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Solar-driven photocatalytic treatment as sustainable strategy to remove pesticide residues from leaching water Texte intégral
2020
Aliste, Marina | Pérez-Lucas, Gabriel | Vela, Nuria | Garrido, Isabel | Fenoll, José | Navarro, Simón
We have demonstrated the potential leaching of eight compounds, one insecticide (flonicamid) and seven fungicides (myclobutanil, penconazole, boscalid, difenoconazole, trifloxystrobin, pyraclostrobin and fenpyroximate) trough a typical Mediterranean soil (Calcaric regosol). The concentrations found in leaching water were in all cases above the limit set by the EU in groundwater (0.1 μg L⁻¹). For this, the efficiency of different homogeneous (photo-Fenton and photo-Fenton-like) and heterogeneous (ZnO and TiO₂) photocatalytic systems was tested in deionized water to choose the most appropriate treatment to remove pesticide residues from leaching water. The efficiency was in the order: ZnO + S₂O₈²⁻ (pH 7) > TiO₂+ S₂O₈²⁻ (pH 7) > ZnO (pH 7) > TiO₂ (pH 7) > Fe³⁺ (pH 3) > Fe³⁺ (pH 5) > Fe²⁺ (pH 3) > Fe²⁺ (pH 5). Thus, in the subsequent experiment we focus on the efficacy of solar heterogeneous photocatalysis (ZnO/Na₂S₂O₈ and TiO₂/ Na₂S₂O₈) on their removal from leaching water. A fast removal was observed for all pesticides at the end of the photoperiod, noticeably higher in the case of ZnO system, with the exception of flonicamid, a recalcitrant pesticide where the degradation rate only reached about 20% after 240 min of solar exposure. Although the mineralisation of the initial dissolved organic carbon was not complete due to the presence of interfering substances in the leaching water, the conversion rate under ZnO/Na₂S₂O₈ treatment was about 1.3 times higher than using TiO₂/Na₂S₂O₈.
Afficher plus [+] Moins [-]Modified biochar from Moringa seed powder for the removal of diclofenac from aqueous solution Texte intégral
2020
Bagheri, Afrouz | Abu-Danso, Emmanuel | Iqbal, Jibran | Bhatnagar, Amit
Modified biochar from Moringa seed powder for the removal of diclofenac from aqueous solution Texte intégral
2020
Bagheri, Afrouz | Abu-Danso, Emmanuel | Iqbal, Jibran | Bhatnagar, Amit
In this study, Moringa seed powder (MSP) was pyrolyzed at 450 °C to synthesize Moringa seed powder biochar (MSPB) and treated with phosphoric acid (H₃PO₄) to synthesize phosphate-modified Moringa seed powder biochar (MSPB-HPO) as an adsorbent for the removal of diclofenac (Dfc) from aqueous solution. Fourier transform infrared (FTIR) analysis, energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and pH point of zero charge (pHₚzc) were conducted to give more insight into the adsorbent’s properties. The SEM analysis showed the transformations in the surface morphology from the parent material to the synthesized materials after the thermal and acid treatment. EDS analysis revealed the variation in the elemental composition of the materials prior to and after adsorption of Dfc ions. The FTIR analysis showed changes and peak intensities of functional groups involved in Dfc removal. The pHₚzc showed the charge carried by MSPB-HPO in different pH conditions. Isotherm data best matched the Sips model, and the pseudo-second-order model best described the adsorption kinetics. The maximum adsorption capacity of MSPB-HPO by Sips model was found to be 100.876 mg g⁻¹.
Afficher plus [+] Moins [-]Modified biochar from Moringa seed powder for the removal of diclofenac from aqueous solution Texte intégral
Bagheri, Afrouz | Abu-Danso, Emmanuel | Iqbal, Jibran | Bhatnagar, Amit
© 2019, The Author(s). In this study, Moringa seed powder (MSP) was pyrolyzed at 450 °C to synthesize Moringa seed powder biochar (MSPB) and treated with phosphoric acid (H3PO4) to synthesize phosphate-modified Moringa seed powder biochar (MSPB-HPO) as an adsorbent for the removal of diclofenac (Dfc) from aqueous solution. Fourier transform infrared (FTIR) analysis, energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and pH point of zero charge (pHpzc) were conducted to give more insight into the adsorbent’s properties. The SEM analysis showed the transformations in the surface morphology from the parent material to the synthesized materials after the thermal and acid treatment. EDS analysis revealed the variation in the elemental composition of the materials prior to and after adsorption of Dfc ions. The FTIR analysis showed changes and peak intensities of functional groups involved in Dfc removal. The pHpzc showed the charge carried by MSPB-HPO in different pH conditions. Isotherm data best matched the Sips model, and the pseudo-second-order model best described the adsorption kinetics. The maximum adsorption capacity of MSPB-HPO by Sips model was found to be 100.876 mg g−1.
