خيارات البحث
النتائج 111 - 120 من 640
Investigating the Influence of Urban River Valleys on Meteorological Parameters at the Local Scale as a Factor for urban sustainability - Case study: Farahzad River Valley
2023
Allahyari, Hadis | Salehi, Esmael | Zebardast, Lobat | Jafari, Hamidreza
Four regions of the Farahzad River Valley with different topography were selected to fully survey it and study the effects of morphology on local climate. then one of the hot days of the month of June 2021 (June 6th) was selected because the wind speeds increase in spring. According to the comparison of the simulation results with the existing site plans, the temperature in area 3 was the highest, 39.60 degrees, and the wind speed was 3.57 m/s. On the other hand, the study and analysis of the maps showed that the temperature of the roads in regions 3 and 4 were higher than the other two regions with a temperature range of 37.69-38.40, so the presence of impervious asphalt surfaces on the roads is very effective in increasing the air temperature in these areas. Comparisons also showed that tall buildings and vegetation create shaded areas and increase wind speed. Based on this, two scenarios were designed. In the first scenario, doubling the height of buildings increased wind speed in Region 3 by 3.42 m/s and decreased temperatures by 1.59 degrees. In the second scenario, when tall trees were planted at certain distances around the streets, the temperature in Region 3 decreased by 1.68 degrees and the wind speed increased by 1.68 m/s. The results show that the differences in the topography of urban valleys cause ventilation of the environment and that the effect of this feature in other environments is more effective through planting than through buildings.
اظهر المزيد [+] اقل [-]Natural Extraction of Dyes from Saffron ‘Crocus sativus L’ Flower Waste, Cotton Dyeing, and Antioxidant Effectiveness
2023
Lachguer, Khadija | Boudadi, Imane | Fayzi, Lahbib | El Merzougui, Soumaya | El Bouchti, Mehdi | Cherkaoui, Omar | Serghini, Mohammed Amine
The production of saffron, the spice obtained from the dried stigmas of Crocus sativus L. (Iridaceae family) flowers, generates, after pruning, considerable quantities of waste containing natural dyes. Saffron flower waste could be a source of extraction of natural dyes with antioxidant activity. In this study, we investigate the possibility of using saffron flower waste for dyeing cotton and evaluating the antioxidant effect of this dye by the DPPH free radical, reducing power and β-carotene bleaching assay. The dye has been evaluated for the composition of the color by the UV-visible spectrum and tested for the dyeing of cotton. The results indicate the presence of polyphenols and flavonoids. The dyeing conditions have been optimized at 6% dye concentration, dye bath pH of 3, dyeing temperature at 98 °C and dyeing time of 60 min. 2% dye concentration with 5 to 10% mordant concentration remains sufficient for dyeing with pre-mordanting. The exhaustion of the bath after dyeing has been improved by a rate of 20% in the case of addition of mordants which have produced a shade of green color. The dye contributes to the significant antioxidant activities with more DPPH scavenging capacity, FRAP reducing power, and β-carotene bleaching inhibition. Cotton fabrics dyed with bio-dyes obtained from saffron flower waste show good color fastness properties and could be a potential source of natural antioxidant agent. It presents an important eco-friendly alternative to synthetic dyes for large-scale application in textile and food industries.
اظهر المزيد [+] اقل [-]Characterization of Groundwater and Distribution of Fluoride in the Eastern Region of the Algerian Northern Sahara (Ouargla)
2023
Abdellaoui, Aicha | Baouia, Kais | Saggai, Sofiane
In the eastern region of the Algerian Northern Sahara, the groundwater is the only resource for drinking water supply and irrigation. This study aimed to assess the physical-chemical quality of groundwater with exposition of the fluoride distribution in the eastern region of Algeria taking as case study Ouargla area. The sampling campaign was carried out in such a way to cover the exploited aquifers (Miopliocene and Senonian). Water temperature, pH, conductivity, hardness, alkalinity, principal ions (Sodium, Potassium Calcium, Magnesium, Bicarbonates, Nitrates, Sulfates, and Chlorides) and the fluoride content in the groundwater were measured and determined. Examination and validation of obtained results were by the use ionic balance method and the hydrochemical analysis by Piper, Stabler and Richards diagrams. The obtained results of our study show that the groundwater of the Ouargla area presents a chlorinated sodium and potassium facies. Moreover, the groundwater quality in the study area is of poor quality; it is hard and characterized by very high mineralization, The Richards' diagram indicates that the groundwater of the study area are unsuitable for irrigation. The spatial distribution of fluoride ions in groundwater of the terminal complex shows that fluoride levels in Ouargla exceed the World Health Organization standard.
