Affiner votre recherche
Résultats 2721-2730 de 5,151
Ethanolic extract of fenugreek seeds moderates dimethoate-induced pancreatic damage in male rats Texte intégral
2018
Dimethoate is a widely used organophosphate insecticide known to be toxic to the pancreas. The aim of this study is to detect the possible protective effects of the fenugreek seed ethanolic extract on the biochemical, histological, and ultra-structural abnormalities induced by dimethoate chronic exposure in the pancreas of adult male rats. The study was conducted on 50 adult male albino rats that were divided equally into 5 groups: (group I) negative control, (group II) vehicle control group, (group III) fenugreek-treated group that was given 400 mg/kg ethanolic fenugreek seed extract once daily, (group IV) dimethoate group received 20 mg/kg/day dimethoate, and (group V) dimethoate- + fenugreek-treated group received a combination of dimethoate and fenugreek in the same previous doses. Dimethoate treatment caused a significant increase in serum glucose, amylase, and lipase levels and a significant decrease in serum insulin. A significant increase in lipid peroxidation and pro-fibrotic cytokine (TGF-β1) together with a significant reduction of the antioxidant {reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD)} activities and the anti-inflammatory (IL-4) in pancreatic tissues was also recorded. There was a histological and ultra-structural evidence of pancreatic acinar and islet cell injury. The recorded abnormalities were reversed in dimethoate+fenugreek treated group indicating that fenugreek ethanolic extract can serve as an antidote for dimethoate-induced pancreatic insult.
Afficher plus [+] Moins [-]Characterization of pig manure-derived hydrochars for their potential application as fertilizer Texte intégral
2018
Song, Chengfang | Shan, Shengdao | Müller, Karin | Wu, Shengchun | Niazi, Nabeel Khan | Xu, Song | Shen, Ying | Rinklebe, Jörg | Liu, Dan | Wang, Hailong
In China, intensive pig farming has led to serious environmental issues with the need to dispose off large quantities of pig manure. Chinese agriculture relies on high inputs of chemical fertilizers leading to gradual decreasing organic matter contents in many arable soils. We propose that hydrochars produced from pig manure could potentially replace chemical fertilizers and, at the same time, resolve the waste disposal problem. The hydrochars used in this study were produced from pig manure at five different pyrolysis temperatures ranging between 160 and 240 °C and three residence times (1, 5, and 8 h). All hydrochars were assessed for composition of major elements. Results showed that the yield and organic matter (OM) contents in hydrochars were 50–74% and 40–56%, respectively. The concentrations of total nitrogen (N), potassium (K₂O), and OM in the hydrochar decreased, whereas contents of phosphorus (P₂O₅), copper (Cu), and zinc (Zn) increased with increasing reaction temperature and time. Hydrothermal carbonization of pig manure is a rapid method for transforming pig manure into an organic fertilizer, but it is necessary to assess the potential soil contamination risk of Cu and Zn for the pig manure hydrochar as organic fertilizer.
Afficher plus [+] Moins [-]Adsorption of ammonium in aqueous solutions by pine sawdust and wheat straw biochars Texte intégral
2018
Yang, Hye In | Lou, Kangyi | Rajapaksha, Anushka Upamali | Ok, Yong Sik | Anyia, Anthony O. | Chang, Scott X.
