasing δD and increasing δ18O values indicate phlogopitization trend, whereas those of increasing δD and decreasing δ18O sign vermiculitization trend. On the other hand, according to granitoid rocks, reflecting initial values for isotopically fractionation, formation temperatures of phlogopite and P-V were obtained as ~ 280 and ~130 °C, respectively that phlogopite and P-V minerals are thought to be pyrometasomatic rather than magmatic origin. In addition, phlogopites are sometimes undergone vermiculite type of negative transformations passing into P-V interphases. © 2016, Hacettepe Universitesi Yerbilmleri. All Rights Reserved.

Groundwater from the La Paz arid coastal aquifer in Baja California, Mexico, is essentially the only source of drinking water for the local population and tourists, as well as irrigation water for agricultural needs. The intensive exploitation of the aquifer and water cycling has resulted in groundwater abatement (up to 10 m) and high salinity (up to ~5800 mg l−1). A study using hydrochemistry, isotopic (deuterium, oxygen-18 and carbon-14) and gaseous tracers (chlorofluorocarbons CFC-11, CFC-12, CFC-113), as well as multivariate statistics, was developed to elucidate groundwater composition, flow and occurrence. Groundwater is of meteoric origin, and a large proportion is subject to evaporation. The primary natural recharge is generated in the El Novillo and Las Cruces ranges, and groundwater subsequently flows in a SE–NW direction toward the coast. The initial water type is the result of discordant dissolution of silicate minerals and ion exchange on soils. In the lower plain portion, the aquifer system is recharged from irrigation return flow and seawater intrusion, which significantly affects groundwater chemistry. Nitrate and chloride concentrations indicate that groundwater is highly affected by an overuse of fertilizers in agricultural activities, but there is little effect from urban activities. Seawater intrusion has progressed rapidly during the past decade, and the impact currently extends 13 km inland. Radiocarbon residence time calculations suggest that groundwater is modern, with the exception of Chametla and El Centerario sites in the central and western lowlands with ages of up to ~5000 years. These waters indicate an additional recharge source for the upconing of fossil groundwater or regional flow. © 2016, The Author(s).

Microcystin-LR (MC-LR) and cylindrospermopsin (CYN) are the most representative cyanobacterial cyanotoxins. They have been simultaneously detected in aquatic systems, but their combined ecotoxicological effects to aquatic organisms, especially microalgae, is unknown. In this study, we examined the effects of these cyanotoxins individually and as a binary mixture on the growth rate of the freshwater algae Chlorella vulgaris. Using the MIXTOX tool, the reference model concentration addition (CA) was selected to evaluate the combined effects of MC-LR and CYN on the growth of the freshwater green algae due to its conservative prediction of mixture effect for putative similar or dissimilar acting chemicals. Deviations from the CA model such as synergism/antagonism, dose-ratio and dose-level dependency were also assessed. In single exposures, our results demonstrated that MC-LR and CYN had different impacts on the growth rates of C. vulgaris at the highest tested concentrations, being CYN the most toxic. In the mixture exposure trial, MC-LR and CYN showed a synergistic deviation from the conceptual model CA as the best descriptive model. MC-LR individually was not toxic even at high concentrations (37 mg L−1); however, the presence of MC-LR at much lower concentrations (0.4–16.7 mg L−1) increased the CYN toxicity. From these results, the combined exposure of MC-LR and CYN should be considered for risk assessment of mixtures as the toxicity may be underestimated when looking only at the single cyanotoxins and not their combination. This study also represents an important step to understand the interactions among MC-LR and CYN detected previously in aquatic systems. © 2016, Springer Science+Business Media New York. This work was supported by the Portuguese Science Foundation (FCT) through CESAM: UID/AMB/50017/2013.

