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The influence of environmental parameters in the biocolonization of the Mithraeum in the roman masonry of casa di Diana (Ostia Antica, Italy)
2016
Scatigno, C. | Moricca, C. | Tortolini, C. | Favero, G.
The microclimatic parameters (Ta, RH, E, and CO₂) reflect the indoor quality of the environment. Their relationship, connected with the design of the building, can facilitate the growth of photo/heterotrophic organisms and therefore facilitate the increase of the relative CO₂ production. Taking this into account, the impact of biological proliferation in a historical building is discussed for the Mithraeum of “Casa di Diana” in the archaeological site of Ostia Antica, which is subjected to guided tours. In this work, for the first time, we propose a study on biological monitoring to evaluate the contribution of bioactivity to air quality, with the objective to increase the comfort of visitors and to open the site for more than one day per week, suggesting possible tools providing a good compromise between building conservation and human comfort. In the sense, it has been possible to distinguish the contribution of the plants from the one deriving from humans: high values of carbon dioxide have been recorded during the night and its scarce removal during the day (air flow). The window present is not sufficient to eliminate the CO₂, involving concentrations of CO₂ relatively high in comparison to the proposed limits and guidelines defined by law. The obtained results strongly encouraged the elimination of flora in order to increase the comfort of visitors and to open the house for more than one day per week. Although, this process involves an important economic effort, the present study allows making an objective decision which has an important value in a cultural heritage management. Graphical Abstract CO₂ contribute by bioactivity as damage to human health
显示更多 [+] 显示较少 [-]Research on dye wastewater decoloration by pulse discharge plasma combined with charcoal derived from spent tea leaves
2016
Wang, Tiecheng | Qu, Guangzhou | Pei, Shuzhao | Liang, Dongli | Hu, Shibin
Pulsed discharge plasma (PDP) combined with charcoal (PDP–charcoal) was employed to treat dye wastewater, with methyl orange (MO) as the model pollutant. The charcoal was prepared using spent tea leaves and was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and Boehm titration to investigate the adsorption and catalytic characteristics before and after adsorption and PDP treatment. The prepared charcoal exhibited a high MO adsorption capacity, and the adsorption process followed the pseudo-second-order kinetic model and the Freundlich model. The MO decoloration efficiency reached 69.8 % within 7.5 min of treatment in the PDP–charcoal system, whereas values of 29.2 and 25.9 % were achieved in individual PDP and charcoal systems, respectively. The addition of n-butanol and H₂PO₄ ⁻ presented inhibitive effects on MO decoloration in the PDP system. However, these effects were much weaker in the PDP–charcoal system. In addition, the effects of charcoal on O₃ and H₂O₂ formation were evaluated, and the results showed that both the O₃ and H₂O₂ concentrations decreased in the presence of charcoal. The MO decomposition intermediates were analyzed using UV–Vis spectrometry and GC-MS. 1,4-Benzoquinone, 4-nitrophenol, 4-hydroxyaniline, and N,N′-dimethylaniline were detected. A possible pathway for MO decomposition in this system was proposed.
显示更多 [+] 显示较少 [-]Enhancement of sludge anaerobic biodegradability by combined microwave-H2O2 pretreatment in acidic conditions
2016
Eswari, Parvathy | Kavitha, S. | Kaliappan, S. | Yeom, Ick-Tae | Banu, J Rajesh
The aim of this study was to increase the sludge disintegration and reduce the cost of microwave (MW) pretreatment. Thermodynamic analysis of MW hydrolysis revealed the best fit with a first-order kinetic model at a specific energy of 18,600 kJ/kg total solids (TS). Combining H₂O₂ with MW resulted in a significant increment in solubilization from 30 to 50 % at 18,600 kJ/kg TS. The pH of H₂O₂-assisted MW-pretreated sludge (MW + H₂O₂) was in the alkaline range (pH 9–10), and it made the sludge unfavorable for subsequent anaerobic digestion and inhibits methane production. In order to nullify the alkaline effect caused by the MW + H₂O₂ combination, the addition of acid was considered for pH adjustment. H₂O₂-assisted MW-pretreated sludge in acidic conditions (MW + H₂O₂ + acid) showed a maximum methane production of 323 mL/g volatile solids (VS) than others during anaerobic biodegradability. A cost analysis of this study reveals that MW + H₂O₂ + acid was the most economical method with a net profit of 59.90 €/t of sludge.
显示更多 [+] 显示较少 [-]Comparison of single extraction procedures and the application of an index for the assessment of heavy metal bioavailability in river sediments
2016
Sakan, Sanja | Popović, Alexandre | Škrivanj, Sandra | Sakan, Nenad | Đorđević, Dragana
Metals in sediments are present in different chemical forms which affect their ability to transfer. The objective of this body of work was to compare different extraction methods for the bioavailability evaluation of some elements, such as Ba, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, V and Zn from Serbian river sediments. A bioavailability risk assessment index (BRAI) was used for the quantification of heavy metal bioavailability in the sediments. Actual and potential element availability was assessed by single extractions with mild (CaCl₂ and CH₃COONH₄) and acidic (CH₃COOH) extractants and complexing agents (EDTA). Aqua regia extraction was used for the determination of the pseudo-total element content in river sediments. In different single extraction tests, higher extraction of Cd, Cu, Zn and Pb was observed than for the other elements. The results of the single extraction tests revealed that there is a considerable chance of metal leaching from the sediments assessed in this study. When the BRAI was applied, the results showed a high risk of heavy metal bioavailability in Serbian river sediments.