Ammonium (NH₄⁺) is a common form of reactive nitrogen in wastewater, and its discharge to water bodies can lead to eutrophication. This study was conducted to understand NH₄⁺ adsorption mechanisms of pine sawdust and wheat straw biochars in aqueous solutions and the factors affecting NH₄⁺ removal. Biochars were produced by pyrolysing pine sawdust at 300 °C (PS300) and 550 °C (PS550) and wheat straw at 550 °C (WS550). Pseudo-second-order and Redlich-Peterson models best fitted the adsorption data. The PS300 showed the highest NH₄⁺ adsorption capacity (5.38 mg g⁻¹), followed by PS550 (3.37 mg g⁻¹) and WS550 (2.08 mg g⁻¹). Higher H/C and O/C ratios of PS300 (0.78 and 0.32, respectively) indicated the greater presence of functional groups on the biochar’s surface as compared to PS550 (0.35 and 0.10, respectively) and WS550 (0.36 and 0.08, respectively), resulting in different NH₄⁺ adsorption through electrostatic interactions. The dominant mechanism for NH₄⁺ adsorption by the biochars was likely chemical bonding and electrostatic interaction of NH₄⁺ with the surface functional groups. Lower pyrolysis temperature resulted in a higher NH₄⁺ adsorption capacity by the pine sawdust biochar. At the same pyrolysis temperature (550 °C), the biochar made with pine sawdust as the feedstock had a higher NH₄⁺ adsorption capacity than biochar made from wheat straw. We conclude that biochars can be efficient absorbents for NH₄⁺ removal from wastewater, and the removal efficiency can be optimised by selecting different feedstocks or the pyrolysis condition for biochar production.
Afficher plus [+] Moins [-]Removal of bisphenol A by Fe-impregnated activated carbons Texte intégral
2018
Arampatzidou, Anastasia | Voutsa, Dimitra | Deliyanni, Eleni
A commercial wood-based activated carbon and the oxidized counterpart were impregnated with iron. The two Fe-impregnated carbons were prepared and characterized for their iron content, textural characteristics, surface chemistry, and their performance for bisphenol A adsorption. Batch adsorption experiments were conducted to study the effect of pH, ionic strength, kinetics, and thermodynamic equilibrium. Equilibrium adsorption data were described by both Langmuir and Freundlich isotherms. The iron impregnated activated carbon and the oxidized impregnated activated carbon presented maximum adsorption capacities of 785.65 and 469.78 mg/g, respectively, while adsorption followed second-order rate kinetics for both impregnated carbons. According to the thermodynamic parameters (ΔΗο, ΔSo, ΔGo), the adsorption is a spontaneous, exothermic, and physical process. Fenton-driven experiments conducted at different molar ratios of [H₂O₂]/[BPA] showed efficient degradation of BPA in spent Fe-impregnated carbons up to 82–95%, with traces of hydroxylated products.
Afficher plus [+] Moins [-]An approach to the heating dynamics of residues from greenhouse-crop plant biomass originated by tomatoes (Solanum lycopersicum, L.) Texte intégral
2018
Garzón, Eduardo | Morales Diez de Ulzurrun, Laura | Ortiz-Rodríguez, Isabel María | Sánchez-Soto, Pedro José
The most representative of greenhouse-crop plant biomass residues of tomatoes (Solanum lycopersicum L.) were selected for this study by using X-ray fluorescence spectrometry (XRF) and X-ray powder diffraction (XRD). The heating dynamics in air in the 600–1150 °C range of these residues for the production of renewable energy and the resultant ashes have been investigated. A total of 11 elements were determined by XRF in the biomass ashes and some minor elements. The content of alkaline elements and chlorides decreased as increasing heating temperature and disappeared at 1150 °C. Alkaline salts, NaCl and KCl, were volatilized by heating since 800 °C. The total contents of S and P in the biomass ashes were associated to CaSO₄, and a complex phosphate identified by XRD. CaCO₃ present at 600 °C was decomposed to CaO with disappearance at 1000 °C. By heating, new silicates were formed by solid-state reactions in the biomass residue. The minor elements have been found in a relative proportion lower than 0.9 wt.% and they characterized the obtained ashes, with potential use as micronutrients.
