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Comparison of multi-criteria analysis methodologies for the prioritization of arsenic-contaminated sites in the southwest of China
2019
Chen, Ruihui | Xiong, Yanna | Li, Jiao | Teng, Yanguo | Chen, Haiyang | Yang, Jie
The issue of contaminated sites has been highlighted as an immediate priority in the 13th Five-Year Plan of China. Identification and prioritization of contaminated sites are of key importance for proposing effective strategies for the regional management of contaminated sites. In this study, three advanced multi-attribute methodologies, the risk-based priority methodology, the regional risk assessment methodology, and the dominance-based rough set approach (DRSA), were comparatively employed to screen contaminated sites in, Guangxi, Southwest of China. The results of the three prioritizations show that the highest ranking site identified by the three methods had great agreement. In regard to the screening attributers, while the risk-based prioritization methodology and regional risk assessment methodology allowed a high discrimination in the screening of contaminated sites associated with different attributes, such as farmland, residential areas, contaminant level, number of people, area, storage quality, site service life, and surrounding communities, the DRSA allowed the identification of contamination strength (CS) and contamination potential (CP).
Afficher plus [+] Moins [-]Preparation and characterization of polycaprolactone nanocapsules containing pretilachlor as a herbicide nanocarrier
2019
Diyanat, Marjan | Saeidian, Hamid | Baziar, Sara | Mirjafary, Zohreh
Polycaprolactone nanocapsules (PCL) containing pretilachlor were prepared, and Fourier transform infrared spectroscopy, atomic force microscopy, and transmission electron microscopy were used for their structural and morphological investigations. The results revealed that the nanocapsules had irregular shape and their particles size was in the range of 70–200 nm. The encapsulation efficiency of pretilachlor was measured as 99.5 ± 1.3% using high-performance liquid chromatography analysis. The physicochemical stability studies over 60 days showed that the nanocapsules were stable in the suspension without any aggregation. The herbicide activity was examined in a pre-emergence manner using barnyard grass as a target plant and rice as a non-target plant. The nanoformulation had no negative effect on rice plant. However, its effect on barnyard grass was significant. The cytotoxicity analysis indicated that the nanocapsulated herbicide is less toxic rather than the commercial formulation. Therefore, encapsulation of pretilachlor in PCL nanocapsules can be used effectively to construct environmentally friendly PCL-herbicide systems in agriculture.
Afficher plus [+] Moins [-]Immobilization of Pb from mine sediments in metakaolin-based geomaterials
2019
Joussein, Emmanuel | Soubrand, Marilyne | Pascaud, Grégoire | Cogulet, Antoine | Rossignol, Sylvie
The aims of this study correspond to (i) determine the feasibility of synthesize geomaterial from two main Pb-contaminated mining sediments (Sed1 and Sed2) without prior activation in substitution to metakaolin (MK), (ii) understand the mechanisms involved toward two types of silicate solution (Na and K one), and (iii) to evaluate the change in the Pb metallic element speciation and leaching after alkali treatment. The raw material as well as consolidated material were characterized by X-ray diffraction, infrared spectroscopy, and electron microscopy. The mechanical properties were evaluated, and the leaching behavior realized according to EN12457-2. The results evidence the limit of mining sediment incorporation by substitution near 50% whatever the sediments and the alkaline solution used. There is no difference in the mechanical properties up to 10% substitution then decrease with the increase of sediment content. The Pb-bearing phases are dissolved during alkaline treatment and redistributed in the geomaterial matrix. Finally, the leaching experiments clearly evidenced the possibility to stabilize Pb into MK-based geomaterial matrix up to 25–30% weight of mine waste.
Afficher plus [+] Moins [-]Ameliorative effect of Spirulina platensis against lead nitrate–induced cytotoxicity and genotoxicity in catfish Clarias gariepinus
2019
Abū al-Saʻūd, Muḥammad Ḥāmid Muʻawwaḍ | Soliman, Hamdy A. M. | Sayed, Alaa El-Din H.
