Enhanced decolorization of dyes by an iron modified clay and thermodynamic parameters

2016 ◽  
Vol 73 (8) ◽  
pp. 2007-2016 ◽  
Author(s):  
N. Contreras Olivares ◽  
M. C. Díaz-Nava ◽  
M. Solache-Ríos
Keyword(s):  
Thermodynamic Parameters ◽  
Adsorption Process ◽  
Sorption Kinetics ◽  
Homogeneous Material ◽  
Modified Clay ◽  
Adsorption Capacities ◽  
Adsorption Processes ◽  
Kinetics And Isotherms ◽  
Material Temperature ◽  
Maximum Removal

The sorption processes of red 5 (R5) and yellow 5 (Y5) dyes by iron modified and sodium bentonite in aqueous solutions was evaluated. The modified clay was prepared, conditioned and characterized. The sodium clay did not remove any of either dye. The sorption kinetics and isotherms of R5 and Y5 dyes by iron modified clay were determined. The maximum removal percentages achieved were 97% and 98% for R5 and Y5, respectively, and a contact time of 72 h; the experimental data were best adjusted to Ho model. The isotherms of both dyes were best adjusted to the Langmuir model and the maximum adsorption capacities of the modified clay were 11.26 mg/g and 5.28 mg/g for R5 and Y5, respectively. These results indicate that adsorption processes have a high probability to be described as chemisorption on a homogeneous material. Temperature range between 283 and 213 K does not affect the adsorption of Y5 by the iron modified clay, but the adsorption process of R5 was affected, and the thermodynamic parameters could be calculated, which indicate a chemisorption mechanism.

scholarly journals High Removal Efficiency of Diatomite-Based X Zeolite for Cu2+ and Zn2+

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6525
Author(s):  
Guangyuan Yao ◽  
Yuqiang Liu ◽  
Shuilin Zheng ◽  
Ya Xu
Keyword(s):  
Ion Exchange ◽  
Adsorption Process ◽  
Interface Properties ◽  
Order Model ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
X Zeolite ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetics And Isotherms

Diatomite-based X zeolite was obtained and its crystallinity, morphology, and interface properties were investigated by XRD, BET, SEM, EDS, and XRF. The obtained X zeolite possessed a unique meso-microporous structure and showed good ion exchange properties for Cu2+ and Zn2+. The pseudo-second-order model and Langmuir isotherm model can best describe the adsorption kinetics and isotherms of Cu2+ and Zn2+, respectively. The maximal adsorption capacities of X zeolite for Cu2+ and Zn2+ were 146 and 195 mg/g at 323 K, respectively. Meanwhile, the adsorption process for Cu2+ and Zn2+ were chemical adsorption and ion exchange, respectively. Furthermore, the adsorption data turned out to be an endothermic and spontaneous process. Compared with other reported materials, the adsorption capacity of X zeolite synthesized from diatomite was among the highest. Therefore, it could be a promising adsorbent for the disposal of wastewater that contains metal ions.

Adsorption of chlorinated acetic acids by quaternary ammonium cationic cellulose

2013 ◽  
Vol 14 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Wenjian Shi ◽  
Haixin Gu ◽  
Xuan Chen ◽  
Yuanxing Huang ◽  
Wei Wu ◽  
...  
Keyword(s):  
Quaternary Ammonium ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Dichloroacetic Acid ◽  
Trimethylammonium Chloride ◽  
Monomolecular Layer ◽  
Adsorption Capacities ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Acetic Acids

Etherifying agent, 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTA) was modified by grafting on cellulose to make quaternary ammonium cationic cellulose (QACC) with 2.01% nitrogen content and a degree of substitution of 0.289. The experiment results showed that at 318 K, the adsorption capacities of QACC on monochloroacetic acid (MCAA), dichloroacetic acid and trichloroacetic acid (TCAA) were 1.80, 1.87 and 2.01 mmol/g, respectively. The adsorption process could be modeled by pseudo second-order kinetics very well. The adsorption rate constant increased with temperature, and the adsorption pattern fitted Langmuir isotherms, which was monomolecular layer absorption. ΔH of the three chlorinated acetic acids were all above zero, and ΔS of them were above zero too. At 298 K, ΔG of the adsorption processes were below zero. These experiment results showed that it was main chemical adsorption accompanied by physical adsorption.

scholarly journals Ionic Surfactant Enhancement of Clay Properties for Heavy Metals Adsorption: Kinetics and Isotherms

2021 ◽  
Vol 21 (4) ◽  
pp. 825
Author(s):  
Adekeye Damilola Kayode ◽  
Asaolu Samuel Sunday ◽  
Adefemi Samuel Oluyemi ◽  
Ibigbami Olayinka Abidemi ◽  
Akinsola Abiodun Folasade ◽  
...  
Keyword(s):  
Surface Properties ◽  
Sodium Dodecyl ◽  
Infrared Spectrometry ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Kaolinite Clay ◽  
X Ray ◽  
Modified Clay ◽  
Adsorption Processes ◽  
Kinetics And Isotherms

