共查询到20条相似文献,搜索用时 15 毫秒
1.
《分离科学与技术》2012,47(3):452-459
In this study, pyromellitic dianhydride (PMDA) modified waste sugarcane bagasse (SCB) was prepared through a simple method to remove two cationic dyes: methylene blue (MB) and malachite green (MG) from aqueous solution. Adsorption performances of MB and MG on the modified sorbent were investigated in details. The adsorption capacities of the modified SCB for MB and MG were 571.4 and 377.4 mg g?1, respectively, which were 10 and 12 times than that obtained on the unmodified SCB. Adsorption kinetics study showed equilibriums were obtained after adsorption for 13 hours for both dyes. The modified SCB could be used repeatedly after regeneration. FTIR results showed that carboxyl and hydroxyl groups on the modified SCB involved in adsorption process. 相似文献
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《分离科学与技术》2012,47(2):330-339
Introduction of xanthate group onto sugarcane (Saccharum officinarum) bagasse has been investigated for the removal of cadmium, lead, nickel, zinc, and copper from their aqueous media. The charred xanthated sugarcane bagasse (CXSB) was found to have significant adsorption capacity which is more than that of various bio-sorbents mentioned in the available literatures. The newly developed bio-sorbent was characterized by SEM, FTIR, TGA/DTA, and elemental analysis. The velocity of sorption of the tested metals was fast, reaching equilibrium within 40 min. The maximum loading capacities was found to be 225 for Cd(II), 318 for Pb(II), 144 for Ni(II), 164 for Zn(II), and 178 for Cu(II) mg g?1, respectively. The fast kinetics results and high adsorption capacity indicated that CXSB can be applied as the selective adsorbent for the treatment of heavy metal ions from aqueous solutions. 相似文献
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Neha Gupta Chandrajit Balomajumder Vijay Kumar Agarwal 《Chemical Engineering Communications》2013,200(7):993-1007
The biosorption of cyanide ions from aqueous solution by bagasse was studied in a batch adsorption system with pH, contact time, cyanide ion concentration, metal ion concentration, and adsorbent dosage as variables. XRD, FT-IR spectroscopy, CHN, proximate, ultimate, and TG/DTG thermal analyses were used for the characterization of bagasse. The biosorption capacities and rates of biosorption of cyanide ions onto bagasse were evaluated. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data were interpreted by the Langmuir model followed by the Freundlich model with maximum adsorption capacity of 98% of cyanide ion on bagasse. The kinetic experimental data were properly correlated with the first- and second-order kinetic model. 相似文献
6.
《分离科学与技术》2012,47(14):2125-2131
The adsorption of Methylene Blue (MB) and Acid Orange 7 (AO7) from aqueous solutions by acid treated coconut coir was investigated under laboratory conditions to assess its potential in removing cationic and anionic dyes. The acid treated coconut coir exhibited better adsorption capacity in cationic dye MB than anionic dye AO7 and the data obtained can be well described by both Langmuir and Freundlich isotherm models. According to the Langmuir isotherm model, the maximum adsorption capacities of MB and AO7 onto acid treated coconut coir were 121 mg/g and 10 mg/g, respectively. The adsorption behavior of MB and AO7 onto acid treated coconut coir was analyzed with first-order Lagergren model and pseudo-second order model. 相似文献
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EFFECT OF TEMPERATURE ON THE ADSORPTION OF METHYLENE BLUE DYE ONTO SULFURIC ACID–TREATED ORANGE PEEL
P. Senthil Kumar P. Sebastina Anne Fernando R. Tanvir Ahmed R. Srinath M. Priyadharshini A. M. Vignesh 《Chemical Engineering Communications》2013,200(11):1526-1547
The present study explains the preparation and application of sulfuric acid–treated orange peel (STOP) as a new low-cost adsorbent in the removal of methylene blue (MB) dye from its aqueous solution. The effects of temperature on the operating parameters such as solution pH, adsorbent dose, initial MB dye concentration, and contact time were investigated for the removal of MB dye using STOP. The maximum adsorption of MB dye onto STOP took place in the following experimental conditions: pH of 8.0, adsorbent dose of 0.4 g, contact time of 45 min, and temperature of 30°C. The adsorption equilibrium data were tested by applying both the Langmuir and Freundlich isotherm models. It is observed that the Freundlich isotherm model fitted better than the Langmuir isotherm model, indicating multilayer adsorption, at all studied temperatures. The adsorption kinetic results showed that the pseudo-second-order model was more suitable to explain the adsorption of MB dye onto STOP. The adsorption mechanism results showed that the adsorption process was controlled by both the internal and external diffusion of MB dye molecules. The values of free energy change (ΔG o) and enthalpy change (ΔH o) indicated the spontaneous, feasible, and exothermic nature of the adsorption process. The maximum monolayer adsorption capacity of STOP was also compared with other low-cost adsorbents, and it was found that STOP was a better adsorbent for MB dye removal. 相似文献
9.
