Preparation of activated carbon from corn cob and its adsorption behavior on Cr(VI) removal

Operation experiments were conducted to optimize the preparation of activated carbons from corn cob. The Cr(VI) adsorption capacity of the produced activated carbons was also evaluated. The impact of the adsorbent dosage, contact time, initial solution pH and temperature was studied. The results showed that the produced corn cob activated carbon had a good Cr(VI) adsorptive capacity; the theoretical maximum adsorption was 34.48 mg g−1 at 298 K. The Brunauer–Emmett–Teller and iodine adsorption value of the produced activated carbon could be 924.9 m2 g−1 and 1,188 mg g−1, respectively. Under the initial Cr(VI) concentration of 10 mg L−1 and the original solution pH of 5.8, an adsorption equilibrium was reached after 4 h, and Cr(VI) removal rate was from 78.9 to 100% with an adsorbent's dosage increased from 0.5 to 0.7 g L−1. The kinetics and equilibrium data agreed well with the pseudo-second-order kinetics model and the Langmuir isotherm model. The equilibrium adsorption capacity improved with the increment of the temperature.

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Characteristics and adsorption study of the activated carbon derived from municipal sewage sludge

Water Science & Technology ◽

10.2166/wst.2017.352 ◽

2017 ◽

Vol 76 (7) ◽

pp. 1697-1705 ◽

Cited By ~ 3

Author(s):

Tiecheng Guo ◽

Sicong Yao ◽

Hengli Chen ◽

Xin Yu ◽

Meicheng Wang ◽

...

Keyword(s):

Activated Carbon ◽

Sewage Sludge ◽

Removal Rate ◽

Freundlich Isotherm ◽

Bet Surface Area ◽

Municipal Sewage ◽

Municipal Sewage Sludge ◽

Isotherm Models ◽

Adsorptive Capacity ◽

Solution Ph

Sewage sludge-based activated carbon is proved to be an efficient and low-cost adsorbent in treatment of various industrial wastewaters. The produced carbon had a well-developed pore structure and relatively low Brunauer–Emmett–Teller (BET) surface area. Adsorptive capacity of typical pollutants, i.e. copper Cu(II) and methylene blue (MB) on the carbon was studied. Adsorptions were affected by the initial solution pH, contact time and adsorbent dose. Results showed that adsorption of Cu(II) and MB on the produced carbon could reach equilibrium after 240 min. The average removal rate for Cu(II) on the carbon was high, up to 97% in weak acidic conditions (pH = 4–6) and around 98% for MB in a very wide pH range (pH = 2–12). The adsorption kinetics were well fitted by the pseudo-second order model, and both Langmuir and Freundlich isotherm models could well describe the adsorption process at room temperature. The theoretical maximum adsorption capacities of Cu(II) and MB on sewage sludge-based activated carbon were 114.94 mg/g and 125 mg/g, respectively. Compared with commercial carbon, the sewage sludge-based carbon was more suitable for heavy metal ions’ removal than dyes’.

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Microwave Preparation of Modified Activated Carbons for Phenol Adsorption in Aqueous Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.1883 ◽

2013 ◽

Vol 726-731 ◽

pp. 1883-1889

Author(s):