Afficher plus [+] Moins [-]Utilization of Modified Attapulgite for the Removal of Sr(II), Co(II), and Ni(II) Ions from Multicomponent System, Part I: Kinetic Studies Texte intégral
2020
Mohammed, Amira A. | Abdel Moamen, Ola A. | Metwally, Sayed S. | El-Kamash, Ahmed M. | Ashour, Ibrahim | Al-Geundi, Mohammed S.
Radionuclide sorption by natural and modified clays is extensively accepted to be an important process from the radioactive waste point of view. This work focused on modification of natural attapulgite with a layered double hydroxide to produce a novel chemisorbent for Sr²⁺, Ni²⁺, and Co²⁺ removal from multicomponent solution. The structural and surface characteristics of both attapulgite (ATP) and modified attapulgite (LDH-ATP) were investigated using XRD, FTIR, SEM, and thermal analysis. Comparison of sorption features of Sr²⁺, Ni²⁺, and Co²⁺ onto ATP and LDH-ATP was achieved; the results indicated that LDH-ATP was the most efficient sorbent for Sr²⁺, Ni²⁺, and Co²⁺. Kinetic studies established that the sorption is fast and reaching >90% within 30 min. The sorption of Sr²⁺, Ni²⁺, and Co²⁺ are well defined by non-linear pseudo-second-order model and controlled by an intra-particle diffusion mechanism. The diffusivity was determined using homogeneous surface diffusion (HSDM) model and found in the order 10⁻¹³ m²/min; this confirmed that the sorption of the three ions is chemisorption process. LDH-ATP can be employed as a candidate chemisorbent for the removal of some metal ions from waste solution.
Afficher plus [+] Moins [-]Structured cobalt oxide catalysts for VOC abatement: the effect of preparation method Texte intégral
2020
Topka, Pavel | Dvorakova, Michaela | Kšírová, Petra | Perekrestov, Roman | Čada, Martin | Balabánová, Jana | Koštejn, Martin | Jirátová, Květuše | Kovanda, František
Magnetron sputtering was employed for the deposition of cobalt oxide thin films on stainless steel meshes. Catalysts prepared by sputtering in inert and oxidation atmosphere were compared with those obtained by electrochemical deposition and hydrothermal synthesis. Systematic characterization using X-ray diffraction, scanning electron microscopy, N₂ physisorption, infrared spectroscopy, Raman spectroscopy, and temperature-programmed reduction by hydrogen allowed detailed monitoring of their physicochemical properties. Ethanol gas-phase oxidation was employed as a model reaction to reveal the catalytic performance of the catalysts. It was shown that the catalyst prepared by magnetron sputtering in oxidation atmosphere exhibited the best mechanical stability among all studied catalysts. Moreover, its catalytic activity was 18 times higher than that of pelletized commercial cobalt oxide.
Afficher plus [+] Moins [-]Antibiotic consumption in developing countries defies global commitments: an overview on Brazilian growth in consumption Texte intégral
2020
Neves e Castro, Paulo Bernardo | da Silva Rodrigues, Daniel Aparecido | Roeser, Hubert Mathias Peter | da Fonseca Santiago, Aníbal | de Cássia Franco Afonso, Robson José
Faster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.