The global health problems arising from ingesting toxic metals necessitate the quest for developing efficient materials for their remediation. Surface properties of raw kaolinite clay collected from Ire-Ekiti, South-western Nigeria, were improved by modification using sodium dodecyl sulphate (SDS) for the adsorptive removal of Pb, Cr, Ni and Cu from their respective aqueous solution. The raw and modified clays were characterized by X-ray fluorescence, Fourier transformed infrared spectrometry, Scanning electron microscope coupled with EDX and Particle induced x-ray emission technique. A batch adsorption study was used to examine the performance efficiency of the modified clay. Optimization of adsorption conditions like temperature, particle size, concentration, agitation time and pH was performed. The clay after modification showed improved surface properties such as increased pore diameter and number. Freundlich, Langmuir and Temkin isotherm models were applied to explicate the adsorption processes, while Pseudo-First order, Pseudo-Second order and the Elovich kinetic models were used to predict possible mechanisms driving the adsorption processes. The adsorption processes driven by chemical mechanisms involved series of complex mechanisms that include ion exchange, direct bonding and surface complexation other than precipitation. The percentage removal of the metals by the modified clay soil reached the values of 98.53, 94.50, 73.82, and 80.40 for Pb, Cu, Ni and Cr.

scholarly journals Adsorption Behavior of Methylene Blue Dye by Novel Crosslinked O-CM-Chitosan Hydrogel in Aqueous Solution: Kinetics, Isotherm and Thermodynamics

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3659
Author(s):  
Nouf Faisal Alharby ◽  
Ruwayda S. Almutairi ◽  
Nadia A. Mohamed
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Thermodynamic Parameters ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Kinetic Studies ◽  
Blue Dye ◽  
Chitosan Hydrogel ◽  
Adsorption Capacities ◽  
Increasing Temperature

The chemical cross-linking of carboxymethyl chitosan (O-CM-chitosan), as a method for its modification, was performed using trimellitic anhydride isothiocyanate to obtain novel cross-linked O-CM-chitosan hydrogel. Its structure was proven using FTIR, XRD and SEM. Its adsorption capacity for the removal of Methylene Blue (MB) dye from aqueous solution was studied. The effects of different factors on the adsorption process, such as the pH, temperature and concentration of the dye, in addition to applications of the kinetic studies of the adsorption process, adsorption isotherm and thermodynamic parameters, were studied. It was found that the amount of adsorbed MB dye increases with increasing temperature. A significant increase was obtained in the adsorption capacities and removal percentage of MB dye with increasing pH values. An increase in the initial dye concentration increases the adsorption capacities, and decreases the removal percentage. It was found that the pseudo-second-order mechanism is predominant, and the overall rate of the dye adsorption process appears to be controlled by more than one step. The Langmuir model showed high applicability for the adsorption of MB dye onto O-CM-chitosan hydrogel. The value of the activation energy (Ea) is 27.15 kJ mol−1 and the thermodynamic parameters were evaluated. The regeneration and reuse of the investigated adsorbent was investigated.

The influence of radiofrequency electromagnetic fields on the adsorption processes in porous media

2012 ◽  
Vol 9 (2) ◽  
pp. 71-75
Author(s):  
L.A. Kovaleva ◽  
Z.Yu. Stepanova ◽  
I.M. Kamaltdinov ◽  
Yu.S. Zamula
Keyword(s):  
Porous Media ◽  
Adsorption Process ◽  
Sorption Kinetics ◽  
Saturated Porous Media ◽  
Polar Components ◽  
Saturated Rock ◽  
Adsorption Processes ◽  
Temperature Dependences ◽  
Em Field ◽  
Field Influence

The experimental results of the polar hydrocarbon adsorption in saturated porous media after radio-frequency (RF) electromagnetic (EM) influence and the thermal heating for comparison are presented. Temperature dependences of the extracted volume of hydrocarbons from models are shown. Comparing the obtained data an additional influence of RF EM field on the desorption of asphaltenes from the porous media surface has been found, that leads to an increase of the extraction of hydrocarbons from the models. The thermodynamic substantiation and mathematical modeling of heat and mass transfer in a saturated porous media under RF EM influence are used as the basis of theoretical study. The equation of sorption kinetics based on the Henry’s Law includes a summand that represents the contribution of thermal and EM fields is to be considered. Researches have discovered that the adsorption process slows down under RF EM field influence, which has a positive effect on the filtration ability of the saturated rock. Investigation of the field influence on the asphaltene adsorption process using atomic force microscopy (AFM) was conducted to identify the mechanism of adsorption and desorption of polar components on the surface of the porous medium under the RF EM field influence.

