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Результаты 3231-3240 из 4,937
Histopathological and biochemical studies on the effect of curcumin and taurine against bisphenol A toxicity in male rats Полный текст
2019
Apaydin, Fatma Gökçe | Aslanturk, Ayşe | Uzunhisarcikli, Meltem | Bas, Hatice | Kalender, Suna | Kalender, Yusuf
Bisphenol A (BPA) is a chemical found in environmental xenoestrogen. In the present study, olive oil, curcumin, taurine, BPA, curcumin plus BPA, and taurine plus BPA were exposed to rats for 4 weeks via gavage. Content of malondialdehyde and activities of antioxidant enzymes (GPx, GST, SOD, CAT) and also histopathological and cytopathological changes of heart were studied. No significant changes in all studied parameters were seen between control, olive oil, curcumin, and taurine-treated groups. However, there were significant differences in levels of malondialdehyde and activities of antioxidant enzymes in BPA-exposed rats and some histo/cytopathological changes determined. In curcumin plus BPA-exposed and taurine plus BPA-exposed groups, we measured the preventive effects on some parameters but not exactly. As a result, curcumin and taurine significantly minimized BPA-induced cardiotoxicity in rats.
Показать больше [+] Меньше [-]Effects of Rhizophagus clarus and biochar on growth, photosynthesis, nutrients, and cadmium (Cd) concentration of maize (Zea mays) grown in Cd-spiked soil Полный текст
2019
Rafique, Mazhar | Ortas, Ibrahim | Rizwan, Muhammad | Sultan, Tariq | Chaudhary, Hassan Javed | Işık, Mehmet | Aydin, Oğuzhan
Cadmium (Cd) toxicity in agricultural crops is a widespread problem. Little is known about biochar and arbuscular mycorrhizal fungi (AMF) effect on Cd concentration in maize plant either applied separately or in combination. Current study was performed to demonstrate effects of biochar and Rhizophagus clarus on plant growth, photosynthesis activity, nutrients (P, Ca, Mg, Fe, Cu, and Mn), and Cd concentration in maize grown in Cd-spiked soil. The alkaline soil was spiked by Cd factor at three levels: 0 (Cd 0), 5 (Cd 5), and 10 (Cd 10) mg/kg; biochar factor at two levels: 0 and 1%; and mycorrhizal inoculum factor at two levels: MF0 and MF1 (R. clraus). Plants were harvested after 70 days of seed germination, and various morphological and physiological parameters, as well as elemental concentration and root colonization, were recorded. Addition of biochar increased plant biomass by 21% (Cd 5) and 93% (Cd 10), MF1 enhanced by 53% (Cd 0) and 69% (Cd 10), while biochar + MF1 enhanced dry plant biomass by 70% (Cd 0) and 94% (Cd 10). Results showed maximum increase of 94% (Cd 10) in plant biomass was observed in Cd-spiked soil. Root colonization decreased proportionally by increasing Cd concentration and at Cd 10, colonization was 36.7% and 31.7% for MF1 and biochar + MF1 treatments, respectively. Besides that, addition of biochar enhanced root attributes (root length, volume, and surface area) by 34–58% compared to control in Cd 10. The MF1 increased these attributes by 11–78% while biochar + MF1 enhanced by 32–61% in Cd-spiked soil. However, biochar + MF1 neutralized Cd stress in maize plant for gaseous attributes (assimilation rate, transpiration rate, intercellular CO₂, and stomatal conductance). The MF1 enhanced Cd concentration in plant as it was 3.32 mg/kg in Cd 5 and 6.73 mg/kg in Cd 10 treatments while addition of biochar phytostabilized Cd and reduced its concentration in plants by 2.0 mg/kg in Cd 5 and 4.27 mg/kg in Cd 10. The biochar + MF1 had 2.9 mg/kg and 4.8 mg/kg Cd concentration in Cd 5 and Cd 10 plants, respectively. Phosphorus concentration was augmented in shoots (up to 26%) and roots (up to 20%) of maize plant in biochar-amended soil than control plants. In biochar + MF1, concentration of P was 1.01% and 0.73% in Cd 5 and Cd 10, respectively. It is concluded that biochar + MF1 treatment enhances plant biomass while addition of sole biochar reduced Cd uptake, slightly indifferent to earlier treatment.