Afficher plus [+] Moins [-]Stable carbon and nitrogen isotopic composition of PM10 over Indo-Gangetic Plains (IGP), adjoining regions and Indo-Himalayan Range (IHR) during a winter 2014 campaign Texte intégral
2018
Sen, Avirup | Karapurkar, Supriya G. | Saxena, Mohit | Shenoy, Damodar M. | Chaterjee, Abhijit | Choudhuri, Anil K. | Das, Trupti | Khan, Altaf H. | Kuniyal, Jagdish Chandra | Pal, Srimata | Singh, D. P. (Dharam Pal) | Sharma, Sudhir Kumar | Kotnala, Ravindra Kumar | Mandal, Tuhin Kumar
For source identification, a field campaign involving simultaneous sampling of particulate matter (PM₁₀) was conducted at eight sampling sites in the Indian mainland during winter 2014. The sampling sites include Delhi (upper IGP), Lucknow (middle IGP), and Kolkata (lower IGP) in the Indo-Gangetic Plains (IGP); Mohal-Kullu and Darjeeling in the Indo-Himalayan Range (IHR). In addition, Ajmer, located upwind of the IGP in NW-India and Giridih and Bhubaneswar, in the downwind to the IGP has also been chosen. To characterize the sources of the ambient PM₁₀, stable isotope ratios of carbon (δ¹³CTC) and nitrogen (δ¹⁵NTN) for the total carbon (TC) and total nitrogen (TN) fractions have been considered. Ancillary chemical parameters, such as organic carbon (OC), elemental carbon (EC), and water-soluble ionic components (WSIC) mass concentrations are also presented in this paper. There was very small variation in the daily average δ¹³CTC ratios (− 24.8 to − 25.9‰) among the sites. Comparison with end-member stable C isotopic signatures of major typical sources suggests that the PM₁₀ at the sites was mainly from fossil fuel and biofuel and biomass combustion. Daily average δ¹⁵NTN ratios were not observed to vary much between sites either (8.3 to 11.0‰), and the low δ¹⁵NTN levels also indicate substantial contributions from biofuel and biomass burning of primarily C3 andC4 plant matter. Graphical abstract Scatter plot of the average (± 1 standard deviation (SD)) δ¹³CTC (‰) compared to δ¹⁵NTN (‰) at the sampling sites.
Afficher plus [+] Moins [-]Transcriptomics and metabonomics analyses of maternal DEHP exposure on male offspring Texte intégral
2018
Zhang, Yunbo | Zhang, Wanying | Fu, Xihang | Zhou, Fenfen | Yu, Haiyang | Na, Xiaolin
The objectives of this study were to evaluate the effect of maternal Di-2-ethylhexyl phthalate (DEHP) exposure on male offspring and to explore the mechanism of changes with the metabolic alterations and differential genes. Pregnant female Sprague-Dawley (SD) rats were intragastrically administered with 600 mg/kg body weight of DEHP or corn oil (CON) throughout pregnancy and lactation. The growth of male offspring was investigated until 14 weeks old, the indices of blood were detected, and mechanism was studied using metabonomics and transcriptomics. Compared with the CON group, body weight, body length, food intake, body fat weight, Lee’s index, organ coefficient, blood lipids, and oral glucose tolerance test (OGTT) of male offspring were not significantly changed in maternal DEHP group. However, serum biochemical indexes such as alanine transaminase (ALT), total protein (TP), albumin (ALB), blood urea nitrogen (BUN), and creatinine (CREA) were markedly reduced in maternal DEHP group (p < 0.05). In addition, insulin level was elevated and catalase (CAT) level was decreased notably in maternal DEHP group compared with the CON group (p < 0.05). Furthermore, thyroxine (T₄) level was lower and thyroid stimulating hormone (TSH) level was higher in maternal DEHP group (p < 0.05). Metabonomics revealed seven principal metabolites were identified, including increased L-allothreonine, creatine, uric acid, retinyl ester, L-palmitoylcarnitine, and decreased glycocholic acid and LysoPC (18:3). Transcriptomics displayed 35 differential genes were involved in the mechanism of maternal DEHP exposure. Therefore, this research confirms the effect of a certain dose of maternal DEHP exposure on male offspring and understands exactly the mechanism of these changes with metabonomics and transcriptomics.
Afficher plus [+] Moins [-]New applied pharmacological approach/trend on utilization of agro-industrial wastes Texte intégral
2018
Ragab, Tamer I. M. | Shalaby, Al Shimaa Gamal | El Awdan, Sally A. | Refaat, Ahmed | Helmy, Wafaa A.
