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41.
Synthesis and utilization of a mesoporous nickel oxide as a novel catalyst for degradation of phenol
Mesoporous nickel oxide (MNO) was synthesized by sol–gel method with saponificated chlorophyll-a (Chl-a) as template and Ni (II) acetate as starting material. XRD, surface area, pore volume, pore diameter and pore size distribution of MNO were determined. It exhibited high surface area and uniform pores with very sharp pore size distribution centered at 3.6 nm. High resolution transmission electron microscope images confirmed the results. MNO showed a high activity toward degradation of phenol at low temperature under atmospheric pressure of oxygen. 相似文献
42.
Fazeli-Attar Seyede Azita Mirjalili Bi Bi Fatemeh 《Environmental Chemistry Letters》2018,16(2):671-676
Environmental Chemistry Letters - In the present study, Gum Arabic was used as a metal-free biocatalyst in the synthesis of quinoxaline derivatives through condensation of 1,2-diamines and... 相似文献
43.
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
44.
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
45.
Fatemeh Ganjeizadeh Rohani Vahideh Mahdavi M. Mehdi Aminaei 《Environmental monitoring and assessment》2014,186(7):3995-3999
Pesticides are considered as the most polluting substances. The residue of pesticides in agricultural crops, especially in greenhouse harvests, has been reported critical. Cucumber, considered as a vegetable, is an agricultural product which is commonly found in the Iranian food basket. The current study aims to assess the level of diazinon and oxydemeton-methyl existing in cucumbers sampled from Kerman greenhouses. The pesticide residue was extracted by acetone and dichloromethane. The extracts were cleaned up according to the solid-phase extraction method. The pesticide residues were then determined by capillary gas chromatography with nitrogen-phosphorus detection. The recoveries were 83 and 85 %, the limit of detection was 0.028 and 0.034 mg/kg, and the limits of qualification were 0.093 and 0.113 mg/kg for diazinon and oxydemeton-methyl in cucumber samples, respectively. The median of diazinon residue was detected 0.582 mg/kg, which was 11.64 times the national maximum residue limit (MRL) (0.05 mg/kg), and the median for oxydemeton-methyl was 1.910 mg/kg, being 1.91 times the MRL (1 mg/kg). 相似文献
46.
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
47.
Esmaeildoost Fatemeh Shahrousvand Mohsen Goudarzi Alireza Bagherieh-Najjar Mohammad B. 《Journal of Polymers and the Environment》2022,30(10):4271-4286
Journal of Polymers and the Environment - Semi-interpenetrating networks (semi-IPNs) of Xanthan gum/poly (acrylic acid) containing Cloisite 15A were prepared via radical polymerization using a... 相似文献
48.
Khosravipour Masoud Safari-Faramani Roya Rajati Fatemeh Omidi Fariborz 《Environmental science and pollution research international》2022,29(28):42347-42371
Environmental Science and Pollution Research - Although several studies have investigated the long-term association of respirable particulate matter (PM?≤?10 µm)... 相似文献
49.
Adabavazeh Fatemeh Nadernejad Nazi Pourseyedi Shahram Razavizadeh Roya Mozafari Hossein 《Environmental science and pollution research international》2022,29(39):59027-59042
Environmental Science and Pollution Research - The present study was carried out to elucidate effects of synthesized magnetic nanoparticles (MNPs) on morphological and physiological parameters and... 相似文献
50.
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