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Barbary sheep tissues as bioindicators of radionuclide and stabile element contamination in Croatia: exposure assessment for consumers
2019
Lazarus, Maja | Gančević, Pavao | Orct, Tatjana | Barišić, Delko | Jerina, Klemen | Šprem, Nikica
Muscle, liver and kidney of 21 Barbary sheep (Ammotragus lervia) from Mosor Mountain, Croatia, were sampled to quantify the activity of caesium and potassium radionuclides and five toxic and ten essential stabile elements in order to establish reference values for this species and to evaluate the potential of Barbary sheep tissues to reflect environmental pollution. We also assessed seasonal diet (botanical composition and dry matter content) of Barbary sheep based on analyses of a rumen content of culled animals. None of the 19 plant species (mostly grasses) identified as part of the Barbary sheep diet is known as a stabile element or radionuclide hyperaccumulator. Measured levels reflected low environmental pollution with arsenic, cadmium, mercury and lead, with levels generally less than those reported for wild herbivorous ungulates. Methodological differences (detection limit of elements in muscle) were shown to hamper interpretation and comparison of the Toxic Contamination Index (TCI) values with those published for other species. There was no homeostasis disturbance of trace elements in Barbary sheep, either due to inadequate intake via food or as an adverse effect due to a high toxic metal(loid) burden. Consumption of the muscle and liver of wild Barbary sheep can be considered safe for the health of adult consumers regarding toxic metal(loid)s and radioactive caesium, though the liver should be avoided as a food item in vulnerable population groups due to the possible adverse effects of cadmium and lead. Otherwise, muscle and liver are a rich source of copper, iron, selenium and zinc for consumers and, as such, can benefit the overall dietary intake of essential elements.
Mostrar más [+] Menos [-]Adsorption and desorption of chromium with humic acid coated iron oxide nanoparticles
2019
Singaraj, Shilpa Gnanamuthu | Mahanty, Biswanath | Balachandran, Darshan | Padmaprabha, Anamika
Presence of carcinogenic chromium, i.e., Cr(VI), in different industrial effluents necessitates design and development of effective abatement technologies. Nanosorbent consisting of iron oxide nanoparticles functionalized with soil-derived humic acid was employed for removal of Cr(VI). The point of zero charge for both humic acid and nanoparticles as estimated from pH shift experiments was between pH 8 and 9. Adsorption isotherm from batch experiments at neutral pH followed Langmuir model with projected maximum adsorption capacities for humic acid coated nanoparticles (24.13 mg/g) much higher than its uncoated counterpart (2.82 mg/g). Adsorption was process very fast and kinetics could be described with pseudo-second-order model (R² > 0.98), for both nanoparticles. High E4/E6 ratio of extracted humic acid and Fourier transform infrared spectroscopy of coated nanoparticles (20–100 nm) indicated enrichment of hydroxyl, carboxylic, and aliphatic groups on surface leading for the better adsorption. Humic acid coated and uncoated nanoparticles regenerated with EDTA, NaOH, urea, Na₂CO₃, and NaCl treatments retained 35.90–59.67 and 26.37–36.28% of their initial adsorption capacities, respectively, in 2nd cycle. Experimental controls (virgin nanoparticles subjected to an identical regenerating environment) revealed irreversible surface modification as the cause for loss of their adsorption capacities.
Mostrar más [+] Menos [-]Firefighting of subsurface coal fires with comprehensive techniques for detection and control: a case study of the Fukang coal fire in the Xinjiang region of China
2019
Tan, Bo | Zhang, Feichao | Zhang, Qingsong | Wei, Hongyi | Shao, Zhuangzhuang
Coal fires are global disasters, and China suffers the most serious coal fire disasters in the world. This paper introduces detailed detection and extinguishing methods for the wide range and complex coal fires at the No. 1 well in the Fukang mining area. First, the characteristics of the large and complex coal fire areas in the No. 1 well in the Fukang mining area are introduced, and 5 large fire areas are detected using the comprehensive detection range method, which detects fire areas before fire engineering practices are implemented. From the characteristics of this large-scale, complex coal fire, the zonal fire extinguishing scheme is formulated, designed, and applied, and the “shallow open fire stripping—construction of the boundary isolation zone—drilling and grouting in the deep fire area” series of events is utilized in the zonal fire extinguishing scheme. A new type of sodium silicate gel in compressive moisturizing plastic packing materials is used, an automatic grouting system is developed, and effective grouting processes are proposed, which can be adjusted according to the grouting effect analysis of the grouting parameters to determine the natural sedimentation and diffusion radius. After the construction was completed, the fire extinguishing effect was tested, revealing that the temperature in the fire zone cooled in a short time, and no subsequent heating phenomenon occurs. The method proposed in this paper provides guidance and a reference for other coal fires in the world.
