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Putative impacts of phytogenic additives to ameliorate lead toxicity in animal feed
2019
Abd El-Hack, Mohamed E. | Abdelnour, Sameh A. | Abd El-Moneim, Abd El-Moneim E. | Arif, Muhammad | Khafaga, Asmaa | Shaheen, Hazem | Samak, Dalia | Swelum, Ayman A.
Lead (Pb) is a toxic heavy metal and an environmental pollutant, particularly because of its anthropogenic activity. The main impacts of Pb is recognized to cause injurious influences of various levels of the tropic chain, due to bio-accumulated lead causes many health issues such as intoxication of different body organs, such as kidneys and liver, and reproductive and nervous systems. Industrial lead toxicity has reduced as a result of the attempts to decrease the lead levels in the surrounding work environment. Conversably, health risks related with long-term environmental exposure to a low dose of Pb have been steadily demonstrated. Long-term exposure to lead toxicity caused inflammatory infiltration, degenerative changes in testicular tissues, reduction in spermatocytes, necrosis of hepatocytes, degeneration in renal tubules, and renal epithelium hypertrophy. Hence, we need an influential approach to vanquish lead toxicity. This consequence has emerged the necessity for potentially safe represent remedy, favorably keeping both enhancement and chelating of the antioxidant competences. Many antioxidants have been used for chelating heavy toxic pollutants such as lead and oxidative stress released in excess during lead exposure. Several studies have stated the noticeable gathering of herbal singly or in combination in modulating lead-induced disturbances, therefore proposing great promise in enhancing health status and welfare of man as well as animals. For this, in the current review, we tried to discuss the enormous harmful influences of lead toxicity on the animal model and the disturbing truth that this detrimental toxic substance can be found quite simply in the surroundings and amplitude.
Mostrar más [+] Menos [-]Influence of fungi and bag mesh size on litter decomposition and water quality
2019
Zhai, Jiexiu | Cong, Ling | Yan, Guoxin | Wu, Yanan | Liu, Jiakai | Wang, Yu | Zhang, Zhenming | Zhang, Mingxiang
Litter decomposition is a complex process that is influenced by many different physical, chemical, and biological processes. Environmental variables and leaf litter quality (e.g., nutrient content) are important factors that play a significant role in regulating litter decomposition. In this study, the effects of adding fungi and using different mesh size litter bags on litter (Populus tomentosa Carr. and Salix matsudana Koidz.) decomposition rates and water quality were investigated, and investigate the combination of these factors influences leaf litter decomposition. Dissolved oxygen (DO), chemical oxygen demand (COD), total phosphorus (TP), and ammonia-nitrogen (NH₃-N) were measured during the 112-day experiment. The salix leaf litter (k = 0.045) displayed faster decomposition rates than those of populous leaf litter (k = 0.026). Litter decomposition was initially slow and then accelerated; and by the end of the experiment, the decomposition rate was significantly higher (p = 0.012, p < 0.05) when fungi were added to the treatment process compared to the blank, and litter bags with different mesh sizes did not influence the decomposition rate. The variations in the decomposition rates and nutrient content were influenced by litter quality and a number of environmental factors. The decomposition rate was most influenced by internal factors related to litter quality, including the N/P and C/P ratios of the litter. By quantifying the interact effect of environment and litter nutrient dynamic, to figure out the revetment plant litter decomposition process in a wetland system in biological physical and chemical aspects, which can help us in making the variables that determine decomposition rates important for assessing wetland function.