We have evaluated the cytotoxic activities of the ethanol extracts of tubers and leaves of eight Cyclamen L. taxa (C. alpinum Dammann ex Spreng., C. cilicicum Boiss. & Heldr., C. coum Mill. subsp. coum, C. graecum subsp. anatolicum Ietsw., C. hederifolium Aiton, C. mirabile Hildebr., C. persicum Mill., and C. pseudibericum Hildebr.) collected from Turkey by using brine shrimp (Artemia salina L.) lethality test and the LC50 values of the extracts were also determined. The strongest cytotoxic activities were obtained by ethanolic tuber extracts. LC50 values were calculated by EPA Probit Analysis Program (version 1.5). The extracts of eight taxa showed moderate cytotoxicity against brine shrimp (LC50 between 2.93 and 533.22 μg/mL). The extracts of C. graecum subsp. anatolicum and C. persicum showed significant cytotoxicity with LC50 values of 2.93 and 3.60 μg/mL, respectively while the extract of C. pseudibericum had LC50 at 533.22 μg/ml. It could be seen among eight tested plant taxa that C. graecum subsp. anatolicum had the most cytotoxicity. © 2016 PSP.

In this study, effects of extracts Lavander (Lavandula angustofolia M i l l e r.) seed and leaf on Zea mays L. and Lens culinaris M. seed germination percentage and postgermination seedling growth were investigated. Seeds were germinated in Petri dishes at 25°C. Seed germination, seedling elongation was determined at day 14. In this study, the n-hexane extracts of the seeds and leaves of industrially grown lavender (Lavandula angustofolia M.) plant was used. After completing the mandatory pre-conditioning phases, the applications were initiated in order to determine their effects on the germination physiology on corn (Zea mays L.) and lentil (Lens culinaris M.) by diluting the plant extracts by 5, 10 and 15% folds. Regarding the lentil seed, while the 15% lavender seed extract showed germination rates, it was observed that the plant extracts had significant effects on the germination of the seeds. As the result, the fact that the extracts of those plants show different allelopathic effects on the germination of the corn and lentil seeds indicates that such extracts may be utilised towards different goals in terms of agricultural, ecologic and physiologic aims.

Aerial pollutants generated from intensive poultry and livestock production raise concerns of health and welfare for the surrounding communities. This article reports emission rates of hydrogen sulfide (H2S) and concentrations of volatile organic compounds (VOCs) from two tunnel-ventilated high-rise houses at a layer site in North Carolina that were tested by the National Air Emissions Monitoring Study (NAEMS). Hydrogen sulfide concentrations exhibited significant seasonal and diurnal variations. The minimum and maximum average hourly mean (AHM) concentrations by hour of day occurred at 15: 00-16: 00 and 6: 00-7: 00, respectively. The lowest and highest daily mean concentrations during the annual cycle were observed in summer and winter, respectively. The AHM H2S concentrations were 1.04 +/- 0.83 ppb for inlet air and 9.52 +/- 6.35 and 9.43 +/- 6.01 ppb, respectively, for exhaust air from the two production houses. The diurnal and seasonal patterns of H2S emission rates from the two production houses were also similar. Slight increases in H2S emission rates occurred at 12: 00 to 14: 00. Higher H2S emission rates occurred in summer. The AHM hen-specific H2S emission rates from the two production houses were 618 +/- 517 and 698 +/- 620 mu g d(-1) hen(-1), respectively. Factors significantly affecting H2S emissions were hen activity, house exhaust air temperature, and ambient air temperature. Time-integrated samples of VOCs were collected over 24 h periods seven times in one production house from 12 April 2009 to 18 September 2009. Of 77 target compounds, the ten most abundant compounds were 2-butanone, iso-propanol, dimethyl sulfide, hexanal, acetic acid, 2,3-butanedione, pentane, acetaldehyde, pentanal, and phenol. Differences in VOC concentrations were observed between the layer room and the manure pit. The highest total VOC concentration was detected in samples taken from the manure pit exhaust air. American Egg Board National Science Foundation (NSF) NSF - Office of the Director (OD) - CBET-0954673

