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Sources and characteristics of carbonaceous aerosols at Agra “World heritage site” and Delhi “capital city of India” 全文
2014
Pipal, A. S. | Tiwari, S. | Satsangi, P. G. | Taneja, Ajay | Bisht, D.S. | Srivastava, A. K. | Srivastava, M. K.
Agra, one of the oldest cities “World Heritage site”, and Delhi, the capital city of India are both located in the border of Indo-Gangetic Plains (IGP) and heavily loaded with atmospheric aerosols due to tourist place, anthropogenic activities, and its topography, respectively. Therefore, there is need for monitoring of atmospheric aerosols to perceive the scenario and effects of particles over northern part of India. The present study was carried out at Agra (AGR) as well as Delhi (DEL) during winter period from November 2011 to February 2012 of fine particulate (PM₂.₅: d < 2.5 μm) as well as associated carbonaceous aerosols. PM₂.₅was collected at both places using medium volume air sampler (offline measurement) and analyzed for organic carbon (OC) and elemental carbon (EC). Also, simultaneously, black carbon (BC) was measured (online) at DEL. The average mass concentration of PM₂.₅was 165.42 ± 119.46 μg m⁻³at AGR while at DEL it was 211.67 ± 41.94 μg m⁻³which is ~27 % higher at DEL than AGR whereas the BC mass concentration was 10.60 μg m⁻³. The PM₂.₅was substantially higher than the annual standard stipulated by central pollution control board and United States Environmental Protection Agency standards. The average concentrations of OC and EC were 69.96 ± 34.42 and 9.53 ± 7.27 μm m⁻³, respectively. Total carbon (TC) was 79.01 ± 38.98 μg m⁻³at AGR, while it was 50.11 ± 11.93 (OC), 10.67 ± 3.56 μg m⁻³(EC), and 60.78 ± 14.56 μg m⁻³(TC) at DEL. The OC/EC ratio was 13.75 at (AGR) and 5.45 at (DEL). The higher OC/EC ratio at Agra indicates that the formation of secondary organic aerosol which emitted from variable primary sources. Significant correlation between PM₂.₅and its carbonaceous species were observed indicating similarity in sources at both sites. The average concentrations of secondary organic carbon (SOC) and primary organic carbon (POC) at AGR were 48.16 and 26.52 μg m⁻³while at DEL it was 38.78 and 27.55 μg m⁻³, respectively. In the case of POC, similar concentrations were observed at both places but in the case of SOC higher over AGR by 24 in comparison to DEL, it is due to the high concentration of OC over AGR. Secondary organic aerosol (SOA) was 42 % higher at AGR than DEL which confirms the formation of secondary aerosol at AGR due to rural environment with higher concentrations of coarse mode particles. The SOA contribution in PM₂.₅was also estimated and was ~32 and 12 % at AGR and DEL respectively. Being high loading of fine particles along with carbonaceous aerosol, it is suggested to take necessary and immediate action in mitigation of the emission of carbonaceous aerosol in the northern part of India.
显示更多 [+] 显示较少 [-]Degradation of tetracycline at a boron-doped diamond anode: influence of initial pH, applied current intensity and electrolyte 全文
2014
Brinzila, C. I. | Monteiro, N. | Pacheco, M. J. | Ciríaco, L. | Siminiceanu, I. | Lopes, A.
The anodic oxidation of tetracycline was performed in an up-flow reactor, operating in batch mode with recirculation, using as anode a boron-doped diamond electrode. The influence on the degradation rate of solution initial pH (2 to 12), applied current intensity (25 to 300 A m⁻²) and type of electrolyte (sodium sulphate or sodium chloride) were investigated. For the assays run at equal current density, with sodium sulphate as electrolyte, the solution’s initial pH of 2 presented the highest absorbance and chemical oxygen demand removals. Regarding the influence of current density, for equal charge passed, the organic load removal rate decreased with the increase in applied current. When sodium sulphate was used as an electrolyte, high-performance liquid chromatography (HPLC) results have shown an almost complete removal of tetracycline after a 2-h assay. HPLC results have also shown the presence of oxamic acid as one of the intermediates of tetracycline anodic oxidation. The complete removal of tetracycline was much faster in the presence of chloride ions that promoted the complete degradation of this antibiotic in 30 min. However, in the presence of chloride ions, the tetracycline mineralization is slower, as observed by the lower organic carbon removal rate when compared to that of the tetracycline degradation in the presence of sulphate.
