Papers by Bahram Ebrahimi
Oriental Journal of Chemistry, 2017
Thermochemical method was used to prepare activated carbon from Kurdistan native acorn as abundan... more Thermochemical method was used to prepare activated carbon from Kurdistan native acorn as abundant raw material. A two steps temperature program was applied for pyrolysis and activation of chemical oxidized raw material in 350 and 700 o C respectively. Surface functional groups were detected in FT-IR spectrum of adsorbent. Also, Formation of uniform porous structure observed in SEM images. Specific surface area (S BET), pore volume (V p) and average pore diameter were determined 520.14 m 2 /g, 0.235 cm 3 /g and 2.8 nm respectively. Effective parameters on batch experiments such as adsorbent dosage, contact time, initial pH and Fe (III) concentration were optimized. Thermodynamic studies showed that the process was spontaneous (∆G 0 <0) and endothermic with high amounts of ∆H 0 and positive ∆S 0. Adsorption of Fe (III) was obeyed from Langmuir model with maximum adsorption capacity 42.12 mg g-1. Pseudo-second order model was best kinetic model (R>0.995) to describe kinetic of adsorption process of Fe (III).
Science Journal of Analytical Chemistry, 2015
Chemical constituents of extracted oil from the nut of Pistacia atlantica kurdica (dried and fres... more Chemical constituents of extracted oil from the nut of Pistacia atlantica kurdica (dried and fresh samples)-which grows in some regions of Kurdistan province in Iran-were extracted by using soxhlet method and analyzed by gas chromatography mass spectrometry. The main goal of this study was qualitative analysis of extracted compounds and optimization of extraction conditions. At three extraction times (7h, 11h and 13h) and with two solvents (n-hexane and methanol), soxhlet extractions were carried out. Extraction time and type of solvents were selected as two important factors. A general full factorial design with selected factors was used. The study reveals that n-hexane extracted more yield than methanol. The highest yield obtained with n-hexane, was 33.59%; while the highest yield obtained by methanol was 3.85%. The results show that when extraction is done by n-hexane, by increasing the extraction time up to 11h, the mass yield percent was also increased. The obtained chromatograms were showed that by increasing the extraction time up to 13h, the main extracted compounds were maintained but compounds with low quantities have been eliminated. The main compounds identified were alpha-pinene, decane, dodecane, tetradecane, hexadecane, palmitic acid, oleic acid and linoleic acid ester. The main identified compounds were nearly similar to dried and fresh samples. This study can be considered as the firs report on the chemical compounds of extracted oil from nut of Pistacia atlantica kurdica in studied region.
Journal of AOAC International
A sensitive and low cost SPE method for the extraction, preconcentration, and flame atomic absorp... more A sensitive and low cost SPE method for the extraction, preconcentration, and flame atomic absorption spectrometric determination of nickel at ng/mL levels is described. Parameters governing the extraction efficiency including pH of the solution, eluent type, sample volume, and matrix ions were investigated for optimization of the presented procedure. The enhancement factor was calculated as 96.5. The calibration curve was linear with R2 of 0.999 in the concentration range from 2 to 200 ng/mL. The RSD was 5.35% (n=7), the LOD was 0.588 ng/mL, and relative recoveries from vegetable samples ranged between 99 and 109.5%.
Journal of the Brazilian Chemical Society, 2013
Este trabalho descreve a determinação de níquel em amostras de alimentos e de água usando microex... more Este trabalho descreve a determinação de níquel em amostras de alimentos e de água usando microextração com agregação induzida à frio e determinação por espectrofotometria UV-Vis. A extração de níquel (II) foi feita na presença de dimetilglioxima (DMG) como agente complexante e hexafluorofosfato de sódio (NaPF6) foi adicionado às amostras contendo pequenas quantidades de 1-hexil-3-metilimidazol hexafluorofosfato [Hmim][PF6] como solvente extrator. Os parâmetros que governam a eficiência da extração, como o líquido iônico, o pH, a temperatura e a força iônica, foram otimizados. O método foi aplicado para a determinação de baixas concentrações de níquel em diferentes tipos de vegetais. Nas condições otimizadas a curva analítica mostrou-se linear no intervalo de concentração de 8-200 ng mL-1 apresentando coeficiente de correlação (r 2) de 0,9996. O limite de detecção (LOD) calculado foi de 0,47 ng mL-1 com fator de enriquecimento de 186. O desvio padrão relativo (RSD) foi de 3,7% para 40 ng L-1 de níquel (n = 10). The determination of nickel in food samples and well water using cold induced aggregation microextraction combined UV-Vis spectrophotometry is described. The extraction of nickel was performed in the presence of dimethylglyoxime (DMG) as the complexing agent. In this method, sodium hexafluorophosphate (NaPF 6) was added to the sample solution containing small amounts of 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF 6 ] as extraction solvent. Parameters governing the extraction efficiency such as amount of ionic liquid, pH, temperature and ionic strength were optimized. The applicability of the technique was evaluated by the determination of trace nickel in different types of vegetables. Under the optimum conditions, the calibration curve was linear in the concentration range 8-200 ng mL-1 with correlation coefficient (r 2) of 0.9996. The limit of detection (LOD) of 0.47 ng mL-1 and enhancement factor of 186 were obtained for nickel. The relative standard deviation (RSD) was 3.7% for 40 ng L-1 nickel (n = 10).