New particle formation in the atmosphere produces around half of the cloud condensation nuclei that seed cloud droplets. Such particles have a pivotal role in determining the properties of clouds and the global radiation balance. Dunne et al. used the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN to construct a model of aerosol formation based on laboratory measured nucleation rates. They found that nearly all nucleation involves either ammonia or biogenic organic compounds. Furthermore in the present day atmosphere cosmic ray intensity cannot meaningfully affect climate via nucleation.Science this issue p. 1119Fundamental questions remain about the origin of newly formed atmospheric aerosol particles because data from laboratory measurements have been insufficient to build global models. In contrast gas phase chemistry models have been based on laboratory kinetics measurements for decades. We built a global model of aerosol formation by using extensive laboratory measurements of rates of nucleation involving sulfuric acid ammonia ions and organic compounds conducted in the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber. The simulations and a comparison with atmospheric observations show that nearly all nucleation throughout the present day atmosphere involves ammonia or biogenic organic compounds in addition to sulfuric acid. A considerable fraction of nucleation involves ions but the relatively weak dependence on ion concentrations indicates that for the processes studied variations in cosmic ray intensity do not appreciably affect climate through nucleation in the present day atmosphere.U http://science.sciencemag.org/content/sci/354/6316/1119.full.pdf

In the open-field warming experiment using infrared heaters, 3 °C warming affected soil respiration more in the deciduous Quercus variabilis Blume plot than in the evergreen Pinus densiflora Sieb. et Zucc. plot, but did not affect the plant biomass in either species. Understanding the species-specific responses of belowground carbon processes to warming is essential for the accurate prediction of forest carbon cycles in ecosystems affected by future climate change. This study aimed to investigate the effect of experimental warming on soil CO2 efflux, soil-air CO2 concentration, and plant biomass for two taxonomically different temperate tree species. Experimental warming was conducted in an open-field planted with Q. variabilis and P. densiflora seedlings. Infrared heaters increased the air temperature by 3 °C in the warmed plots compared with the air temperature in the control plots over a 2-year period. The increase in air and soil temperature stimulated soil CO2 efflux by 29 and 22 % for the Q. variabilis and P. densiflora plots, respectively. Seasonal variation in the warming effect on soil CO2 efflux was species-specific. Soil CO2 efflux was also positively related to both soil temperature and soil water content. The soil moisture deficit decreased the difference in soil CO2 efflux between the control and warmed plots. Warming did not affect soil CO2 concentration and plant biomass in either species; however, the mean soil CO2 concentration was positively correlated with root and total biomass. Warming increased soil CO2 efflux in both Q. variabilis and P. densiflora plots, while the increase showed remarkable seasonal variations and different magnitudes for the two species.

Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. � 2007 Elsevier Ltd. All rights reserved.

Soylak, Mustafa/0000-0002-1017-0244 WOS: 000250640600009 PubMed: 17482351 A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 mol L-1 HNO3 in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 mu g L-1, respectively. The preconcentration factor was 200. The relative standard deviation of the method was < 6%. The adsorption capacity of the resin was 12.3 mg g(-1). The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples. (c) 2007 Elsevier B.V. All rights reserved.

Long-term field experiments have been carried out in the Chernobyl exclusion zone in order to determine the parameters governing radiochlorine (36Cl) transfer to plants from four types of soil, namely, Podzoluvisol, Greyzem, Phaeozem and Chernozem. Radiochlorine concentration ratios (CR = concentration of 36Cl in the fresh plant material divided by its concentration in the dried soil in the upper 20 cm layer) were obtained in green peas (2.6 ± 0.4), onions (1.5 ± 0.5), potatoes (8 ± 1), clover (90 ± 26) and ryegrass (158 ± 88) hay, oat seeds (36 ± 23) and straw (305 ± 159), wheat seeds (35 ± 10) and straw (222 ± 82). These values correlate with the stable chlorine values for the same plants. It was shown that 36Cl plant/soil CR in radish roots (CR = 9.7 ± 1.4) does not depend on the stable chlorine content in the soil (up to 150 mg kg-1), soil type and thus, that stable chlorine CR values (9.4 ± 1.2) can also be used for 36Cl. Injection of additional quantities of stable chlorine into the soil (100 mg kg-1 of dry soil) with fertilizer does not change the soil-to-plant transfer of 36Cl. The results from a batch experiment showed that chlorine is retained in the investigated soils only by live biota and transfers quickly (in just a few hours) into the soil solution from dry vegetation even without decomposition of dead plants and is integrated in the migration processes in soil. © 2007 Elsevier Ltd. All rights reserved.

