Adsorption of Copper Ions from Aqueous Solutions by Chitin

2012 ◽  
Vol 550-553 ◽  
pp. 2424-2427
Author(s):  
Chung Hsin Wu ◽  
Chao Yin Kuo ◽  
Meng Jia Chen

This study utilizes chitin to remove dissolved Cu(II) from aqueous solutions. The effects of the dissolved Cu(II) concentration, chitin dosage, and pH on adsorption of dissolved Cu(II) by chitin are determined. Adsorption capacity for 20 and 80 mg/L dissolved Cu(II) onto chitin (2 g/L) was 3.86 mg/g and 5.12 mg/g, respectively. The dissolved Cu(II) adsorption percentage increased from 39% to 70% when the chitin dosage was increased from 2 g/L to 4 g/L. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained. Analytical results demonstrate that the Freundlich isotherm fitted experimental results better than did the Langmuir isotherm. Enthalpy (ΔH0) and entropy (ΔS0) for dissolved Cu(II) adsorption were 8.46 kJ/mol and 123.1 J/mol.K, respectively.

2017 ◽  
Vol 23 (3) ◽  
pp. 223 ◽  
Author(s):  
H.B. Senin ◽  
O. Subhi ◽  
R. Rosliza ◽  
N. Kancono ◽  
M.S. Azhar ◽  
...  

Sawdust, inexpensive material has been utilized as an absorbent for the removal of iron from aqueous solution for their safe disposal. The adsorption experiments of untreated sawdust (SD) and treated sawdust (SDC) have been carried out at room temperature using the batch test. The Langmuir and Freundlich isotherms were used to observe sorption phenomena of sawdust in the removal of iron. The results indicate that the sawdust was capable in removing iron in aqueous solution. The results have shown that the Langmuir isotherm was found well fitted into the experimental data as compared to the Freundlich isotherm. It was found that, chemisorptions and physisorption were the prime mechanism for the process of adsorption to occur between the sawdust and iron. The results also proved that the acid sulphuric treated sawdust is much better than that of untreated sawdust as an adsorbent for iron.


2021 ◽  
Author(s):  
Ferda Civan Çavuşoğlu

Abstract Adsorption of gliclazide from aqueous solutions with carbon-based adsorbents is the aim of this study. For this purpose, magnetic, versatile, and inexpensive magnetic activated carbon (MAC) and magnetic multi-walled carbon nanotube (MMWCNT) adsorbents have been developed. MAC and MMWCNT characterization were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA) techniques. In order to find the optimum conditions in batch adsorption experiments, the effects of parameters such as adsorbent dose, gliclazide solution pH, contact time, temperature and presence of foreign ions were investigated. Parameters were calculated for adsorption isotherms using Langmuir and Freundlich models. The adsorption studies of MAC and MMWCNT materials with gliclazide were in accordance with the nonlinear Langmuir and Freundlich isotherm models for all temperatures (298, 308, 318 K). The correlation coefficients of the Langmuir isotherm model are slightly higher than the Freundlich model. MAC adsorbent has maximum monolayer adsorption capacity at T=298 K (qmax=101.66 mg/g, R2=0.88) while MMWCNT has maximum monolayer adsorption capacity at T=308 K (qmax=71.59 mg/g, R2=0.90). For MAC and MMWCNT - Gliclazide adsorption systems, pseudo-first and secondorder kinetic models were examined and found to be more appropriate to the pseudo-secondorder kinetic model. The results showed that the MAC and MMWCNT could be could be promising adsorbents for gliclazide removal.


2009 ◽  
Vol 620-622 ◽  
pp. 555-558
Author(s):  
Yi Li ◽  
Xue Gang Luo ◽  
Zhao Liu ◽  
Yan Huang ◽  
Xiao Yan Long

The modified valonian tannin was prepared through sulfonated-mannich reaction and used to adsorb Cu (II) from the aqueous solutions. The adsorption capacity rapidly reached equilibrium within 2 hours. The effect of pH on adsorption was apparent, the amount of adsorption increased significantly as the pH increased from 2.0 to 4.0 and then leveled off at pH 4.0-6.0. Equilibrium data fitted well with Freundlich isotherm model compared to Langmuir isotherm model, indicating that adsorption takes place on heterogeneous surface of the modified valonia tannin. The adsorption capacity was increased by increasing initial concentrations. The maximum adsorption capacity of cooper ion was determined to be 56.200 mg/g at 100 mg/L concentration.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç

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.


