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The synthesis strategy to enhance the performance and cyclic utilization of granulated activated carbon-based sorbent for bisphenol A and triclosan removal Texte intégral
2020
Ndagijimana, Pamphile | Liu, Xuejiao | Li, Zhiwei | Yu, Guangwei | Wang, Yin
For a potential and efficient solution in the mitigation of aquatic pollution, this study reported a well-designed and developed protected granulated activated carbon (GAC) material which ensures high strength property and adsorption performance to meet the industrial application. The prepared GAC material was shaped into a spherical core using natural binders basically assumed to constitute waste solids materials. Then after, the granulated carbon core (GAC core) was protected by a porous ceramic shell which confined the material with strong protection and high mechanical strength to resist against degeneration and pressure drop as a limiting factor for most sorbents employed in solution. The CSGAC characterization results proved that the ceramic shell has a smaller thickness (0.1 cm), good mechanical strength (2.0 MPa), and additionally, it presents larger porous channels which promote the fast and higher adsorption performance making it the desired material for the application in the real liquid environment. The test results showed that the prepared material had higher removal of triclosan (TCS) (30–40 mg/L) than BPA counterpart from the aqueous solutions. Moreover, it showed higher adsorption performance compared to the unprotected carbon materials. Furthermore, the mechanisms of BPA and TCS adsorption by core-shell granulated activated carbon (CSGAC) were discussed.
Afficher plus [+] Moins [-]Improving of the Mg-Co nanoferrites efficiency for crude oil adsorption from aqueous solution by blending them with chitosan hydrogel Texte intégral
2020
Abdeen, Zizi I. | Ghoneim, Amina I.
The efficiency of the as-prepared Mg₀.₂₅Co₀.₇₅Fe₂O₄ spinel nanoparticles for adsorption of crude oil from aqueous solution was improved by blending them with chitosan hydrogel (CH) prepared using epichlorohydrin as cross-linker resulting (CH/Mg₀.₂₅Co₀.₇₅Fe₂O₄) nanocomposites. Mg₀.₂₅Co₀.₇₅Fe₂O₄ nanocrystals was prepared by the chemical co-precipitation method and characterized by using X-ray diffraction (XRD), infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), and differential thermal analysis (DTA)/thermogravimetric analysis (TGA). DTA/TGA results showed that the net weight loss of the samples heated from room temperature up to 1000 °C lies in the range 2.2–26.5% weight, where the maximum weight loss appeared at 100 °C and 614 °C. The blending nanocomposites prepared, were characterized by FT-IR and SEM micrographs. The effect of the nanoparticles ratio on the water uptake of nanocomposites and their capability to adsorb the crude oil was estimated by the gravimetric method. TEM results showed that the average nanoparticle size (Z) of Mg₀.₂₅Co₀.₇₅Fe₂O₄ is 30.06 nm and the SEM illustrated the presence of a very clear and rough layer of pores which are homogenously arranged structures that could play an important role in the adsorption and stability of crude oil on polymers. The adsorption ability of crude oil from waste water on the CH/Mg₀.₂₅Co₀.₇₅Fe₂O₄ nanocomposites hydrogel was reported and it was found that the CH/Mg₀.₂₅Co₀.₇₅Fe₂O₄ with 95/5% ratio showed the improvement in the oil adsorption (72.5%) than the 0/100% one (50.2%). As a consequence, it is highly suggested that the potential of blending CH with Mg₀.₂₅Co₀.₇₅Fe₂O₄ to obtain CH/Mg₀.₂₅Co₀.75Fe2O₄ for enhancing crude oil adsorption in oily waste water treatment with a low cost.
Afficher plus [+] Moins [-]Surface temperature variations and their relationships with land cover in the Pearl River Delta Texte intégral
2020
Hu, Mengmeng | Wang, Yafei | Xia, Beicheng | Huang, Guohe
The characteristics of land use/land cover (LULC) types may affect the thermal environment of urban zones. In this study, the urban zones of the Pearl River Delta (PRD) were examined to explore the spatiotemporal variations in land surface temperature (LST) from 2001 to 2017, as well as the relationships between LST and various influencing factors. Landscape pattern analysis was undertaken to explore the correlation between patch metrics and LST with resolutions from 100 m to 1 km. The results showed that (1) the high-temperature zones were mainly distributed on built-up land; the area of LST hot spots increased from 16% (2001) to 23% (2017). (2) The mean LST of each LULC type was calculated, indicating that the temperature of forestland was more than 5 °C lower than that of built-up land. (3) The landscape patterns of different land use types exhibited various effects on LST in terms of magnitude and importance. Considering the significance of the landscape indexes, it is necessary to avoid a large-scale layout of a single built-up land type when planning an urban environment. It is thus recommended that multiple contiguous forestlands be planned to mitigate urban heat island (UHI) effects. Furthermore, the landscape patterns and structure of different LULC types have various effects on LST and need to be explored in fine detail. This study helped reveal the impact of different LULC types on LST and provides urban planners in the PRD with optional schemes for mitigating the impacts of urbanization on the UHI.