Mostrar más [+] Menos [-]Modeling long-term performance of full-scale anaerobic expanded granular sludge bed reactor treating confectionery industry wastewater
2019
Dereli, Recep Kaan
Production and consumption of confectionery products, such as chocolate, sugar, and cookies, have increased worldwide. Thus, management and treatment of confectionery effluents, as one of the most important agro-industrial wastewaters, become essential. Confectionery industries produce high-strength and highly biodegradable wastewaters that are appropriate for biological treatment prior to discharge. In this study, long-term dynamic performance of a full-scale anaerobic expanded granular sludge bed (EGSB) reactor treating confectionery effluent was simulated by using Anaerobic Digestion Model No. 1 (ADM1). Substrate fractionation was carried out based on the ADM1 state variables, and then, the model was calibrated with 300 days of operation data. The calibrated model could capture the dynamic performance of the anaerobic reactor for a long validation period of 500 days. Although the reactor was operated under highly fluctuating volumetric loading rates (VLR) between 0.2 and 5 kg chemical oxygen demand (COD)/m³ day, the model results indicated medium to high prediction accuracy for effluent COD, methane generation, total volatile fatty acids (VFA), and pH parameters. Mean relative absolute errors for COD, methane flow, VFA, and pH parameter simulations were 22%, 16%, 29%, and 1%, respectively. The study presents the applicability of ADM1 for full-scale reactors treating industrial wastewaters.
Mostrar más [+] Menos [-]Unsafe herbal sex enhancement supplements in Nigerian markets: a human risk assessment
2019
Igweze, Zelinjo Nkiruka | Amadi, Cecilia Nwadiuto | Orisakwe, Orish Ebere
High rates of irreversible oligo- or azoospermia are found among Nigerian men, leading many to consume herbal male sex enhancement products. The possibility of reproductive toxicity due to heavy metal contamination (Cr, As, Co, Hg, Cd, and Pb) of herbal products commonly used to boost libido or treat erectile dysfunction necessitated this study. In this study, herbal sex enhancement supplements were bought from pharmaceutical shops in Port Harcourt, Nigeria, and analyzed for heavy metals (Cr, As, Co, Hg, Cd, and Pb) contents using atomic absorption spectroscopy. The estimated daily metal intake (EDImetal), target hazard quotients (THQ), and total target hazard quotients (TTHQ) were determined. All the herbal sex enhancers used in this study contained heavy metals in these ranges: lead (0.032–0593), cobalt (0.025–0.075), cadmium (0.0011–0.048), and chromium (0.016–0.49) mg/kg. About 24.32% of the samples had TTHQ greater than 1. The EDImetal, THQ, and TTHQ of herbal sex enhancement supplements suggest that the use of some of these herbal sex enhancement supplements may not be risk-free after chronic exposure. Herbal sex enhancement supplements sold in Nigeria contain high levels of lead and cadmium. Since these metals are known to have male reproductive toxicity, these supplements may be adding to both the body burden of these metals and also implicated in the increasing incidence of male infertility in Nigeria.
Mostrar más [+] Menos [-]Effects of energy consumption, economic growth, and financial development on carbon emissions: evidence from heterogeneous income groups
2019
Ehigiamusoe, Kizito Uyi | Lean, Hooi Hooi
This paper examines the effects of energy consumption, economic growth, and financial development on carbon emissions in a panel of 122 countries. We employ both first-generation and second-generation cointegration and estimation procedures in order to address diverse economic and econometric issues such as heterogeneity, endogeneity, and cross-sectional dependence. We find a cointegration relationship between the variables. Energy consumption, economic growth, and financial development have detrimental effects on carbon emissions in the full sample. When the sample is split into different income groups, we reveal that economic growth and financial development mitigate carbon emissions in high-income group but have the opposite effects in low-income and middle-income groups. The implication of the findings is that energy consumption increases carbon emissions. While high levels of income and financial development decrease carbon emissions, low levels of income and financial development intensify it. Based on the findings, the paper makes some policy recommendations.