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Yusuke Koto ◽  
Naoki Kano ◽  
Yudan Wang ◽  
Nobuo Sakamoto ◽  
Hiroshi Imaizumi

Biosorption experiment from aqueous solutions containing known amount of rare earth elements (REEs) using pre-treatedBuccinum tenuissimumshell was explored to evaluate the efficiency of shell biomass as sorbent for REEs. In this work, four kinds of sieved shell samples: (a) “Ground original sample”, (b) “Heat-treatment (480∘C, 6 hours) sample”, (c) “Heat-treatment (950∘C, 6 hours) sample” and (d) “Heat-treatment (950∘C, 6 hours) and water added sample” were used. Furthermore, to confirm the characteristics of the shell biomass, the crystal structure, the surface morphology, and the specific surface area of these shell samples were determined. Consequently, the following matters have been mainly clarified. (1) The crystal structure of the shell biomass was transformed from aragonite (CaCO3) into calcite (CaCO3) phase by heat-treatment (480∘C, 6 hours); then mainly transformed into calcium oxide (CaO) by heat-treatment (950∘C, 6 hours), and calcium hydroxide(Ca(OH)2)by heat-treatment (950∘C, 6 hours) and adding water. (2) The shell biomass showed excellent sorption capacity for lanthanides. (3) Adsorption isotherms using the shell biomass can be described by Langmuir and Freundlich isotherms satisfactorily for lanthanides except “heat-treatment (950∘C, 6 hours) sample”. (4) Shell biomass (usually treated as waste material) can be an efficient sorbent for lanthanides in future.


2013 ◽  
Vol 361-363 ◽  
pp. 709-715
Author(s):  
Xin Long Jiang ◽  
Yi Hua Jiang

The adsorption of Cr(VI) by modified Bamboo shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified Bamboo shell is at 298 K and pH = 1.0, which gives a static saturated adsorption capacity of 12.68 mg·g-1, an apparent adsorption rate constant of k298 = 9.56 × 10-4 s-1, and an apparent adsorption activation energy of 7.38 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 66.04 kJ·mol-1, ΔS = 0.2974 kJ·mol-1·K-1, ΔG = −22.58~−28.52 kJ·mol-1. The anions HPO42-, H2PO4- and SO42- have negligible influence on the adsorption capacity. Small amount of desorption is observed only at pH > 11. The adsorption of Cr(VI) by modified bamboo shell is mainly a chemical process.


Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.


2011 ◽  
Vol 356-360 ◽  
pp. 1469-1474
Author(s):  
Jun Jing Guo ◽  
Wen Bin Chen

In this study, calcium alginate immobilized bacillus subtilis body was used as an adsorbent for the aim of adsorpting Cu(Ⅱ) ions form the aqueous solutions, On sutiable condition, this study use purely bacteria eliminate other bacteria come in life-form bacteria .Through the orthogonal experiment obtains the optimum condition of sodium alginate fossilization bacillus subtilus pellet to the Cu(Ⅱ) adsorption, The biosorption efficiency was strongly influenced by the pH and the initial concentration ofthe Cu(Ⅱ) aqueous solutions. We also discusses the influence of single factor to the sodium alginate fossilization bacillus subtilus pellet to the Cu(Ⅱ) adsorption ,which included pH, contact time, temperature, initial metal ion concentrations and ionic strength in the adsorption process. The adsorption of the adsorbent on Cu(Ⅱ) is related to its concentration . From the research,we know the maximum adsorption rate to the Cu(Ⅱ) is about 83.2%. Using different model to analyse data. The sorption process follows pseudo-second-order kinetics very well,and the correlation coefficients R all reached to 0.9, and the rate constant of this kinetics model for the adsorption processes, k2, increased with the increasing temperatures. The isothermal data could be well described by the Langmuir adsorption isothermal equations.The experimental results showed that heavy metals could be eficciently accumulated by the immobilized bacteria.


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