Atmospheric concentrations and gas/particle partition coefficients were determined for polycyclic aromatic hydrocarbons (PAHs) in the city of Bursa, Turkey between August 2004 and May 2005. The average total (gas + particle) PAH concentration was 456 ± 524 ng m − 3 . The ambient air concentrations were mainly influenced by traffic and industrial activities. PAH compounds considered in this study predominantly existed in the gas phase and the average contribution of gas phase to total (gas + particle) PAH concentrations was about 90% which was in line with the previously reported values. The partitioning between the particle and gas phases was investigated in this study because gas/particle-partitioning coefficient ( K p ) has an important role on the fate of PAHs. Experimentally determined K p values correlated well with the subcooled liquid vapor pressures ( P L 0 ) of PAHs. The octanol-air partition coefficient ( K OA ), which can also be used to calculate K p values, gave high correlation coefficients with the P L 0 . In another approach, the K p values were estimated by considering adsorption onto the soot carbon and absorption into organic matter of atmospheric particulates. In general, K p values calculated based on K OA gave smaller values than the ones predicted based on soot/air ( K SA ) partition coefficient. Sorption of PAHs on particles was underestimated by K OA suggesting that absorption would not be enough to explain partitioning and adsorption would still be important.

The objectives of this study were to identify regional variations in soil polycyclic aromatic hydrocarbon (PAH) contamination in Bursa, Turkey, and to determine the distributions and sources of various PAH species and their possible sources. Surface soil samples were collected from 20 different locations. The PAH concentrations in soil samples were analyzed using gas chromatography-mass spectrometry (GC-MS). The total PAH concentrations (Sigma(12) PAH) varied spatially between 8 and 4970 ng/g dry matter (DM). The highest concentrations were measured in soils taken from traffic+barbecue+residential areas (4970 ng/g DM) and areas with cement (4382 ng/g DM) and iron-steel (4000 ng/g DM) factories. In addition, the amounts of Sigma(7) carcinogenic PAH ranged from 1 to 3684 ng/g DM, and between 5 and 74 % of the total PAHs consisted of such compounds. Overall, 4-ring PAH compounds (Fl, Pyr, BaA and Chr) were dominant in the soil samples, with 29-82 % of the Sigma(12) PAH consisting of 4-ring PAH compounds. The Sigma(12) BaPeq values ranged from 0.1 to 381.8 ng/g DM. Following an evaluation of the molecular diagnostic ratios, it was concluded that the PAH pollution in Bursa soil was related to pyrolytic sources; however, the impact of petrogenic sources should not be ignored.

There has been limited study of the removal of polycyclic aromatic hydrocarbons (PAHs) from inorganic clay minerals. Determining the amount of PAH removal is important in predicting their environmental fate. This study was carried out to the degradation and evaporation of PAHs from bentonite, which is an inorganic clay mineral. UV apparatus was designed specifically for the experiments. The impacts of temperature, UV, titanium dioxide (TiO2), and diethylamine (DEA) on PAH removal were determined. After 24 h, 75 and 44 % of Sigma(12) PAH in the bentonite were removed with and without UV rays, respectively. DEA was more effective as a photocatalyst than TiO2 during UV application. The Sigma(12) PAH removal ratio reached 88 % with the addition of DEA to the bentonite. It was concluded that PAHs were photodegraded at high ratios when the bentonite samples were exposed to UV radiation in the presence of a photocatalyst. At the end of all the PAH removal applications, higher evaporation ratios were obtained for 3-ring compounds than for heavier ones. More than 60 % of the amount of Sigma(12) PAH evaporated consisted of 3-ring compounds.

