scholarly journals Au-O-MWCNTs and TiO2-O-MWCNTs as Efficient Nanocarriers for Dexamethasone: Adsorption Isotherms and Kinetic Studies

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Maryam Haghighi ◽  
Azadeh Khoshfetrat
Keyword(s):  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Multiwall Carbon Nanotubes ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Second Order ◽  
X Ray Diffraction ◽  
Pseudo Second Order ◽  
Drug Nanocarriers

In this research, the fabrication of drug delivery systems based on oxidized multiwall carbon nanotubes (O-MWCNTs) was studied. Herein, TiO2 and Au were conjugated with O-MWCNTs to prepare efficient nanocarriers for dexamethasone (dex). The samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In addition, dex loading was studied using adsorption isotherms including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich. The results show that dex adsorption agreed well with the Freundlich isotherm. Increasing the TiO2 to O-MWCNT ratio from (1 : 4) to (1 : 2) can improve the adsorption capacity from 290   mg ⋅ g − 1 to 320 320   mg ⋅ g − 1 . The increasing Au amount increases the adsorption capacity from 437.78   mg ⋅ g − 1 (SA1) to maximum 476.19   mg ⋅ g − 1 (SA6). The maximum equilibrium binding energy A T 1.67   L ⋅ mg − 1 was obtained for SA2, and SA7 shows high binding strength between dex and the nanoadsorbent. Carbon nanotubes (CNTs) show good affinity with high loading capabilities for dexamethasone adsorption. The synthesized TiO2-O-MWCNTs:1/2 with the maximum removal percent (80%) was proposed as an appropriate nanocarrier for dexamethasone. Pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion models were investigated for all synthesized drug nanocarriers. According to regression coefficients, experimental data are in good agreement with the pseudo-second order model for all adsorbents except O-MWCNT/CTAB. Experimental results revealed that the Elovich model could account for the O-MWCNT/CTAB adsorbent.

Kinetics of lead ion biosorption from aqueous solution onto lyophilized Aspergillus niveus

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç
Keyword(s):  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Lead Ions ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Aspergillus Niveus ◽  
Pseudo Second Order

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

scholarly journals Parametric, equilibrium and kinetic studies on the removal of mercury using ion exchange resin

2017 ◽  
Vol 12 (2) ◽  
pp. 305-313 ◽  
Author(s):  
N. Rajamohan ◽  
M. Rajasimman
Keyword(s):  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Strong Acid ◽  
Ion Exchange Resin ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Acid Cation ◽  
Pseudo Second Order ◽  
Langmuir Constants

This experimental research was an investigation into removal of mercury by using a strong acid cation resin, 001 × 7. Parametric experiments were conducted to determine the optimum pH, resin dosage, agitation speed and the effect of change in concentration in the range of 50–200 mg/L. High resin dosages favoured better removal efficiency but resulted in lower uptakes. Equilibrium experiments were performed and fitted to Langmuir and Freundlich isotherm models. Langmuir model suited well to this study confirming the homogeneity of the resin surface. The Langmuir constants were estimated as qmax = 110.619 mg/g and KL = 0.070 L/g at 308 K. Kinetic experiments were modeled using Pseudo second order model and higher values of R2 (>0.97) were obtained. The Pseudo second order kinetic constants, namely, equilibrium uptake (qe) and rate constant (k2), were evaluated as 59.17 mg/g and 40.2 × 10−4 g mg−1 min−1 at an initial mercury concentration of 100 mg/L and temperature of 308 K.

Biopolymeric Adsorbent for the Removal of Methylene Blue: Characterizations, Equilibrium Isotherms and Kinetic Studies

2015 ◽  
Vol 1125 ◽  
pp. 281-285
Author(s):  
Siti Aishah Muhmed ◽  
Mohd Ghazali Mohd Nawawi
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Correlation Coefficient ◽  
Kinetic Studies ◽  
Second Order ◽  
Equilibrium Isotherms ◽  
Chi Square ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.

Removal of Pb (II) from Aqueous Solution by Blast-Furnace Slags

2013 ◽  
Vol 726-731 ◽  
pp. 2736-2741
Author(s):  
Ming Da Liu ◽  
Ge Tian ◽  
Liang Jie Zhao ◽  
Yao Sheng Wang ◽  
Lei Guo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Blast Furnace ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Sorption Process ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Solution Kinetic ◽  
Second Order Model

Five blast-furnace slags were used as adsorbents to remove Pb (II) from aqueous solution. Kinetic studies showed that the sorption process was best described by pseudo-second-order model. Among Langmuir, Freundlich and Temkin isotherms, the Freundlich isotherm had a better fit with the simulation of the adsorption of Pb (II).

scholarly journals Removal of triphenylmethane dye from aqueous solutions through an adsorption process over waste materials

2020 ◽  
Vol 10 (4) ◽  
pp. 5772-5779
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Dye Removal ◽  
Functional Group ◽  
Adsorption Process ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Pseudo Second Order ◽  
Best Fit