اظهر المزيد [+] اقل [-]Analysis of the Effect of Green Packaging on Attracting and Retaining Environmentally Friendly Customers with the Mediating role of Green Brand Image
2023
Seifollahi, Naser
Increasing the level of environmental knowledge of consumers and their level of concern towards the environment and green brands are among the important factors that have been considered in the discussion of consumer behavior in recent years. Marketing managers also try to attract customers' attention to their green products and brands in order to succeed in selling and marketing their products. Therefore, the present study was conducted with the aim of investigating the effect of green packaging on attracting and retaining environmentally friendly customers with the mediating role of green brand image. In terms of the purpose of the research, the type of applied research, the method of collecting descriptive data is of the correlation type. The statistical population of this research is the students of University of Mohaghegh Ardabili, 373 of them were selected as a sample by referring to Morgan's table and using the available sampling method. The required data were collected using a questionnaire and analyzed based on the structural equation modeling method and using SPSS and Smart PLS software. The results of the research showed that green packaging has a positive and significant effect on attracting and retaining environmentally friendly customers as well as the image of the green brand. On the other hand, the image of the green brand has a positive and significant effect on attracting and retaining environmentally friendly customers. Finally, green brand image acts as a mediating factor in the relationship between green packaging and attracting and retaining environmentally friendly customers.
اظهر المزيد [+] اقل [-]Current Eco-friendly and Sustainable Methods for Heavy Metals Remediation of Contaminated Soil and Water: Special Emphasis on Use of Genetic Engineering and Nanotechnology
2023
Yadav, Meena | Sharma, Poonam
Anthropogenic activities have polluted soil and aquatic ecosystems by introducing harmful heavy metals (HMs) such as cadmium, copper, mercury, lead, manganese, nickel, zinc, and others. These HMs lead to serious health conditions in humans like cancer, skin lesions, birth defects, liver and kidney damage, and mental retardation leading to other disabilities. Conventional methods of HM remediation of contaminated soil and water include physical, chemical, biological, and integrated methods. The use of physical and chemical methods, in isolation, has been reduced in practice, owing to their negative impacts, however, work on suitable integrated approaches, and the use of organisms for HM remediation has been in steady progress since past few decades. These approaches have proved to be eco-friendly, cost-effective, and show reduced negative impacts on the environment and biota. However, there is consistent increase in anthropogenic contribution to this problem, so, to keep pace with it, more recently work is in advancement on exploiting the biological system to increase the efficiency of bioremediation, using the latest technologies such as genetic engineering and nanotechnology. This paper provides an overview of the current methods deployed to address this problem, developments made in this field in past few decades, and evokes a research thrust that might lead to novel remediation approaches in the future.