Afficher plus [+] Moins [-]Protective effects of thymoquinone against acrylamide-induced liver, kidney and brain oxidative damage in rats Texte intégral
2020
Abdel-Daim, Mohamed M. | Abo El-Ela, Fatma I. | Alshahrani, Fatima K. | Bin-Jumah, May | Al-Zharani, Mohammed | Almutairi, Bader | Alyousif, Mohamed S. | Bungau, Simona | Aleya, Lotfi | Alkahtani, Saad
Acrylamide (AA), an industrial monomer, may cause multi-organ toxicity through induction of oxidative stress and inflammation. The antioxidant properties of thymoquinone (TQ), an active constituent of Nigella sativa, have been established before. The aim of the current study was to assess the protective effects of TQ against AA-induced toxicity in rats. Forty-eight male Wistar rats were divided into six groups each of eight rats. The first group acted as a negative control and received normal saline. Groups II and III were administered TQ orally at doses of 10 and 20 mg/kg b.wt., respectively, for 21 days. The four group received AA (20 mg/kg b.wt.) for 14 days. The five and six groups were given TQ at either dose for 21 days, starting seven days before AA supplementation (for 14 days). Acrylamide intoxication was associated with significant (p < 0.05) increases in serum levels of liver injury biomarkers (alanine transferase, aspartate transferase, and alkaline phosphatase), renal function products (urea, creatinine), DNA oxidative damage biomarker (8-oxo-2′-deoxyguanosine), and pro-inflammatory biomarkers (interleukin-1β, interleukin-6, and tumor necrosis factor-α). Moreover, AA intoxication was associated with increased lipid peroxidation and nitric oxide levels, while reduced glutathione concentration and activities of glutathione peroxidase, superoxide dismutase, and catalase in the liver, kidney, and brain. TQ administration normalized AA-induced changes in most serum parameters and enhanced the antioxidant capacity in the liver, kidney, and brain tissues in a dose-dependent manner. In conclusion, the current experiment showed that TQ exerted protective and antioxidant activities against AA-induced toxicity in mice.
Afficher plus [+] Moins [-]Effects of lead ions on germination, initial growth, and physiological characteristics of Lolium perenne L. species and its bioaccumulation potential Texte intégral
2020
Gholinejad, Bahram | Khashij, Shima | Ghorbani, Farshid | Bandak, Isa | Farajollahi, Asghar
The present study was conducted to investigate the responses of Lolium perenne L. species to lead ions. To do this, the effects of lead ions at five levels: control (blank), 250, 500, 750, and 1000 mg/kg or mg/L (depending on germination in the soil or petri dish) on the germination, initial growth, and physiological characteristics of Lolium perenne were investigated. The results showed that the difference between various lead concentrations was statistically significant at 1% confidence level in all of the germination, vegetative, and physiological characteristics. In addition, the results of translocation and stress factors indicated that there was a significant difference between the control treatment and the concentrations of 250, 500, 750, and 1000 mg/L of lead ions. Results show that the mean value of stress, which was 0.3196 in the control value, reached 0.4154 at the concentrations 1000 mg/L. Different levels of lead ions had significant effect on the estimated characteristics including germination percentage, seed vigor, germination index, chlorophyll a, chlorophyll b, carotenoids, root, and shoot. The average germination percentage in the control was 46.66%, which decreased by 5% at the highest lead concentration. In addition, the average of seed vigor, which was 34.06 in the control conditions, decreased to 0.72 at the highest lead concentration. Also, the chlorophyll a dropped from 0.5261 mg/g in the control conditions to 0.3149 mg/g. On the other hand, increase in lead ion concentration affected the physiological characteristics of Lolium perenne species. Results suggest that Lolium perenne is capable of accumulating lead and is well tolerant to lead in soil. Therefore, it is concluded that it can be used for sowing on lands which are polluted to this heavy metal (up to the concentration of 1000 mg/kg).
