Removal of Silver (I) from Aqueous Solutions by Chitosan/Carbon Nanotube Nanocomposite Beads

2014 ◽  
Vol 893 ◽  
pp. 166-169 ◽  
Author(s):  
Walaikorn Nitayaphat ◽  
Thanut Jintakosol
Keyword(s):  
Adsorption Equilibrium ◽  
Ph Value ◽  
Dosage Level ◽  
Maximum Adsorption Capacity ◽  
Optimal Conditions ◽  
Adsorption Efficiency ◽  
Composite Adsorbent ◽  
Adsorbent Dosage ◽  
Composite Beads ◽  
Initial Ph

Chitosan/CNT nanocomposites were prepared by blending chitosan with carbon nanotubes (CNTs) and forming composite beads. The composites were used as Ag+adsorbents. Adsorption equilibrium experiments were carried out as a function of contact time, CNTs concentration, pH value, and adsorbent dosage level. The equilibrium time of Ag+adsorption was found to be 160 min. Composite adsorbent had the highest adsorption efficiency when the weight of CNTs was 0.01 wt%. The maximum Ag+removal took place at the initial pH value of 3. The optimum adsorbent dosage for Ag+removal was 5 g. Under above optimal conditions the maximum Ag+removal was 99.7%. The adsorption isotherm of chitosan/CNT nanocomposite bead agreed well with the Langmuir model. The maximum adsorption capacity was 0.393 mg/g.

Adsorption of cadmium by biochar produced from pyrolysis of corn stalk in aqueous solution

2016 ◽  
Vol 74 (6) ◽  
pp. 1335-1345 ◽  
Author(s):  
Fengfeng Ma ◽  
Baowei Zhao ◽  
Jingru Diao
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Ionic Strength ◽  
Ph Value ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Corn Stalk ◽  
Adsorbent Dosage ◽  
Initial Ph ◽  
Adsorbent Particle

The purpose of this work is to investigate adsorption characteristic of corn stalk (CS) biochar for removal of cadmium ions (Cd2+) from aqueous solution. Batch adsorption experiments were carried out to evaluate the effects of pH value of solution, adsorbent particle size, adsorbent dosage, and ionic strength of solution on the adsorption of Cd2+ onto biochar that was pyrolytically produced from CS at 300 °C. The results showed that the initial pH value of solution played an important role in adsorption. The adsorptive amount of Cd2+ onto the biochar decreased with increasing the adsorbent dosage, adsorbent particle size, and ionic strength, while it increased with increasing the initial pH value of solution and temperature. Cd2+ was removed efficiently and quickly from aqueous solutions by the biochar with a maximum capacity of 33.94 mg/g. The adsorption process was well described by the pseudo-second-order kinetic model with the correlation coefficients greater than 0.986. The adsorption isotherm could be well fitted by the Langmuir model. The thermodynamic studies showed that the adsorption of Cd2+ onto the biochar was a spontaneous and exothermic process. The results indicate that CS biochar can be considered as an efficient adsorbent.

Preparation of Persimmon Tannins Immobilized on Collagen Adsorbent and Research on its Adsorption to Cr(VI)

2013 ◽  
Vol 743-744 ◽  
pp. 523-530 ◽  
Author(s):  
Jian Cui ◽  
Zhong Min Wang ◽  
Feng Lei Liu ◽  
Pei Bang Dai ◽  
Ran Chen ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Ph Value ◽  
Effect Of Temperature ◽  
Major Influence ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Adsorption Data ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ph Range

Persimmon tannins (PT) were immobilized on a matrix of collagen fiber by cross-linking of glutaraldehyde. The adsorption behaviours to Cr (VI) on PT were investigated including the effects of initial pH, initial concentration of Cr (VI), temperature, adsorbent dosage, adsorption kinetics and the recycling performance of PT adsorbents. The results showed that pH value had a major influence in adsorption. PT showed a strong adsorbability to Cr (VI) in the pH range of 1.0 to 3.0, whereas the effect of temperature on the adsorption was comparatively weaker. The adsorption equilibrium could be well described by Freundlich equation. PT adsorption efficiency of Cr (VI) reached 98.04% and the maximum equilibrium adsorption capacity of Cr (VI) was up to 49.01 mg/g at 303 K with a pH value of 2.0, 100 mg/L of initial concentration of Cr (VI) and 0.1g of adsorbent dosage. The adsorption data could be well fitted by pseudo-second-order rate model. PT adsorbents were characterized by FTIR and EDS. The analysis indicated that the adsorption mechanism was mainly contributed by redox adsorption.

