scholarly journals Preparation and Characterization of Cationized Cellulose for the Removal of Anionic Dyes

2001 ◽  
Vol 19 (3) ◽  
pp. 197-210 ◽  
Author(s):  
A. Hashem ◽  
Reda M. El-Shishtawy
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Structural Features ◽  
Isotherm Models ◽  
Acid Orange 7 ◽  
Anionic Dyes ◽  
Adsorption Parameters ◽  
Direct Blue ◽  
Equilibrium Data

The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by IR analysis. The ability of cationized cellulose to adsorb anionic dyes, viz. Acid Orange 7, Direct Blue 75 and Direct Violet 31, was investigated at 25°C and 50°C. The equilibrium data obtained were fitted by the Langmuir and Freundlich isotherm models, allowing the corresponding adsorption parameters to be determined. The results showed that the adsorption capacity was dependent on the adsorbent, temperature, the nature of the dye and (to some extent) on van der Waals and hydrogen bonding. Cationized cellulose exhibited a much better adsorption capacity towards anionic dyes than cellulose.

Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Initial Concentration

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0，enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.

ADSORPTION OF ACID ORANGE 7 BY CETYLPYRIDINIUM BROMIDE MODIFIED SUGARCANE BAGASSE

2016 ◽  
Vol 78 (1-2) ◽  
Author(s):  
Nik Ahmad Nizam Nik Malek ◽  
Nurain Mat Sihat ◽  
Mahmud A. S. Khalifa ◽  
Auni Afiqah Kamaru ◽  
Nor Suriani Sani
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Sugarcane Bagasse ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Acid Orange 7 ◽  
Cetylpyridinium Bromide ◽  
Batch Mode ◽  
Acid Orange ◽  
Adsorption Data

In the present study, the adsorption of acid orange 7 (AO7) dye from aqueous solution by sugarcane bagasse (SB) and cetylpyridinium bromide (CPBr) modified sugarcane bagasse (SBC) was examined. SBC was prepared by reacting SB with different concentrations (0.1, 1.0 and 4.0 mM) of cationic surfactant, CPBr. The SB and SBC were characterized using Fourier transform infrared (FTIR) spectroscopy. The adsorption experiments were carried out in a batch mode. The effect of initial AO7 concentrations (5-1000 mg/L), initial CPBr concentrations and pH of AO7 solution (2-9) on the adsorption capacity of SB and SBC were investigated. The experimental adsorption data were analyzed using Langmuir and Freundlich isotherm models. The adsorption of AO7 onto SB and SBC followed Freundlich and Langmuir isotherm models, respectively. The maximum uptake of AO7 was obtained by SBC4.0 (SB treated with 4.0 mMCPBr) with the adsorption capacity of 144.928 mg/g. The highest AO7 removal was found to be at pH 2 and 7 for SB and SBC, respectively. As a conclusion, sugarcane bagasse modified with CPBr can become an alternative adsorbent for the removal of anionic compounds in aqueous solution.

scholarly journals A Biosorption of Mercury from Wastewater Using Isolated Aspergillus Sp. Modified 1,10-Phenanthroline: Hill Isotherm Model

2017 ◽  
Vol 5 (4) ◽  
pp. 288 ◽  
Author(s):  
Shameran J. Salih ◽  
Sewgil S. Anwer ◽  
Rezhna H. Faraj
Keyword(s):  
Process Design ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Dead Cell ◽  
Adsorption Parameters ◽  
Hill Model ◽  
Equilibrium Data ◽  
Aspergillus Sp ◽  
Langmuir And Freundlich Models

