scholarly journals Synthesis of Iron Oxide Nanoparticle Functionalized Activated Carbon and Its Applications in Arsenic Adsorption

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hoang Thu Ha ◽  
Pham Tuan Phong ◽  
Tran Dinh Minh

This work reveals the As(V) adsorption behaviors onto iron oxide (Fe3O4) nanoparticles modified activated carbon (AC), originally developed from biochar (BC), as a green adsorbent denoted by FAC. Since FAC has abundant surface functional groups and a desired porous structure that is favorable for the removal of As(V) in contaminated water, FAC has greatly enhanced the As(V) adsorption capacity of the original BC. Various methods were employed to characterize the FAC characteristics and adsorption mechanism, including pHpzc determination, BET specific surface area, elemental analysis (EA), and scanning electron microscopy (SEM). Results show that the AC surface was successfully modified by iron oxide nanoparticles, enhancing the porosity and specific surface area of original adsorbent. Batch adsorption tests indicated a well-fitted Langmuir model and pseudo-second-order model for As(V) adsorption. Additionally, the highest adsorption capacity (Qmax = 32.57 mg/g) by FAC was higher than previously reported literature reviews. Until now, no article was conducted to research the effect of carbon surface chemistry and texture on As removal from waters. It is required to obtain a rational view of optimal conditions to remove As from contaminated water.

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.


2020 ◽  
Vol 850 ◽  
pp. 16-21
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang

Diatomite or diatomaceous earth (DE) is one of materials which can be used as an adsorbent to treat heavy metal ions from waste water, even there are many factories used it to clean the water for drinking. However, natural DE (raw DE) has very low adsorption capacity because of low specific surface area. In this work, natural DE from Lam Dong province, Viet Nam was demagnetized to remove iron and activated by HCl solution for 90 minutes with concentration of 10% at room condition. Adsorbent capacity was evaluated using As solution and the results show that the activated diatomite has adsorption capacity three times higher than that of raw DE, and the specific surface area of activated diatomite was increased 47.5% with the main chemical composition of 90.8% SiO2 and high porosity


1992 ◽  
Vol 9 (4) ◽  
pp. 244-257 ◽  
Author(s):  
S. Hawash ◽  
J.Y. Farah ◽  
M.S. El-Geundi

Natural and activated clays have been investigated as adsorbents for the removal of nickel from wastewater. Analysis of the natural clay under test showed that it was composed, approximately of 51% kaolinite, 46% montmorillonite and 3% illite, having a specific surface area of 65 m2/g. The natural clay was treated with different activators (HCl, NaCl and H2O2) to enhance its adsorption capacity towards nickel. The efficiency of such activation was greater by 16.0% and 23.2% in the case of NaCl and H2O2, respectively, relative to untreated clay. No significant increase in the adsorption capacity was brought about by HCl treatment. A limited comparison has been made between clay and activated carbon by performing isotherm studies under similar conditions. The results indicate that the adsorption capacity of clay activated with H2O2, clay activated with NaCl and natural clay is 216.9%, 204.2% and 176.1% that of activated carbon, respectively. Based solely on the adsorption capacity, an economic analysis demonstrates that natural clay is the cheapest material, followed by clay activated with NaCl and clay activated with H2O2. The relative costs of removing nickel using natural clay, clay activated with NaCl and clay activated with H2O2 were found to be 2.8%, 5.4% and 25.4%, respectively, that of activated carbon.


2014 ◽  
Vol 976 ◽  
pp. 207-211 ◽  
Author(s):  
Alejandra Alicia Peláez Cid ◽  
Araceli Vázquez Barranco ◽  
Ana María Herrera González