Mostrar más [+] Menos [-]Phytoremediatory efficiency of Chrysopogon zizanioides in the treatment of landfill leachate: a case study
2019
Fasani, E. (Elisa) | DalCorso, Giovanni | Zerminiani, Andrea | Ferrarese, Alberto | Campostrini, Paolo | Furini, Antonella
A common approach for waste management is their disposal in landfills, which is usually associated with the production of dangerous gases and of liquid leachate. Due to its toxicity, polluted liquid negatively impacts on the environment with the possible contamination of large volumes of soil, groundwater, and surface water. Leachate remediation is therefore subject of intensive research, and phytoremediation has been achieving increasing interest in recent decades. We describe here the suitability of vetiver grass for the remediation of two leachates collected in urban landfills of northern Italy, characterized by different composition. Our objective was measuring the accumulation/tolerance potential of this species and the evapotranspiration ability in a pot experiment, to evaluate applicability of vetiver plants for the reduction and decontamination of landfill leachate. Plants were grown for 4 months in pots with a zeolite growth bed and watered with either tap water (control) or undiluted landfill leachate. Plant growth and fitness and elemental content in shoots and roots were evaluated at the end of the experiment. In these experimental conditions, the high bioaccumulation of metals highlights the suitability of this species for its employment in phytoremediation; however, vetiver growth under leachate treatment was strongly dependent on leachate composition, making a case-to-case evaluation of plant tolerance necessary before large-scale application.
Mostrar más [+] Menos [-]Constructing magnetic Pt-loaded BiFeO3 nanocomposite for boosted visible light photocatalytic and antibacterial activities
2019
Jaffari, Zeeshan Haider | Lam, Sze Mun | Sin, Jin Chung | R̲ahmān, Eṃ. Ē.
Visible light–responsive Pt-loaded coral-like BiFeO₃ (Pt-BFO) nanocomposite at different Pt loadings was synthesized via a two-step hydrothermal synthesis method. The as-synthesized photocatalyst was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and magnetic hysteresis loop (M-H loop) analyses. The FESEM images revealed that Pt nanoparticles were evenly distributed on the coral-like BFO. The UV–vis DRS results indicated that the addition of Pt dopant modified the optical properties of the BFO. The as-synthesized Pt-BFO nanocomposite was effectively applied for the photodegradation of malachite green (MG) dye under visible light irradiation. Specifically, 0.5 wt% Pt-BFO nanocomposite presented boosted photocatalytic performance than those of the pure BFO and commercial TiO₂. Such a remarkably improved photoactivity could be mainly attributed to the formation of good interface between Pt and BFO, which not only boosted the separation efficiency of charge carriers but also possessed great redox ability for significant photocatalytic reaction. Moreover, the strong magnetic property of the Pt-BFO nanocomposite was helpful in the particle separation along with its great recyclability. The radical scavenger test indicated that hole (h⁺), hydroxyl (·OH) radical, and hydrogen peroxide (H₂O₂) were the main oxidative species for the Pt-BFO photodegradation of MG. Finally, the Pt-BFO nanocomposite was revealed high antibacterial activity towards Bacillus cereus (B. cereus) and Escherichia coli (E. coli) microorganisms, highlighting its potential photocatalytic and antibacterial properties at different industrial and biomedical applications.
Mostrar más [+] Menos [-]Cost-effectiveness of boron (B) removal from irrigation water: an economic water treatment model (EWTM) for farmers to prevent boron toxicity
2019
Türker, Onur Can | Yakar, Anıl | Türe, Cengiz | Saz, Çağdaş
Protection of water sources which are used for irrigation has raised great interest in the last years among the environmental strategists due to potential water scarcity worldwide. Excessive boron (B) in irrigation water poses crucial environmental problems in the agricultural zones and it leads to toxicity symptoms in crops, as well as human beings. In the present research, economic water treatment models consist of dried common wetland plants (Lemna gibba, Phragmites australis, and Typha latifolia) and Lemna gibba accumulation was tested and assessed to create a simple, cost-effective, and eco-friendly method for B removal from irrigation water. Significant amount of B was removed from irrigation water samples by EWTMs and B concentrations decreased below < 1 mg L⁻¹ when the components were exposed to 4 and 8 mg L⁻¹ initial B concentrations. Moreover, the results from batch adsorption study demonstrated that dried L. gibba had a higher B loading capacity compare to other dried plants, and B sorption capacity of dried L. gibba was found as 2.23 mg/g. The optimum pH value for sorption modules was found as neutral pH (pH = 7) in the batch adsorption experiment. Boron sorption from irrigation water samples fitted the Langmuir model, mostly B removed from irrigation water during the first 2 h of contact time. Techno-economic analysis indicated that EWTM is a promising method that appears to be both economically and ecologically feasible, and it can also provide a sustainable and practical strategy for farmers to prevent B toxicity in their agricultural zones.