Water pollution is the most significant issue due to rapid growing industrial development especially textile dye industry. Therefore, the adsorption process experiment was conducted to determine the removal ability of the adsorbent chosen. The removal rate and adsorption capacity of Phenol red and Cresol were analyzed by using eggshell adsorbent in the adsorption process. The experiment was conducted with parameters of initial concentration, dosage, pH and contact time. Results indicated that the removal rate achieved more than 90% and the adsorption capacity exceeded more than 5 mg/g. The functional group before adsorption process eggshell adsorbent and after adsorption process eggshell adsorbent was analyzed by using FTIR (Fourier Transform Infrared Spectroscopy). The study of adsorption isotherm and kinetics model was carried out to identify the efficiency of the eggshell adsorbent reacting with the dye solution. The adsorption isotherm that applied in this research was Langmuir isotherm, Jovanovic isotherm and Freundlich isotherm. Moreover, Pseudo-first-order and Pseudo-second-order chosen were conducted to determine the kinetic studies. In short, eggshell adsorbent is highly effective on dye removal through adsorption capacity. The functional group of the eggshell adsorbent was found such as alcohols, phenol, alkanes, carbonyls, ester, saturated aliphatic, aldehydes, aromatics, 2°amines and phosphorus. For kinetics study, Freundlich isotherm was analyzed as the best fit isotherm model as it achieved the highest R2 value which is closed to 1 and Pseudo-second-order was analyzed as the best fit kinetic model in this experiment. Therefore, eggshell adsorbent is highly effective in dye removal.

The Removal of Heavy Metals from Aqueous Solution by Utilizing Modified β-Cyclodextrin Microspheres

2010 ◽  
Vol 113-116 ◽  
pp. 632-638
Author(s):  
Feng Yu Li ◽  
Xiao Mei Sun ◽  
Bu Hai Li
Keyword(s):  
Heavy Metals ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Heavy Metal Concentration ◽  
Second Order ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

Batch adsorption experiments were carried out to remove heavy metals Cu(II)and Ni(II) by pyromellitic dianhydride (PMDA) grafted β-Cyclodextrin (β-CD). The effects concerning the pH of the solution, contact time and initial heavy metal concentration were studied and discussed. The adsorption values increased significantly after a large number of carboxyl groups were gragfted on the microspheres surface. In order to investigate the mechanism of sorption, adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetic equation. It was found that kinetic studies showed good correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by chemical adsorption. The equilibrium process was better described by the Langmuir isotherm than the Freundlich isotherm. XPS analysis further confirmed that the carboxyl group which grafted on the surface of the β-CD microspheres play a very important role in the removal of heavy metals.

scholarly journals Preparation, characterization and application of the nanocomposite PCL-PEG-PCL / Bentonite-TBHSA to the removal of methylene blue (MB) dye: Adsorption, Kinetics, and Isotherm studies

2021 ◽  
Author(s):  
Zohra Draoua ◽  
Amine Harrane ◽  
Mehdi Adjdir
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Dye Adsorption ◽  
Second Order ◽  
X Ray Diffraction ◽  
Optimal Value ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm ◽  
Best Fit

Abstract This study focuses on the synthesis, characterization, and application of amphiphilic PCL-PEG-PCL/Bentonite-TBHSA (A2). The prepared of A2 nanocomposite was prepared from Algerian Bentonite modified by the intercalation of tetrabutylammonium hydrogen sulfate (TBHSA) (A1), were characterized by different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction(XRD), (TEM),(DSC) and thermogravimetric analysis (TGA ). The removal efficiency of of methylene blue, from aqueous solutions. The effects of the initial pH of a solution, contact time, and nanocomposite mass on the adsorption efficiency were investigated. Pseudo-first/second-order isotherms were applied to determine the efficiency of nanocomposite solid. The experimental data fitted well with the pseudo-second-order model for MB dye adsorption. The mass of nanocomposite increased, the adsorption capacity of dye increases to reach an optimal value at 0.13 g of adsorbent in pH = 6.8. The Langmuir isotherm exhibited the best fit, with an adsorption capacity equal to 600 mg/g .

scholarly journals Kinetics and Isotherm Studies on Adsorption of Hexavalent Chromium Using Activated Carbon from Water Hyacinth

2021 ◽  
Vol 15 (1) ◽  
pp. 1-8
Author(s):  
Angelica Macalalad ◽  
◽  
Quennie Rose Ebete ◽  
Dominic Gutierrez ◽  
Madelaine Ramos ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Hexavalent Chromium ◽  
Water Hyacinth ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study is focused on the use of activated carbon derived from water hyacinth (WH-AC) as adsorbent for the removal of Cr(VI) from aqueous solution. The optimized WH-AC was found to be mesoporous and considered as granular. The surface area of 11.564 m2/g was found to have a good adsorption capacity. The adsorption data of the optimized WH-AC followed a pseudo-second order kinetics and the Freundlich isotherm model. Based on the correlation coefficient obtained from pseudo-second-order kinetic model, the R2 values were all above 0.99, which is closer to unity of one (1) indicating that it followed a chemisorption process. The adsorption capacity of WH-AC increased from 1.98 to 4.68 mg/g when adsorbate concentration increased from 20 to 50 mg/l. The overall study proved that the adsorption by activated carbon derived from water hyacinth can be an alternative and efficient technique in hexavalent chromium removal.

scholarly journals Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

2018 ◽  
Vol 16 (1) ◽  
pp. 36 ◽  
Author(s):  
Idha Yulia Ikhsani ◽  
Sri Juari Santosa ◽  
Bambang Rusdiarso
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Disperse Dyes ◽  
Order Kinetic ◽  
Initial Ph ◽  
Isotherm Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

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