Показать больше [+] Меньше [-]Identification and analysis of odor-active substances from PVC-overlaid MDF Полный текст
2019
Dong, Huajun | Jiang, Liqun | Shen, Jun | Zhao, Zheng | Wang, Qifan | Shen, Xiwei
This study sought to identify volatile organic compounds (VOCs) and examine the characteristics of odor-active substances from polyvinyl chloride (PVC)-overlaid medium density fiberboard (MDF). A microchamber thermal extractor was used for sampling, gas chromatography–mass spectrometry was used to identify VOCs, and gas chromatography–olfactometry–mass spectrometry was used to analyze odor-active substances from PVC-overlaid MDF over 28 days. The results showed that 38 VOCs were identified from PVC-overlaid MDF, while only 23 odor-active substances were detected by gas chromatography–olfactometry, which indicated that some VOCs did not generate odor. The main VOCs released by PVC-overlaid MDF were aromatic hydrocarbons, ketones, and esters. There was a strong correlation between concentration and odor intensity of the main VOCs. When the total amount of odor-active substances was not significantly different, the overall odor intensity was determined by the intensity of the key odorants. The greater the intensity of the key odorants, the greater the overall odor intensity. There were eight main classes of odors from PVC-overlaid MDF: aromatic, fresh scent, fruity, sour, sweet, grassy, pungent, and special scent. Among them, the main odor characteristics were aromatic, sour, and fresh scent, which were primarily generated by toluene, ethylbenzene, phenanthrene, and dibutyl phthalate.
Показать больше [+] Меньше [-]Blood and seminal plasma mercury levels and predatory fish intake in relation to low semen quality Полный текст
2019
Ai, Chin-En | Li, Jingren | Tsou, Ming-Chien | Chen, Jun-Lin | Hsi, Hsing-Cheng | Chien, Ling-Chu
Declining human sperm quality has been demonstrated in several recent studies. Age, environmental factors, and nutritional factors can affect semen quality. Mercury (Hg) is considered a male reproductive toxicant. Animal studies indicated that exposure to Hg can cause DNA damage, sperm dysfunction, and decreased sperm motility. Some previous studies also revealed that blood Hg levels in infertile or subfertile males were higher than those in normal males. In this study, we recruited 84 male participants from a reproductive medical center and investigated the Hg, lead, and selenium levels in blood and seminal plasma. Participants were divided into two groups, low- and high-quality semen groups, according to the World Health Organization reference values for human semen characteristics. The distribution of blood reproductive hormones and information on participants’ lifestyle and medical history were collected from structured questionnaires. Average Hg levels in blood were 9.3±5.9 versus 8.9±5.9 and in seminal plasma were 1.26±0.61 versus 1.05±0.52 μg/L in the low- and high-quality semen groups, respectively. There was a dose-dependent relationship between blood Hg levels and normal sperm morphology (p=0.02). Participants with predatory fish intake and high blood Hg level had lower sperm with a normal morphology. Therefore, predatory fish intake may be a critical risk factor for elevated Hg levels in males and cause low semen quality.
Показать больше [+] Меньше [-]Effect of earthworms and plants on the efficiency of vertical flow systems treating university wastewater Полный текст
2019
Lavrnić, Stevo | Cristino, Sandra | Zapater-Pereyra, Maribel | Vymazal, Jan | Cupido, Domenico | Lucchese, Giovanni | Mancini, Benedetta | Mancini, Maurizio L.