Mostrar más [+] Menos [-]Impacts of salinity on CO 2 spatial distribution and storage amount in the formation with different dip angles
2019
Jing, Jing | Yang, Yanlin | Tang, Zhonghua | Wang, Fugang
Formation dip angle and the distortion of salinity affect the spatial distribution and storage capacity of carbon dioxide (CO₂). In this numerical study, based on an actual CO₂ injection demonstration project (Shiqianfeng group in the Ordos Basin) in China, CO₂ was injected for a period of 20 years at four different formation dip angles (0°, 5°, 10°, 15°). In conjunction, some salinity values were chosen, ranging from saturation salinity to no salinity. A three-dimensional (3D) model was established to systematically explore the influence of different formation dip angles and salinities on the CO₂ spatial distribution and storage amount. The simulation results showed that larger salinity and higher pressure near the injection well will lead the CO₂ gas-phase saturation and mass fraction to be smaller for a given formation dip angle. When salinity is held constant at the saturation value, a larger dip angle will cause a smaller CO₂ gas saturation in the upper right units of the injection well, and a larger gas saturation in the lower left units at the 20th year of CO₂ injection. For large salinity values (full, half, and quarter saturation salinity), the larger the formation dip angle is, the greater the CO₂ total storage amount. For smaller salinity values (0.00 and 0.03), a transition point existed (at 8 and 18.2 years) during the 20-year injection period. Before the transition point, the CO₂ total storage amount also increases with the dip angle. After the transition point, however, the larger the formation dip angle is, the smaller the CO₂ total storage amount becomes. In addition, a lower salinity may lead to the earlier appearance of the transition point.
Mostrar más [+] Menos [-]Investigation of toxic effects of amorphous SiO2 nanoparticles on motility and oxidative stress markers in rainbow trout sperm cells
2019
Özgür, Mustafa Erkan | Ulu, Ahmet | Özcan, İmren | Balcioglu, Sevgi | Ateş, Burhan | Köytepe, Süleyman
In this study, we investigated the effects of SiO₂ nanoparticles (SiO₂-NPs) (1, 10, 25, 50, and 100 mg/L) for 24 h in vitro on the motility parameters and oxidative stress markers such as total glutathione (TGSH), catalase (CAT), and malondialdehyde (MDA) of rainbow trout, Oncorhynchus mykiss sperm cells. Therefore, SiO₂-NPs were synthesized with sol-gel reaction from tetraethoxy orthosilicate (TEOS). The prepared nanoparticle structures were characterized for chemical structure, morphology and thermal behavior employing Fourier transform infrared spectroscopy, X-ray spectroscopy, scanning electron micrograph, and thermal analysis (DTA/TGA/DSC) techniques. After exposure, there was statistically significant (p < 0.05) decreases in velocities of sperm cells. CAT activity significantly (p < 0.05) decreased by 9.6% in sperm cell treated with 100 mg/L. In addition, MDA level significantly increased by 70.4% and 77.5% in sperm cell treated with 50 and 100 mg/L SiO₂-NPs, respectively (p < 0.05). These results showed that SiO₂-NPs may have toxic effect on rainbow trout sperm cells in 50 mg/L and more.
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