Afficher plus [+] Moins [-]Baseline radioecological data for the soil and selected bioindicator organisms in the temperate forest of Plitvice Lakes National Park, Croatia Texte intégral
2020
Babić, Dinko | Skoko, Božena | Franić, Zdenko | Senčar, Jasminka | Šoštarić, Marko | Petroci, Ljerka | Avdić, Mak | Kovačić, Milica | Branica, Gina | Petrinec, Branko | Bituh, Tomislav | Franulović, Iva | Marović, Gordana
The aim of this study was to provide baseline radioecological data for the temperate forest ecosystem in Plitvice Lakes National Park. Emphasis was placed on the determination of naturally occurring radionuclides since there is an acknowledged lack of data for these radionuclides in non-accident conditions in wildlife, even for bioindicator organisms. Activity concentrations of ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²³²Th, ⁴⁰K, ¹³⁴Cs, and ¹³⁷Cs were measured by gamma spectrometry in soil and bioindicators: earthworms, conifer needles, mosses, and lichens. From the measured activity concentrations, concentration ratios were calculated to quantify the transfer of these radionuclides from soil to bioindicators. Our results show that soil activity concentrations are biased toward results from other studies conducted within the Dinaric mountain region. However, in moss and lichen samples, we measured higher activity concentrations of ²²⁶Ra and lower activity concentrations of ⁴⁰K and ¹³⁷Cs in comparison to similar studies. Also, we estimated lower concentration ratios for all radionuclides from soil to these organisms, except for ²¹⁰Pb, in comparison to generic values. The transfer of ²³⁸U was generally low for all of the bioindicator organisms. For conifer needles, a correlation was found between activity concentrations of ²²⁶Ra and ¹³⁷Cs in soil and related concentration ratios. Correlation was also found between the activity concentration of ⁴⁰K in soil and transfer of ⁴⁰K and ¹³⁷Cs to mosses and lichens. A comparison with literature data highlighted the lack of ²²⁶Ra related concentration ratios for conifer trees and especially for earthworms. Therefore, the results of this study could supplement the sparse data currently available on radionuclide background data in similar ecosystems and related soil-to-wildlife transfer of radionuclides. Dose rate assessments, performed by the ERICA Tool, estimated that 96% of the overall exposure of wildlife in the Park area is due to the background dose rates, while 0.06 μGy h⁻¹ on average can be attributed as an incremental dose rate from ¹³⁴Cs and ¹³⁷Cs.
Afficher plus [+] Moins [-]The relationship between increased air pollution expressed as PM10 concentration and the frequency of percutaneous coronary interventions in patients with acute coronary syndromes—a seasonal differences Texte intégral
2020
Januszek, Rafał | Staszczak, Bartłomiej | Siudak, Zbigniew | Bartuś, Jerzy | Plens, Krzysztof | Bartuś, Stanisław | Dudek, Dariusz
The aim of the presented study was to assess the relationship between air pollution expressed as particulate air matters less than 10 μm (PM₁₀) and acute coronary syndromes (ACSs). In this observational study, we selected regions with low pollution according to PM₁₀ (non-polluted) and with the highest pollution (polluted). The occurrence of percutaneous coronary interventions (PCIs) in patients with ACSs was matched according to the location. The current study included 7678 patients in polluted areas and 4327 patients from non-polluted regions. Analysing the period from January to December 2017, the number of patients undergoing angioplasty in monitored catheterization laboratories and the mean daily concentration of PM₁₀ in all selected cities were calculated for each day. The annual average concentration of PM₁₀ amounts to 50.95 μg/m³ in polluted and 26.62 μg/m³ in non-polluted cities (P < 0.01). The rise in PM₁₀ pollution levels was related with the increased frequency of PCIs in patients with ACSs in polluted (P < 0.01) and non-polluted (P < 0.01) areas. In the non-polluted regions, the increase in PM₁₀ concentration by every 1 μg/m³ causes 0.22 additional ACS angioplasties per week. In polluted regions, the same increase in PM₁₀ concentration causes 0.18 additional ACS angioplasties per week. In non-winter weeks, the mean number of ACS PCIs expressed in promiles was lower than in winter weeks in polluted (P = 0.03) and non-polluted cities (P = 0.02). The study shows that the increase in air pollution expressed as PM₁₀ concentration and winter time influences the frequency of ACS-related PCIs.