The removal of cationic dyes from aqueous solutions by adsorption onto pistachio hull waste 总被引:1,自引:0,他引:1
The efficacy of pistachio hull powder (PHP) prepared from agricultural waste was investigated in this study as a novel adsorbent for the elimination of dye molecules from contaminated streams. Removal of methylene blue (MB) as a cationic model dye by PHP from aqueous solution was studied under different experimental conditions. The selected parameters were solution pH (2–10), PHP dosage (0.5–3 g/L), MB concentrations (100–400 mg/L), contact time (1–70), and solution temperature (20–50 °C). The experimental results indicated that the maximum MB removal could be attained at a solution pH of 8. The dosage of PHP was also found to be an important variable influencing the MB removal percentage. The removal efficiency of MB improved from 94.6 to 99.7% at 70 min contact time when the MB concentration was decreased from 300 to 100 mg/L at a pH and PHP dosage of 8 and 1.5 g/L, respectively. The kinetic analysis showed that the pseudo-second-order model had the best fit to the experimental data. The Langmuir equation provided the best fit for the experimental data of the equilibrium adsorption of MB onto PHP at different temperatures. In addition, the maximum adsorption capacity increased from 389 to 602 mg/g when the temperature was increased from 20 to 50 °C. The thermodynamic evaluation of MB adsorption on PHP revealed that the adsorption phenomenon under the selected conditions was a spontaneous physical process. Accordingly, pistachio hull waste was shown to be a very efficient and low-cost adsorbent, and a promising alternative for eliminating dyes from industrial wastewaters. 相似文献
10.
G. D. Vilakati A. K. Mishra S. B. Mishra B. B. Mamba J. M. Thwala 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(4):802-808
The effect of nano-particles of TiO2 on the mechanical and thermal properties of sugarcane bagasse (SCB)–ethylene co-vinyl acetate (EVA) composite was investigated.
Composite materials were prepared using a melt-mix intercalation method on a rheomex mixer coupled with a single screw extruder.
differential scanning calorimeter (DSC), thermogravimetric (TG) analyser and an Instron, were used to probe the thermal and
mechanical properties of the samples. Composites with TiO2 were compared with those without TiO2 but with the same content of sugarcane bagasse (SCB). After the addition of TiO2, the tensile strength increased by 10%, from 11.26 MPa for neat EVA, which correlated with the enthalpy of fusion, however,
the tensile strength decreased by 18% at higher SCB loading. Elongation at break decreased from 463 to 0% as the filler (SCB)
was increased which was inversely proportional to the modulus. The composite showed an improved thermal stability with the
addition of TiO2. 相似文献
11.
《分离科学与技术》2012,47(13):1898-1905
Batch adsorption studies were carried out using H2SO4 modified sugarcane bagasse (HMSB) for the removal of hazardous Crystal Violet (CV) dye from aqueous solutions. The effects of initial solution pH, adsorbent dose, and temperature on the adsorption process were investigated. The Langmuir isotherm model well described the equilibrium dye uptake while the pseudo-second-order kinetic model showed good agreement with the experimental kinetic data. Gibb's free energy change (ΔG0) was spontaneous for all interactions, and the adsorption process exhibited endothermic enthalpy values. Results suggest that HMSB is an effective adsorbent for the removal of CV from wastewater. 相似文献
12.