显示更多 [+] 显示较少 [-]Impact of molybdenum nanoparticles on survival, activity of enzymes, and chemical elements in Eisenia fetida using test on artificial substrata
2016
Lebedev, Sviatoslav | Yausheva, Elena | Galaktionova, Lyudmila | Sizova, Elena
The influence of molybdenum oxide nanoparticles (MoO₃) on the growth and survival of Eisenia fetida was established. The activity of antioxidant enzymes and changes in concentration of molybdenum in the body of E. fetida were determined. The degree of bacterial bioluminescence inhibition in extracts of substrates and worm was studied using luminescent strain Escherichia coli K12 TG1. The enzymatic activity of substrates before and after exposure with nanoparticles and worms was assessed. Nanoparticles have concentrations of 10, 40, and 500 mg/kg of dry matter, and substrata are made of artificial soil (substrate A) and microcrystalline cellulose (substrate B). Spherical nanoparticles MoO₃, yellow in color, with size 92 ± 0.3 nm, Z-potential 42 ± 0.52 mV, molybdenum content 99.8 mass/%, and specific area 12 m²/g were used in the study. A significant decrease by 23.3 % in weight was registered (for MoO₃ NPs at 500 mg/kg) on substrate A (p ≤ 0.05). On substrate B, the maximum decrease in weight by 20.5, 33.3, and 16.9 % (p ≤ 0.05) was registered at a dose of 10, 40, and 500 mg/kg, respectively; mortality was from 6.6 to 73 %. After the assessment of bacterial bioluminescence inhibition in substrates A and B (extracts) and before worms were put, the toxicity of substrates was established at doses of 40 and 500 mg/kg, expressed in inhibitory concentration (IC) 30 and IC 50 values. Comparatively, on days 7 and 14, after exposure in the presence of E. fetida, no inhibition of bioluminescence was registered in extracts of substrates A and B, indicating the reduction in toxicity of substrates. The initial content of molybdenum in E. fetida was 0.9 ± 0.018 mg/kg of dry matter. The degree of molybdenum accumulation in worm tissue was dependent on the dose and substrate quality. In particular, 2–7 mg/kg of molybdenum accumulated from substrate A, while up to 15 kg/kg of molybdenum accumulated from substrate B (day 7). Molybdenum concentration decreased by 64.8 and 57.4 % at doses 40 and 500 mg/kg, respectively, on day 14. The reaction of antioxidant enzymes was shown in an insignificant increase of glutathione reductase (GSR) and catalase (CAT) at concentrations of 10 and 40 mg/kg in substrate A, followed by the subsequent reduction of their activity at the dose of 500 mg/kg MoO₃. The activity of GSR in substrate B against the presence of MoO₃ nanoparticles decreased, with significant difference of 33.5 % (p ≤ 0.05) at the dose of 500 mg/kg compared with untreated soil. In experiments with substrate A, an increase of catalase activity was registered for the control sample. The presence of MoO₃ nanoparticles at the concentration of 10 mg/kg in the environment promoted enzymatic activity on days 7 and 14, respectively. A further increase of nanoparticle concentration resulted in the decrease of catalase activity with a minimum value at the concentration of MoO₃ of 500 mg/kg. In the experiment with substrate B at the concentration of MoO₃ nanoparticles of 40 mg/kg, enzymatic activity increases on day 7 of exposure. However, the stimulating effect of nanoparticles stops by day 14 of the experiment and further catalase activity is dose dependent with the smallest value in the experiment with MoO₃ having the concentration of 500 mg/kg.
显示更多 [+] 显示较少 [-]Cs-137 in milk, vegetation, soil, and water near the former Soviet Union’s Semipalatinsk Nuclear Test Site
2016
Kakimov, Aitbek | Yessimbekov, Zhanibek | Kakimova, Zhainagul | Bepeyeva, Aigerim | Stuart, Marilyne
The present study was carried out to evaluate Cs-137 activity concentration in soil, water, vegetation, and cow’s milk at 10 locations within three regions (Abai, Ayaguz, and Urdzhar) to the southeast of the Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan. Cs-137 activity concentrations, determined using a pure Ge gamma-ray spectrometer, showed that, all samples collected did not exceed the National maximum allowable limits of 10,000 Bq/kg for soil, 100 Bq/kg for cow’s milk, 74 Bq/kg for vegetation, and 11 Bq/kg for water. Cs-137 is, therefore, not considered a health hazard in these regions. The highest levels of contamination were found in the Abai region, where the highest activity concentration of Cs-137 was 18.0 ± 1.0 Bq/kg in soil, 7.60 ± 0.31 Bq/kg in cow’s milk, 4.00 ± 0.14 Bq/kg in the vegetation, and 3.00 ± 0.24 Bq/kg in water. The lowest levels were measured within the Urdzhar region, where 4.00 ± 0.14 Bq/kg was found in the soil, 0.30 ± 0.02 Bq/kg in the cow’s milk, 1.00 ± 0.03 Bq/kg in the vegetation, and 0.20 ± 0.02 Bq/kg in the water.
