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11.
Mahdavian Seyed Mohammadreza Ahmadpour Borazjani Mahmoud Mohammadi Hamid Asgharipour Mohammad Reza Najafi Alamdarlo Hamed 《Environmental science and pollution research international》2022,29(35):52457-52472
Environmental Science and Pollution Research - Iran’s agricultural production has expanded significantly in recent years. Environmental pollution caused by the use of energy and chemical... 相似文献
12.
Sorption-desorption of cadmium in aqueous palygorskite, sepiolite, and calcite suspensions: isotherm hysteresis 总被引:2,自引:0,他引:2
Sorption isotherms have been widely used to assess the heavy metal retention characteristics of soil particles. Desorption behavior of the retained metals, however, usually differ from that of sorption, leading to a lack of coincidence in the experimentally obtained sorption and desorption isotherms. In this study, we examine the nonsingularity of cadmium (Cd) sorption–desorption isotherms, to check the possible hysteresis and reversibility phenomena, in aqueous palygorskite, sepiolite and calcite systems. Sorption of Cd was carried out using a 24-h batch equilibration experiment with eight different Cd solution concentrations, equivalent to 20–100% of maximum sorption capacity of each mineral. Immediately after sorption, desorption took place using successive dilution method with five consecutive desorption steps. Both Cd sorption and desorption data were adequately described by Freundlich equation (0.81 < r2 < 0.99). The sorption and desorption reactions, however, did not provide the same isotherms, indicating that hysteresis occurred in Cd sorption–desorption processes. The extent of hysteresis was quantified based on the differences obtained from sorption and desorption isotherms regarding the amount of Cd sorbed, the Freundlich exponent, and the Cd distribution coefficient. The results revealed that, sepiolite possessed the most hysteretic behavior among the minerals studied. Calcite showed much smaller hysteresis compared to the other two silicate clays at low Cd surface load, but its hysteresis indices significantly increased, and exceeded that of palygorskite, as the amount of Cd in the systems increased. The average amount of Cd released after five desorption steps, was 13.8%, 2.2% and 3.6% for the palygorskite, sepiolite and calcite, respectively, indicating that a large portion of Cd was irreversibly retained by the minerals. 相似文献
13.
Shahbazi Mohammadreza Najafi Mehdi Marji Mohammad Fatehi 《Mitigation and Adaptation Strategies for Global Change》2019,24(3):373-398
Mitigation and Adaptation Strategies for Global Change - Underground coal gasification (UCG) is an energy production pathway in underground coal deposits with the potential advantage of decreasing... 相似文献
14.
M. Yavarmanesh M. Abbaszadegan A. Alum A. Mortazavi M. B. Habibi Najafi M. R. Bassami M. R. Nassiri 《Food and environmental virology》2013,5(2):103-109
Noroviruses are responsible for approximately 44 % of outbreaks involving dairy products for which causative agents are reported. Recovery of viruses from milk and dairy products is a difficult task. The role of different components of milk in the recovery of viral RNA was evaluated in this study. Four model milk formulations (A–D) were prepared by mixing different combinations of lactose, whey protein, casein, and fat in water. Each model formulation was spiked with five concentrations of bacteriophage MS2. The phenol-guanidine thiocyanate-chloroform protocol was used for extracting viral RNA from the model milk formulations and then extracted RNA was measured by a nanodrop spectrophotometer in ng/μl. The results showed that casein and whey protein had the highest negative impact on RNA yield, especially when the number of MS2 was less than 1.3 pfu/ml. The highest RNA recovery was obtained from the model milk formulation containing all four components; lactose, whey protein, casein, and fat. The amount of extracted RNA was closely correlated with the dry matter content of each formulation and the spiked concentration of coliphage using response surface modeling (R2:0.93). It was determined that milk fat is the most effective component in facilitating RNA extraction and the highest RNA yield can be achieved via elimination of whey protein and casein from milk by centrifugation at 40,000×g for 60 min. To achieve the highest viral RNA recovery efficiency by the proposed method, milk fat must be recombined with the supernatant of the centrifuged sample and then homogenized before performing the extraction protocol. 相似文献
15.
A novel improved preconcentration method known as rapidly synergistic cloud point extraction (RS-CPE) was established for nickel preconcentration and determination prior to its determination by flame atomic absorption spectrometry. In this work, the traditional CPE pattern was changed and greatly simplified in order to be applicable in metal extraction and detection. This method was accomplished in room temperature in 1 min. Non-ionic surfactant Triton X-114 was used as extractant. Octanol worked as cloud point revulsant and synergic reagent. The various parameters affecting the extraction and preconcentration of nickel such as sample pH, 2,2′-Furildioxime concentration, amounts of octanol, amounts of Triton X-114, type of diluting solvent, extraction time, and ionic strength were investigated and optimized. Under optimal conditions, the calibration curve showed an excellent linearity in the concentration range of 2–200 μg L?1, and the limit of detection was 0.6 μg L?1 for nickel. The developed method was successfully applied for the determination of nickel in food and water samples. The results showed that, the proposed method can be used as a cheap, rapid, and efficient method for the extraction and preconcentration of nickel from real samples. 相似文献
16.