显示更多 [+] 显示较少 [-]Cytotoxicity, genotoxicity and oxidative stress of malachite green on the kidney and gill cell lines of freshwater air breathing fish Channa striata 全文
2014
Majeed, S Abdul | Nambi, K. S. N. | Taju, G. | Vimal, S. | Venkatesan, C. | Hameed, A. S Sahul
The cytotoxicity, genotoxicity and oxidative stress of malachite green (MG) was investigated using the fish Channa striata kidney (CSK) and Channa striata gill (CSG) cell lines. Five concentrations ranging from 0.001 to 10 μg mL⁻¹were tested in three independent experiments. Cytotoxicity was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Rhodamine 123 and Alamar Blue. The mitochondrial changes and apoptosis of MG-exposed cells were observed by Rhodamine 123 and acridine orange/ethidium bromide (AO/EB) staining, respectively. In vitro potential DNA damaging effect of MG was tested using comet assay. Mitochondrial damage, apoptosis and DNA fragmentation increased in a concentration-dependent manner. Additionally, DNA electrophoretic mobility experiments were carried out to study the binding effect of MG to double-stranded DNA (dsDNA) of cells. DNA shift mobility experiments showed that MG is capable of strongly binding to linear dsDNA causing its degradation. Biochemical parameters such as lipid peroxidation (MDA), catalase (CAT) activity and reduced glutathione (GSH) levels were evaluated after exposure to MG. In CSK and CSG cell lines exposed to MG for 48 h, a significant increase in lipid peroxidation, which might be associated with decreased levels of reduced glutathione and catalase activity in these cell lines (p < 0.001), was observed.
显示更多 [+] 显示较少 [-]Effect of dietary supplementation of essential oils mixture on performance, eggshell quality, hatchability, and mineral excretion in quail breeders 全文
2014
Olgun, Osman | Yıldız, Alp Önder
The main aim of this study was to investigate the effect of six different levels (0, 50, 100, 200, 400, and 600 mg/kg) of phytogenic feed additive containing a mixture essential oils from thyme, black cumin, fennel, anise and rosemary on performance, eggshell quality, reproductive traits, and mineral excretion in quail breeders. In this trial, a total of 60 male and 120 female quails, 91 days old, were randomly distributed in six experimental groups. During the 60-day experiment period, birds were fed with six treatment diets. Performances, eggshell qualities, hatchability, and mineral excretion data were evaluated at the end of the experiment. Results showed that the different dietary levels of essential oil mixture had no significant effect on performance parameters, damaged eggs, eggshell weight, fertility, hatchability of fertile eggs, hatchability of set eggs, and lead and boron excretion. On the other hand, 50 mg/kg supplementation of essential oil mixture (EOM) significantly improved egg-breaking strength and eggshell thickness, and ash, calcium, phosphorus, magnesium, manganese, zinc, and cadmium excretion was significantly depressed in quail breeders supplemented with the two higher doses (400 or 600 mg/kg) of EOM. These results concluded that supplementing diets with EOM improved egg-breaking strength and decreased excretion of minerals in breeder quails.
显示更多 [+] 显示较少 [-]Fate and effects of metal-based nanoparticles in two marine invertebrates, the bivalve mollusc Scrobicularia plana and the annelid polychaete Hediste diversicolor 全文
2014
Mouneyrac, Catherine | Buffet, Pierre-Emmanuel | Poirier, Laurence | Zalouk-Vergnoux, Aurore | Guibbolini, Marielle | Faverney, Christine Risso-de | Gilliland, Douglas | Berhanu, Déborah | Dybowska, Agnieszka | Châtel, Amélie | Perrein-Ettajni, Hanane | Pan, Jin-Fen | Thomas-Guyon, Hélène | Reip, Paul | Valsami-Jones, Eugenia
The objective of this paper is to synthesize results from seven published research papers employing different experimental approaches to evaluate the fate of metal-based nanoparticles (Ag NPs, Au NPs, CuO NPs, CdS NPs, ZnO NPs) in the marine environment and their effects on two marine endobenthic species, the bivalve Scrobicularia plana and the ragworm Hediste diversicolor. The experiments were carried out under laboratory (microcosms) conditions or under environmentally realistic conditions in outdoor mesocosms. Based on results from these seven papers, we addressed the following research questions: (1) How did the environment into which nanoparticles were released affect their physicochemical properties?, (2) How did the route of exposure (seawater, food, sediment) influence bioaccumulation and effects?, (3) Which biomarkers were the most responsive? and (4) Which tools were the most efficient to evaluate the fate and effects of NPs in the marine environment? The obtained results showed that metal‐based NPs in general were highly agglomerated/aggregated in seawater. DGT tools could be used to estimate the bioavailability of metals released from NPs under soluble form in the aquatic environment. Both metal forms (nanoparticulate, soluble) were generally bioaccumulated in both species. Among biochemical tools, GST and CAT were the most sensitive revealing the enhancement of anti-oxidant defenses in both species exposed to sub-lethal concentrations of metal-based NPs. Apoptosis and genotoxicity were frequently observed.