Adsorption behavior of cationic dyes on citric acid esterifying wheat straw: kinetic and thermodynamic profile 总被引:2,自引:0,他引:2
Renmin Gong Shengxue Zhu Demin Zhang Jian Chen Shoujun Ni Rui Guan 《Desalination》2008,230(1-3):220-228
The kinetic and thermodynamic behaviors of cationic dye adsorption onto citric acid esterifying wheat straw (EWS) from aqueous solution were investigated. Two cationic dyes, methylene blue (MB) and crystal violet (CV) were selected as adsorbates. The kinetic and thermodynamic parameters of dye adsorption were examined with a batch system by changing various experimental factors (e.g. initial pH, EWS dosage, dye concentration, contact time, temperature). The MB and CV removal ratios came up to the maximum value beyond pH 4. The 2.0 g/L or up of EWS could almost completely remove MB and CV from 250 mg/L of dye solution. The adsorption percentages of MB and CV kept above 95% over a range from 50 to 350 mg/L of dye concentration when 2.0 g/L of EWS was used. The isothermal data followed the Langmuir model. The adsorption processes could be described by the pseudosecond-order kinetic model. The dual linear plots of intraparticle diffusion indicated that two intraparticle diffusion steps occurred in the dye adsorption processes. The thermodynamic study indicated that the adsorptions of dyes were spontaneous and endothermic. High temperatures favored the adsorption processes. 相似文献
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P. Esparza M. E. Borges L. Díaz M. C. Alvarez‐Galván J. L. G. Fierro 《American Institute of Chemical Engineers》2011,57(3):819-825
Volcanic ashes (VAs) and Ti‐modified volcanic ashes (TVA) were investigated as inexpensive adsorbents to remove methylene blue (MB) from aqueous solutions. TVA displayed higher and faster MB adsorption than VA. Adsorption studies were carried out in a batch system at room temperature. In this work, several variables were studied: contact time, pH, initial MB concentration, and adsorbent dosage. The equilibrium data of MB adsorption were analyzed according to the Langmuir and Freundlich adsorption isotherm models. Optimum adsorption performance for TVAs particles, prepared using a hydrothermal method, was obtained at pH = 10 and 3 g/l adsorbent dose. MB adsorption isotherm data can be described satisfactorily by the Langmuir equation, whereas adsorption kinetic data fit a pseudo second‐order kinetics model. © 2010 American Institute of Chemical Engineers AIChE J, 2011 相似文献
14.
Mehrorang Ghaedi Shaaker Hajati Behnaz Barazesh Farahnaz Karimi Gholamreza Ghezelbash 《Journal of Industrial and Engineering Chemistry》2013,19(1):227-233
In this work, biosorption of Brilliant green (BG) and Methylene blue (MB) dyes in binary mixture onto Saccharomyces cerevisiae were studied. pH at which the biosorption capacity of biomass is maximum was found to be 6 which is close to the pH of natural aqueous solutions. This is a big advantage of S. cerevisiae which makes it applicable for the technology of dye removal from natural aqueous dye solutions. Note that the time for the applied biosorption process for the dye removal is considerably short (about 5 min) which is a big improvement for the adsorption processes. This proves that the S. cerevisiae is a promising adsorbent. The BG and MB dyes were simultaneously analyzed using the fifth and fourth order derivative spectrophotometric method, respectively. Several isotherm models were applied to experimental data and the isotherm constants were calculated for BG and MB dyes. Among the applied models, Freundlich isotherm model showed best fit to the biosorption equilibrium data. 相似文献
15.
《分离科学与技术》2012,47(9-10):2489-2502
Abstract Surfactant adsorption from aqueous electrolyte solutions onto metal surfaces was characterized through the use of a Quartz Crystal Microbalance (QCM). The need for a better understanding of the surfactant adsorption process became apparent in previous studies by Morton et al., directed toward the development of a thermodynamically-based model of oil removal from metal surfaces. These modeling efforts utilized existing data on surfactant adsorption data, yet required the estimation of surfactant adsorption phenomena, such as the transition between monolayer adsorption and multi-layer adsorption and the location of the critical micelle concentration (CMC). Experimental techniques utilizing the quartz crystal microbalance (QCM) have been shown to be highly reliable for measuring slight changes, on the order of a nanogram, in the adsorption behavior of surfactants from aqueous solutions. The current study demonstrates that the addition of low concentrations (< 100 mM) of sodium chloride to aqueous solutions of ionic surfactant can have a significant effect on the adsorption of the surfactant to a gold surface. An analysis of the QCM measurements as well as a discussion of the effects of salt addition on various solution properties will be presented. Impacts of the current results to previously published work as well as potential applications will be discussed. 相似文献
16.