Synthesis of NH2-Functionalized Nano-Fe3O4 Magnetic Polymer Adsorbent and its Application for the Removal of Cr (VI) from Industrial Wastewater

2009 ◽  
Vol 79-82 ◽  
pp. 1883-1886 ◽  
Author(s):  
Yong Gang Zhao ◽  
Hao Yu Shen ◽  
Mei Qin Hu ◽  
Feng Wei ◽  
Yun Jie Luo ◽  
...  
Keyword(s):  
Langmuir Isotherm ◽  
Industrial Wastewater ◽  
Ph Value ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Adsorption Efficiency ◽  
Mechanism Study ◽  
Study Results ◽  
Isotherm Adsorption ◽  
Effects Of Ph

In this study, a novel NH2-functionalized nano-sized magnetic polymer (TEPA-NMP) adsorbent coupling with tetraethylenepentamine (TEPA) had been prepared. Its application for the removal of Cr(VI) from industrial wastewater was investigated. Batch adsorption studies were carried out to evaluate the effects of pH value, initial concentration, adsorption isotherm, adsorption kinetics, and desorption characters etc. The adsorption of Cr(VI) reached equilibrium rapidly within 30 mins. The adsorption efficiency of the TEPA-NMP on Cr(VI) was dependent on pH value and the initial Cr(VI) concentration. The adsorption efficiency of Cr(VI) decreased with the increasing of the initial Cr(VI) concentration and pH value. The adsorption data were well fitted with the Langmuir isotherm. The maximum adsorption capacity calculated from the Langmuir isotherm was 370.4 mg/g at temperature of 35 °C and pH of 2.0. Regeneration studies indicated that the adsorbent could be reused for 8 times with only 3.4 % lost of adsorption efficiency. The adsorption mechanism study results suggested that the adsorption of Cr(VI) could be related with electrostatic attraction, ion exchange and coordination interactions.

scholarly journals Insights into Kinetics of Magnesium Removal by Titain Yellow Supported on Classic Thiourea-Formaldehyde Resin

2020 ◽  
Author(s):  
Khalid Elwakeel
Keyword(s):  
Formaldehyde Resin ◽  
Maximum Adsorption Capacity ◽  
Sorption Behavior ◽  
Optimal Conditions ◽  
Maximum Sorption ◽  
Initial Ph ◽  
Sorption Effect ◽  
Magnesium Removal ◽  
Kinetics Of ◽  
Efficient Adsorbent

<p>It was evaluated for the adsorption behavior and the underlying kinetics of magnesium sorption on Titian yellow (TY) supported on thiourea-formaldehyde resin (TF). The results of analyzing sorption behavior showed that the sorption environment had different effects on the sorption of Mg(II) ions. It could be found that pH had the best sorption effect on Mg(II) ions, The maximum adsorption capacity of Mg was 19.45 mg g<sup>−1</sup> when it was at initial pH = 10.5. Under the optimal conditions, the maximum sorption capacities of Mg(II) ions was 19.45 mg g<sup>−1</sup>. Therefore, TF-TY was found to be a most efficient adsorbent for Mg(II) removal from water.</p>

scholarly journals A Fungal Modified Material With High Uranium (VI) Absorption Capacity And Strong Anti-Interference Ability

2022 ◽  
Author(s):  
Ni Tan ◽  
Qiaorong Ye ◽  
Yaqing Liu ◽  
Yincheng Yang ◽  
Zui Ding ◽  
...  
Keyword(s):  
Ph Value ◽  
Orthogonal Experiment ◽  
Target Material ◽  
Absorption Capacity ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Solid Liquid

Abstract With polydioxyethylene ether as the bridge chain, a new fungal modified material with diamidoxime groups was prepared by a series of uncomplex synthesis reaction. The orthogonal experiment obtained its optimized adsorption conditions as follows: the initial pH value 6.5, the initial uranyl concentration 40 mg L-1, the contact time 130 min, and the solid-liquid ratio 25 mg L-1. The maximum adsorption capacity of target material was 446.20 mg g-1, and it was much greater than that of the similar monoamidoxime material (295.48 mg g−1). The linear Langmuir (R2 = 0.9856) isotherm models and the linear pseudo-second-order kinetic model (R2 = 0.9931) fit the experimental data of uranium (VI) adsorption better, indicating the adsorption mechanism should mainly be the monolayer adsorption and chemical process. In addition, the relevant experiments exhibited the prepared material was of the good reuse and the excellent anti-interference performance, which suggested the new acquisition should also have well-applied prospect in the future.

Synthesis and Characterization of Zeolite X Obtained from Coal Gangue for Adsorption of Cu2+

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Copper Ions ◽  
Removal Rate ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Zeolite X ◽  
Initial Ph

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.