显示更多 [+] 显示较少 [-]Sorption of pharmaceuticals and personal care products to polyethylene debris
2016
Wu, Chenxi | Zhang, Kai | Huang, Xiaolong | Liu, Jiantong
Presence of plastic debris in marine and freshwater ecosystems is increasingly reported. Previous research suggested plastic debris had a strong affiliation for many pollutants, such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and heavy metals. In this study, the sorption behavior of pharmaceuticals and personal care products (PPCPs), including carbamazepine (CBZ), 4-methylbenzylidene camphor (4MBC), triclosan (TCS), and 17α-ethinyl estradiol (EE2), to polyethylene (PE) debris (250 to 280 μm) was investigated. The estimated linear sorption coefficients (K d) are 191.4, 311.5, 5140, and 53,225 L/kg for CBZ, EE2, TCS, and 4MBC, and are related to their hydrophobicities. Increase of salinity from 0.05 to 3.5 % did not affect the sorption of 4MBC, CBZ, and EE2 but enhanced the sorption of TCS, likely due to the salting-out effect. Increase of dissolved organic matter (DOM) content using Aldrich humic acid (HA) as a proxy reduced the sorption of 4MBC, EE2, and TCS, all of which show a relatively strong affiliation to HA. Results from this work suggest that microplastics may play an important role in the fate and transport of PPCPs, especially for those hydrophobic ones.
显示更多 [+] 显示较少 [-]Immobilization of Mn and NH4 +-N from electrolytic manganese residue waste
2016
Chen, Hongliang | Liu, Renlong | Liu, Zuohua | Shu, Jiancheng | Tao, Changyuan
The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH₄ ⁺-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO₂) and alkaline additives. NH₄ ⁺-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO₂ and quicklime (CaO) was higher than using CO₂ and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH⁻ during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH₄ ⁺-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl₂ · 6H₂O + Na₃PO₄ · 12H₂O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH₄ ⁺-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH₄ ⁺-N was an effective pretreatment method in the harmless treatment of the EMR.
显示更多 [+] 显示较少 [-]Cytotoxicity and alterations at transcriptional level caused by metals on fish erythrocytes in vitro
2016
Morcillo, Patricia | Romero, Diego | Meseguer, José | Esteban, M Ángeles | Cuesta Arranz, Alberto
The in vitro use of fish erythrocytes to test the toxicity of aquatic pollutants could be a valuable alternative to fish bioassays but has received little attention. In this study, erythrocytes from marine gilthead sea bream (Sparus aurata L.) and European sea bass (Dicentrarchus labrax L.) specimens were exposed for 24 h to Cd, Hg, Pb and As and the resulting cytotoxicity was evaluated. Exposure to metals produced a dose-dependent reduction in the viability, and mercury showed the highest toxicity followed by MeHg, Cd, As and Pb. Moreover, fish erythrocytes incubated with each one of the metals exhibited alteration in gene expression profile of metallothionein, superoxide dismutase, catalase, peroxiredoxin, glutathione reductase, heat shock proteins 70 and 90, Bcl2-associated X protein and calpain1 indicating cellular protection, stress and apoptosis death as well as oxidative stress. This study points to the benefits for evaluating the toxicological mechanisms of marine pollution using fish erythrocytes in vitro.
显示更多 [+] 显示较少 [-]Impact of anti-inflammatories, beta-blockers and antibiotics on leaf litter breakdown in freshwaters
2016
Hughes, S. R. | Kay, P. | Brown, L. E.
Pharmaceuticals are now recognised as important pollutants in freshwater systems, but a shortcoming of effects studies is that they have focused on structural endpoints and impacts on ecosystem functioning are poorly understood. The decomposition of organic matter is an important functional process in aquatic systems, and it is known that this can be impacted by the presence of pollutants. Previous studies on leaf litter breakdown have only considered the effects of antibiotics and not other groups of drugs though. The current study investigated the effects of anti-inflammatories, a beta-blocker and an antibiotic on microbially mediated breakdown of leaf litter in the laboratory; colonisation of leaf packs by benthic macroinvertebrates when placed in a stream; and shredding of leaf litter by these organisms. Furthermore, the effects of single compounds relative to their mixture were assessed. It was found that exposure of leaf litter to the study compounds did not influence its breakdown by microbes in the laboratory or macroinvertebrates in a stream. Exposure of leaf litter to pharmaceuticals also had no effect on its colonisation by macroinvertebrates in this study. Many unknowns remain, however, and further studies of the effects of pharmaceuticals on structural and functional endpoints are needed to aid aquatic conservation.
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