One of the possible ways to improve the operation efficiency of constructed wetlands and to prevent their clogging is the application of earthworms. They have already been successfully applied for vermicomposting and for sludge dewatering and treatment. A few studies have already examined the effect of earthworms on the treatment of wastewater by vertical flow constructed wetlands (VFCWs), but none of them have provided a yearlong research result from an open-air system or compared the effect that different seasons in a temperate climate area can have on these invertebrates. The goal of this research was to estimate the effect that earthworms and plants have on VFCW’s operation. Four mesocosms (a filter, a filter with earthworms, a VFCW and a VFCW with earthworms) were built and their influent and effluent water quality was monitored for a period of 1 year. They were fed with wastewater coming from a building of the University of Bologna (Italy). The results have shown that the presence of earthworms in this specific system did not reduce the organic matter content of the substrate, but it has positively influenced plants’ growth. However, since neither earthworms nor plants had a statistically significant effect on the effluent quality, it can be concluded that the integration of these invertebrates cannot improve wastewater treatment of vertical flow filters or constructed wetlands.
Показать больше [+] Меньше [-]Harvesting zero waste from co-digested fruit and vegetable peels via integrated fermentation and pyrolysis processes Полный текст
2019
Soltan, Mohamed | Elsamadony, Mohamed | Mostafa, Alsayed | Awad, Hanem | Tawfik, Ahmed
The aim of this study is to assess an innovative economic approach for the production of both fermentative hydrogen and biochar from fruit and vegetable peels (FVPs) via fermentation/pyrolysis process. Firstly, in fermentation batches, multi-fermentation of FVPs positively affected the harvested hydrogen yield and COD reduction efficiency, which reached their maximal values of 3.9 ± 0.6 mmol/gCOD and 56.2 ± 4.6% at batch of 25% pea + 25% tomato + 25% banana + 25% orange (M4). Secondly, digestates produced from all batches were pyrolyzed at 500 °C for investigating the potential for biochar production. Based on the characteristics of the pyrolyzed digestate, biochar produced from S1 (spinach) exhibited the highest specific surface area, density, pore volume, biochar production yield, and pyrolysis profit of 28.43 ± 3.95 m²/g, 1.93 ± 0.18 g/cm³, 0.59 ± 0.08 cm³/g, 59.04 ± 2.36%, and 3.66 $/kgfₑₑdₛₜₒcₖ, respectively. However, the maximum overall profit from both fermentation and pyrolysis processes was 5.21 $/kgfₑₑdₛₜₒcₖ and was denoted for M4.
Показать больше [+] Меньше [-]Biodegradation of persistent environmental pollutants by Arthrobacter sp Полный текст
2019
Guo, Xiaohong | Xie, Chengyun | Wang, Lijuan | Li, Qinfan | Wang, Yan
Persistent environmental pollutants are a growing problem around the world. The effective control of the pollutants is of great significance for human health. Some microbes, especially Arthrobacter, can degrade pollutants into nontoxic substances in various ways. Here, we review the biological properties of Arthrobacter adapting to a variety of environmental stresses, including starvation, hypertonic and hypotonic condition, oxidative stress, heavy metal stress, and low-temperature stress. Furthermore, we categorized the Arthrobacter species that can degrade triazines, organophosphorus, alkaloids, benzene, and its derivatives. Metabolic pathways behind the various biodegradation processes are further discussed. This review will be a helpful reference for comprehensive utilization of Arthrobacter species to tackle environmental pollutants.
Показать больше [+] Меньше [-]A survey of municipal solid waste landfills in Beijing during 2009–2011 Полный текст
2019
Liu, Xinyi | Fu, Huizhen | Jiang, Hanlin | Shao, Yan | Wu, Xiaoyang | Li, Zhenshan
The investigation of municipal solid waste (MSW) treatment in China is rare due to its sensitivity and difficulty in terms of access. We chose Beijing, the capital of China, as an example to identify the characteristics of MSW landfill treatments using a 2-month investigation with 20 participants. MSW landfill treatments account for nearly 70% of the annual MSW disposal in Beijing; the landfill processes are equipped with many kinds of technologies and consume a large amount of energy and produce a variety of contaminants. The cover method (the most obvious difference in landfill tamping) mainly includes high-density polyethylene (HDPE) geomembranes with loess and soil alone (i.e., loess or sandy soil). We investigated the actual conditions of landfills and collected data on leachate and landfill gas (LFG) emissions and energy consumption during 2009–2011. The results indicated that the cover method employed by landfills was related to treatment quantity, operation, and especially landfill location. Early large-scale landfills located in plains were covered with HDPE geomembranes, and newly built landfills covered with soil tended to be equipped with HDPE covers. Using HDPE cover also contributed greatly to LFG production due to its impermeability but had no remarkable effect on leachate yield reduction due to the dry climate in Beijing. The potential was reinforced by the potentials of decrement and reuse. The disposal method of LFG can be optimized, and the power generated by the LFG process can meet the landfill demand. The gray water recycled from the leachate could be used in the landfill process.