Sylvain Tome Dzoujo T. Hermann Victor O. Shikuku Stephen Otieno 《Ceramics International》2021,47(15):20965-20973
In this work, two geopolymers were prepared by acid activation (GPAc) and alkaline activation (GPAl) approaches using volcanic ash (VA) as the precursor material. The geosorbents were characterized by X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier-transform infrared and Brunauer-Emmett-Teller (BET) surface area analyses and their comparative adsorptive potential for anionic (Eriochrome Black T/EBT) and cationic (methylene blue/MB) dyes from water is herein reported for the first time. GPAl and GPAc had 74.47 and 42.75 m2/g BET surface areas, respectively. Equilibrium adsorption data were described by the isotherm models in the order Freundlich > Sips > Langmuir model. Relative to acid activation (GPAc), alkaline activated geopolymer (GPAl) had the highest adsorption capacity for both MB and EBT, estimated at 952 mg/g and 251 mg/g, respectively, consistent with the BET surface areas. The adsorption rates were best described by the pseudo-second order (PSO) kinetic model. GPAl exhibited faster adsorption kinetics than GPAc as denoted by the adsorption half-life, t1/2. The thermodynamic functions indicated that the adsorption of both MB and EBT onto the geopolymers was spontaneous, exothermic and feasible. The adsorption was pH-dependent implying electrostatic interactions is the dominant driving mechanism of adsorption. The results show that alkaline activated geopolymers are better sorbents for dye removal than acid activated geopolymers under the examined conditions. 相似文献
17.
ABSTRACT Our work focuses on the study of the adsorption of methylene blue (MB) on adsorbents based on zeolite HUSY and (γAl2O3-SiO2). To optimize the process of removing MB onto Ni/Co USY, different parameters were studied such as contact time, initial pH, initial dye concentration, zero charge’s point, and adsorbent dosage. The adsorption isotherm follows the Langmuir model. The maximum adsorption capacities of MB were 59.88 mg g?1 for Ni/Co USY and 43.86 mg g?1 for Ni/Co (γAl-Si) at 298°K. The thermodynamic parameters and activation energy’s values obtained suggested that the adsorption was a physical process, spontaneous, and endothermic in nature. MB adsorption on Ni/Co USY may occur via electrostatic interaction, hydrogen bonding, and Lewis acid–base interaction. 相似文献
18.
Removal of hexavalent chromium from aqueous solution by adsorption on treated sugarcane bagasse using response surface methodological approach 总被引:1,自引:0,他引:1
Umesh K. Garg 《Desalination》2009,249(2):475-479
In the present study, effect of adsorbent dose, pH and agitation speed on the removal of chromium from aqueous medium using an agricultural waste biomass (sugarcane bagasse treated with succinic acid) has been investigated. Batch mode experiments were carried out to assess the adsorption equilibrium. The influence of three parameters on the removal of chromium was examined using a response surface methodological approach. The Central Composite Face-Centered Experimental Design in Response Surface Methodology (RSM) by Design Expert Version 6.0.10 (Stat Ease, USA) was used for designing the experiments as well as for full response surface estimation and 20 trials as per the model were run. The optimum conditions for maximum removal of chromium from an aqueous solution of 50 mg/L were as follows: adsorbent dose (20 g/L), pH (2.0) and stirring speed (250 rpm). This was evidenced by the higher value of coefficient of determination (r2 = 0.9873). 相似文献
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In this work, we report the synthesis of polyaniline emaraldine salt (PAni-ES) by a chemical oxidative polymerization method. The obtained PAni-ES samples prepared under different conditions were used for the removal of indigo carmine anionic dye and Pb(II) ion from aqueous solutions. The results also showed that the pseudo–second-order kinetic model fitted better than the data obtained from pseudo–first-order model for the adsorption of anionic dye and Pb(II) ion onto PAni-ES. The fit of the data for indigo carmine and Pb(II) ion adsorption onto PAni-ES suggested that the Langmuir model gave closer fittings than Freundlich model. 相似文献
20.
In order to remove the organic dyes of textile waste water, the silica aerogel was successfully prepared by using E-40 as a novel precursor and then dried in ambient pressure. The synthesized sample was verified by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). After calcining, the hydrophilic silica aerogel (HSA) was used as adsorbent to remove Methylene Blue (MB), Malachite Green (MG), and Gentian Violet (GV) from aqueous solution. The effects of initial concentration of dyes and adsorbent dosage on the adsorption process were examined. It was found that HSA showed excellent adsorption capacities, the maximum percentage of removal dyes could reach 98%. Herein, the Langmuir, Freundlich and de Boer-Zwikker isotherm modes were employed to discuss the adsorption behavior. The results indicated that the de Boer–Zwikker model can effectively describe the adsorption behavior. Besides, the HSA could be utilized as the recyclable adsorbent in degradation experiment, after five cycles, no obvious loss of adsorption capacity was found. As an efficient, low-cost, environmental friendly and recyclable adsorbent, silica aerogel is expected to be used for dyes removal. 相似文献