Afficher plus [+] Moins [-]Modeling heterogeneous dynamic interactions among energy investment, SO2 emissions and economic performance in regional China Texte intégral
2020
Ahmad, Munir | Zhao, Zhen-Yu | Irfan, Muhammad | Mukeshimana, Marie Claire | Rehman, Abdul | Jabeen, Gul | Li, Heng
Massive investments in energy industry may either promote or mitigate the air pollution which is likely to influence the economic performance. In light of this, the current work is an empirical examination of heterogeneous dynamic causal interactions among energy investment, sulphur dioxide (SO₂) emissions and economic growth in regional China. A modified STIRPAT model is developed to introduce energy investment as a determinant of technology. Based on a modified model, a simultaneous equations system has been established to examine the three-way causal interactions among the variables of interest. As a first step, an error-correction-based second generation Westerlund (Oxford Bulletin of Economics and Statistics 69: 0305–9049, (2007). cointegration has been employed and found the long-run relationship. The simultaneous equations have been estimated by employing second generation dynamic common correlated effects mean group estimator (DCCEMGE) for 30 Chinese provinces and cities from 2001 to 2017. The empirical analysis has revealed that the energy investment induces emissions promotion effect while economic growth introduces emissions curtailment effect. However, the emissions curtailment effect remained slightly stronger than emissions promotion effect both at country and regional levels. Further, the energy investment growth uncovered economic performance enhancement effect. Furthermore, the SO₂ emissions growth induced economic performance deterioration effect. In this regard, the economic performance deterioration effect exceeded the economic performance enhancement effect. Besides, there is a bidirectional causality operative between SO₂ emissions and gross regional product (GRP) growth for the country as well as regional samples. On the contrary, a positive bilateral causal relationship between energy investment and GRP growth is found for the country as well as regional samples. Similarly, it has been found that there exists a positive bilateral causal association between SO₂ emissions and energy investment. Graphical abstract
Afficher plus [+] Moins [-]Analysis of multiclass organic pollutant in municipal landfill leachate by dispersive liquid-liquid microextraction and comprehensive two-dimensional gas chromatography coupled with mass spectrometry Texte intégral
2020
Beldean-Galea, Mihail Simion | Vial, Jerôme | Thiébaut, Didier | Coman, Maria-Virginia
We propose a simple, fast, and inexpensive method for the analyses of 72 organic compounds in municipal landfill leachate, based on dispersive liquid-liquid microextraction and comprehensive two-dimensional gas chromatography coupled with mass spectrometry. Forty-one organic compounds belonging to several classes including hydrocarbons, mono- and polyaromatic hydrocarbons, carbonyl compounds, terpenes, terpenoids, phenols, amines, and phthalates, covering a wide range of physicochemical properties and linked to municipal landfill leachate, were quantitatively determined. Another 31 organic compounds such as indoles, pyrroles, glycols, organophosphate flame retardants, aromatic amines and amides, pharmaceuticals, and bisphenol A have been identified based on their mass spectra. The developed method provides good performances in terms of extraction recovery (63.8–127%), intra-day and inter-day precisions (< 7.7 and < 13.9 respectively), linearity (R² between 0.9669 and 0.9999), detection limit (1.01–69.30 μg L⁻¹), quantification limit (1.87–138.6 μg L⁻¹), and enrichment factor (69.6–138.5). Detailed information on the organic pollutants contained in municipal landfill leachate could be obtained with this method during a 40-min analysis of a 4-mL leachate sample, using only 75 μL of extraction solvent.
Afficher plus [+] Moins [-]A mineralogical and chemical investigation of road dust in Philadelphia, PA, USA Texte intégral
2020
O’Shea, Michael J. | Vann, David R. | Hwang, Wei-Ting | Gieré, Reto
Road dust was investigated within Philadelphia, a major United States city with a long history of industrial activities, in order to determine pollution levels. Almost all of the investigated minor elements were enriched relative to the continental crust. Furthermore, mean concentrations of Cr, Co, Cu, and Pb were high compared with those reported in cities in other countries. Lead pollution should be investigated further in Philadelphia, where 8 of the 30 sample sites, including those heavily trafficked by civilians, were at or above the EPA’s child safety threshold for Pb in bare soil. High Spearman correlations between Zn and Cu, Zn and Cr, Cu and Cr, and Sn and V, as well as factor analysis of minor elements suggests that the primary sources of these elements were anthropogenic. Potential sources included the breakdown of alloys, non-exhaust traffic emissions, paint, smelting, and industry. We found that higher organic content in road dust may be related to higher traffic densities, which could be due to tire-wear particles. Additionally, higher mean concentrations of Fe, Cr, Cu, and Zn were found at sites with elevated traffic densities. Land use impacted some of the elements not influenced by traffic density, including Co, Sn, and Pb. Bulk mineral content was similar across different land uses and traffic densities and, thus, did not appear to be influenced by these factors. Our research emphasized the complexity of road dust and utilized a more comprehensive approach than many previous studies. This study established fundamental groundwork for future risk assessment in Philadelphia, as it identified several key pollutants in the city. Overall, this assessment serves as an informative reference point for other formerly heavily industrialized cities in the USA and abroad.
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