Mostrar más [+] Menos [-]Constructed wetland microcosms as sustainable technology for domestic wastewater treatment: an overview
2019
Kumar, Saroj | Dutta, Venkatesh
Constructed wetland microcosms (CWMs) are artificially designed ecosystem which utilizes both complex and ordinary interactions between supporting media, macrophytes, and microorganisms to treat almost all types of wastewater. CWMs are considered as green and sustainable techniques which require lower energy input, less operational and maintenance cost and provide critical ecological benefits such as wildlife habitat, aquaculture, groundwater recharge, flood control, recreational uses, and add aesthetic value. They are good alternatives to conventional treatment systems particularly for smaller communities as well as distant and decentralized locations. The pH, dissolved oxygen (DO), and temperature are the key controlling factors while several other parameters such as hydraulic loading rates (HLR), hydraulic retention time (HRT), diversity of macrophytes, supporting media, and water depth are critical to achieving better performance. From the literature survey, it is evaluated that the removal performance of CWMs can be improved significantly through recirculation of effluent and artificial aeration (intermittent). This review paper presents an assessment of CWMs as a sustainable option for treatment of wastewater nutrients, organics, and heavy metals from domestic wastewater. Initially, a concise note on the CWMs and their components are presented, followed by a description of treatment mechanisms, major constituents involved in the treatment process, and overall efficiency. Finally, the effects of ecological factors and challenges for their long-term operations are highlighted.
Mostrar más [+] Menos [-]Two hybrid data-driven models for modeling water-air temperature relationship in rivers
2019
Zhu, Senlin | Hadzima-Nyarko, Marijana | Gao, Ang | Wang, Fangfang | Wu, Jingxiu | Wu, Shiqiang
River water temperature (RWT) forecasting is important for the management of stream ecology. In this paper, a new method based on coupling of wavelet transformation (WT) and artificial intelligence (AI) techniques, including multilayer perceptron neural network (MLPNN) and adaptive neural-fuzzy inference system (ANFIS) for RWT prediction is proposed. The performances of the hybrid models are compared with regular MLPNN and ANFIS models and multiple linear regression (MLR) models for RWT forecasting in two river stations in the Drava River, Croatia. Model performance was evaluated using the coefficient of correlation (R), the Willmott index of agreement (d), the root mean squared error (RMSE), and the mean absolute error (MAE). Results indicate that the combination of WT and AI models (WTMLPNN and WTANFIS) yield better models than the conventional forecasting models for RWT simulation for both regular periods and heatwave events. The MLPNN and ANFIS models outperform the MLR models for RWT simulation for the studied river stations. RMSE values of WTMLPNN2 and WTANFIS2 models range from 1.127 to 1.286 °C, and 1.216 to 1.491 °C for the Botovo and Donji Miholjac stations respectively. Additionally, modeling results further confirm the importance of the day of year (DOY) on the thermal dynamics of the river. The results of this study indicate the potential of coupling of WT and MLPNN, ANFIS models in forecasting RWT.