Brim Stevy Ondon ◽

Bing Sun ◽

Zhi Yu Yan ◽

Xiao Mei Zhu ◽

Hui Liu

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Adsorption Capacity ◽

Activated Carbons ◽

Microwave Energy ◽

Adsorptive Capacity ◽

Obvious Effect ◽

Phenol Adsorption ◽

Adsorption Capacities ◽

Modified Activated Carbons

Microwave energy was used to prepare modified activated carbons (GAC, GAC/MW, GAC/Ni, and GAC/Cu). The modified activated carbons were used for phenol adsorption in aqueous solution. The adsorption conditions were optimized. Adsorption capacities of the different modified activated carbons were evaluated. The effect of microwave pretreatment of activated carbons was investigated. A comparative study on the activated carbons adsorption capacities was also investigated. Under optimal conditions the results showed that there was no obvious effect on activated carbons adsorption when rising temperature and pH during the adsorption process. Stirring has a very high effect on the activated carbons adsorption capacity. The adsorption capacity of the modified activated carbons reaches 95%. MW/GAC, GAC/Ni and GAC/Cu adsorptive capacity was higher compared to the Granulated Activated Carbon (GAC) used as received. GAC treated with microwave energy has highest adsorption capacity. The adsorption capacity of GAC loaded with ion Ni2+ is higher than the activated carbon loaded with Cu2+. The untreated GAC has the lowest adsorption capacity. These results can be explained by the effect of microwave irradiation on GAC.The activated carbon loaded with Ni2+ adsorbs more microwave energy than the GAC loaded with Cu2+.

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Comparison Study on Adsorption and Removal of Antimony from Acidic Aqueous Solution by Activated Carbons and Machine-Made Charcoal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.779-780.1600 ◽

2013 ◽

Vol 779-780 ◽

pp. 1600-1606 ◽

Cited By ~ 1

Author(s):

Miao Jia ◽

Ji Wei Hu ◽

Jin Luo ◽

Su Ming Duan ◽

Zhi Bin Li ◽

...

Keyword(s):

Aqueous Solution ◽

Activated Carbon ◽

Adsorption Capacity ◽

Activated Carbons ◽

Solution Concentration ◽

Adsorptive Capacity ◽

Acidic Aqueous Solution ◽

Constant Rate ◽

Methylene Blue Number ◽

Relationship Of

Adsorption effects of three kinds of activated carbons and a type of machine-made charcoal on the removal of antimony from acidic aqueous solution were investigated and compared. With an initial antimony solution concentration of 1000 μgL-1, the antimony adsorption by selected adsorbents were found to descend in the following order: machine-made charcoal (52.4%) > coconut activated carbon (42.6%) > coal based activated carbon (31.1%) > apricot stone based activated carbon (24.6%). The machine-made charcoal has the best adsorption capacity with a maximum adsorption values of 523.76 μgL-1. Five kinetic models were used for the fitting of the process of antimony adsorption, including Elovich, parabola diffusion, second order, first order and double-constant. Results showed that parabola diffusion and double-constant rate equation were the most suitable models in describing the relationship of antimony adsorption with time in acidic aqueous solution, implying that the adsorption kinetics of the antimony by the selected adsorbents in water might be a surface diffusion. Three adsorptive capacity indicators (iodine number, methylene blue number and phenol number) were determined in this paper. However, machine-made charcoal, which has a relatively high adsorption capacity, is of the lowest levels of the adsorptive capacity indicators. Thus, some complex mechanisms might be involved for the antimony adsorption by the machine-made charcoal, consequently considering the mechanism for the adsorption of antimony by the charcoal has not been verified, a further study still needs to be done.

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Hydrothermal Synthesis of Sodalite-Type N-A-S-H from Fly Ash to Remove Ammonium and Phosphorus from Water

Materials ◽

10.3390/ma14112741 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2741

Author(s):

Pengcheng Lv ◽

Ruihong Meng ◽

Zhongyang Mao ◽

Min Deng

Keyword(s):

Fly Ash ◽

Adsorption Capacity ◽

Removal Rate ◽

Kinetic Studies ◽

Solute Concentration ◽

Raw Material ◽

Sodium Aluminosilicate ◽

Equilibrium Data ◽

One Step ◽

Ft Ir

In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.