This paper presents the results of the adsorption of textile dyes in static systems, using adsorbent materials prepared from broccoli waste collected after harvest. The adsorption capacities of the non-activated lignocellulosic residue (BrocNat), the chemically activated waste using sodium hydroxide (BrocNaOH), the thermally activated at 823 K ash (AshBroc), and the chemically activated carbon using phosphoric acid at 673 K (CarBrocQ) were tested. Aqueous solutions containing cationic and anionic dyes as well as textile effluents generated after the dyeing process of a cotton-processing factory containing vat and reactive dyes were treated. Lignocellulosic materials were only effective in removing dyes when they were found in aqueous solution. The carbonaceous adsorbent CarBrocQ presented removal percentages close to 100% and between 13 and 75% for reactive and vat dyes contained in the effluents respectively. To accomplish the complete elimination of color from effluents containing vat dyes, these were treated before adsorption, using aluminum chlorohydrate and poly(acrylamide-co-sodium acrylate) as coagulant and flocculant agents, respectively. The COD of the effluent containing vat dyes was reduced up to 93% after both treatments were combined, and the removal of color was absolute. The high adsorption capacity of CarBrocQ occurs because of its high specific surface area, which was determined by N2 adsorption to be 1177 m2g-1. In the case of the lignocellulosic material, the specific surface area was determined by means of adsorption of methylene blue, and it was 485 m2g-1 for both. The adsorption capacity of CarBrocQ was compared with that of commercial carbons, and proved to be similar. The adsorption results obtained indicate that broccoli waste can be used to prepare activated carbon with applications in the removal of dyes present in textile effluents.


Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 496
Author(s):  
Krzysztof Kuśmierek ◽  
Andrzej Świątkowski ◽  
Katarzyna Skrzypczyńska ◽  
Lidia Dąbek

Three carbon materials with a highly diversified structure and at the same time much less different porosity were selected for the study: single-walled carbon nanotubes, heat-treated activated carbon, and reduced graphene oxide. These materials were used for the adsorption of 2,4-D herbicide from aqueous solutions and in its electroanalytical determination. Both the detection of this type of contamination and its removal from the water are important environmental issues. It is important to identify which properties of carbon materials play a significant role. The specific surface area is the major factor. On the other hand, the presence of oxygen bound to the carbon surface in the case of contact with an organochlorine compound had a negative effect. The observed regularities concerned both adsorption and electroanalysis with the use of the carbon materials applied.


2018 ◽  
Vol 55 (1B) ◽  
pp. 109 ◽  
Author(s):  
Nguyen Huu Hieu

In this work, graphene oxide–manganese ferrite (GO–MnFe2O4) magnetic nanohybrids were synthesized by co–precipitation technique. The adsorption properties of GO–MnFe2O4 for efficient removal of Cd(II) from contaminated water were investigated. The nanohybrids were characterized by using X–ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller specific surface area (BET), transmission electron microscopy, and vibrating sample magnetometry (VSM). VSM result showed the high saturation magnetization values Ms = 27.1 emu/g, the BET specific surface area was 84.236 m2/g. Adsorption experiments were carried out to evaluate the adsorption capacity of the GO–MnFe2O4 magnetic nanohybrids and compared with MnFe2O4 nanoparticles and GO nanosheets. The equilibrium time for adsorption of Cd(II) onto the nanohybrids was 240 minutes. Experimental adsorption data were well–fitted to the Langmuir isotherm and the pseudo–second–order kinetic equation. The experimental results showed that adsorption of Cd(II) using GO–MnFe2O4 magnetic nanohybrids was better than MnFe2O4 and GO with a maximum adsorption capacity of 121.951 mg/g at pH 8.  Reusability, ease of magnetic separation, high removal capacity, and fast kinetics lead the GO–MnFe2O4 nanohybrids to be promising adsorbents for removal heavy metals from contaminated water.


2021 ◽  
Author(s):  
Xiaoxia Ren ◽  
Changming Zhang ◽  
Lifang Kou ◽  
Rongxian Wang ◽  
Yaqi Wang ◽  
...  

Abstract Activated carbon spheres with high specific surface area and hierarcal porous texture were prepared from polystyrene-based macroreticular resin spheres by air pre-oxidization and steam activation. The as-prepared carbon spheres had a specific surface area of 1274.95 m2 g− 1, total pore volume of 1.09 cm3 g− 1 and micropore volume of 0.47 cm3 g− 1. Moreover, these carbon spheres showed a hierarcal porous texture composed of ultrafine micropores (0.5-1 nm), micropores (1–2 nm), mesopores (10–50 nm) and macropores (50–100 nm). A CO2 adsorption capacity of 2.82 mmol g− 1 for carbon spheres can be obtained at 30 ℃ and 1 atm. Further, after introducing nitrogen-containing functional groups by gaseous ammonia at 600 ℃, these carbon spheres exhibited a high CO2 adsorption capacity of 3.2 mmol g− 1. In addition, excellent cyclic stability, low hygroscopicity and regenerability temperature suggested these carbon spheres were favorable for CO2 capture.