Community attitudes toward forest conservation programs through collaborative protected area management in Bangladesh 总被引:1,自引:0,他引:1
Mohammad Shaheed Hossain Chowdhury Chloe Gudmundsson Shigeyuki Izumiyama Masao Koike Nahid Nazia Md. Parvez Rana Sharif Ahmed Mukul Nur Muhammed Mohammed Redowan 《Environment, Development and Sustainability》2014,16(6):1235-1252
The formulation of conservation policies with options for creating protected areas is significantly influenced by the social factors of the surrounding communities. Therefore, indigenous knowledge, attitudes and perceptions of the local communities need to be explored during the planning and implementation stages of conservation projects. A government-initiated experiment in co-management was conducted in the Rema-Kalenga Wildlife Sanctuary, Bangladesh. This paper analyzes the attitudes toward conservation by members of local communities living in and around the wildlife sanctuary. Training incentives on alternative income-generating (AIG) activities and allotment of agricultural lands were distributed among the Forest User Groups. It is of interest to policy makers and resource managers whether this technique leads to improved attitudes on the part of local people. Although there were different attitudes toward protected areas and conservation, overall, a favorable attitude of the respondents was observed. The opinions of respondents also varied based on factors such as village position, village dependency level on forest resources, ethnicity and gender. Increase in annual income resulting from the augmented skills by trainings on AIG activities and getting agricultural lands leased from the Forest Department contributed significantly to the variation in respondents’ conservation attitudes. It is suggested that eliminating inequity and inequality in incentive distribution, discovering and launching training on more need-based livelihood activities, and liberalizing the restriction of resource extraction from the protected area by fixing the harvesting limit would encourage the community to be more cordially and actively involved in the conservation efforts of the sanctuary. 相似文献
17.
Nahid Akhtar Hidetoshi Inada Taisuke Kondo Ryo Funada 《Environmental pollution (Barking, Essex : 1987)》2010,158(9):2970-2976
To assess the effects of tropospheric O3 on rice cultivated in Bangladesh, four Bangladeshi cultivars (BR11, BR14, BR28 and BR29) of rice (Oryza sativa L.) were exposed daily to charcoal-filtered air or O3 at 60 and 100 nl l−1 (10:00-17:00) from 1 July to 28 November 2008. The whole-plant dry mass and grain yield per plant of the four cultivars were significantly reduced by the exposure to O3. The exposure to O3 significantly reduced net photosynthetic rate of the 12th and flag leaves of the four cultivars. The sensitivity to O3 of growth, yield and leaf gas exchange rates was not significantly different among the four cultivars. The present study suggests that the sensitivity to O3 of yield of the four Bangladeshi rice cultivars is greater than that of American rice cultivars and is similar to that of Japanese rice cultivars and that O3 may detrimentally affect rice production in Bangladesh. 相似文献
18.
19.
Saeed Kazemi Najafi Morteza Mostafazadeh-Marznaki Majid Chaharmahali 《Journal of Polymers and the Environment》2010,18(4):720-726
In this research, the influence of thermo-mechanical degradation of polypropylene (PP) on water absorption and thickness swelling
of beech wood flour–PP composites were studied. For this purpose, a virgin PP was thermo-mechanically degraded by two times
extrusion under controlled conditions. The results showed that the melt flow index, water absorption and thickness swelling
of PP significantly increase by extrusion and re-extrusion. The virgin PP and degraded polypropylene were compounded with
wood flour (at 60% by weight wood flour loading) in a counter-rotating twin-screw extruder in presence or absence of MAPP
to produce wood flour–PP composites. From the results, the composites containing recycled PP exhibited higher water absorption
and thickness swelling. The use of MAPP decreased water absorption and thickness swelling in composites made of virgin or
recycled PP. 相似文献
20.
Study on the conversion of waste plastics/petroleum resid mixtures to transportation fuels 总被引:4,自引:0,他引:4
Mohammad Farhat?AliEmail author Mohammad?Nahid Siddiqui S. Halim Hamid?Redhwi 《Journal of Material Cycles and Waste Management》2004,6(1):27-34
Catalytic coprocessing of model and waste plastics with light Arabian crude oil residue was investigated using NiMo/Al2O3, ZSM-5, FCC, and hydrocracking catalysts. Reaction systems that were studied included low density polyethylene (LDPE), high density polyethylene (HDPE), polystyrene (PS), and polypropylene (PP). A series of single (plastic/catalyst) and binary (plastic/resid/catalyst) reactions were carried out in a 25-cm3 micro autoclave reactor under different conditions of weight and type of catalyst, duration, pressure, and temperature. The optimum conditions selected for our work were: 1% catalyst by weight of total feedstock weight, 60min reaction time, 8.3Mpa of H2, and 430°C. The product distribution for the binary system using plastic and petroleum residue provided some encouraging results. High yields of liquid fuels in the boiling range of 100°–480°C and gases were obtained along with a small amount of heavy oils and insoluble material such as gums and coke. In general, this study helps to demonstrate the technical feasibility of upgrading both waste plastics and petroleum resid, as well as an alternative approach to feedstock recycling. 相似文献