Evaluation of U(VI) adsorption from Ca2+ coexisted bicarbonate solution by synthetic inorganic and mineral materials

2020 ◽  
Vol 108 (12) ◽  
pp. 955-965
Author(s):  
Jun Liu ◽  
Shilong Shi ◽  
XiaoYu Yin ◽  
Yong Jin ◽  
Chunhai Lu ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Structural Stability ◽  
Adsorption Process ◽  
Natural Uranium ◽  
Chemical Adsorption ◽  
Surface Chemical ◽  
Weakly Alkaline ◽  
Adsorption Behaviors ◽  
Study Results ◽  
Kinetics And Isotherms

AbstractPart weakly alkaline natural uranium-containing water contains abundant Ca2+ and (bi)carbonate. Herein, two kinds of materials, namely mesoporous hydrous manganese dioxide (MHMO) and polyacrylonitrile (PAN)/dolomite composites were synthesized and characterized to evaluate their adsorption behaviors of U(VI) from Ca2+ coexisted bicarbonate solution. Characterization results showed that both samples exhibited good structural stability after U(VI) load. MHMO could coordinate U(VI) through the surface –OH sites, whereas an unfavorable U(VI) adsorption onto mineral composites was deduced. Adsorption tests indicated that increasing Ca2+ and (bi)carbonate amounts suppress U(VI) adsorption process, and ∼19.0 mg/g U adsorbed by MHMO could be obtained in solutions with 1 mmol/L [Ca2+], 5 mmol/L [CO3]T, 50 mg/L [U(VI)]initial at pH 8.0. Moreover, a heterogeneous surface chemical adsorption was verified through kinetics and isotherms study. Results from our study should be useful in exploring the adsorption behaviors and mechanisms of U(VI) on selected inorganic and mineral materials from natural uranium-containing water.

scholarly journals Eggshell Powder as an Adsorbent for Removal of Fluoride from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Fluoride Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Maximum Removal

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

Adsorption of Ni (II) from Aqueous Solution Based on Porous Magnetic/Chitosan Resin

2014 ◽  
Vol 936 ◽  
pp. 829-833
Author(s):  
Hai Song ◽  
Xing Hai Yu ◽  
Xiao Qin Zhang ◽  
Gui Fang Yan ◽  
Yuan Zhi Zhen
Keyword(s):  
Aqueous Solution ◽  
Aqueous Medium ◽  
Thermodynamic Parameters ◽  
Adsorption Process ◽  
Low Cost ◽  
Second Order ◽  
Magnetic Chitosan ◽  
Spontaneous Process ◽  
Chitosan Resin ◽  
Kinetics And Thermodynamic

The purpose of this work is to prepare a low-cost biosorbent,Porous Magnetic/Chitosan Resin(MCR), and determine the ability of this biosorbent to removing Ni (II) ion from aqueous medium. Both kinetics and thermodynamic parameters of the adsorption process were also estimated. The thermodynamic parameters indicated an exothermic spontaneous process and the kinetics followed the second-order adsorption process.

scholarly journals Removal of toxic metals from aqueous solution by biochars derived from long-root Eichhornia crassipes

2018 ◽  
Vol 5 (10) ◽  
pp. 180966 ◽  
Author(s):  
Qiang Li ◽  
Lizhou Tang ◽  
Jiang Hu ◽  
Ming Jiang ◽  
Xiaodong Shi ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Eichhornia Crassipes ◽  
Adsorption Process ◽  
Correlation Coefficients ◽  
Sorption Ability ◽  
Different Temperatures ◽  
Lead Zinc ◽  
Pseudo Second Order ◽  
Cyano Groups ◽  
Maximum Removal

Biochars were produced from long-root Eichhornia crassipes at four temperatures: 200, 300, 400 and 500°C, referred to as LEC200, LEC300, LEC400 and LEC500, respectively. The sorption ability of lead, zinc, copper and cadmium from aqueous solutions by four kinds of biochars was investigated. All the biochars had lower values of CEC and higher values of pH. LEC500 was the best one to bind toxic metals which can be reflected in the results of SEM, BET and elemental analyser. It was also found that alkyl, carboxyl, phosphate and cyano groups in the biochars can play a role in binding metals. In addition, the sorption processes of four metals by the biochars in different metal concentration were all excellently represented by the pseudo-second-order model with all correlation coefficients R 2 > 0.95. And the sorption processes of four metals in different temperatures could be described satisfactorily by the Langmuir isotherms. According to calculated results by the Langmuir equation, the maximum removal capacities of Pb(II), Zn(II), Cu(II) and Cd(II) at 298 K were 39.09 mg g −1 , 45.40 mg g −1 , 48.20 mg g −1 and 44.04 mg g −1 , respectively. The positive value of the Δ H 0 confirmed the adsorption process was endothermic and the negative value of Δ G 0 confirmed the adsorption process was spontaneous. The sorption capacities were compared with several other lignocellulosic materials which implied the potential of long-root Eichhornia crassipes waste as an economic and excellent biosorbent for eliminating metal ions from contaminated waters.

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