2021 ◽  
Vol 2 ◽  
pp. 21-32
Author(s):  
Ju.V. Таmarkina ◽  
I.B. Frolova ◽  
O.O. Velichko ◽  
V.O. Кucherenko

The aim of the work is to evaluate the adsorption capacity of activated carbons (ACs) from brown coal in relation to phenol (Ph) and 4-chlorophenol (CPh) and the influence of the AСs formation temperature under carbonization with potassium hydroxide on capacities. The samples of ACs were prepared by heating with KOH (1 g/g, 1 h) at a given temperature in the range of t=400-800°C and marked as AC(t). The ACs porosity characteristics were determined by low-temperature (77 K) adsorption – desorption nitrogen isotherms (Micromeritics ASAP 2020) calculated by the 2D-NLDFT method. They are as follows: total pore volume Vt (cm3 /g), specific surface area S (m2 /g), volume (Vmi) and surface (Smi) of micropores, volume (V1nm) and surface (S1nm) of subnanopores, the total surface of meso- and macropores Sme+ma. The adsorption of phenol and 4-chlorophenol was determined at equilibrium concentrations in aqueous solutions ≤5 mmol/l (25 °C). The alkaline carbonization temperature of brown coal was found to be a key factor in the formation of micro- and subnanopores, the growth of the AC specific surface area (from 12.8 m2 /g to 1142 m2 /g) and adsorption activity against phenolic compounds. Its increase to 800°C causes an exponential increase in the AC adsorption capacity in 8.7 times (Ph) and 6.7 times (CPh), which is proportional to the concentration of surface adsorption centers (AdCs). The values of the effective activation energy of forming AdCs being active in relation to adsorbates were determined as 29.5 kJ/mol (Ph) and 31.5 kJ/mol (CPh). The kinetics of Ph and CPh absorption was found to obey the pseudosecond-order model, and the adsorption rate is limited by the interaction of the adsorbate molecules with the AdCs. Adsorption isotherms at equilibrium concentrations ≤ 5 mmol/l are approximated by the Langmuir model (R2 ≥ 0.994). Compared with Ph, the degree of CPh extraction is much higher, which is a consequence of its stronger connection with the AC surface. The specific adsorption capacity for Ph and CPh shows a sharp decrease (10-16 times) with increasing carbonization temperature from 400° C to 550 °C and a weak temperature dependence at 550-800 °C. In this range, ACs are formed with similar concentrations of AdCs, but different for various phenolic compounds. Adsorption on brown coal ACs was postulated to include π-π interaction, formation of electron-donor-acceptor complexes and formation of hydrogen bonds, but their contributions depend on adsorbate nature and they change while increasing alkaline carbonization temperature. Keywords: brown coal, alkaline carbonization, activated carbon, porosity, adsorption, phenol, 4-chlorophenol. Corresponding author Таmarkina Ju.V., e-mail: [email protected]


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3811
Author(s):  
Zhongbao Liu ◽  
Jiayang Gao ◽  
Xin Qi ◽  
Zhi Zhao ◽  
Han Sun

In this study, the hydrothermal method was used to synthesize MIL-101(Cr), and activated carbon (AC) with different content was incorporated in to MIL-101(Cr), thereby obtaining AC-MIL-101(Cr) composite material with a huge specific surface area. The physical properties of MIL-101(Cr) and AC-MIL-101(Cr) were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and desorption and specific surface area testing, and ethanol vapor adsorption performance testing. The results show that with the increase of activated carbon content, the thermal stability of AC-MIL-101(Cr) is improved. Compared with the pure sample, the BET specific surface area and pore volume of AC-MIL-101(Cr) have increased; In the relative pressure range of 0–0.4, the saturated adsorption capacity of AC-MIL-101(Cr) to ethanol vapor decreases slightly. It is lower than MIL-101(Cr), but its adsorption rate is improved. Therefore, AC-MIL-101(Cr)/ethanol vapor has a good application prospect in adsorption refrigeration systems. The exploration of AC-MIL-101(Cr) composite materials in this paper provides a reference for the future application of carbon-based/MOFS composite adsorbent/ethanol vapor working fluid in adsorption refrigeration.


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