The present study was designed to investigate the protective role of dietary supplementation of Spirulina platensis (SP) against cytotoxic and genotoxic effects of lead nitrate in Clarias gariepinus. Four groups of fishes were used: first group as control which fed on basal diet, second group fed on basal diet and exposed to (1 mg/L of lead nitrate), third group fed on diet containing 0.25% SP and exposed to (1 mg/L of lead nitrate), and fourth group fed on diet containing 0.5%SP and exposed to (1 mg/L of lead nitrate). Fish samples were taken at 2nd and 4th week of exposure. The hematological indices of lead nitrate–exposed group were decreased significantly compared to the control group at 2nd and 4th week of exposure. Lead nitrate caused a significant increase in the percentage of poikilocytosis, micronuclei, and apoptotic cells as well as comet tail length and olive tail moment compared with the control group at 2nd and 4th week of exposure. The highest level of damage was found on 4th week of exposure with all parameters. Dietary inclusion of SP ameliorated these cytotoxic and genetic changes, as well as this amelioration was concentration and time dependent. Consequently, the present study proposed that the addition of SP to the fish diet can be used as a promising protective agent to oppose cytotoxic and genotoxic effects of lead nitrate in aquaculture. Graphical abstract
Afficher plus [+] Moins [-]Quantifying nitrate sources in a large reservoir for drinking water by using stable isotopes and a Bayesian isotope mixing model
2019
Jin, Zanfang | Cen, Jiarong | Hu, Yuming | Li, Linjun | Shi, Yasheng | Fu, Guowei | Li, Feili
Drinking water reservoirs are threatened globally by anthropogenic nitrogen pollution. Hydrochemistry and isotopes were analyzed to identify spatial and temporal varieties of main nitrate sources in a large drinking water reservoir in East China. The results showed that NO₃⁻ was the main nitrogen form in both the dry and wet seasons, but dissolved organic nitrogen (DON) was increased in the wet season. The δ¹⁵N-NO₃⁻ values (+ 1.3‰ to + 11.8‰) and δ¹⁸O-NO₃⁻ values (+ 2.5‰ to + 13.5‰), combined with principal component analysis (PCA), indicated that chemical fertilizer was the main nitrate source during the dry season, while chemical fertilizer, soil N, and sewage/manure were the main nitrate sources during the wet season in the Qiandao Lake area. And, the nitrate isotopes showed the significant nitrification and assimilation in the Qiandao Lake area. A Bayesian isotopic mixing model (Stable Isotope Analysis in R) was applied to the spatial and seasonal trends in the proportional contribution of four NO₃⁻ sources (chemical fertilizer (CF), soil nitrogen (SN), sewage and manure (SM), and atmospheric deposition (AD)) in the Qiandao Lake area. It was revealed that CF was the most important nitrate source in the dry season, accounting for 53.4% with 19.2% of SM and 18.9% of SN, while the contribution of SN increased in the wet season, accounting for 31.6%, followed by CF (30.8%) and then SM (24.2%). The main nitrate sources in the urban area, rural area, and central lake area were CF and SN, accounting for 66.1% in the urban area, 71.7% in the rural area, and 68.2% in the central lake area. Measures should be made to improve chemical fertilizer use efficiency and to reduce nitrogen loss in the Qiandao Lake area. Graphical abstract .
