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متن کامل


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

ROMANKEVICH O.V. | RED KO Y.V.

نشریه: 

FIBRE CHEMISTRY

اطلاعات دوره: 
  • سال: 

    2006
  • دوره: 

    38
  • شماره: 

    2
  • صفحات: 

    155-157
تعامل: 
  • استنادات: 

    315
  • بازدید: 

    6175
  • دانلود: 

    9195
کلیدواژه: 
چکیده: 

آمار یکساله:  

بازدید 6175

دانلود 9195 استناد 315 مرجع 0
نویسندگان: 

NOUNOU M. | NOUNOU H.N.

اطلاعات دوره: 
  • سال: 

    2010
  • دوره: 

    7
  • شماره: 

    3 (27)
  • صفحات: 

    1735-1472
تعامل: 
  • استنادات: 

    455
  • بازدید: 

    34275
  • دانلود: 

    28659
چکیده: 

adsorption plays an important role in water and wastewater treatment. The analysis and design of processes that involve adsorption rely on the availability of isotherms that describe these adsorption processes. adsorption isotherms are usually estimated empirically from measurements of the adsorption process variables. Unfortunately, these measurements are usually contaminated with errors that degrade the accuracy of estimated isotherms. Therefore, these errors need to be filtered for improved isotherm estimation accuracy. Multiscale wavelet based filtering has been shown to be a powerful filtering tool. In this work, multiscale filtering is utilized to improve the estimation accuracy of the Freundlich adsorption isotherm in the presence of measurement noise in the data by developing a multiscale algorithm for the estimation of Freundlich isotherm parameters. The idea behind the algorithm is to use multiscale filtering to filter the data at different scales, use the filtered data from all scales to construct multiple isotherms and then select among all scales the isotherm that best represents the data based on a cross validation mean squares error criterion. The developed multiscale isotherm estimation algorithm is shown to outperform the conventional time-domain estimation method through a simulated example.

آمار یکساله:  

بازدید 34275

دانلود 28659 استناد 455 مرجع 2664
نویسندگان: 

SUBRAMANYAM B. | ASHUTOSH D.

اطلاعات دوره: 
  • سال: 

    2012
  • دوره: 

    6
  • شماره: 

    1
  • صفحات: 

    265-276
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    18758
  • دانلود: 

    19369
چکیده: 

Liquid-phases adsorption equilibrium of phenol onto two naturally available soils namely Kalathur soil (Kr) and Adhanur soil (Ar) were studied. The experimental data were analyzed using fourteen isotherm models, ranging from single-parametric model to multi-parametric models (up to 5 parameters) of the system. Results show that in general the accuracy of models to fit experimental data improves with the degree of freedom. To understand the mechanism involved with different types of sorbate-sorbent system as well as to find out the best fitting isotherm model, the correlation coefficients, and average percentage error and student t-test were carried out. Temkin isotherm model, Langmuir-Freundlich isotherm model and Fritz-Schlunder model as well as Baudu model were found to be the best fit models amongst the two-parametric models, three parametric models and four parametric isotherms modeling, respectively. This study brings out the need of simultaneous solution of multi-parametric equations (using relevant softwares, MATLAB, in present case) than solution of their linearized forms, which is mostly followed by contemporary investigators.

آمار یکساله:  

بازدید 18758

دانلود 19369 استناد 0 مرجع 0
گارگاه ها آموزشی
نویسندگان: 

AL ANBER M.A.

اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    12
  • شماره: 

    1
  • صفحات: 

    0-0
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    20031
  • دانلود: 

    9450
چکیده: 

The removing of ferric ions (Fe3+) from aqueous solution using natural feldspar (NF) has been studied in a batch operation mode. The factors affecting of the sorption equilibrium, such as contact time, initial concentration of the ferric ions (Fe3+), feldspar dosage concentration and temperature, were investigated. The maximum removal is 93 % (approx.) using low-level concentration of Fe3+ions (30 mg L-1) and high dosage concentration (40 g L-1). The adsorption equilibrium is achieved during the first 90 min. Freundlich model has successfully analyzed the equilibrium of isotherms with R 2 = 1. The adsorption mechanism of aqueous ferric ion on NF follows Freundlich isotherm models (R 2 = 0.997). The capacity (K f) and intensity (1/n) of Freundlich adsorption are 1.70 and 0.621, respectively. The results reveal that the adsorption mechanism of ferric ion on NF is chemisorptions, heterogeneous multilayer and spontaneous in nature (DG = -19.778 kJ mol-1). adsorption reaction kinetic models, such as pseudo-first order and pseudo-second order, and adsorption diffusion model, such as Weber-Morris intraparticle diffusion model, have been used to describe the adsorption rate and mechanism of the ferric ion onto NF surface. adsorption of ferric ion on the NF has achieved Lagergren pseudo-second-order model (R 2 = 1.0 approx.) more than Lagergren pseudo-first-order model. The kinetic parameters, rate constant and sorption capacities have been calculated. The new information in this study suggests that NF could be used as a novel filtering materials for removing ferric ions from water.