Journal of Chromatography A, 2009
A monolithic ametryn molecular-imprinted polymer based on a simple polymerization method was fabr... more A monolithic ametryn molecular-imprinted polymer based on a simple polymerization method was fabricated for use as new solid-phase microextraction (SPME) fiber, which can be coupled with GC and GC/MS for selective extraction and analysis of triazine herbicides. Methacrylic acid (MAA), ethylene glycol dimethacrylate (EDMA) and ametryn bear role of functional monomer, cross-linker and template, respectively. In the optimized conditions the fabricated fiber showed better molecular recognition abilities for methylthiotriazine herbicides than chloro-triazine herbicides. By use of bi-Langmuir isotherm model the evaluated equilibrium constants for ametryn were 0.01 and 890.69 M −1 , and the numbers of binding sites were 129.98 and 5.82 nmol g −1 , respectively. The high extraction efficiency was obtained for ametryn, prometryn, terbutryn, atrazine, simazine, propazine, and cyanazine, yielding the detection limits of 14, 28, 45, 56, 85, 95 and 74 ng mL −1 , respectively by GC with flame ionization detection. The reliability of the prepared fiber for extraction of ametryn and other analogues in real samples has been investigated and proved by using spiked samples such as tap water, rice, maize, and onion.
Analytica Chimica Acta, 2008
ABSTRACT A simple polymerization strategy has been used to produce a monolithic solid phase micro... more ABSTRACT A simple polymerization strategy has been used to produce a monolithic solid phase micro extraction (SPME) fiber on the basis of molecularly imprinted polymer able to couple with GC and GC-MS for selective extraction and analysis of triazine herbicides. A fiber was produced by copolymerization of methacrylic acid-ethylene glycol dimethacrylate imprinted with atrazine. The effective factors influencing the polymerization have been investigated and are detailed here. At the optimum conditions the prepared fiber is firm, inexpensive, durable and thermally stable up to 280 degrees C which has vital importance in SPME coupled with GC or GC/MS. In addition, the influences of pH, extraction time and temperature on the extraction efficiency of analytes were optimized. Selectivity of prepared fibers in relation to triazine herbicides and some of the other pesticide has been investigated. The high extraction efficiency was obtained for atrazine, simazine, propazine, cyanazine, ametryn, terbutryn and prometryn yielding the detection limits of 20, 70, 80, 81, 69, 88 and 68 ng mL(-1), respectively and the high quantities of recoveries. The reliability of prepared fiber to extraction of atrazine and other analogues in real samples has been investigated and proved by implementation of SPME in spiked samples such as tap water, onion and rice.
Journal of Advances in Environmental Health Research
Background: Bio-remediation methods of organic pollutants are promising due to their high efficie... more Background: Bio-remediation methods of organic pollutants are promising due to their high efficiency, low cost, and green chemistry. These methods are effective alternatives to traditional elimination methods. Methods: Bacillus cereus PTCC 1015S strain was used to eliminate acid blue 113 (AB113) and acid orange 7 (AO7) from aqueous solutions. The bacteria were activated in the Luria Bertani Broth (MILLER) culture medium. The effective parameters such as incubation time and temperature, pH of dye solution, dye concentration, and the bacterial inoculation quantity on decolorization were investigated. Kinetic and thermodynamic studies were done to clarify the different aspects of the introduced method. Also, the reliability of the method to remove studied dyes was investigated in dye factory wastewater samples. Results: The first-order kinetic model was the best model to describe the kinetics of decolorization. The obtained thermodynamic data showed that the elimination process was end...