Afficher plus [+] Moins [-]Toxicological responses, bioaccumulation, and metabolic fate of triclosan in Chlamydomonas reinhardtii Texte intégral
2020
Wang, Xiaodong | Lu, Yi Chen | Xiong, Xiao Hui | Yuan, Yi | Lu, Li Xia | Liu, Yuan Jian | Mao, Jia Hao | Xiao, Wei Wei
Triclosan (TCS) is a broad-spectrum antimicrobial agent that is broadly used in personal care products. It has been shown to cause the contamination of a variety of aquatic environments. Since algae has been the primary producers of aquatic ecosystems, understanding the toxicological mechanisms and the metabolic fate of TCS is vital for assessing its risk in an aquatic environment. In our study, 0.5–4 mg L⁻¹ TCS treatments for 72 h in a culture of Chlamydomonas reinhardtii (C. reinhardtii) showed progressive inhibition of cell growth and reduced the chlorophyll content. The EC₅₀ value of C. reinhardtii after 72 h was 1.637 mg L⁻¹, which showed its higher level of resistance to TCS in comparison with other algal species. The exposure to TCS led to oxidative injuries of algae in relation to the increment of malonaldehyde content, cell membrane permeability, and H₂O₂ levels. Furthermore, the oxidative stress from TCS stimulated a series of antioxidant enzyme activities and their gene expressions. Simultaneously, the accumulated TCS in C. reinhardtii arouses the detoxification/degradation-related enzymes and related gene transcriptions. In the medium, approximately 82% of TCS was removed by C. reinhardtii. Importantly, eight TCS metabolites were identified by ultra-performance liquid chromatography-high-resolution mass spectrometry and their relative abundances were measured in a time-course experiment. Six of these metabolites are reported here for the first time. The metabolic pathways of triclosan via C. reinhardtii including reductive dechlorination, hydroxylation, sulfhydrylation, and binding with thiol/cysteine/GSH/glycosyl were manifested to broaden our understanding of the environmental fate of TCS. Graphical Abstract
Afficher plus [+] Moins [-]Association of intronic polymorphisms (rs1549339, rs13402242) and mRNA expression variations in PSMD1 gene in arsenic-exposed workers Texte intégral
2020
Ahmad, Saqiba | Arif, Bushra | Akram, Zertashia | Ahmed, Malik Waqar | K̲h̲ān, Asadullāh | Hussain, Muhammad Zahid | Rahman, Faisal | Kayani, Mahmood Akhtar | Mahjabeen, Ishrat
Ubiquitin-proteasome system (UPS) gene, PSMD1, is an important gene for neutralization of damaged and misfolded protein(s). The current study was designed to study the genetic and expression variations of PSMD1 gene as a consequence of arsenic exposure and its potential implications in arsenic induced diseases. In the present study, 250 blood samples of exposed industrial workers along with 250 controls were used. Initially, tetra amplification refractory mutation system-PCR was used to determine the role of PSMD1 gene polymorphisms (rs1549339, rs13402242) in industrial workers and controls. Frequency of homozygous mutant genotype of rs1549339 (OR: 2.23, 95% CI: 1.51–3.32, p = 0.0001) and rs13402242 (OR: 2.96, 95% CI: 1.52–5.75, p = 0.001) was observed significantly higher in exposed individuals vs controls. Secondly, qPCR was performed for expression analysis of PSMD1 gene. Significant down-regulated expression of PSMD1 gene (p < 0.0001) was observed vs controls, and this down-regulation was observed more pronounced in smokers (p < 0.0001) with maximum exposure duration (p < 0.0008). This down-regulated expression was observed significantly more pronounced in welding (p < 0.004) and brick kiln industries (p < 0.04) compared to other selected industries. The obtained results suggest that the exposure to arsenic may have an increased risk of developing disease(s) because of arsenic-induced PSMD1 variations.
Afficher plus [+] Moins [-]Hydrogeochemical investigation of arsenic in drinking water of schools and age dependent risk assessment in Vehari District, Punjab Pakistan: a multivariate analysis Texte intégral
2020
Murtaza, Behzad | Nazeer, Humaira | Andrews, Martina | Amjad, Muhammad | Imran, Muhammad | Shāhid, Muḥammad | Shah, Noor S. | Farooq, Abu Bakr Umer | Amjad, Muhammad | Murtaza, Ghulam
Globally, a large number of school-aged children is suffering from water-borne diseases, particularly in low-income countries. Arsenic (As) is a hazardous and potentially carcinogenic metal(loid) in drinking water. Nowadays, alarming levels of As have been reported in the groundwater of Vehari District, Punjab Pakistan. In this study, drinking water supplies for high and higher secondary schools were examined in Vehari District. A total of 164 water samples were collected from schools and subjected to heavy metal(loid) analysis (As) and basic water physicochemical parameters. The results were analyzed with respect to sampling area, school type, school education level, sources of sample collection, and the depth of the source. The results revealed that As concentration of water samples in boys’ and girls’ schools was 12.8 μg/L and 9.2 μg/L, respectively. However, when the As concentration in drinking water was evaluated at the school education level, a notable higher concentration of As was observed in the higher secondary schools than the high schools with an average of 19.5 and 9.7 μg/L, respectively. The risk assessment indices were calculated based on education level and different age groups of the children (primary, elementary, high, and higher secondary). High carcinogenic (cancer risk = 0.001) and non-carcinogenic (hazard quotient = 2.0) risks were noted for the children in higher secondary school. The current findings anticipated that the drinking water of schools in Vehari District did not meet the requirement of the World Health Organization (WHO) drinking water quality guidelines. Safe drinking water is crucial for the development and growth of children. Therefore, it is important for educational authorities to take steps for provision of As free safe drinking water to students and local inhabitants.