آمار یکساله:  

بازدید 20031

دانلود 9450 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2008
  • دوره: 

    5
  • شماره: 

    4
  • صفحات: 

    49-55
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    17951
  • دانلود: 

    9450
چکیده: 

The optimization of adsorption-based operations requires an accurate model to represent the separation process. In the present study, single-component adsorption data of L-lysine on its imprinted polymer were fitted to Freundlich, Langmuir-type and Jovanovic-type models. L-Lysine imprinted polymer (LLIP) was prepared by free radical solution polymerization. The best estimate of the parameters of these models by regression analysis was obtained. The statistical analysis of results showed that the experimental data fit the Jovanovic-Freundlich mode, better than other models in terms off value. The best prediction of retention capacity equal to 0.186 mmol lysine per g of LLIP, which is the nearest value to the experimental data, was obtained by applying the Jovanovic model.

آمار یکساله:  

بازدید 17951

دانلود 9450 استناد 0 مرجع 0
اطلاعات دوره: 
  • سال: 

    2014
  • دوره: 

    0
  • شماره: 

    8
تعامل: 
  • بازدید: 

    1050
  • دانلود: 

    0
چکیده: 

THE adsorption CAPACITY OF CEPHALEXIN WAS DETERMINED ON WALNUT SHELL ACTIVATED CARBON. THE WALNUT SHELL ACTIVATED CARBON WAS PRODUCED USING CHEMICAL ACTIVATION METHOD IN THE PRESENCE OF ZNCL2. EQUILIBRIUM adsorption CAPACITIES RANGING FROM 195.79 TO 265.34 MG.G-1 WERE OBTAINED (AT 30OC AND PH=6).THE LANGMUIR AND FREUNDLICH isothermS WERE USED IN ORDER TO DESCRIBE THE adsorption EQUILIBRIUM. LUNGMUIR isotherm REVEALED THE BEST FIT FOR THE EXPERIMENTAL DATA. IT WAS OBSERVED THAT THE MAXIMUM adsorption CAPACITY WAS 270.27 MG.G-1. IT CAN BE CONCLUDED THAT WALNUT SHELL ACTIVATED CARBON CAN BE AN EFFECTIVE ADSORBENT FOR THE REMOVAL OF CEPHALEXIN FROM AQUEOUS SOLUTION.

آمار یکساله:  

بازدید 1050

دانلود 0
strs
نویسندگان: 

مرادی امید | زارع کریم

اطلاعات دوره: 
  • سال: 

    1390
  • دوره: 

    21
  • شماره: 

    80 (ویژه نامه شیمی)
  • صفحات: 

    41-50
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    534
  • دانلود: 

    279
چکیده: 

  لطفا برای مشاهده چکیده به متن کامل (PDF) مراجعه فرمایید.

آمار یکساله:  

بازدید 534

دانلود 279 استناد 0 مرجع 0
نویسندگان: 

SARVANI RAMIN | DAMANI ELHAMH | AHMADI SHAHIN

اطلاعات دوره: 
  • سال: 

    2018
  • دوره: 

    6
  • شماره: 

    1
  • صفحات: 

    33-42
تعامل: 
  • استنادات: 

    0
  • بازدید: 

    18887
  • دانلود: 

    18718
چکیده: 

Background and purpose: Phenol is an aromatic hydrocarbon and one of the banzan derivatives which has a higher dissolution rate in water. Therefore, it must be removed for water pollution prevention. The aim of this study was to investigate the possibility of Pistaciamuticabio mass as an alternative adsorbent for phenol removal from aqueous solution.Materials and Methods: The effect of various parameters including contact time (10-102 min), pH (2-8), adsorbent dosage (0.4-1.5g/L), phenol concentration (50-150mg/L) were investigated in this experimental-lab study. Also, the isotherm and kinetic investigations were performed for phenol adsorption process. The adsorption equilibriums were analyzed by Langmuir, Temkin, Freundlich and Harkins Jura isotherm models.Results: It was found that the data fitted to Langmuir (R2=0.98) better than other isotherm models.Batch kinetic experiments showed that the adsorption followed Pseudo second-order kinetic model with correlation coefficients greater than 0.998.Conclusion: It was revealed that P. mutica was not only an inexpensive absorbent, but also a quite effective factor in removal of phenol from water and wastewater.

