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Suppressive effects of thermal-treated oyster shells on cadmium and copper translocation in maize plants
2017
Wang, Chunyan | Alidoust, Darioush | Isoda, Akihiro | Li, Maosong
The effect of varied concentrations of thermal-treated oyster shells (TOS) on the suppression of cadmium (Cd) and copper (Cu) uptake and translocation into the shoots of maize plants was examined. Maize plants were grown in Cd- and Cu-contaminated Andosol for 70 days. The concentration of mobile Cd (extracted with 1 M NH₄NO₃) decreased with increasing TOS applications, whereas an increase in the concentration of mobile Cu in soil resulted from cumulative TOS additions. The addition of 2% TOS had no prohibitive effects on Cd uptake in maize shoots, but the 4 and 8% TOS treatments decreased Cd accumulation in shoots by 41 and 59%, respectively. The possible mechanisms underlying Cd suppression in maize shoots were the enhanced Cd adsorption caused by pH-induced increases in the negative charge of the soil and the antagonistic effects of Ca resulting from competition for exchange sites at the root surface. Cu accumulation in maize shoots increased by 34, 51, and 53% with the addition of 2, 4, and 8% TOS, respectively, but this increase was not observed for Cd accumulation. These results suggested that, in multi-metal-contaminated soils, attention should be paid to the potential mobility of target metals and the pH of the contaminated soil. From a plant physiological perspective, contaminated soils slightly reduced photosynthetic performance. However, the addition of TOS to the soil at levels higher than 4% substantially decreased photosynthetic performance, indicating that CaO-based suppressants at critical loads might damage the net photosynthetic rates of sensitive maize plants.
显示更多 [+] 显示较少 [-]Comparative analysis between academic and patent publications based on Fenton Technologies among China, Brazil, and the rest of the world
2017
de Luna, Airton José | Santos, Douglas Alves
Worldwide, year by year, Fenton’s Technologies have been highlighted in both academic and patent scopes, in part due to their proven efficiency as environment-friendly technologies destined to the abatement of organic pollutants, and also by their growing interest to produce industrial applications. Thus, aiming to understand the effective dynamic between two worlds, academy vs patents, the present study performs a comparative analysis about publications on Fenton-based Technologies (FbT). Therefore, in this work, technological foresight techniques were adopted focusing on patent and non-patent databases, employing for this, the Web of Science (WoS) database as a prospecting tool. The main results for the last decade point out to a strong increment of the Fenton’s Technologies, as much in R&D as in patent applications in the world. Chinese Universities and firms command the scenario. There is an expressive gap between the academic and patent issues.
显示更多 [+] 显示较少 [-]Coated mesh photocatalytic reactor for air treatment applications: comparative study of support materials
2017
Passalia, Claudio | Nocetti, Emanuel | Alfano, Orlando | Brandi, Rodolfo
An experimental comparative study of different meshes as support materials for photocatalytic applications in gas phase is presented. The photocatalytic oxidation of dichloromethane in air was addressed employing different coated meshes in a laboratory-scale, continuous reactor. Two fiberglass meshes and a stainless steel mesh were studied regarding the catalyst load, adherence, and catalytic activity. Titanium dioxide photocatalyst was immobilized on the meshes by dip-coating cycles. Results indicate the feasibility of the dichloromethane elimination in the three cases. When the number of coating cycles was doubled, the achieved conversion levels were increased twofold for stainless steel and threefold for the fiberglass meshes. One of the fiberglass meshes (FG2) showed the highest reactivity per mass of catalyst and per catalytic surface area.
显示更多 [+] 显示较少 [-]Degradation of organic contaminants in effluents—synthetic and from the textile industry—by Fenton, photocatalysis, and H2O2 photolysis
2017
de Lima, L. B. | Pereira, L. O. | de Moura, S. G. | Magalhães, F.
In this study, the oxidation of the dye rhodamine B (RhB), present in a synthetic effluent, and the degradation of organic matter present in a textile effluent, were assessed by photolysis (H₂O₂, UV), homogeneous Fenton (Fe²⁺, H₂O₂), and photocatalysis (TiO₂, UV). The results showed that photolysis and Fenton had an efficiency of 100 % and photocatalysis, 96 %, to discoloration 10 mg L⁻¹ RhB, present in the synthetic effluent. The best experimental conditions determined for these reactions showed that the one performed with 51 mg L⁻¹ H₂O₂ and UV light had the best results, where 100 % of RhB was discolored in only 6 min of reaction. The optimum conditions determined in the first part of this study for the RhB oxidation did not show satisfactory results for the degradation of organic matter present in the textile effluent sample, and it was necessary to increase the amount of reagents in the three processes. After resizing the concentration of the reagents for the reactions with the textile effluent, the following reductions of color, total organic carbon (TOC), and total soluble solids (SS) were obtained: photocatalysis 29, 25, and 32 %; photolysis 85, 69, and 35 %; Fenton 98, 90, and 23 %; and biological (followed by physicochemical) treatment carried out by the textile industry 96, 48, and 9 %. It is observed that the Fenton reaction showed the best result, followed by photolysis reaction, a treatment carried out by industry and, at last, photocatalysis.