Semi-volatile organic compounds (SVOCs) are indoor air pollutants that may have significant adverse effects on human health. Although emissions of volatile chemicals from building materials and consumer products are usually characterized in small chambers, few chamber studies have been conducted for SVOCs due to the challenges associated with analysis and the lack of validation procedures. There is an urgent need for a reliable and accurate chamber test method to verify these measurements. A reference method employing a specially-designed chamber has been developed and is undergoing extensive evaluation. A pilot inter-laboratory study (ILS) has been conducted with six laboratories performing chamber tests under identical conditions for di-2-ethylhexyl phthalate (DEHP). Results from this study showed inter-laboratory variations of 24% for DEHP emission rates, with closer agreement observed among intra-laboratory measurements for most of the participating laboratories. A mechanistic emission model fits well to the measured concentration profiles, demonstrating the feasibility of the proposed reference method to independently assess laboratory performance and validate SVOC emission tests.

Near-ground air (26 substances) and surface seawater (55 substances) concentrations of persistent toxic substances (PTS) were determined in July 2012 in a coordinated and coherent way around the Aegean Sea based on passive air (10 sites in 5 areas) and water (4 sites in 2 areas) sampling. The direction of air–sea exchange was determined for 18 PTS. Identical samplers were deployed at all sites and were analysed at one laboratory. hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs) as well as dichlorodiphenyltrichloroethane (DDT) and its degradation products are evenly distributed in the air of the whole region. Air concentrations of p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) and o,p′-DDT and seawater concentrations of p,p′-DDE and p,p′-DDD were elevated in Thermaikos Gulf, northwestern Aegean Sea. The polychlorinated biphenyl (PCB) congener pattern in air is identical throughout the region, while polybrominated diphenylether (PBDE)patterns are obviously dissimilar between Greece and Turkey. Various pollutants, polycyclic aromatic hydrocarbons (PAHs), PCBs, DDE, and penta- and hexachlorobenzene are found close to phase equilibrium or net-volatilisational (upward flux), similarly at a remote site (on Crete) and in the more polluted Thermaikos Gulf. The results suggest that effective passive air sampling volumes may not be representative across sites when PAHs significantly partitioning to the particulate phase are included., Granting Agency of the Czech Republic (312334); Czech Ministry of Education (LO1214--LM2011028); European Social Fund (CZ.1.07/2.3.00/30.0037); European Commission FP7 (262254 ACTRIS)

Real-time measurements of inorganic (sulfate, nitrate, ammonium, chloride and black carbon (BC)) and organic submicron aerosols (particles with an aerodynamic diameter of less than 1 Î1/4m) from a continental background site (Montsec, MSC, 1570 m a.s.l.) in the western Mediterranean Basin (WMB) were conducted for 10 months (July 2011-April 2012). An aerosol chemical speciation monitor (ACSM) was co-located with other online and offline PM1 measurements. Analyses of the hourly, diurnal, and seasonal variations are presented here, for the first time, for this region. Seasonal trends in PM1 components are attributed to variations in evolution of the planetary boundary layer (PBL) height, air mass origin, and meteorological conditions. In summer, the higher temperature and solar radiation increases convection, enhancing the growth of the PBL and the transport of anthropogenic pollutants towards high altitude sites. Furthermore, the regional recirculation of air masses over the WMB creates a continuous increase in the background concentrations of PM1 components and causes the formation of reservoir layers at relatively high altitudes. The combination of all these atmospheric processes results in a high variability of PM1 components, with poorly defined daily patterns, except for the organic aerosols (OA). OA was mostly composed (up to 90%) of oxygenated organic aerosol (OOA), split in two types: semivolatile (SV-OOA) and low-volatility (LV-OOA), the rest being hydrocarbon-like OA (HOA). The marked diurnal cycles of OA components regardless of the air mass origin indicates that they are not only associated with anthropogenic and long-range-transported secondary OA (SOA) but also with recently produced biogenic SOA. Very different conditions drive the aerosol phenomenology in winter at MSC. The thermal inversions and the lower vertical development of the PBL leave MSC in the free troposphere most of the day, being affected by PBL air masses only after midday, when the mountain breezes transport emissions from the adjacent valleys and plains to the top of the mountain. This results in clear diurnal patterns of both organic and inorganic concentrations. OA was also mainly composed (71%) of OOA, with contributions from HOA (5%) and biomass burning OA (BBOA; 24%). Moreover, in winter sporadic long-range transport from mainland Europe is observed. The results obtained in the present study highlight the importance of SOA formation processes at a remote site such as MSC, especially in summer. Additional research is needed to characterize the sources and processes of SOA formation at remote sites., This study was supported by the Ministry of Economy and Competitiveness and FEDER funds under the PRISMA (CGL2012-39623-C02-1) and CARIATI (CGL2008- 06294/CLI) projects, and by the Generalitat de Catalunya (AGAUR 2009 SGR8 and the DGQA). The research received funding from the European Union Seventh Framework Programme (FP7/ 2007-2013) ACTRIS under grant agreement no. 262254. We would like to extend their gratitude to the personnel from the COU and the OAdM. We would also like to express our gratitude to the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model, and boundary layer height calculation, used in this publication. D. A. Day and J. L. Jimenez thank the DOE (BER/ASR) DE-SC0011105 and NOAA NA13OAR4310063.