This study aimed to transform the locally available lignocellulosic residual palm frond (PF) and rice straw (RS) wastes into multifunction added products like methylated cellulose and sulfated and phosphorylated hemicelluloses by simple processes. Hydrolysis with 2 N sulfuric acid was the most suitable reaction for microcrystalline cellulose production. The characteristics of the prepared products were studied to obtain the optimum reaction conditions. Palm frond hemicellulose (PFHC) recorded the highest antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans (22, 22, 26 mm), respectively, and phosphorylated palm frond hemicellulose (PPFHC) exhibited the highest potential antioxidant activity of approximately 60%, suggesting a possible correlation between the two bioactivities. Most of extracted celluloses and their derivatives had a variety of promising probiotic activities which are expected to reduce the side effects of the gastric mucosa and possibly play a role in curing the gastric ulcer. Accordingly, the determination of anti-inflammatory and gastroprotective activity results revealed that methylcellulose, sulfated and phosphorylated hemicelluloses showed anti-inflammatory and gastroprotective activities and the capability of all tested compounds to ameliorate the ethanol-induced gastric ulcer in rats’ stomach. All results recommended PF and RS and their derivatives to be used as a medicinal food.
Afficher plus [+] Moins [-]Degradation of propyl paraben by activated persulfate using iron-containing magnetic carbon xerogels: investigation of water matrix and process synergy effects Texte intégral
2018
Metheniti, Maria Evangelia | Frontistis, Zacharias | Ribeiro, Rui S. | Silva, Adrián M.T. | Faria, Joaquim L. | Gomes, Helder T. | Mantzavinos, Dionissios
An advanced oxidation process comprising an iron-containing magnetic carbon xerogel (CX/Fe) and persulfate was tested for the degradation of propyl paraben (PP), a contaminant of emerging concern, in various water matrices. Moreover, the effect of 20 kHz ultrasound or light irradiation on process performance was evaluated. The pseudo-first order degradation rate of PP was found to increase with increasing SPS concentration (25–500 mg/L) and decreasing PP concentration (1690–420 μg/L) and solution pH (9–3). Furthermore, the effect of water matrix on kinetics was detrimental depending on the complexity (i.e., wastewater, river water, bottled water) and the concentration of matrix constituents (i.e., humic acid, chloride, bicarbonate). The simultaneous use of CX/Fe and ultrasound as persulfate activators resulted in a synergistic effect, with the level of synergy (between 35 and 50%) depending on the water matrix. Conversely, coupling CX/Fe with simulated solar or UVA irradiation resulted in a cumulative effect in experiments performed in ultrapure water.
Afficher plus [+] Moins [-]Enhanced photocatalytic activity using GO/TiO2 catalyst for the removal of DCA solutions Texte intégral
2018
Ribao, Paula | Rivero, Maria J. | Ortiz, Inmaculada
This work aimed to optimize high-performance photocatalysts based on graphene oxide/titanium dioxide (GO/TiO₂) nanocomposites for the effective degradation of aqueous pollutants. The catalytic activity was tested against the degradation of dichloroacetic acid (DCA), a by-product of disinfection processes that is present in many industrial wastewaters and effluents. GO/TiO₂ photocatalysts were prepared using three different methods, hydrothermal, solvothermal, and mechanical, and varying the GO/TiO₂ ratio in the range of 1 to 10%. Several techniques were applied to characterize the catalysts, and better coupling of GO and TiO₂ was observed in the thermally synthesized composites. Although the results obtained for DCA degradation showed a coupled influence of the composite preparation method and its composition, promising results were obtained with the photocatalysts compared to the limited activity of conventional TiO₂. In the best case, corresponding to the composite synthesized via hydrothermal method with 5% of GO/TiO₂ weight ratio, an enhancement of 2.5 times of the photocatalytic degradation yield of DCA was obtained compared to bare TiO₂, thus opening more efficient ways to promote the application of photocatalytic remediation technologies.
Afficher plus [+] Moins [-]