显示更多 [+] 显示较少 [-]Water quality of a coastal lagoon (ES, Brazil): abiotic aspects, cytogenetic damage, and phytoplankton dynamics
2017
Duarte, Ian Drumond | Silva, Nayara Heloisa Vieira Fraga | da Costa Souza, Iara | de Oliveira, Larissa Bassani | Rocha, Lívia Dorsch | Morozesk, Mariana | Bonomo, Marina Marques | de Almeida Pereira, Thaís | Dias, Mauro Cesar | de Oliveira Fernandes, Valéria | Matsumoto, Silvia Tamie
Assessment of water resources requires interdisciplinary studies that include multiple ecosystem aspects. This study evaluated the water quality of Juara Lagoon (ES, Brazil) based on physical and chemical variables, cytogenetic responses in Allium cepa and phytoplankton dynamics. Three sampling sites were defined and water samples were collected during two sampling periods. Analyses such as determination of photic zone, conductivity, and concentrations of nutrients and metals were conducted as well as cytotoxic, mutagenic, and genotoxic potentials using A. cepa test. The main attributes of phytoplankton community, such as total richness, total density, density by class, dominance, and diversity, were also evaluated. Results have revealed that Juara Lagoon has signs of artificial eutrophication at two sampling sites due to high levels of total phosphorus and ammonia nitrogen. Cytotoxic, genotoxic, and mutagenic potentials were detected as well as high concentrations of Fe and Mn. Furthermore, 165 phytoplankton taxa were recorded, with highest richness in Chlorophyceae and Cyanophyceae classes. In addition, Cyanophyceae presented as the highest density class. A. cepa test and phytoplankton community evaluation indicated that the ecological quality of Juara Lagoon is compromised.
显示更多 [+] 显示较少 [-]Consumption of organic meat does not diminish the carcinogenic potential associated with the intake of persistent organic pollutants (POPs)
2017
Hernández, Ángel Rodríguez | Boada, Luis D. | Mendoza, Zenaida | Ruiz-Suárez, Norberto | Valerón, Pilar F. | Camacho, Maria | Zumbado, Manuel | Almeida-González, Maira | Henríquez-Hernández, Luis A. | Luzardo, Octavio P.
Numerous studies have shown an epidemiological link between meat consumption and the incidence of cancer, and it has been suggested that this relationship may be motivated by the presence of carcinogenic contaminants on it. Among the most frequently detected contaminants in meat are several types of persistent organic pollutants (POPs), and it is well known that many of them are carcinogenic. On the other hand, an increasing number of consumers choose to feed on what are perceived as healthier foods. Thus, the number of consumers of organic food is growing. However, environmental contamination by POPs is ubiquitous, and it is therefore unlikely that the practices of organic food production are able to prevent this contamination. To test this hypothesis, we acquired 76 samples of meat (beef, chicken, and lamb) of two modes of production (organic and conventional) and quantified their levels of 33 carcinogenic POPs. On this basis, we determined the human meat-related daily dietary exposure to these carcinogens using as a model a population with a high consumption of meat, such as the Spanish population. The maximum allowable meat consumption for this population and the carcinogenic risk quotients associated with the current pattern of consumption were calculated. As expected, no sample was completely free of carcinogenic contaminants, and the differences between organically and conventionally produced meats were minimal. According to these results, the current pattern of meat consumption exceeded the maximum limits, which are set according to the levels of contaminations, and this is associated with a relevant carcinogenic risk. Strikingly, the consumption of organically produced meat does not diminish this carcinogenic risk, but on the contrary, it seems to be even higher, especially that associated with lamb consumption.