Afficher plus [+] Moins [-]An imazethapyr-based herbicide formulation induces genotoxic, biochemical, and individual organizational effects in Leptodactylus latinasus tadpoles (Anura: Leptodactylidae) Texte intégral
2020
Pérez-Iglesias, Juan M. | Brodeur, Julie C. | Larramendy, Marcelo L.
Genotoxic, biochemical, and individual organizational effects on Leptodactylus latinasus tadpoles were evaluated after exposure to an imazethapyr (IMZT)-based commercial herbicide formulation, Pivot® H (10.59% IMZT). A determination of the value of the lethal concentration (LC50) was determined as a toxicological endpoint. Alterations in animal behavior and morphological abnormalities as well as cholinesterase (ChE), catalase (CAT), and glutathione S-transferase (GST) activities were employed as individual sublethal endpoints. Micronuclei frequencies (MNs), binucleated cells (BNs), blebbed nuclei (BLs), lobed nuclei (LBs), notched nuclei (NTs), erythroplastids (EPs), and evaluation of DNA strand breaks were employed as genotoxic endpoints. All biomarkers were evaluated after 48 and 96 h of exposure to concentrations of IMZT within 0.07–4.89 mg/L. LC50₉₆ₕ values of 1.01 and 0.29 mg/L IMZT were obtained for Gosner stages 25 and 36, respectively. Irregular swimming, diamond body shape, and decreased frequency of keratodonts were detected at both sampling times. Results showed that IMZT increased GST activity and MN frequency at 48 and 96 h of exposure. Other nuclear abnormalities were also observed in the circulating erythrocytes of tadpoles, i.e., NT and BL values after 48 h, and LN, BL, and EP values after 96 h. Finally, results showed that IMZT within 0.07–0.22 mg/L increased the genetic damage index in tadpoles exposed for both exposure times (48 and 96 h). This study is the first to report the sublethal biochemical effects of IMZT in anurans and is also the first report using L. latinasus tadpoles as a bioindicator for ecotoxicological studies.
Afficher plus [+] Moins [-]A hybrid prediction model for forecasting wind energy resources Texte intégral
2020
Zhang, Yagang | Pan, Guifang
Wind energy is important to the transformation and development of global energy, because it is clean and renewable. However, the productivity of wind power is low due to its volatility, randomness, and uncertainty. Therefore, a new hybrid prediction model based on combined Elman-radial basis function (RBF) and Lorenz disturbance is proposed, which can promote the productivity of wind power by better predicting wind speed, firstly, applying the variational mode decomposition (VMD) algorithm to original nonstationary wind speed data to obtain several relatively stationary intrinsic mode functions (IMF), so as to fully exploit its potential characteristics. Meanwhile, the sample entropy is introduced to determine the decomposition number K. Afterwards, different IMF components with different characteristics are used for training and prediction: Elman neural network with sensitivity to historical state data is used for wind speed trend components; RBF with strong nonlinear mapping capability is adopted for other stochastic modal components. Next, the first-step prediction values can be obtained by reconstructing the predicted results of the respective IMF components. Finally, the Lorenz equation is introduced in view of the effects of atmospheric disturbances on wind fluctuations, which can be used to revise the first-step prediction results to obtain more realistic prediction results. By experimenting with the real data from two different wind farms and comparing with other predictive models, we found that (1) VMD can solve the problem of modal aliasing in empirical mode decomposition, to obtain a better decomposition result; (2) the combined prediction method of Elman and RBF is used for modal components, that is, different algorithms are adopted for different components, which have better prediction effects; (3) in this research, the results of the proposed combination prediction model is more accurate by comparison with the other neural network models. This research work will help the power system to rationally formulate wind farm control strategies, enhance the self-regulation of wind farm, and further promote global energy innovation.
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