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مرکز اطلاعات علمی SID1
مرکز اطلاعات علمی SID
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
نویسندگان: 

SAMIMI S.V. | AKBARIRAD R. | GHANIZADEH F.

اطلاعات دوره: 
  • سال: 

    2009
  • دوره: 

    6
  • شماره: 

    1
  • صفحات: 

    47-52
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    20057
  • دانلود: 

    11670
چکیده: 

Tehran as the biggest city of Iran with a population of more than 10 millions has potentially high pollutant exposures of gas oil and gasoline combustion from vehicles that are commuting in the highways every day. The vehicle exhausts contain polycyclic aromatic hydrocarbons, which are produced by incomplete combustion and can be directly deposited in the environment. In the present study, the presence of polycyclic aromatic hydrocarbons contamination in the collected samples of a western highway in Tehran was investigated. The studied location was a busy highway in Tehran. High performance liquid chromatography equipped with florescence detector was used for determination of polycyclic aromatic hydrocarbons concentrations in the studied samples. Total concentration of the ten studied polycyclic aromatic hydrocarbons compounds ranged from 11107 to 24342 ng/g dry weight in the dust samples and increased from 164 to 2886 ng/g dry weight in the soil samples taken from 300 m and middle of the highway, respectively. Also the average of Σ PAHs was 1759 ng/L in the water samples of pools in parks near the highway. The obtained results indicated that polycyclic aromatic hydrocarbons contamination levels were very high in the vicinity of the highway.

آمار یکساله:  

بازدید 20057

دانلود 11670 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    43
  • شماره: 

    SUPPLEMENT 2
  • صفحات: 

    131-131
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    12562
  • دانلود: 

    9450
چکیده: 

Background: Here we studied the dynamics of the bacterial community, the number of heterotrophs and PAH degraders, during the bioremediation process of PAHs in presence and abcense of hexadecane.Methods: Three microcosms prepared using soil sample gathered from KhangIran, khorasan Province Iran, The polluted soil microcosm was constructed by addition of phenantherene, antheracene, pyrene and fluoranthene to the soil, each in 50 ppm concentration with 1% hexadecane (MH microcosm) and the other one without hexadecane (M microcosm). Apparently non-polluted soil of the region was used as control (C microcosm). The microcosms were amended with additional nitrogen and phosphate sources. Humidity and PAHs degradation were monitored in monthly intervals over a six months period. PAHs and hexadecane degradation was monitored by HPLC and GC respectively and the bacterial number assessed by plate count method.Results: At the first point the number of bacteria is almost the same in all of the three microcosms, but after 8 weeks the number of bacteria in the MH microcosm (1.85×107 per gram soil) was 15 times greater than M microcosm and 90 times greater than C microcosm. HPLC analysis showed increased PAHs degradation in MH microcosm, i.e. almost 1.5 times greater than M microcosm. During the bioremediation process more than 70% of initial concentration of phenanthrene and Pyrene were disappeared.Conclusion: The findings revealed that PAHs degradation is significantly increased in the presence of hexadecane likely due to increasing the bioavailabilty of PAHs and number of oil degraders by hexadecane.

آمار یکساله:  

بازدید 12562

دانلود 9450 استناد 0 مرجع 0
نویسندگان: 

OWABOR C.N. | OGBEIDE S.E. | SUSU A.A.

اطلاعات دوره: 
  • سال: 

    2010
  • دوره: 

    4
  • شماره: 

    4
  • صفحات: 

    807-816
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    18034
  • دانلود: 

    14628
چکیده: 

The solutions of mathematical models for the estimation of the kinetic, and biokinetic parameters of naphthalene, anthracene and pyrene during degradation in surface and subsurface soils are presented in this work. The models were developed using the twin concepts of rate-determining step and steady-state approximation method. They described the biodegradation of single and a mixture of polycyclic aromatic hydrocarbons. Prediction of the concentration of the reactive PAHs with time was aided by fitting the models to the experimental data obtained from a soil microcosm reactor. Given an initial concentration of 100mg/L, approximately 2.9%, 1.9% and 1.4% of naphthalene, pyrene and anthracene present in the microcosm reactor at zero time were found to be utilized in a minute when the velocity of the reaction remained constant for the period. The rate-determining step model gave a better fit as its reaction rate constant (k) closely fitted the experimental values. Prediction by the steady state approximation model was not feasible as a comparative analysis of both single and multisubstrate results showed that the steady state approximation overestimates the biodegradation rates. Using the relative error method, results indicated that the rate-determining step model showed a deviation of 7.5%. The rate-determining step model was chosen because the differences in the model fits were small and its prediction of mixture experiment was more enhanced.