显示更多 [+] 显示较少 [-]Environmental characterisation of sewage sludge/paper ash-based composites in relation to their possible use in civil engineering
2017
Mladenovič, Ana | Hamler, Sandra | Zupančič, Nina
The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably. In the SwS the Ba, Cd, Cr, Cu, Hg, Ni and Zn contents are above the legally permitted limits. The PTE content of PA are lower, but still somewhat above the permitted values for Ba and Cu. Mixing these two materials together resulted in a decrease in the PTE, but the Ba, Cu and Zn contents are still too high for agricultural application. However, leachates from composites that had been cured for 28 days are highly alkaline, and the As, Ba, Cd, Cr, Hg, Mo, Ni, Pb and Zn contents in them are well below the permitted values. The Cu contents (2.4 to 5.4 mg/kg) are above the permitted limit for inert material, but inside the range for non-hazardous material. In a leachate of composite which was prepared with fresh PA and a lower PA to SwS ratio, the Cu content was 1.4 mg/kg, since fresh PA is more reactive and therefore has a higher ability to immobilise Cu. Therefore, such mixtures can be utilised for covers and liners for sanitary landfills.
显示更多 [+] 显示较少 [-]Semi-autonomous inline water analyzer: design of a common light detector for bacterial, phage, and immunological biosensors
2017
Descamps, Elodie C.T. | Meunier, Damien | Brutesco, Catherine | Prévéral, Sandra | Franche, Nathalie | Bazin, Ingrid | Miclot, Bertrand | Larosa, Philippe | Escoffier, Camille | Fantino, Jean-Raphael | Garcia, Daniel | Ansaldi, Mireille | Rodrigue, Agnès | Pignol, David | Cholat, Pierre | Ginet, Nicolas
The use of biosensors as sensitive and rapid alert systems is a promising perspective to monitor accidental or intentional environmental pollution, but their implementation in the field is limited by the lack of adapted inline water monitoring devices. We describe here the design and initial qualification of an analyzer prototype able to accommodate three types of biosensors based on entirely different methodologies (immunological, whole-cell, and bacteriophage biosensors), but whose responses rely on the emission of light. We developed a custom light detector and a reaction chamber compatible with the specificities of the three systems and resulting in statutory detection limits. The water analyzer prototype resulting from the COMBITOX project can be situated at level 4 on the Technology Readiness Level (TRL) scale and this technical advance paves the way to the use of biosensors on-site.
显示更多 [+] 显示较少 [-]Photosynthetic pigments and peroxidase activity of Lepidium sativum L. during assisted Hg phytoextraction
2017
Smolinska, Beata | Leszczynska, Joanna
The study was conducted to evaluate metabolic answer of Lepidium sativum L. on Hg, compost, and citric acid during assisted phytoextraction. The chlorophyll a and b contents, total carotenoids, and activity of peroxidase were determined in plants exposed to Hg and soil amendments. Hg accumulation in plant shoots was also investigated. The pot experiments were provided in soil artificially contaminated by Hg and/or supplemented with compost and citric acid. Hg concentration in plant shoots and soil substrates was determined by cold vapor atomic absorption spectroscopy (CV-AAS) method after acid mineralization. The plant photosynthetic pigments and peroxidase activity were measured by standard spectrophotometric methods. The study shows that L. sativum L. accumulated Hg in its aerial tissues. An increase in Hg accumulation was noticed when soil was supplemented with compost and citric acid. Increasing Hg concentration in plant shoots was correlated with enhanced activation of peroxidase activity and changes in total carotenoid concentration. Combined use of compost and citric acid also decreased the chlorophyll a and b contents in plant leaves. Presented study reveals that L. sativum L. is capable of tolerating Hg and its use during phytoextraction assisted by combined use of compost and citric acid lead to decreasing soil contamination by Hg.
显示更多 [+] 显示较少 [-]Emergency material allocation and scheduling for the application to chemical contingency spills under multiple scenarios
2017
Liu, Jie | Guo, Liang | Jiang, Jiping | Jiang, Dexun | Wang, Peng
In the emergency management relevant to chemical contingency spills, efficiency emergency rescue can be deeply influenced by a reasonable assignment of the available emergency materials to the related risk sources. In this study, an emergency material scheduling model (EMSM) with time-effective and cost-effective objectives is developed to coordinate both allocation and scheduling of the emergency materials. Meanwhile, an improved genetic algorithm (IGA) which includes a revision operation for EMSM is proposed to identify the emergency material scheduling schemes. Then, scenario analysis is used to evaluate optimal emergency rescue scheme under different emergency pollution conditions associated with different threat degrees based on analytic hierarchy process (AHP) method. The whole framework is then applied to a computational experiment based on south-to-north water transfer project in China. The results demonstrate that the developed method not only could guarantee the implementation of the emergency rescue to satisfy the requirements of chemical contingency spills but also help decision makers identify appropriate emergency material scheduling schemes in a balance between time-effective and cost-effective objectives.
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