The Behaviors of Removing Silver Ions by Low-Cost Expanded Rice Husk, Nature Diatomite and Nature Bentonite as Sorbents

2012 ◽  
Vol 724 ◽  
pp. 472-475
Author(s):  
Xuan Liang ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Qiang Mei
Keyword(s):  
Adsorption Capacity ◽  
Rice Husk ◽  
Ph Value ◽  
Low Cost ◽  
Silver Ions ◽  
Maximum Adsorption Capacity ◽  
Removal Of Heavy Metals ◽  
Initial Ph ◽  
Influence Of Ph ◽  
By Products

Low cost industrial and agricultural by-products are promising materials for water pollution treatment such as removal of heavy metals. This work deals with removal of silver ions from solutions using expanded rice husk (ERH), nature diatomite (ND) and nature bentonite (NB). Firstly the influence of pH value of the solution on adsorption capacity for silver ions was studied, and then the effect of initial silver concentration on adsorbents adsorption capacity was investigated. The silver ions removal percentage increases with initial pH and achieves a maximum value of nearly 94% at pH= 5.0 ± 0.5 for ERH. The maximum adsorption capacity is 18.6 mg/g for ERH.

Characteristics of Cu2+ Adsorption by Modified Rice Straw

2013 ◽  
Vol 726-731 ◽  
pp. 2622-2628
Author(s):  
Ming Da Liu ◽  
Lei Guo ◽  
Jun Yang ◽  
Yao Jing Wang
Keyword(s):  
Rice Straw ◽  
Ph Value ◽  
Removal Rate ◽  
Maximum Adsorption Capacity ◽  
Static State ◽  
Metal Biosorption ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Sorption Time

In this paper, modified rice straw was investigated for its Cu2+removal ability from aqueous solution. The effects of environmental factors on metal biosorption were studied under static state, including initial concentration of metal ions, sorption time, initial pH value and adsordent dosage. In addition, the relevant equilibrium, kinetics were discussed. The results showed that the rice straw which was modified by NaOH had been improved greatly in its Cu2+removal ability. The rice straw had good effects on adsorption of low concentration of Cu2+solution. The adsorption data fit Langmuir isotherm model well, the maximum adsorption capacity for Cu2+reached 8.48 mg·g-1. The adsorption of Cu2+on the modified rice straw was a very rapid process, the kinetics fit a pseudo-second-order equation well. The pH value had prominent effect on the removal rate of Cu2+, adsorption efficient could reach over 92% when pH value was between 5 and 6.5. With increasing adsordent dosage, the removal rate of Cu2+increased.

Adsorption of lead using a novel xanthated carboxymethyl chitosan

2013 ◽  
Vol 69 (2) ◽  
pp. 298-304 ◽  
Author(s):  
Qingping Song ◽  
Chongxia Wang ◽  
Ze Zhang ◽  
Jiangang Gao
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Carboxymethyl Chitosan ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Visible Spectra ◽  
Initial Ph ◽  
Uv Visible

Adsorption of Pb(II) was studied using a novel xanthated carboxymethyl chitosan (XCC). The XCC was synthesized using the xanthation reaction of N-carboxymethyl chitosan (NCMC). The chemical structure of XCC was characterized by UV–visible spectra. The effects of initial pH value of the solutions, contact time and adsorption isotherms on adsorption of Pb(II) were investigated. Moreover, the possible adsorption mechanism was identified using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The experimental results showed XCC experienced a high adsorption capacity. The adsorption isotherm followed the Langmuir model. The maximum adsorption capacity obtained from the Langmuir model was 520.8 mg/g. Thermodynamic studies revealed a spontaneous and exothermic adsorption process. FTIR and XPS studies showed that the carboxyl groups, nitrogen atoms and sulfur atoms participated in the adsorption of Pb(II).

scholarly journals KINETIC AND ISOTHERM STUDY OF CUPPER ADSORPTION FROM AQUEOUS SOLUTION USING WASTE EGGSHELL

2014 ◽  
Vol 22 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Ayben Polat ◽  
Sukru Aslan
Keyword(s):  
Ph Value ◽  
Experimental System ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Isotherm Study ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The sorption of Cu2+ ions from aqueous solutions by eggshell was investigated in a batch experimental system with respect to the temperature, initial Cu2+ concentrations, pH, and biosorbent doses. The adsorption equilibrium was well described by the Langmuir isotherm model with the maximum adsorption capacity of 5.05 mg Cu2+/g eggshell at 25 °C. The value of qe increased with increasing the temperature while also increases the release of Ca2+ and HCO−3 ions from the eggshell. The highest sorption of Cu onto the waste eggshell was determined at the initial pH value of 4.0. The results confirming that the adsorption reaction of Cu2+ on the eggshell was thought to be endothermic. A comparison of the kinetic models such as pseudo first and second-order kinetics, intraparticle diffusion, and Elovich on the sorption rate demonstrated that the system was best described by the pseudo second-order kinetic model.

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