Fecal contamination of surface waters is one the major sources of waterborne pathogens and consequently, is an important concern for public health. For reliable fecal source tracking (FST) monitoring, there is a need for a multi-marker toolbox as no single all-encompassing method currently exists. Mitochondrial DNA (mtDNA) as a source tracking marker has emerged as a promising animal-specific marker. However, very few comprehensive field studies were done on the occurrence of this marker in surface waters. In this report, water samples were obtained from 82 sites in different watersheds over a six year period. The samples were analyzed for the presence of human, bovine and porcine mtDNA by endpoint nested PCR, along with the human-specific Bacteroidales HF183 marker. These sites represented a mix of areas with different anthropogenic activities, natural, urban and agricultural. The occurrences of mitoHu (human), mitoBo (bovine), mitoPo (porcine) and HF183 specific PCR amplifications from the samples were 46%, 23%, 6% and 50%, respectively. The occurrence of mitoHu and HF183 was high in all environment types with higher occurrence in the natural and urban areas, whereas the occurrence of mitoBo was higher in agricultural areas. FST marker concentrations were measured by real-time PCR for samples positive for these markers. The concentration of the mitoHu markers was one order of magnitude lower than HF183. There was co-linearity between the concentrations of the mitoHu and HF183 markers. Co-linearity was also observed between HF183 concentration and fecal coliform levels. Such a relationship was not observed between the mitoHu concentration and fecal coliform levels. In summary, our results showed a high incidence of human fecal pollution throughout the environment while demonstrating the potential of mtDNA as suitable FST markers.

Thirty-three ambient air samples were collected during spring and summer (2003) in the metropolitan area of Bursa, Turkey. All airborne samples were analyzed for crustal (Mg, Ca, Mn, Fe) and anthropogenic (Cr, Co, Ni, Cu, Zn, Cd, Pb) trace metals. A TSP sampler was employed using glass and quartz fiber filters to collect air samples. Average individual trace element concentrations fluctuated between 4896.3 ± 3754.3 ng/m 3 (Ca) and 0.7 ± 0.9 ng/m 3 (Cd). The measured concentrations of the trace elements were within the ranges of previously reported values obtained from different places including Turkey, Argentina, Spain, Korea, and Brasil. The concentrations were arranged according to day and night, weekend and weekdays, spring and summer samples. Concentrations were also evaluated based on the filter types used, glass fiber and quartz filters. Enrichment factors (EFs) were calculated to identify anthropogenic versus natural emission sources of trace elements. The prevailing winds from various sectors were examined to determine the transport of metal particles from different districts. Principal component analysis (PCA) was employed to define the possible origins of trace elements in airborne particulate matter. The result suggested that industrial activities along with traffic emissions and suspension of street dusts have important effects on ambient air concentrations of trace metals. Dry deposition fluxes were estimated using documented dry deposition velocities in the literature and concentrations measured in this study.