Afficher plus [+] Moins [-]Arsenic content in two-year-old Acer platanoides L. and Tilia cordata Miller seedlings growing under dimethylarsinic acid exposure–model experiment
2019
Budzyńska, Sylwia | Goliński, Piotr | Niedzielski, Przemysław | Gąsecka, Monika | Mleczek, Mirosław
The presence of cacodylic acid (dimethylarsinic acid, DMA) can be an important factor in limiting the abilities of young tree seedlings to adapt to unfavorable environmental conditions. For this reason, the aim of the study was to estimate the influence of different DMA additions (from 0.01 to 0.6 mM) to modified Knop solution to arsenic (As) and selected forms of this metalloid (As(III), As(V), DMA) phytoextraction by two-year-old Acer platanoides L. and Tilia cordata Miller seedlings. Additionally, the biomass and other elements important in As transport in plants were analyzed. Seedlings of both tree species were able to grow in all experimental systems except the one with the highest DMA concentration (0.6 mM). Exposure of tree seedlings was related to a general decrease in plant biomass. Phytoextraction of As in roots, stems, and leaves increased with a rise of DMA concentration in solution to the highest content of As in A. platanoides and T. cordata roots growing under 0.3 mM (135 ± 13 and 116 ± 14 mg kg⁻¹ dry weight). Arsenic was accumulated mainly in roots, thereby confirming bioconcentration factor values BCF > 1 for all tree seedlings treated with DMA. Exposure of plants to low DMA concentrations (0.01 and 0.03 mM) was related to the transport of this element to aboveground parts, while increased DMA concentration in other experimental systems led to the limitation of As transport to stems, as confirmed by translocation factor values TF < 1. Changes in many other elements such as boron, silicon, phosphorus, or sulfur concentration indicated the possible influence of DMA on the transport of As from roots to leaves. The obtained results show that DMA can be an important factor in modulating As phytoextraction in the studied tree species.
Afficher plus [+] Moins [-]Technologies for deodorization of malodorous gases
2019
Wysocka, Izabela | Gębicki, Jacek | Namieśnik, Jacek
There is an increasing number of citizens’ complaints about odor nuisance due to production or service activity. High social awareness imposes pressure on entrepreneurs and service providers forcing them to undertake effective steps aimed at minimization of the effects of their activity, also with respect to emission of malodorous substances. The article presents information about various technologies used for gas deodorization. Known solutions can be included into two groups: technologies offering prevention of emissions, and methodological solutions that enable removal of malodorous substances from the stream of emitted gases. It is obvious that the selection of deodorization technologies is conditioned by many factors, and it should be preceded by an in-depth analysis of possibilities and limitations offered by various solutions. The aim of the article is presentation of the available gas deodorization technologies as to facilitate the potential investors with selection of the method of malodorous gases emission limitation, suitable for particular conditions.
Afficher plus [+] Moins [-]Trace elements and human health risks assessment of finer aerosol atmospheric particles (PM1)
2019
Caggiano, Rosa | Sabia, Serena | Speranza, Antonio
The present study investigated PM₁ (aerosol particles with an aerodynamic diameter ≤ 1.0 μm) mass concentrations and sixteen (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, S, Ti, and Zn) PM₁-related trace elements. PM₁ samples were collected in an anthropized area of international attention close to oil/gas pre-treatment plants in Agri Valley (Southern Italy). The PM₁ mass concentrations varied from 3 to 16 μg/m³. The decreasing pattern of the trace element concentrations was S > Ca > Na > K ≈ Mg ≈ Fe> Al > Li > Cr > Zn > Ti> Cu > Ni ≈ Mn > Pb ≈ Cd. Anthropogenic local emissions such as biomass burning, vehicular traffic, and industrial sources mainly related to oil/gas pre-treatment plants were identified by the principal component analysis. Further, air mass back-trajectory analyses suggest an important contribute to the long-range transport on PM₁ at Agri Valley. The carcinogenic (Cd, Cr(VI), Ni, and Pb) and non-carcinogenic (Cd, Cr(VI), Cu, Mn, Ni, Pb, and Zn) health risks both for children and for adults were assessed using the United State Environmental Protection Agency (USEPA) methods considering inhalation, ingestion, and dermal contact pathway. Chromium (VI) posed the highest carcinogenic risk for both children and adults. The integrated carcinogenic risks were respectively 3.45 × 10⁻⁵ and 1.38 × 10⁻⁴ for children and adults indicating that attention should be paid for carcinogenic health effects. Nickel posed the highest non-carcinogenic risk for children through inhalation pathway. The integrated non-carcinogenic risk showed a value higher than 1 highlighting that Cd, Cr(VI), Cu, Mn, Ni, Pb, and Zn may cause cumulative non-carcinogenic health effect for children from inhalation exposure.
