در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Progress in Biological Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Taguchi Method,Decolorization,Azo dye,halophilic bacteria,media optimization
- چکیده:
- چکیده انگلیسی: Halophilic and halotolerant microorganisms are good candidates for decolorization of azo dyes
which are routinely used in the dyeing process in textile industries. In this paper, the
optimization of biological decolorization of synthetic dye solutions containing Remazol Black B
by the previously isolated halophilic bacterium Halomonas sp. D2 is investigated. In a primary
investigation using a one-factor–at-a-time method, temperature, initial pH of the solution, and
concentrations of glucose, yeast extract, and sodium chloride were chosen for optimizing dye
removal using the Taguchi method. Based on the statistical analysis of the results, the most
significant parameter by far was the yeast extract concentration which accounted for 72.67% of
the total effect, followed by pH (11.84%) and the NaCl concentration (8.90%). The optimized
conditions for dye removal were predicted to be a temperature of 35°C, an initial pH of 10,
glucose concentration of 1% (w/v), yeast extract concentration of 1% (w/v), and sodium
chloride of 10% (w/v). Under these conditions, 95% decolorization was achieved in confirming
experiments.- انتشار مقاله: 09-09-1392
- نویسندگان: Sedigheh Asad,Seyed Mohammad Mehdi Dastgheib,Mohammad Ali Amoozegar
- مشاهده
- جایگاه : پژوهشی
- مجله: Progress in Biological Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Taguchi Method,Decolorization,Azo dye,halophilic bacteria,media optimization
- چکیده:
- چکیده انگلیسی: Halophilic and halotolerant microorganisms are good candidates for decolorization of azo dyes
which are routinely used in the dyeing process in textile industries. In this paper, the
optimization of biological decolorization of synthetic dye solutions containing Remazol Black B
by the previously isolated halophilic bacterium Halomonas sp. D2 is investigated. In a primary
investigation using a one-factor–at-a-time method, temperature, initial pH of the solution, and
concentrations of glucose, yeast extract, and sodium chloride were chosen for optimizing dye
removal using the Taguchi method. Based on the statistical analysis of the results, the most
significant parameter by far was the yeast extract concentration which accounted for 72.67% of
the total effect, followed by pH (11.84%) and the NaCl concentration (8.90%). The optimized
conditions for dye removal were predicted to be a temperature of 35°C, an initial pH of 10,
glucose concentration of 1% (w/v), yeast extract concentration of 1% (w/v), and sodium
chloride of 10% (w/v). Under these conditions, 95% decolorization was achieved in confirming
experiments.- انتشار مقاله: 09-09-1392
- نویسندگان: Sedigheh Asad,Seyed Mohammad Mehdi Dastgheib,Mohammad Ali Amoozegar
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Biotechnology
- نوع مقاله: Journal Article
- کلمات کلیدی: Bioremediation,Diesel,Mud pit,Microflora,Nutrient optimization,Oil-based drilling
- چکیده:
- چکیده انگلیسی: Background: Petroleum drilling and exploration operations generate a significant amount of oily wastes. Comparing with physical and chemical remediation methods, bioremediation is cost-effective, highly efficient, and environment-friendly technology.
Objectives: The aim of this study was to evaluate biological treatment efficiency for an oil-contaminated soil prepared from an abandoned drilling mud pit located in the Khangiran region , Khorasan Razavi Provinvce, Iran.
Materials and Methods: Following chemical analysis of the contamination, isolation and phylogenetic analysis of the predominant hydrocarbon-utilizing bacteria were performed in order to elucidate microbial diversity. Afterwards, the full factorial design was used to optimize the concentration of nitrogen (0, 100, 250, and 500 ppm) and phosphate (0, 10, 25, and 50 ppm) in the soil. The prepared microcosms were incubated at 30 °C for a 60-day period. The total heterotrophic bacterial content was enumerated during bioremediation process. The total petroleum hydrocarbon concentration was analyzed after 60 days to evaluate biodegradation extent.
Results: The mud pit was mainly contaminated with the weathered diesel compounds ranging from C12 to C30. Investigation of the indigenous microflora showed that a variety of hydrocarbon-utilizing bacteria were present in the untreated soil dominated by Actinobacteria including the genera Gordonia, Nocardia, Nocardioides, and Rhodococcus. The full-factorial soil microcosms’ nutrient optimization indicated that nitrogen amendment could be the most effective at 250 ppm, while excess nitrogen would lead to a diminished microbial activity. The main effect statistical analysis demonstrated that addition of phosphate did not cause a significant improvement in the remediation process. In the optimal nutrient conditions, the total microbial count increased from 1.76 × 107 CFU.g-1 to 1.24 × 109 CFU.g-1 and led into 75.4 % w/w biodegradation in two months, while in the control microcosm without nutrient amendment only 36.6 % of the depletion was observed.
Conclusions: These results indicate that biostimulation could be a promising candidate for a successful field-scale bioremediation process in the studied drilling mud pit.- انتشار مقاله: 22-03-1394
- نویسندگان: Masumeh Shaeyan,Hassan Tirandaz,Somayeh Ghanbarpour,Nasim Seyedipour,Mahmoud Shavandi,Seyed Mohammad Mehdi Dastgheib
- مشاهده
- جایگاه : پژوهشی
- مجله: Environmental Energy and Economic Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Air pollution,VOCs,Photocatalysis,Ethylbenzene,Annular Photoreactor
- چکیده:
- چکیده انگلیسی: The contaminated environment by various pollutants in the last decades is a serious concern for the governments and human societies all over the world. Volatile Organic Compounds (VOCs), emitted from a wide range of industries, are among such pollutants which can easily move in the air due to their volatile nature and are toxic and harmful to the environment and human health. Removal of gaseous ethylbenzene as an aromatic VOC using photocatalytic oxidation in an annular photoreactor packed with TiO2 nanoparticle-coated glass beads has been investigated in this research. The TiO2 nano-catalysts were characterized by XRD and FE-SEM. The removal efficiencies of about 75-100% could be yielded for the initial ethylbenzene concentrations up to 0.6 g/m3 in the UV irradiated reactor at a relatively low residence time. The inlet flow rate and initial ethylbenzene concentration were effective parameters on the removal efficiency and their increase caused reduction of removal efficiency. CO2 production in the photoreactor showed the mineralization of the pollutant during photocatalytic decomposition of ethylbenzene.
- انتشار مقاله: 29-05-1397
- نویسندگان: Morteza Kamaei,Hamid Rashedi,Seyed Mohammad Mehdi Dastgheib,Saeideh Tasharrofi
- مشاهده