اظهر المزيد [+] اقل [-]Characterization and Evaluation of the Nickel-Removal Capacity of Kluyvera cryocrescens M7 Isolated from Industrial Wastes
2023
Bisht, Heena | Kumar, Narayan
Heavy metal contamination poses grave risks to all kinds of life. The fastest growing automotive, electroplating, and battery industries release the most common heavy metal, Nickel, into the environment, which has lethal impacts on human health. Our research aims to find Ni-resistant bacteria in the metal-contaminated soil that have a great potential for removing Ni from the environment. Attempts have been made to extract and characterize Ni-resistant bacteria from automobile and electroplating industry waste-contaminated soil using serial dilution, streak plating, and various morphological, biochemical, and genetic techniques. The maximum tolerable concentration of Ni and other heavy elements, such as cadmium, lead, and aluminium for the selected isolate, was investigated using the UV-Vis spectrophotometric method. Additionally, the bacterial strain's ability to remove Ni was assessed using an atomic absorption spectrophotometer. The current research reveals a novel strain of Kluyvera cryocrescens that could withstand Ni, Cd, Pb, Al, and combinations of these heavy metals. The maximum tolerance concentration of K. cryocrescens M7 for Ni, Cd, Pb, and Al was found to be 150 ppm, 200 ppm, 1000 ppm, and 150 ppm, respectively. Additionally, it was also observed that the bacterial strain could remove Ni by 29.57%, 35.36%, 48.41%, 46.91%, and 44.88% after 12, 24, 48, 72, and 96 hours, respectively. The strain has also exhibited resistance to vancomycin, ampicillin, carbenicillin, and streptomycin. This research discovered a novel bacterial strain, K. cryocrescens M7 that may be beneficial for removing heavy metals, particularly Ni, from metal-contaminated soil.
اظهر المزيد [+] اقل [-]Assessing the Natural and Anthropogenic Radionuclide Activities in Fish from Arctic Rivers (Northwestern Russia)
2023
Puchkov, Andrey | Druzhinina, Anna | Yakovlev, Evgeny | Druzhinin, Sergey
This scientific article presents the results of studies on the distribution of natural and artificial radionuclides in fish living in the rivers of the northwestern sector of the Arctic zone of the Russian Federation. Fish sampling (about 76 kg in total) was carried out in the White Sea, in the Northern Dvina and Mezen Rivers, and in the Sukhoe Sea Bay of the Arkhangelsk Region, as well as in the rivers of the Nenets Autonomous District: Pesha, Oma, Vizhas, Nes, and Pechora. The results showed the presence of artificial radionuclides Cs-137 and Sr-90 in fish only in the Nes River of the Nenets Autonomous District. The levels of radionuclides in whole bodies perch and pike in the Nes River range from 3.73 to 14.0 Bq/kg wet weight for Cs-137 and less than 3.72 to 23.1 Bq/kg wet weight for Sr-90. In addition to Cs-137 and Sr-90, the presence of the radionuclide K-40, which is the main dose-forming radionuclide, was noted in the fish of all the studied rivers and seas. K-40 activity was in the reached values 138 Bq/kg for whole fish bodies. The only assumption that can explain the presence of artificial radionuclides in the fish of the Nes River is a possible radioactive trace formed as a result of global nuclear tests, including in the Novaya Zemlya archipelago. At the same time, it is noted that the current levels of technogenic radioactivity in fish from the Nes River do not pose a radiological hazard to the local population.
اظهر المزيد [+] اقل [-]Trichoderma tomentosum Ts141 as a Potential Candidate for Bioremediation of Cadmium, Lead, and Nickel Ions
2023
Hosseinzadeh, Samira | Aliloo, Ali Asghar | Shahabivand, Saleh | Ghaderi, Mohammad
Fungi are successful microorganisms in the bioremediation of environmental pollution. So, this study aimed to determine the potential of Trichoderma tomentosum to remediate cadmium, lead, and nickel contaminations from potato dextrose agar (PDA) and potato dextrose broth (PDB) media. Growth rates, toxicity tolerance sporulation, bio-sorption capacity, and bio-sorption efficiency of the fungus were evaluated under different concentrations of CdCl2, Pb(NO3)2, and NiCl2. The findings demonstrated that the growth rate of the fungus differed depending on concentration, metal type, and medium. More metals in PDA medium induced more inhibition on fungus growth rates; however, the rate was independent from the heavy metals concentrations in PDB medium. Cadmium was the most toxic metal tested against T. tomentosum, with a 72h LC50 of 37 ppm. It was about 3.16 and 4.24 times as toxic as nickel and lead, respectively. In the control condition, sporulation of the fungus began at 72 hours, but under the heavy metals, it began at 168, 168, and 192 hours, respectively, for Pb, Ni, and Cd. Both the bio-sorption capacity and efficacy of the fungus were significantly enhanced by an increase in metal content and the highest values were obtained at 200 ppm of the salts. The heavy metals total bio-sorption capacity order was Ni < Cd < Pb in the aqueous medium. The conclusion was that T. tomentosum has a greater potential for the biosorption of heavy metals; hence, the fungus may be employed for the bioremediation of heavy metals from polluted sites, particularly wastewater and industrial influents.