Equilibrium biosorption of mercury (II) onto new developed biosorbent (1,10-phenanthroline-graft- cell/Filamentous fungi) in both free, immobilized and dead cell were investigated. The product was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In this work several isotherm models applied to predict the process design for the adsorption system. Hill, Sips, Langmuir and Freundlich utilized to determine the adsorption parameters, the equilibrium data fitted well to Hill and Sips isotherm models followed by Langmuir. Meanwhile, the maximum adsorption capacity proposed by Hill model was 78.67(mg/g) and Sips 78.42(mg/g) were lower than Langmuir models which was 85.16(mg/g). In other hand, the equilibrium data almost fitted to the Freundlich isotherm supporting the postulation of the heterogeneous shape of biosorption to certain range. Hence, On the bases of Langmuir model the biosorption of Hg2+ onto 1,10-phenanthroline-graft- cell/Filamentous was in the favourable area and that confirmed by calculating the separation factor (RL< 1). Nevertheless, new isotherm (Eq. 4) has been derived by the combination of a Langmuir and Freundlich models. The new model agreed well enough (R2 = 0.9863) with the experimental data.

scholarly journals Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water

2021 ◽  
Vol 13 (7) ◽  
pp. 3954
Author(s):  
Vanderlane C. Silva ◽  
Maria Eduarda B. Araújo ◽  
Alisson M. Rodrigues ◽  
Juliana M. Cartaxo ◽  
Romualdo R. Menezes ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Raw Material ◽  
Adsorption Behavior ◽  
Isotherm Model ◽  
Adsorptive Capacity ◽  
Anionic Dyes ◽  
Adsorption Parameters ◽  
X Ray ◽  
Adsorption Desorption

The effect of acid treatment on the adsorptive capacity of a Brazilian palygorskite to remove the crystal violet (CV) and congo red (CR) dyes was investigated. The raw palygorskite was acid-treated by different HCl solutions (2, 4, and 6 mol/L). The modifications on the palygorskite structure were investigated using X-ray diffraction, X-ray fluorescence, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, and thermogravimetric and differential thermal analysis. The efficiency of CV and CR adsorption was investigated, and the effect of the initial concentration, contact time, pH, and adsorbent amount was analyzed. The results revealed that CV adsorption in the acid-treated palygorskite was higher than that of the raw material. A Langmuir isotherm model was observed for the adsorption behavior of CV, while a Freundlich isotherm model was verified for the CR adsorption. A pseudo-second-order model was observed for the adsorption kinetics of both dyes. The higher CV adsorption capacity was observed at basic pH, higher than 97%, and the higher CR removal was observed at acidic pH, higher than 50%. The adsorption parameters of enthalpy (ΔH), entropy (ΔS), and Gibbs energy (ΔG) were evaluated. The adsorption process of the CV and CR dyes on the raw and acid-treated Brazilian palygorskite was predominantly endothermic and occurred spontaneously. The studied raw palygorskite has a mild-adsorption capacity to remove anionic dyes, while acid-treated samples effectively remove cationic dyes.

scholarly journals Biochars derived from bamboo and rice straw for sorption of basic red dyes

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254637
Author(s):  
Ebenezer Ampofo Sackey ◽  
Yali Song ◽  
Ya Yu ◽  
Haifeng Zhuang
Keyword(s):  
Adsorption Capacity ◽  
Rice Straw ◽  
Low Cost ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Acceptor Interaction ◽  
Equilibrium Data ◽  
Pseudo Second Order

The primary purpose of this study is to eliminate Basic Red 46 dye from aqueous solutions utilizing batch experiments by adsorption on biochars prepared from bamboo and rice straw biomass. Biochars prepared from bamboo (B), and rice straw (R) was pyrolyzed at 500°C (B500 and R500). Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), and surface area and porosity analyzers were used to characterize the B500 and R500 samples. The characterization results indicated that the biochars possessed an amorphous porous structure with many functional groups consisting primarily of silicates. The adsorption rate of BR46 was evaluated using two kinetic models (pseudo-first-order and pseudo-second-order), and the results indicated that the pseudo-second-order model fitted to the experimental data well (R2>0.99). Nearly 24 h was sufficient to achieve equilibrium with the dye adsorption for the two biochars. R500 had a greater adsorption efficiency than B500. As pH levels increased, the dye’s adsorption capability increased as well. The Langmuir and Freundlich isotherm models were used to investigate the equilibrium behavior of BR46 adsorption, and the equilibrium data fitted well with the Langmuir model (R2>0.99) compared to the Freundlich model (R2>0.89). The maximum adsorption capacities of BR46 are 9.06 mg/g for B500 and 22.12 mg/g for R500, respectively. Additionally, adsorption capacity increased as temperature increased, indicating that adsorption is favored at higher temperatures. The electrostatic interaction is shown to be the dominant mechanism of BR46 adsorption, and BR46 acts as an electron-acceptor, contributing to n-π EDA (Electron Donor-Acceptor) interaction. Thermodynamic parameters for the dye-adsorbent system revealed that the adsorption process is spontaneous and feasible. The values of the adsorption coefficient (Kd) were on the order of 102−103. Kd of R500 was greater than that of B500, indicating that R500 had a greater adsorption capacity. The results showed that R500 could be used as a low-cost alternative adsorbent for removing BR46 from effluents.