Mostrar más [+] Menos [-]The concentration of potentially toxic elements (PTEs) in muscle tissue of farmed Iranian rainbow trout (Oncorhynchus mykiss), feed, and water samples collected from the west of Iran: a risk assessment study
2019
Heshmati, Ali | Sadati, Rafieh | Ghavami, Mehrdad | Mousavi Khaneghah, Amin
The pollution of the environment by potentially toxic elements (PTEs) is one of the most important raised concerns. Therefore, the current investigation was devoted to measuring the concentration of lead (Pb), cadmium (Cd), elemental mercury (Hg), nickel (Ni), iron (Fe), zinc (Zn), and copper (Cu) in muscle tissue of farmed rainbow trout (n = 30) as well as their feed (n = 15) and water (n = 15) samples collected from farms (Hamadan Province, Iran) by the aid of an inductively coupled plasma atomic emission spectrometer (ICP-OES). Also, the associated risk for human and biomagnification factor (BMF) and bioconcentration factor (BCF) for PTEs in the fish muscle through feed and water were calculated. The mean concentration of Pb, Cd, Hg, Ni, Fe, Zn, and Cu in rainbow trout muscle was reported as 0.056 ± 0.040 μg g⁻¹ wet weight, <LOD, 0.014 ± 0.016 μg g⁻¹ wet weight, 0.140 ± 0.188 μg g⁻¹ wet weight, 1.051 ± 0.909 μg g⁻¹ wet weight, 0.635 ± 0.725 μg g⁻¹ wet weight, and 0.275 ± 0.325 μg g⁻¹ wet weight, respectively, while all of the samples were contaminated in the concentrations below the permitted limits by regulatory bodies such as EC, Food and Agriculture Organization (FAO), and WHO/FAO. No significant difference between the amounts of PTEs among the collected feed and water samples was noted, while the corresponded values for PTE concentrations also were lower than the allowable limits. The values of BMF and BCF for all analyzed PTEs through water and feed were lower than 1000, demonstrating that the rainbow trout muscle could not be considered as a bioaccumulative tissue for PTEs. Additionally, no health risk due to ingestions of investigated PTEs via consumption of this rainbow trout fish was noted.
Mostrar más [+] Menos [-]Effects of biochar amendment on bacterial and fungal communities in the reclaimed soil from a mining subsidence area
2019
Liu, Yuan | Zhu, Jirong | Gao, Wenhui | Guo, Zonghao | Xue, Chen | Pang, Jiayin | Shu, Liangzuo
Biochar amendment of soil is well known to improve soil fertility and microbial function. However, little is known about the effect of biochar addition to reclaimed soil in coal mining subsidence area on microbial community. A plant soil cultivation experiment was conducted with wheat grown and four treatments were included: P and K fertilizer (CK); NPK inorganic fertilizer (NPK); NPK inorganic fertilizer and straw (NPKS); and NPK inorganic fertilizer and biochar (NPKB). The results indicated that biochar amendment significantly increased the concentrations of NH₄⁺-N, total N, and available P and K compared with the NPK. Biochar addition also significantly increased the grain yield and total biomass of wheat. Furthermore, biochar amendment treatment increased the absolute abundance and altered the community structure of soil bacteria and fungi in the reclaimed soil. Illumina MiSeq sequencing showed that the addition of biochar increased α-diversity of bacteria and relative abundances of Proteobacteria, Actinobacteria, and Bacteroidetes, whereas the relative abundance of Firmicutes were decreased by 61%. However, biochar addition did not change the relative abundance of dominant fungal phyla. Redundancy analysis (RDA) suggested that total N, available P, and K contents were the key factors correlated with changes in microbial community structure. Overall, our results suggest that biochar amendment in reclaimed soil in coal mine subsidence area could increase wheat yield and abundance and alter microbial community compositions.
Mostrar más [+] Menos [-]Fungal-mediated synthesis of pharmaceutically active silver nanoparticles and anticancer property against A549 cells through apoptosis
2019
Akther, Tahira | Vabeiryureilai Mathipi, | Nachimuthu Senthil Kumar, | Davoodbasha, MubarakAli | Srinivasan, Hemalatha
Generally, fungi have the ability to secrete large amounts of secondary metabolites which have the ability to reduce metal ions to metallic nanoparticles. In this report, silver nanoparticles (AgNPs) were synthesized by using an endophytic fungus isolated from the medicinal plant, Catharanthus roseus (Linn.). The endophytic fungus was identified as Botryosphaeria rhodina based on the ITS sequencing. The synthesized AgNPs were characterized by adopting various high-throughput techniques, scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HR-TEM) and UV–Visible spectrophotometer. In vitro anticancer efficacy of AgNPs was tested on A-549 cells. The synthesized AgNPs were effective in scavenging free radicals and induced hallmarks of apoptosis including nuclear and DNA fragmentation in lung (A549) cancer cell lines under in vitro conditions. The results suggested that the natural biomolecules in the endophytic fungi incorporated into the nanoparticles could be responsible for the synergetic cytotoxic activity against cancer cells. The AgNPs were found to have cytotoxicity IC₅₀ of 40 μg/mL against A549 cells. To the best our knowledge, this is the first report demonstrating that AgNPs from Botryosphaeria rhodina could be able to induce apoptosis in various types of cancer cells as a novel strategy for cancer treatment.