显示更多 [+] 显示较少 [-]Different decay patterns observed in a nineteenth-century building (Palma, Spain) 全文
2014
Genestar, Catalina | Pons, Carmen | Cerro, José Carlos | Cerdá, Victor
The effects of atmospheric pollutants and climatic conditions were studied in a decayed column in the Seminary of Sant Pere. This nineteenth-century building is situated in the historic centre of Palma (Mallorca, Spain), less than 0.5 km from the sea. Samples were collected from the internal and external part of the crusts formed in the four sides of the column. The samples were analysed by means of thermal analysis, X-ray diffractometry, scanning electron microscopy, Fourier transform infrared spectroscopy and ion chromatography. Results show significant differences in the four sides of the column. A high degree of carbonate stone sulfation is observed in all of the samples analysed. A synergistic effect between atmospheric factors and micropollutants on the deterioration of stone is observed. A high uptake of atmospheric particulate matter is found in the external part of the black crusts.
显示更多 [+] 显示较少 [-]Electro-Fenton degradation of the antibiotic sulfanilamide with Pt/carbon-felt and BDD/carbon-felt cells. Kinetics, reaction intermediates, and toxicity assessment 全文
2014
El-Ghenymy, Abdellatif | Rodríguez, Rosa Ma. (Rosa María) | Brillas, Enric | Oturan, Nihal | Oturan, Mehmet A.
The degradation of 230 mL of a 0.6-mM sulfanilamide solution in 0.05 M Na₂SO₄of pH 3.0 has been studied by electro-Fenton process. The electrolytic cell contained either a Pt or boron-doped diamond (BDD) anode and a carbon-felt cathode. Under these conditions, organics are oxidized by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton’s reaction between initially added (and then electrochemically regenerated) Fe²⁺and cathodically generated H₂O₂. From the decay of sulfanilamide concentration determined by reversed-phase liquid chromatography, an optimum Fe²⁺concentration of 0.20 mM in both cells was found. The drug disappeared more rapidly using BDD than Pt, and, in both cases, it was more quickly removed with raising applied current. Almost total mineralization was achieved using the BDD/carbon-felt cell, whereas the alternative use of Pt anode led to a slightly lower mineralization degree. In both cells, the degradation rate was accelerated at higher current but with the concomitant fall of mineralization current efficiency due to the greater increase in rate of the parasitic reactions of hydroxyl radicals. Reversed-phase liquid chromatography allowed the identification of catechol, resorcinol, hydroquinone, p-benzoquinone, and 1,2,4-trihydroxybenzene as aromatic intermediates, whereas ion exclusion chromatography revealed the formation of malic, maleic, fumaric, acetic, oxalic, formic, and oxamic acids. NH₄⁺, NO₃⁻, and SO₄²⁻ions were released during the electro-Fenton process. A plausible reaction sequence for sulfanilamide mineralization involving all detected intermediates has been proposed. The toxicity of the solution was assessed from the Vibrio fischeri bacteria luminescence inhibition. Although it acquired its maximum value at short electrolysis time, the solution was completely detoxified at the end of the electro-Fenton treatment, regardless of the anode used.
显示更多 [+] 显示较少 [-]Dechlorane Plus in surface soil of North China: levels, isomer profiles, and spatial distribution 全文
2014
Ma, Jin | Qiu, Xinghua | Liu, Di | Zhao, Yifan | Yang, Qiaoyun | Fang, Di
Eighty-seven soil samples collected from North China were analyzed for Dechlorane Plus (DP). The concentrations of DP ranged from not detectable (ND) to 12.21 ng/g with a mean of 0.55 ng/g. The mean concentrations of total DP and syn-DP in four regions of North China were in the following order: Jingjin (Beijing and Tianjin) > Shandong > Shanxi > Hebei, while the mean concentrations of anti-DP in the four regions were in a different order: Shandong > Jingjin > Shanxi > Hebei. The mean fₛyₙvalues for Jingjin (0.27), Hebei (0.24), and Shanxi (0.24) were close to 0.25, while the mean fₛyₙvalue for Shandong (0.31) was closer to 0.35. In addition, the fₛyₙvalue for Shandong was significantly higher (P < 0.01) than those of the other regions (Jingjin, Heibei, and Shanxi), indicating specific sources of DP. Syn-DP displayed a strong linear relationship with anti-DP (R² = 0.74), indicating that no obvious stereoselective process occurred in the soil of North China. Ordinary kriging was undertaken to map the spatial patterns of DP. High concentrations of DP in soils were present in south of Shanxi, central Hebei, south of Tianjin, and the south and northeast of Shandong, which were suggested to be connected with human activities such as e-waste dismantling.