Показать больше [+] Меньше [-]Photodegradation using TiO2-activated borosilicate tubes Полный текст
2019
Khalaf, Samer | Shoqeir, Jawad H. | Scrano, Laura | Karaman, Rafik | Bufo, Sabino A.
This study examines the photocatalytic activity of titanium dioxide (TiO₂) semiconductor supported on borosilicate tubes (cut-off 290 nm) towards removal of a mix of persistent organic pollutants (POPs) from water. For this purpose, two widely used analgesic and anti-inflammatory drugs (NSAIDs), ibuprofen (IBU) and mefenamic acid, along with MCPA sodium monohydrate, which is a common herbicide frequently used in the agricultural activities, were selected as a case study. Borosilicate tubes were coated with titanium oxide through two different approaches: sol-gel dip-coating and a hybrid nanoparticle dip-coating and plasma-enhanced chemical vapour deposition (PECVD) process. The photochemical reactor that hosts the titania-coated tubes was designed to permit continuous throughput of liquid feed stream. The photodegradation experiments were performed in laboratory conditions under artificial irradiation simulating solar light. The efficiency of direct photolysis and heterogeneous photocatalysis (TiO₂) was investigated, and the performance of each coating method was evaluated. Kinetic studies for each experiment were accomplished, the overall results showed poor efficiency and insufficient removal for NSAIDs through direct photolysis, whereas applying heterogeneous photacatalysis with TiO₂ coated on borosilicate tubes was found to accelerate their degradation rate with complete decomposition. Concomitantly, kinetic experimental results showed a critical difference of performance for the two coating methods used; in particular, the degradation rates of pollutants by the sol-gel-coated tubes were much faster than the degradation by the nanoparticle/PECVD-coated tubes. Using TiO₂ supported on borosilicate tubes appears to be a promising alternative to conventional TiO₂ suspension and avoid post-separation stages. The results achieved in this study can be used to optimise large-scale applications, and expanding the study to cover a wide range of pollutants will lead to achieve more representative results.
Показать больше [+] Меньше [-]Design and synthesis of organic rectorite-based composite nanofiber membrane with enhanced adsorption performance for bisphenol A Полный текст
2019
Sun, Zhiming | Yuan, Fang | Zhang, Xinchao | Zhu, Rui | Shen, Xinyi | Sun, Bingyan | Wang, Bin
Nowadays, most of mineral-based adsorbents are powder form, which makes them inconvenient to collect and always easy to cause secondary pollution. In this work, an organic rectorite composite nanofiber membrane (SRt-PAN) was designed and prepared by electrospinning technique. The as-received composite nanofiber membranes were characterized by XRD and SEM analysis, proving the homodisperse and existence of SRt in PAN nanofiber membrane. A series of batch experiments for BPA adsorption were carried out to investigate the effect of different adsorption parameters, including initial concentration, pH, and temperature of pollutant solution. The influences of modifier dosage and adsorbent dosage on the adsorption performance were investigated as well. On the basis of the experiment results, the adsorption process could be well described by the pseudo-second-order model and the Langmuir isotherm. In addition, the thermodynamic parameters indicate that this adsorption process is exothermic and spontaneous. Moreover, compared with pure nanofiber membranes and organic rectorite powders, the resultant SRt-PAN adsorbents exhibited higher adsorption capacity, superior reusability, and adsorption stability. It is indicated that the hydrophobicity surface of organic rectorite should be the key factor to not only the intimate interfacial combination between the mineral and PAN, but also the enhancement of BPA adsorption capacity.
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