آمار یکساله:  

بازدید 18887

دانلود 18718 استناد 0 مرجع 3108
اطلاعات دوره: 
  • سال: 

    2012
  • دوره: 

    12
  • شماره: 

    1
  • صفحات: 

    45-53
تعامل: 
  • استنادات: 

    455
  • بازدید: 

    50444
  • دانلود: 

    28352
چکیده: 

Background: Hexavalent chromium (Cr (VI)) is an important contaminant in surface and groundwater and its removal from contaminated water and wastewater has received interest in recent years. This study aimed to explain the removal process of Cr (VI) from aqueous solution using nano hydroxyapatite (n-HAp) as an adsorbent material.Methods: Cr (VI) removal experiments with the prepared n-HAp were carried out as the batch test in 100 ml flask while agitating on the shaker. The influence of pH (3 to11), contact time (3-60 min), Cr (VI) concentration (1 to 2 mg/L) and adsorbent dosage (0.025 to 1 g/L) were explored. Three isotherms models and eight kinetics models were used to evaluate the experimental data, respectively. For validation of kinetic and isotherm data, correlation coefficient, sum of square errors (SSE) and normalized deviation were used.Results: The removal efficiency of Cr (VI) was improved an increase in Cr (VI) and n-HAp concentration. The results best fitted with Langmuir model and the pseudo-second-order rate reaction. Analysis of data with Dubinin-Radushkevich isotherm showed that the adsorption of Cr (VI) onto synthetic n- HAp is a chemisorption process.Conclusion: The n-HAp as an ecofriendly compound is effective adsorbent for the removal of Cr (VI) from aqueous solution. Accordingly, n-HAp is feasible and promise adsorbent for treating polluted Cr (VI) groundwater.

آمار یکساله:  

بازدید 50444

دانلود 28352 استناد 455 مرجع 0
نویسنده: 

REZAIE S. | SHOKRI M.

اطلاعات دوره: 
  • سال: 

    2015
  • دوره: 

    0
  • شماره: 

    7
تعامل: 
  • بازدید: 

    1260
  • دانلود: 

    0
چکیده: 

SULFUR COMPOUNDS ARE THE MOST COMMON IMPURITIES PRESENT IN THE CRUDE OIL. SULFUR IN LIQUID FUEL OIL LEADS DIRECTLY TO THE EMISSION OF SO2 AND SULFATE PARTICULATE MATTER (SPM) THAT ENDANGERS PUBLIC HEALTH AND COMMUNITY PROPERTY; AND REDUCES THE LIFE OF THE ENGINE DUE TO CORROSION [1]. THE REMOVAL OF SULFUR FROM PETROLEUM IS ALSO NECESSARY FROM INDUSTRIAL POINT OF VIEW. adsorption PROCESSES ARE SOME OF THE MOST ECONOMICALLY ATTRACTIVE DESULFURIZATION METHODS THAT HAVE THE POTENTIAL TO PRODUCE ULTRA-CLEAN FUELS. ACTIVATED CARBONS (ACS) DUE TO THEIR LOW COST, HIGH SURFACE AREA, THERMAL AND CHEMICAL STABILITY UNDER ANOXIC CONDITIONS, RECEPTIVITY FOR MODIFICATION, AND HIGH AFFINITY TOWARD adsorption OF AROMATIC AND REFRACTORY SULFUR COMPOUNDS HAVE BEEN EXTENSIVELY STUDIED FOR THE REMOVAL OF SULFUR COMPOUNDS FROM DIFFERENT FUELS [2]. IN THE PRESENT WORK, adsorption OF REFRACTORY THIOPHENIC SULFUR COMPOUND, DIBENZOTHIOPHENE (DBT) FROM ISO-OCTANE SOLUTIONS ONTO ACTIVATED CARBONS AT ROOM TEMPERATURE WAS INVESTIGATED. WE ALSO STUDIED THE KINETICS AND isotherm MODELS OF THE adsorption OF DBT ON ACTIVATED CARBON AT DIFFERENT INITIAL DBT CONCENTRATIONS (100-500 PPM). RESULTS OBTAINED FROM adsorption isotherm MODELS INDICATED THAT LANGMUIR adsorption isotherm MODEL BEST DESCRIBED THE DBT adsorption PROCESS. KINETIC isotherm RESULTS DEMONSTRATED THAT THE adsorption OF DBT ON THE AC OBEYED A PSEUDO SECOND-ORDER KINETIC REACTION. THE PRESENT STUDY PROVIDES SOME NEW INSIGHT INTO THE FUNDAMENTAL UNDERSTANDING OF adsorption OF SULFUR COMPOUNDS ON CARBON SURFACE, WHICH BENEFITS THE DESIGN AND PREPARATION OF BETTER ACTIVATED CARBON BASED ADSORBENT FOR THE ADSORPTIVE DESULFURIZATION.

آمار یکساله:  

بازدید 1260

دانلود 0
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