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Oxytetracycline Adsorption from Aqueous Solutions on Commercial and High-Temperature Modified Activated Carbons

Energies ◽

10.3390/en14123481 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3481

Author(s):

Joanna Lach ◽

Agnieszka Ociepa-Kubicka ◽

Maciej Mrowiec

Keyword(s):

Activated Carbon ◽

Aqueous Solutions ◽

Activated Carbons ◽

Electricity Consumption ◽

Solution Ph ◽

Carbon Modification ◽

Modification Method ◽

Flow Through ◽

Proposed Modification ◽

Modified Activated Carbons

The aim of the work was to evaluate the possibility of using commercial and modified activated carbons for the removal of oxytetracycline from aqueous solutions. The kinetics and statics of adsorption as well as the effect of the activated carbon dose and solution pH on the efficiency of the oxytetracycline adsorption were analyzed. Based on the study of oxytetracycline adsorption isotherms, the activated carbons were ranked in the following order: F-300 > WG-12 > Picabiol > ROW08 > WACC 8 × 30 > F-100 > WAZ 0.6–2.4. The most effective activated carbons were characterized by large specific surfaces. The best matching results were obtained for: Redlich–Peterson, Thot and Jovanovic models, and lower for the most frequently used Freundlich and Langmuir models. The adsorption proceeded better from solutions with pH = 6 than with pH = 3 and 10. Two ways of modifying activated carbon were also assessed. A proprietary method of activated carbon modification was proposed. It uses the heating of activated carbon as a result of current flow through its bed. Both carbons modified at 400 °C in the rotary kiln and on the proprietary SEOW (Joule-heat) modification stand enabled to obtain adsorbents with higher and comparable monolayer capacities. The advantage of the proposed modification method is low electricity consumption.

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Comparison of Coal Ash and Activated Carbon for Removal of Humic Acid from Aqueous Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.1509 ◽

2013 ◽

Vol 864-867 ◽

pp. 1509-1512

Author(s):

Xue Mei Zhang ◽

Yan Zhang ◽

Di Fan

Keyword(s):

Aqueous Solution ◽

Humic Acid ◽

Activated Carbons ◽

Removal Rate ◽

Coal Ash ◽

Cost Effective ◽

Solution Ph ◽

Adsorption Behaviors ◽

Calcium Loading ◽

Working Solution

This paper presents the adsorption behaviors of humic acid (HA) on coal ashes and powdered activated carbons (PACs). A bituminous coal, with or without calcium-loading, was used as a feedstock for coal ash preparation. The working solution of HA with a concentration of 20 mg/L was used in all adsorption tests. The results showed that calcium-enriched coal ash (CECA) gave rise to the removal rate of HA as high as 84.05%, much higher than those of raw coal ash (RCA) and PACs. The impacts of solution pH and adsorbent dosage on HA adsorption capacity were also investigated. It was found that lower pH facilitated to the removal of HA from aqueous solution by means of CECA, and the optimal CECA dosage was about 1.0g/L at pH 7.00. The data obtained in this study suggested that calcium-enriched coal ash could be useful and cost-effective in the treatment of wastewaters containing HA-like organic macro-molecules.

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Key Factors for Activated Carbon Adsorption of Pharmaceutical Compounds from Wastewaters: A Multivariate Modelling Approach

Water ◽

10.3390/w14020166 ◽

2022 ◽

Vol 14 (2) ◽

pp. 166

Author(s):

Rui M. C. Viegas ◽

Ana S. Mestre ◽

Elsa Mesquita ◽

Miguel Machuqueiro ◽

Marta A. Andrade ◽

...

Keyword(s):

