Study on Treatment of Cr (VI)-Containing Wastewater with Nitric Acid Modified Activated Carbon

2011 ◽  
Vol 413 ◽  
pp. 38-41
Author(s):  
Xiu Ling Song ◽  
Hui Qian
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Nitric Acid ◽  
Ph Value ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Exchange Capacity ◽  
Modified Activated Carbon ◽  
Exchange Adsorption ◽  
Adsorption Curve

After activated carbon is oxidized and modified with nitric acid (1:1), its cation exchange capacity can amount to 1.840 mmol • g-1. The modified activated carbon is used as adsorbent for the treatment of Cr (Ⅵ)-containing wastewater at room temperature, and its removal mechanism is discussed in this paper. It is shown that: when the pH value of the aqueous solution being 2.5-3.0;the adsorption time being 3.0h, the removal rate of Cr (Ⅵ) in the aqueous solution can reach 97% and its adsorption capacity can amount to 45.66 mg • g-1. From the results, it can be also seen that the adsorption curve to chromium in wastewater by the modified activated carbon better meets the Freundlich isotherm, and ion exchange adsorption mainly does its work.

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.

scholarly journals Adsorption of gold from thiosulfate solutions with chemically modified activated carbon

2017 ◽  
Vol 36 (1-2) ◽  
pp. 408-428 ◽  
Author(s):  
Hong Yu ◽  
Futing Zi ◽  
Xianzhi Hu ◽  
Yanhe Nie ◽  
Yunlong Chen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Freundlich Isotherm ◽  
Modified Activated Carbon ◽  
New Approach ◽  
Complex Adsorption ◽  
Adsorption Kinetics And Isotherm ◽  
Thiosulfate Leaching ◽  
Adsorption Desorption

Adsorption of the gold–thiosulfate complex ion ([Formula: see text]) on silver ferrocyanide (AgFC)-impregnated activated carbon in aqueous solution has been studied in order to find an effectual adsorbent for the thiosulfate extracting gold from ores. This study was performed using AgFC-impregnated activated carbon (AC-Ag-R-FC: AC: activated carbon, Ag: silver nitrate, R: heating, FC: potassium ferrocyanide) and an artificial aqueous solution of [Formula: see text]. Gold–thiosulfate complex adsorption kinetics and isotherm studies were carried out at pH = 9.0 on modified materials. It has been also found that the adsorption fits the intraparticle diffusion and Freundlich isotherm well. In order to understand the adsorption mechanism, raw and modified materials were characterized by N2 adsorption–desorption measurements at 77 K, scanning electron microscopy and X-ray photoelectron spectroscopy. The maximum adsorption capability of [Formula: see text]on AC-Ag-R-FC is 3.55 kgt−1. Clearly, the extraordinary adsorption capacity of AC for [Formula: see text] offers a new approach to address challenging gold–thiosulfate complex separation and could promote the future development of thiosulfate leaching gold process.

High Cr(VI) Adsorption Performance of Coal-Based Activated Carbon in Aqueous Solution

2013 ◽  
Vol 798-799 ◽  
pp. 1123-1127
Author(s):  
Hua Lei Zhou ◽  
Qiong Qiong Zhu ◽  
Dong Hua Huang
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Pore Structure ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Koh Activation ◽  
Transmission Electron ◽  
Mesoporous Adsorbent ◽  
Initial Ph

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.

Removal of metallic trace elements (Pb2+, Cd2+, Cu2+, and Ni2+) from aqueous solution by adsorption onto cerium oxide modified activated carbon

2021 ◽  
Vol 193 (8) ◽  
Author(s):  
Daouda Kouotou ◽  
Mohammed Ghalit ◽  
Julius Nsami Ndi ◽  
Luisa M. Pastrana Martinez ◽  
Meriam El Ouahabi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Trace Elements ◽  
Activated Carbon ◽  
Cerium Oxide ◽  
Modified Activated Carbon ◽  
Metallic Trace Elements

scholarly journals Adsorption of aquatic Cd2+ using a combination of bacteria and modified carbon fiber

2017 ◽  
Vol 36 (3-4) ◽  
pp. 857-871 ◽  
Author(s):  
Chao Xue ◽  
Peishi Qi ◽  
Yunzhi Liu
Keyword(s):  
Aqueous Solution ◽  
Composite Material ◽  
Carbon Fiber ◽  
Active Sites ◽  
Ph Value ◽  
Removal Rate ◽  
Sorption Process ◽  
Acid Sites ◽  
Heterogeneous Distribution ◽  
Carbon Fiber Material

Batch experiments were conducted to investigate the capacity and mechanisms for adsorbing Cd2+ from aqueous solutions by the composite material. The composite material was manufactured with Plesiomonas shigelloides strain H5 and modified polyacrylonitrile-based carbon fiber. Experimental results showed that the surface areas of modified polyacrylonitrile-based carbon fiber increased by 58.54% and pore width increased by 40.19% compared with unmodified polyacrylonitrile-based carbon fiber. Boehm’s titration results show the surface acid sites of composite material were increased by 712% compared with unmodified polyacrylonitrile-based carbon fiber. The field emission scanning electron microscope results show P. shigelloides H5 can be grown on the surface of modified polyacrylonitrile-based carbon fiber closely. The equilibrium removal rate and sorption quantity of composite material were 71.56% and 7.126 mg g−1, respectively. With the pH value of aqueous solution increased, the removal rate of Cd2+ ions was also increased, but the change of temperature and ionic strength had no significant effect on the removal rate. Furthermore, the results showed the whole sorption process was a good fit to Lagergren pseudo-second-order model and Freundlich isotherms model. Therefore, the results infer that there was a heterogeneous distribution of active sites, and then the sorption process was chemical adsorption and multilayer adsorption. In a word, microbial composite carbon fiber material can adsorb Cd2+ ions from aqueous solution effectively, which might be helpful in wastewater treatment in the future.

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
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Nitric Acid ◽  
Carbon Fiber ◽  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Activated Carbon Fiber ◽  
Order Kinetic ◽  
Adsorption Amount

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.

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