Journal of Advances in Environmental Health Research (JAEHR), 2023
Background: Bio-remediation methods of organic pollutants are promising due to their high efficie... more Background: Bio-remediation methods of organic pollutants are promising due to their high efficiency, low cost, and green chemistry. These methods are effective alternatives to traditional elimination methods.
Methods: Bacillus cereus PTCC 1015S strain was used to eliminate acid blue 113 (AB113) and acid orange 7 (AO7) from aqueous solutions. The bacteria were activated in the Luria Bertani Broth (MILLER) culture medium. The effective parameters such as incubation time and temperature, pH of dye solution, dye concentration, and the bacterial inoculation quantity on decolorization were investigated. Kinetic and thermodynamic studies were done to clarify the different aspects of the introduced method. Also, the reliability of the method to remove studied dyes was investigated in dye factory wastewater samples.
Results: The first-order kinetic model was the best model to describe the kinetics of decolorization. The obtained thermodynamic data showed that the elimination process was endothermic (ΔH0 = + 29.03, 30.53) while it was spontaneous (ΔG0 < 0) for both studied dyes and so entropy change (ΔS0 = + 109.63, 116.32) was an effective force in the decolorization. Under optimized conditions, B. cereus PTCC 1015S showed high average removal; 98.5 and 99.3 % for AB113 and AO7 respectively in dye model solutions. The removal efficiency was more than 85 % for both
studied dyes in wastewater spiked samples.
Conclusions: The B. cereus PTCC 1015 strain was capable of being exploited in the removal of AB113 and AO7 dye molecules as an affordable and eco-amiable method for the treatment of aqueous samples contaminated with the studied azo dyes.
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Papers by Bahram Ebrahimi
Methods: Bacillus cereus PTCC 1015S strain was used to eliminate acid blue 113 (AB113) and acid orange 7 (AO7) from aqueous solutions. The bacteria were activated in the Luria Bertani Broth (MILLER) culture medium. The effective parameters such as incubation time and temperature, pH of dye solution, dye concentration, and the bacterial inoculation quantity on decolorization were investigated. Kinetic and thermodynamic studies were done to clarify the different aspects of the introduced method. Also, the reliability of the method to remove studied dyes was investigated in dye factory wastewater samples.
Results: The first-order kinetic model was the best model to describe the kinetics of decolorization. The obtained thermodynamic data showed that the elimination process was endothermic (ΔH0 = + 29.03, 30.53) while it was spontaneous (ΔG0 < 0) for both studied dyes and so entropy change (ΔS0 = + 109.63, 116.32) was an effective force in the decolorization. Under optimized conditions, B. cereus PTCC 1015S showed high average removal; 98.5 and 99.3 % for AB113 and AO7 respectively in dye model solutions. The removal efficiency was more than 85 % for both
studied dyes in wastewater spiked samples.
Conclusions: The B. cereus PTCC 1015 strain was capable of being exploited in the removal of AB113 and AO7 dye molecules as an affordable and eco-amiable method for the treatment of aqueous samples contaminated with the studied azo dyes.
Methods: Bacillus cereus PTCC 1015S strain was used to eliminate acid blue 113 (AB113) and acid orange 7 (AO7) from aqueous solutions. The bacteria were activated in the Luria Bertani Broth (MILLER) culture medium. The effective parameters such as incubation time and temperature, pH of dye solution, dye concentration, and the bacterial inoculation quantity on decolorization were investigated. Kinetic and thermodynamic studies were done to clarify the different aspects of the introduced method. Also, the reliability of the method to remove studied dyes was investigated in dye factory wastewater samples.
Results: The first-order kinetic model was the best model to describe the kinetics of decolorization. The obtained thermodynamic data showed that the elimination process was endothermic (ΔH0 = + 29.03, 30.53) while it was spontaneous (ΔG0 < 0) for both studied dyes and so entropy change (ΔS0 = + 109.63, 116.32) was an effective force in the decolorization. Under optimized conditions, B. cereus PTCC 1015S showed high average removal; 98.5 and 99.3 % for AB113 and AO7 respectively in dye model solutions. The removal efficiency was more than 85 % for both
studied dyes in wastewater spiked samples.
Conclusions: The B. cereus PTCC 1015 strain was capable of being exploited in the removal of AB113 and AO7 dye molecules as an affordable and eco-amiable method for the treatment of aqueous samples contaminated with the studied azo dyes.