آمار یکساله:  

بازدید 18034

دانلود 14628 استناد 0 مرجع 0
گارگاه ها آموزشی
اطلاعات دوره: 
  • سال: 

    2000
  • دوره: 

    66
  • شماره: 

    -
  • صفحات: 

    1834-1834
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    3832
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 3832

دانلود 9195 استناد 315 مرجع 0
نویسندگان: 

VINAS M. | SABATE J.

اطلاعات دوره: 
  • سال: 

    2005
  • دوره: 

    71
  • شماره: 

    11
  • صفحات: 

    7008-7018
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    5556
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 5556

دانلود 9195 استناد 315 مرجع 0
اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    11
  • شماره: 

    8
  • صفحات: 

    0-0
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    19471
  • دانلود: 

    9450
چکیده: 

Traffic is one of the prominent sources of polycyclic aromatic hydrocarbons (PAHs), and road surfaces are the most critical platform for stormwater pollution. Build-up of pollutants on road surfaces was the focus of this research study. The study found that PAHs build-up on road surfaces primarily originate from traffic activities, specifically gasoline powered vehicles. Other sources such as diesel vehicles, industrial oil combustion and incineration were also found to contribute to the PAH build-up. Additionally, the study explored the linkages between concentrations of PAHs and traffic characteristics such as traffic volume, vehicle mix and traffic flow. While traffic congestion was found to be positively correlated with 6-ring and 5-ring PAHs in road build-up, it was negatively correlated with 3-ring and 4 ring PAHs. The absence of positive correlation between 3-ring and 4-ring PAHs and traffic parameters is attributed to the propensity of these relatively volatile PAHs to undergo re-suspension and evaporation. The outcomes of this study are expected to contribute to effective transport and land use planning for the prevention of PAH pollution in the urban environment.

آمار یکساله:  

بازدید 19471

دانلود 9450 استناد 0 مرجع 0
strs
نویسندگان: 

ARULAZHAGAN P. | VASUDEVAN N. | YEOM I.T.

اطلاعات دوره: 
  • سال: 

    2010
  • دوره: 

    7
  • شماره: 

    4 (28)
  • صفحات: 

    639-652
تعامل: 
  • استنادات: 

    2275
  • بازدید: 

    36087
  • دانلود: 

    27570
چکیده: 

The biodegradability of polycyclic aromatic hydrocarbons such as naphthalene, fluorene, anthracene and phenanthrene by a halotolerant bacterial consortium isolated from marine environment was investigated. The polycyclic aromatic hydrocarbons degrading bacterial consortium was enriched from mixture saline water samples collected from Chennai (Port of Chennai, salt pan), India. The consortium potently degraded polycyclic aromatic hydrocarbons (>95%) at 30g/L of sodium chloride concentration in 4 days. The consortium was able to degrade 39 to 45% of different polycyclic hydrocarbons at 60 g/L NaCl concentration. Due to increase in salinity, the percent degradation decreased. To enhance polycyclic aromatic hydrocarbons degradation, yeast extract was added as an additional substrate at 60g/L NaCl concentration. After the addition of yeast extract, the consortium degraded>74 % of polycyclic aromatic hydrocarbons at 60 g/L NaCl concentration in 4 days. The consortium was also able to degrade PAHs at different concentrations (5, 10, 20, 50 and 100 ppm) with 30g/L of NaCl concentration. The polycyclic aromatic hydrocarbons degrading halotolerant bacterial consortium consists of three bacterial strains, namely Ochrobactrum sp., Enterobacter cloacae and Stenotrophomonas maltophilia.