اظهر المزيد [+] اقل [-]Aeration, Alum, and Kaolin Ore for Nutrient and Heavy Metal Removal from Urban Wastewater for the Purpose of Reuse and Conservation
2023
Soliman, Mohamed | Rashed, Mohamed | Soltan, Mohamed
Domestic and industrial wastewater contributed to some urban wastewater, which requires specific processing before being disposed into surface waters or reused for irrigation. This paper aimed to employ kaolin as an adsorbent to remove heavy metals from wastewater, as well as aeration and alum to remove nutrients. Experiment were conducted in three parts: first, involved using the aeration method to determine the ideal amount of time to remove or minimize the nutrients. Second, involves treating the solution with potassium alum using various alum doses at the obvious times to eliminate or minimize the nutrients, while third step involves treating the solution with kaolin ore with a size of < 63 µm at various doses, pH, and contact times to remove heavy metals. The findings showed that the aeration method completely removed CO3, OH, PO4, NO3, Ca, and Mn ions after contact time equal 120, 24, 192, 24, 120, and 48 hrs, respectively. Applaying alum treatment method can remove completely CO3, OH, PO4, NO3, and Mn, after contact time 120, 24, 120, 24, and 24 hrs, respectively. When Kaolin ore used as adsorbent, the removal efficiency of Fe, Cd, Cr, Cu, Sr, Mn, and Zn were; 92, 100, 100, 100, 94, 100, and 88 % ,respectively in 24 hours contact time. The experiment succeeds in treatment of industrial wastewater that was within the range of specified limitations for disposing into surface water or reuse in irrigation field as stated by Egyptian standard code using the three successive treatment techniques.
اظهر المزيد [+] اقل [-]Histomorphometry of Liver and some Blood Factors of Nile Tilapia, Oreochromis niloticus Exposed to Different Concentrations of Ammonia
2023
Nochalabadi, Azadeh | Morovvati, Hassan | Abdi, Rahim
Most tilapias are microphytes, but some prefer higher plants. Ammonia is one of the most important toxic compounds of nitrogen, which is a serious problem in the environment and aquaculture industry. In the present study, juvenile Oreochromis niloticus were exposed to 10, 20, and 30% (96h LC50) of ammonia for two weeks, which are equivalent to 0.9, 1.8, and 2.7 mg / l, respectively. After this period, the fish were anesthetized and blood samples were taken from the caudal stalk with a heparin syringe for evaluating blood indicators. The tissue samples were taken 0.5 cm from the liver, fixed in 10% formalin buffer, and after dehydration with alcohol, clarification with xylol, blocking with paraffin, and cutting 4-6 microns thick with microtome were done. Finally, the stained slides were studied with a light microscope. The results showed phenomena such as hyperemia, nuclear hypertrophy, sinusoidal dilatation, increased melanomacrophage centers, nucleus margination, hepatocyte vacuolation, and cell necrosis in the liver. In the studies of blood serum factors with the increase of ammonia, it has been increased in AST, ALT, and ALP compared to the control and other groups. Also, as the ammonia concentration increased, the severity of the lesions also increased. Therefore, ammonia causes changes in the structure and activity of metabolic enzymes of the liver, which must be controlled by creating the appropriate ammonia and management conditions in the aquatic environment.
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