scholarly journals Adsorption Behavior of Inorganic and Organic Phosphate by Iron Manganese Plaques on Reed Roots in Wetlands

2018 ◽  
Vol 10 (12) ◽  
pp. 4578 ◽  
Author(s):  
Yingjie Zhu ◽  
Xiaoli Du ◽  
Can Gao ◽  
Zhenya Yu
Keyword(s):  
Adsorption Capacity ◽  
Fine Particles ◽  
Freundlich Isotherm ◽  
Organic Phosphate ◽  
Photoelectron Spectra ◽  
Phosphate Adsorption ◽  
Isotherm Models ◽  
Hydroxyl Groups ◽  
Iron Manganese ◽  
Inorganic And Organic

Inorganic and organic phosphate adsorption by iron–manganese (Fe–Mn) plaques extracted from reed roots was investigated. Scanning electron microscopy indicated the roots had rough surfaces and fine particles attached. X-ray photoelectron spectra indicated that Fe and Mn in the Fe–Mn plaques were mainly in the +III and +IV oxidation states, respectively. The contact time, initial phosphate concentration, and temperature effects on inorganic and organic phosphate adsorption were investigated by performing batch tests. Pseudo-second-order model described inorganic and organic phosphate adsorption, indicating the chemisorption was the dominant adsorption process. Langmuir and Freundlich isotherm models were fitted to the equilibrium data, and the Langmuir model fitted best. The maximum inorganic and organic phosphate adsorption capacities at 298 K were 7.69 and 3.66 mg/g, respectively. The inorganic and organic phosphate adsorption processes were spontaneous and exothermic. The inorganic phosphate adsorption capacity was higher than the organic phosphate adsorption capacity, and the presence of organic phosphate did not negatively affect adsorption at inorganic to organic phosphate molar ratios between 1:1 and 3:1. Fourier-transform infrared spectra before and after adsorption showed abundant functional groups on Fe–Mn plaques and that phosphate was probably adsorbed via replacement of hydroxyl groups and inner-sphere surface complexation.

scholarly journals Zero-Cost Agricultural Wastes as Sources for Activated Carbons Synthesis: Lead Ions Removal from Wastewaters

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 652 ◽  
Author(s):  
George Z. Kyzas ◽  
Athanasios C. Mitropoulos
Keyword(s):  
Activated Carbons ◽  
Freundlich Isotherm ◽  
Lead Ions ◽  
Isotherm Models ◽  
Activation Process ◽  
Strong Impact ◽  
Equilibrium Data ◽  
Preparation Route ◽  
Temperature Equilibrium ◽  
Gibb’S Free Energy

In the present study, activated carbons (PAC) were hydrothermally prepared with an environmental friendly preparation route after pyrolysis from biomass (specifically from agricultural (potato) peels). The prepared biochars were activated with potassium hydroxide (chemical activities). The preparation route had a strong impact on the pore structure of PAC. In addition, surface chemistry was also affected by the preparation and activation process. The adsorbent materials were also characterized by Scanning Electron Microscopy. The prepared activated carbons were used as adsorbents for the removal of lead ions. Batch experiments were performed to investigate the effect of physico-chemical parameters, such as pH, contact time, initial metal concentration and temperature. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The thermodynamic parameters such as the change of enthalpy (ΔH0), entropy (ΔS0) and Gibb’s free energy (ΔG0) of adsorption systems were also determined and evaluated.

scholarly journals Adsorption of Mn2+ from Aqueous Solution Using Manganese Oxide-Coated Hollow Polymethylmethacrylate Microspheres (MHPM)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari
Keyword(s):  
Aqueous Solution ◽  
Manganese Oxide ◽  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Coated Sand

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.

