Effect of Modification with Nitric Acid and Hydrogen Peroxide on Chromium (VI) Adsorption by Activated Carbon Fiber

2012 ◽  
Vol 518-523 ◽  
pp. 2099-2103
Author(s):  
Guang Zhou Qu ◽  
Hai Bing Ji ◽  
Ran Xiao ◽  
Dong Li Liang

The activated carbon fiber (ACF) was treated by different concentration nitric acid (HNO3) and hydrogen peroxide (H2O2) oxidization to enhance its adsorption capacity to hexavalent chromium (Cr6+) ion. The adsorption amount and adsorption kinetics of Cr6+ion on ACFs, and the surface chemical groups were investigated. The results showed that the modified ACFs with 1% HNO3and 10% H2O2had a better adsorption capacity, respectively. The adsorption amount of ACFs was affected strongly solution pH value, and decreased significantly with increasing of the pH value. The adsorption kinetics indicated that the adsorption rates of Cr6+ ion on different modified ACFs were well fitted with the pseudo-second-order kinetic model. After 1% HNO3and 10% H2O2modification, respectively, the total acidic oxygen-containing groups on ACFs surface had an increase obviously, which might be enhance the adsorption amount of Cr6+ion on ACFs.

2020 ◽  
Vol 12 (10) ◽  
pp. 3986
Author(s):  
Xianzhen Li ◽  
Yue Hu ◽  
Diao She ◽  
Wei-Bo Shen

As an antibiotic, Norfloxacin (NOR) is widely found in the water environment and presents considerable harm to human beings. At present, the preparation of removal materials is complicated, and the removal efficiency is not high. The adsorption effect of modified activated carbon fiber felt (MACFF) electrosorption and its influencing factors on NOR were studied. Activated carbon fiber felt (ACFF) was modified with 20% nitric acid, and the ACFFs were characterized by SEM, TEM, and FTIR both before and after modification. The optimal working conditions for electrosorption with an MACFF electrode were as follows: the voltage was 1.0 V, the pH was 6, and the plate spacing was 10 mm. The maximum adsorption capacity of the MACFF for NOR was 128.55 mg/g. Model fitting showed that pseudo-second-order kinetic model and Langmuir model were more suitable for explaining this adsorption process. In addition, this study found that, with 20% nitric acid as the regeneration liquid and under the reverse charging method, the regeneration rate of the MACFF electrode was maintained at approximately 96% and the regeneration was good, therefore, this technology can not only save operation costs but also has good development prospects in sewage treatment.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

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.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1377 ◽  
Author(s):  
Ruoke Ma ◽  
Xianxian Qin ◽  
Zhigao Liu ◽  
Yunlin Fu

Activated carbon fiber was prepared from liquefied wood by chemical activation with ZnCl2 (Z-LWACF) at different impregnation ratios, with a particular focus on its adsorption property, kinetic and isotherm. The characterization and properties of Z-LWACFs were investigated by nitrogen adsorption/desorption, X-ray photoelectron spectroscopy (XPS), methylene blue (MB) and iodine adsorption. Two activation process methods were employed to prepare Z-LWACF and contrasted with others fibers. The results showed that the Z-LWACF obtained by one-step ZnCl2 activation present higher yields and specific surface area than others fibers. Besides, the change of MB adsorption value at different impregnation ratios was consistent with pore structure distribution above 1.5 nm pore size, indicating that larger micropores (1.5 to 2 nm) and mesopores played a major role in the MB adsorption by Z-LWACF. The kinetics of MB adsorption process was found to follow the pseudo-second-order kinetic model and the adsorption rate was controlled by chemisorption. It was also found that MB adsroption by Z-LWACF belonged to monolayer adsorption and Z-LWACF was easy to adsorb MB.


2013 ◽  
Vol 807-809 ◽  
pp. 1343-1346
Author(s):  
Yi Fan Li ◽  
Ying Liu ◽  
Hou Qi Liu ◽  
Li Li

The research used activated carbon fiber (ACF) as adsorbent to remove atrazine, a kind of herbicide. It set a series of static adsorption experiments under different solution temperature, pH value and initial concentration to get a optimum adsorption condition. The experiment shows that the optimum pH for the removal of atrazine is 7. The adsorption rate is highest at 20°C. The adsorption rate decreases while the initial concentration increases.


1994 ◽  
Vol 344 ◽  
Author(s):  
F U Ruowen ◽  
Yun Lu ◽  
Haifeng Lu ◽  
Hanmin Zeng

AbstractIn this paper, the characteristic of a new preparation technique of activated carbon fiber (ACF) was discussed. The structures and properties of the ACF produced were investigated simultaneously. The experimental results indicated that this new technique is a high efficient method for the preparation of ACF. It needs simple facilities and is easy to be operated. The products obtained possess high specific surface area and adsorption capacity.


2019 ◽  
Vol 80 ◽  
pp. 98-105 ◽  
Author(s):  
Dong-Yeon Ryu ◽  
Takaaki Shimohara ◽  
Koji Nakabayashi ◽  
Jin Miyawaki ◽  
Joo-Il Park ◽  
...  

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang

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.


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