Mostrar más [+] Menos [-]Mg-Al-CO3 layered double hydroxide reinforced polymer inclusion membrane as an extractant phase for thin-film microextraction of cyanide from environmental water samples
2019
Heidarbeigi, Maliheh | Saraji, Mohammad | Jafari, Mohammad Taghi
In this paper, a flexible and efficient nano-reinforced polymer inclusion membrane (PIM) was fabricated and used for cyanide (CN⁻) extraction from water samples. Aliquat 336 (a liquid anion exchanger) was embedded in poly(vinyl chloride) (PVC) support as the extractant. Mg-Al-CO₃ layered double hydroxide (LDH) with high surface area and anion exchange ability was applied to promote the extraction efficiency of PIM. A PIM comprising 56% PVC, 40% Aliquat 336, and 4% Mg-Al-CO₃ LDH showed the best extraction efficiency. A single beam ultraviolet-visible spectrophotometer was used for the detection of cyanide. Surface morphology of the PIM was studied by field emission scanning electron microscopy. The experimental parameters influencing the extraction process were investigated and optimized. The intra- and inter-day relative standard deviations at two different concentrations were in the range of 2.8–7.6%. The dynamic range of the method was in the range of 5–500 μg L⁻¹, and the detection limit was 1.4 μg L⁻¹. The LDH reinforced PIM showed proper characteristics for the extraction of cyanide from real water and wastewater samples with recoveries between 82 and 115%.
Mostrar más [+] Menos [-]Physiological response of fish under variable acidic conditions: a molecular approach through the assessment of an eco-physiological marker in the brain
2019
Mukherjee, Amrita | Bhowmick, Amiya Ranjan | Mukherjee, Joyita | Moniruzzaman, Mahammed
The current study demonstrates oxidative damage and associated neurotoxicity following pH stress in two freshwater carp Labeo rohita and Cirrhinus cirrhosus. Carp (n = 6, 3 replicates) were exposed to four different pH (5.5, 6, 7.5, and 8) against control (pH 6.8 ± 0.05) for 7 days. After completion of treatment, levels of enzymatic (superoxide dismutase [SOD], catalase [CAT], glutathione reductase [GRd]) and non-enzymatic antioxidants (malondialdehyde [MDA], glutathione [GSH]), brain neurological parameters (Na⁺-K⁺ATPase, acetylcholinesterase [AcHE], monoamine oxidase [MAO], and nitric oxide [NO]), xanthine oxidase (XO), heat shock proteins (HSP70 and HSP90), and transcription factor NFkB were measured in carp brain. Variation in the pH caused a significant alteration in the glutathione system (glutathione and glutathione reductase), SOD-CAT system, and stress marker malondialdehyde (MDA). Xanthine oxidase was also induced significantly after pH exposure. Brain neurological parameters (MAO, NO, AChE, and Na⁺-K⁺ATPase) were significantly reduced at each pH-treated carp group though inhibition was highest at lower acidic pH (5.5). Cirrhinus cirrhosus was more affected than that of Labeo rohita. Molecular chaperon HSP70 expression was induced in all pH-treated groups though such induction was more in acid-stressed fish. HSP90 was found to increase only in acid-stressed carp brain. Expression of NFkB was elevated significantly at each treatment group except for pH 7.5. Finally, both acidic and alkaline pH in the aquatic system was found to disturb oxidative balance in carp brain which ultimately affects the neurological activity in carp. However, acidic environment in the aquatic system was more detrimental than the alkaline system regarding oxidative damage and subsequent neurotoxicity in carp brain.
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