آمار یکساله:  

بازدید 36087

دانلود 27570 استناد 2275 مرجع 6660
نویسندگان: 

SHAFIEE P. | SHOJA ALSADATI S.A. | CHARKHABI A.H.

اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    25
  • شماره: 

    3
  • صفحات: 

    73-78
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    23542
  • دانلود: 

    16944
چکیده: 

In this study, the degradation potential of five polycyclic aromatic hydrocarbons (PAHs) by aerobic mixed bacterial cultures was investigated. Microorganisms were isolated from hydrocarbon contaminated soils of Shade an wetland located in southwest of Iran. The degradation experiments were conducted in liquid cultures. PAH or PAHs concentration was 100 mg/L at the beginning of degradation experiments. After ten days incubation, the mixed culture was capable of degrading phenanthrene completely and anthracene 80%, pyrene 60%, fluorine 30%, and fluoranthene 20%, individually. Optimal temperature and pH were as 30 °C and 7.0 respectively. Results showed that in samples containing a mixture of the five PAHs, fluoranthene could degrade cometabolically and the rate of degradation increased from 20 to 44%. It was observed also that PAHs degradation could be enhanced by the individual addition of yeast extract or glucose. The isolated mixed culture is valuable in bioremediation of PAH-contaminated environments.

آمار یکساله:  

بازدید 23542

دانلود 16944 استناد 0 مرجع 2835
اطلاعات دوره: 
  • سال: 

    2005
  • دوره: 

    0
  • شماره: 

    4
تعامل: 
  • بازدید: 

    2310
  • دانلود: 

    0
کلیدواژه: 
چکیده: 

One of the major environmental pollutant has been stated frequently by many researchers is PAH. Currently, potential interest for biodegradation was vastly developed. Therefore, acute toxic responses may cause liver damage or dermatitis was reported. The derivatives of PAH compounds, which are more water soluble and reactive, may easily bind to protein, DNA, and other macromolecules, leading to cell damage, mutagenesis, or possible of the stomach, lung, and skin cancers. In points of view of human being, the goal of biodegradation is the protection of global environment and preservation of biodiversity. Also, in eyes of environmental scientist, biodegradation prescribes medicine for healthy environment. The purpose of this study is to demonstrate a potential mixed culture to degrade on high concentration of phenanthrene as sole carbon and energy source. Batch culture by induction of mineral salt medium, the seeding contained phenanthrene, and the biodegradation was monitored for the incubation period of 7 days. Throughout the experiments, samples for determination of phenanthrene were analyzed using GC-FID with capillary column. Kinetic model related to biodegradation of PAH were obtained for microbial growth and utilization of phenanthrene was defined based on modified Monod rate model.

آمار یکساله:  

بازدید 2310

دانلود 0
نویسندگان: 

NNAMCHI C.I. | OBETA J.A.N. | EZEOGU L.I.

اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    3
  • شماره: 

    2
  • صفحات: 

    181-190
تعامل: 
  • استنادات: 

    910
  • بازدید: 

    32445
  • دانلود: 

    19047
چکیده: 

Twenty-four bacteria capable of utilizing naphthalene, as their sole source of carbon and energy for growth were isolated from three different sites in Nsukka, Nigeria. By standard bacteriological methods, these bacteria were characterized taxonomically as belonging to the genus Pseudomonas, Burkholderia or Actinomycetes. Two of the isolates, which showed the highest growth during screening as demonstrated by an increase in their optical densities (OD600) and identified as Pseudomonas aeruginosa and Burkholderia cepacia respectively, were also able to grow in anthracene and carbazole, but not very much so in 2,4-dichlorophenol and D-camphor. The isolates showed a concentration-dependent growth in all the compounds they grew in. There were visible changes in the colour of the growth medium of the isolates during their incubation, suggesting the production of different metabolites. There were also changes in their medium pH during growth. These studies demonstrate the possession by the bacterial species of novel degradative systems.

آمار یکساله:  

بازدید 32445

دانلود 19047 استناد 910 مرجع 0
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