Chitosan-coated black sesame (Sesamum indicum L.) seed pulp as a novel candidate adsorbent for Cr(VI) elimination

2019 ◽  
Vol 79 (4) ◽  
pp. 688-698
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna ◽  
Elif Özdemir ◽  
Erol Pehlivan
Keyword(s):  
Adsorption Capacity ◽  
Sesame Seed ◽  
Sesamum Indicum ◽  
Isotherm Models ◽  
Physical Treatment ◽  
Adsorption Isotherm Models ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Data ◽  
Synthetic Solution ◽  
Maximum Removal

Abstract This study evaluates the application of Cr(VI) adsorption from the prepared synthetic solution by black sesame (Sesamum indicum L.) seed pulp (BSSP) and chitosan (Cts)-coated black sesame seed pulp beads (Cts-BSSP). BSSP and Cts-BSSP were used as an adsorbent without any chemical or physical treatment to remove Cr(VI) from an aqueous medium. The results indicated that the Cr(VI) removal was pH-dependent and reached an optimum at pH 2.0. It has been observed that the percentage of adsorption increased from 62% to 95% when the amount of Cts-BSSP increased from 0.0125 g to 0.0250 g. The required adsorbent amount for the maximum removal was 0.05 g and 0.1 g for Cst-BSSP and BSSP, respectively. The contact time for the adsorption was 120 min and 90 min for BSSP and Cst-BSSP, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to explore the possible adsorption mechanism for Cr(VI). The equilibrium data for the BSSP and Cts-BSSP were used with the Langmuir and Freundlich adsorption isotherm models to assess the adsorption capacity and relevant mechanism. The adsorption capacity of the Cts-BSSP for Cr(VI) is relatively high compared to BSSP. The monolayer maximum adsorption capacities for Cr(VI) ions were 31.44 and 18.32 mg/g for Cts-BSSP and BSSP, respectively.

scholarly journals Adsorption of Direct Blue 78 Using Chitosan and Cyclodextrins as Adsorbents

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1003 ◽  
Author(s):  
Ainoa Murcia-Salvador ◽  
José A. Pellicer ◽  
María I. Fortea ◽  
Vicente M. Gómez-López ◽  
María I. Rodríguez-López ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Advanced Oxidation Process ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Direct Blue ◽  
Complementary Action ◽  
Coupled Process ◽  
Kinetic Tests ◽  
Equilibrium Data ◽  
Pseudo Second Order

The dyeing industry is one of the most polluting in the world. The adsorption of dyes by polymeric matrixes can be used to minimize the discharge of dyes into the environment. In the present study, chitosan-NaOH and β-cyclodextrin-epichlorohydrin polymers were used to remove the dye Direct Blue 78 from a wastewater model. To understand the adsorption behavior of Direct Blue 78 onto the polymers, adsorption rate and maximum adsorption capacity were calculated using kinetic tests and isotherm curves respectively. The kinetic data and mechanism of the adsorption process were analyzed by three models and the equilibrium data by three adsorption isotherms; also the different thermodynamic parameters were calculated. Results showed that the adsorption process follows pseudo-second-order kinetics in both polymers and the Langmuir isotherm best-fitted data for chitosan-NaOH polymer and the Freundlich isotherm for the β-CDs-EPI polymer. The adsorption process is exothermic in both cases and spontaneous for the β-CDs-EPI polymer to a certain temperature and not spontaneous for the chitosan-NaOH polymer and β-CDs-EPI polymer at higher temperatures. The complementary action of an advanced oxidation process eliminated >99% of the dye from water. The coupled process seems to be suitable for reducing the environmental impact of the dyeing industry.

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