显示更多 [+] 显示较少 [-]Sequential electrochemical treatment of dairy wastewater using aluminum and DSA-type anodes 全文
2014
Borbón, Brenda | Oropeza-Guzman, Mercedes Teresita | Brillas, Enric | Sirés, Ignasi
Dairy wastewater is characterized by a high content of hardly biodegradable dissolved, colloidal, and suspended organic matter. This work firstly investigates the performance of two individual electrochemical treatments, namely electrocoagulation (EC) and electro-oxidation (EO), in order to finally assess the mineralization ability of a sequential EC/EO process. EC with an Al anode was employed as a primary pretreatment for the conditioning of 800 mL of wastewater. A complete reduction of turbidity, as well as 90 and 81 % of chemical oxygen demand (COD) and total organic carbon (TOC) removal, respectively, were achieved after 120 min of EC at 9.09 mA cm⁻². For EO, two kinds of dimensionally stable anodes (DSA) electrodes (Ti/IrO₂-Ta₂O₅and Ti/IrO₂-SnO₂–Sb₂O₅) were prepared by the Pechini method, obtaining homogeneous coatings with uniform composition and high roughness. The·OH formed at the DSA surface from H₂O oxidation were not detected by electron spin resonance. However, their indirect determination by means of H₂O₂measurements revealed that Ti/IrO₂-SnO₂–Sb₂O₅is able to produce partially physisorbed radicals. Since the characterization of the wastewater revealed the presence of indole derivatives, preliminary bulk electrolyses were done in ultrapure water containing 1 mM indole in sulfate and/or chloride media. The performance of EO with the Ti/IrO₂-Ta₂O₅anode was evaluated from the TOC removal and the UV/Vis absorbance decay. The mineralization was very poor in 0.05 M Na₂SO₄, whereas it increased considerably at a greater Cl⁻content, meaning that the oxidation mediated by electrogenerated species such as Cl₂, HClO, and/or ClO⁻competes and even predominates over the·OH-mediated oxidation. The EO treatment of EC-pretreated dairy wastewater allowed obtaining a global 98 % TOC removal, decreasing from 1,062 to <30 mg L⁻¹.
显示更多 [+] 显示较少 [-]Larvicidal, ovicidal, and oviposition-deterrent activities of four plant extracts against three mosquito species 全文
2014
Prathibha, K. P. | Raghavendra, B. S. | Vijayan, V. A.
In mosquito control programs, insecticides of botanical origin have the potential to eliminate eggs, larvae, and adults. So, the larvicidal, ovicidal, and oviposition-deterrent activities of petroleum ether and ethyl acetate extracts of the leaves of Eugenia jambolana, Solidago canadensis, Euodia ridleyi, and Spilanthes mauritiana were assayed against the three vector mosquito species, namely Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus. The larval bioassay was conducted following the World Health Organization method. The maximum larval mortality was found with ethyl acetate extract of S. mauritiana against the larvae of A. stephensi, A. aegypti, and C. quinquefasciatus with LC₅₀values of 11.51, 28.1, 14.10 ppm, respectively. The mean percent hatchability of the ovicidal activity was observed at 48-h post-treatment. The percent hatchability was found to be inversely proportional to the concentration of the extract and directly proportional to the number of eggs. The flower head extract of S. mauritiana gave 100 % mortality followed by E. ridleyi, S. canadensis, and E. jambolana against the eggs of the three mosquito vectors. For oviposition-deterrent effect, out of the five concentrations tested (20, 40, 60, 80, and 100 ppm), the concentration of 100 ppm showed a significant egg laying-deterrent capacity. The oviposition activity index value of E. jambolana, E. ridleyi, S. canadensis, and S. mauritiana against A. aegypti, A. stephensi, C. quinquefasciatus at 100 ppm were −0.71, −0.71, −0.90, −0.93, −0.85, −0.91, −1, −1, −0.71, −0.85, −1, and −1, respectively. These results suggest that the leaf/flower extracts of certain local plants have the potential to be developed as possible eco-friendly means for the control of mosquitoes.
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