Adsorption Capacity ◽

Activated Carbons ◽

Univariate Analysis ◽

Pharmaceutical Compounds ◽

Pls Regression ◽

Short Term ◽

Latent Structures ◽

The Impact ◽

Inorganic Matrix ◽

Modelling Approach

Projection to Latent Structures (PLS) regression, a generalization of multiple linear regression, is used to model two datasets (40 observed data points each) of adsorption removal of three pharmaceutical compounds (PhCs), of different therapeutic classes and physical–chemical properties (carbamazepine, diclofenac, and sulfamethoxazole), from six real secondary effluents collected from wastewater treatment plants onto different powdered activated carbons (PACs). For the PLS regression, 25 descriptors were considered: 7 descriptors related to the PhCs properties, 10 descriptors related to the wastewaters properties (8 related to the organic matrix and 2 to the inorganic matrix), and 8 descriptors related to the PACs properties. This modelling approach showed good descriptive capability, showing that hydrophobic PhC-PAC interactions play the major role in the adsorption process, with the solvation energy and log Kow being the most suitable descriptors. The results also stress the importance of the competition effects of water dissolved organic matter (DOM), namely of its slightly hydrophobic compounds impacting the adsorption capacity or its charged hydrophilic compounds impacting the short-term adsorption, while the water inorganic matrix only appears to impact PAC adsorption capacity and not the short-term adsorption. For the pool of PACs tested, the results point to the BET area as a good descriptor of the PAC capacity, while the short-term adsorption kinetics appears to be better related to its supermicropore volume and density. The improvement in these PAC properties should be regarded as a way of refining their performance. The correlations obtained, involving the impact of water, PhC and PAC-related descriptors, show the existence of complex interactions that a univariate analysis is not sufficient to describe.

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Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

10.20944/preprints201908.0076.v1 ◽

2019 ◽

Author(s):

Lorena Alcaraz ◽

María Esther Escudero ◽

Francisco J. Alguacil ◽

Irene Llorente ◽

Ana Urbieta ◽

...

Keyword(s):

Adsorption Capacity ◽

Activated Carbons ◽

Chemical Study ◽

Bet Surface Area ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

Microporous Material ◽

Physico Chemical ◽

Spent Coffee Ground ◽

Coffee Ground

This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.

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Nanoparticle Fe3O4 magnetized activated carbon from Armeniaca sibirica shell for the adsorption of Hg(II) ions

BioResources ◽

10.15376/biores.16.3.6100-6120 ◽

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.

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Pinecone-Derived Activated Carbons as an Effective Medium for Hydrogen Storage

Energies ◽

10.3390/en13092237 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2237

Author(s):

Sara Stelitano ◽

Giuseppe Conte ◽

Alfonso Policicchio ◽

Alfredo Aloise ◽

Giovanni Desiderio ◽

...

Keyword(s):

Activated Carbon ◽

Hydrogen Storage ◽

Adsorption Capacity ◽

Surface Area ◽

Hydrogen Adsorption ◽

Activated Carbons ◽

Chemical Activation ◽

Textural Properties ◽

Biomass Waste ◽

Wavelength Dispersive Spectrometry

Pinecones, a common biomass waste, has an interesting composition in terms of cellulose and lignine content that makes them excellent precursors in various activated carbon production processes. The synthesized, nanostructured, activated carbon materials show textural properties, a high specific surface area, and a large volume of micropores, which are all features that make them suitable for various applications ranging from the purification of water to energy storage. Amongst them, a very interesting application is hydrogen storage. For this purpose, activated carbon from pinecones were prepared using chemical activation with different KOH/precursor ratios, and their hydrogen adsorption capacity was evaluated at liquid nitrogen temperatures (77 K) at pressures of up to 80 bar using a Sievert’s type volumetric apparatus. Regarding the comprehensive characterization of the samples’ textural properties, the measurement of the surface area was carried out using the Brunauer–Emmett–Teller method, the chemical composition was investigated using wavelength-dispersive spectrometry, and the topography and long-range order was estimated using scanning electron microscopy and X-ray diffraction, respectively. The hydrogen adsorption properties of the activated carbon samples were measured and then fitted using the Langmuir/ Töth isotherm model to estimate the adsorption capacity at higher pressures. The results showed that chemical activation induced the formation of an optimal pore size distribution for hydrogen adsorption centered at about 0.5 nm and the proportion of micropore volume was higher than 50%, which resulted in an adsorption capacity of 5.5 wt% at 77 K and 80 bar; this was an increase of as much as 150% relative to the one predicted by the Chahine rule.

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