Afficher plus [+] Moins [-]An analysis of the dust deposition on solar photovoltaic modules
2019
Styszko, Katarzyna | Jaszczur, Marek | Teneta, Janusz | Hassan, Qusay | Burzyńska, Paulina | Marcinek, Ewelina | Łopian, Natalia | Samek, Lucyna
Solid particles impair the performance of the photovoltaic (PV) modules. This results in power losses which lower the efficiency of the system as well as the increases of temperature which additionally decreases the performance and lifetime. The deposited dust chemical composition, concentration and formation of a dust layer on the PV surface differ significantly in reference to time and location. In this study, an evaluation of dust deposition on the PV front cover glass during the non-heating season in one of the most polluted European cities, Kraków, was performed. The time-dependent particle deposition and its correlation to the air pollution with particulate matter were analysed. Dust deposited on several identical PV modules during variable exposure periods (from 1 day up to 1 week) and the samples of total suspended particles (TSP) on quartz fibre filters using a low volume sampler were collected during the non-heating season in the period of 5 weeks. The concentration of TSP in the study period ranged between 12.5 and 60.05 μg m⁻³ while the concentration of PM10 observed in the Voivodeship Inspectorate of Environmental Protection traffic station, located 1.2 km from the TSP sampler, ranged from 14 to 47 μg m⁻³. It was revealed that dust deposition density on a PV surface ranged from 7.5 to 42.1 mg m⁻² for exposure periods of 1 day while the measured weekly dust deposition densities ranged from 25.8 to 277.0 mg m⁻². The precipitation volume and its intensity as well as humidity significantly influence the deposited dust. The rate of dust accumulation reaches approximately 40 mg m⁻²day⁻¹ in the no-precipitation period and it was at least two times higher than fluxes calculated on the basis of PM10 and TSP concentrations which suggest that additional forces such as electrostatic forces significantly influence dust deposition.
Afficher plus [+] Moins [-]Life cycle assessment of autoclaved aerated fly ash and concrete block production: a case study in China
2019
Shi, Yifei | Li, Yue | Tang, Yuzhou | Yuan, Xueliang | Wang, Qingsong | Hong, Jinglan | Zuo, Jian
With the rapid development of construction industry, consumption of concrete block has increased rapidly in China. As a kind of green building material and resource comprehensive utilization product, autoclaved aerated fly ash and concrete block have better performance in terms of heat preservation, sound insulation, and fire resistance. However, some typical issues are associated with autoclaved aerated fly ash and concrete block production process such as energy and material consumption as well as pollutant emissions. To examine the environmental and economic impacts of its production process is imperative. Choosing 1 m³ of autoclaved aerated fly ash and concrete block product as functional unit and “cradle to gate” as system boundary, a life cycle inventory is developed. The key processes and key materials with significant environmental impact are identified. Results show that the top four environmental impact categories are marine ecotoxicity, freshwater ecotoxicity, freshwater eutrophication, and human toxicity. Key processes are fly ash slurry production, lime grinding, and steam curing processes. These processes account for 46.58%, 26.00%, and 19.62% of the total environmental load respectively. The key materials are cement, lime, and natural gas, which account for 44.91%, 22.79%, and 20.61% respectively of overall environmental impact. Sensitivity analysis shows that the fly ash slurry production should be optimized preferentially, followed by lime grinding and steam curing processes. These findings are helpful to facilitate the sustainable production of autoclaved aerated fly ash and concrete block.
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