Efecto del grupo funcional en la adsorción de Ag(I) en soluciones sintéticas con materiales mesoroprosos de silica

One of the main methodologies used in the industry for the recovery of gold and silver from cyanidation-rich solutions is the adsorption of activated carbon, a process that presents as the main disadvantage the formation of fines in the sorting screens that is where it is recovered, These fines represent a considerable loss of values in the process, which is why the search for alternatives that allow the recovery of gold and silver from the cyanidation rich solutions is of interest to hydrometallurgy, in this sense the magnetic preconcentration could be an alternative to this process; The present work shows the synthesis, characterization and study of the adsorption capacity of Ag (I) of mesoporous materials of silica modified with magnetite. These materials showed a good retention of magnetite in their structure based on the presence of amino groups in their structure, as well as silver adsorption capacities of 86.21-19.8 mgg-1.

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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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Adsorption behaviour and mechanism of the PFOS substitute OBS (sodium p -perfluorous nonenoxybenzene sulfonate) on activated carbon

Royal Society Open Science ◽

10.1098/rsos.191069 ◽

2019 ◽

Vol 6 (9) ◽

pp. 191069 ◽

Cited By ~ 3

Author(s):

Wei Wang ◽

Xin Mi ◽

Huilan Shi ◽

Xue Zhang ◽

Ziming Zhou ◽

...

Keyword(s):

Particle Size ◽

Activated Carbon ◽

Pore Size ◽

Adsorption Capacity ◽

Organic Pollutant ◽

Chemical Properties ◽

Hot Water ◽

Adsorption Behaviour ◽

Adsorption Capacities ◽

Naoh Solution

Perfluorooctane sulfonate (PFOS) was listed as a persistent organic pollutant by the Stockholm Convention. As a typical alternative to PFOS, sodium p -perfluorous nonenoxybenzene sulfonate (OBS) has recently been detected in the aquatic environment which has caused great concern. For the first time, the adsorption behaviour and mechanism of OBS on activated carbon (AC) with different physical and chemical properties were investigated. Decreasing the particle size of AC can accelerate its adsorption for OBS, while AC with too small particle size was not conducive to its adsorption capacity due to the destruction of its pore structure during the mechanical crushing process. Intra-particle diffusion had a lesser effect on the adsorption rate of AC with smaller particle size, higher hydrophilicity and larger pore size. Reactivation of AC by KOH can greatly enlarge their pore size and surface area, greatly increasing their adsorption capacities. The adsorption capacity of two kinds of R-GAC exceeded 0.35 mmol g −1 , significantly higher than that of other ACs. However, increasing the hydrophilicity of AC would decrease their adsorption capacities. Further investigation indicated that a larger pore size and smaller particle size can greatly enhance the adsorptive removal of OBS on AC in systems with other coexisting PFASs and organic matter due to the reduction of the pore-blocking effect. The spent AC can be successfully regenerated by methanol, and it can be partly regenerated by hot water and NaOH solution. The percentage of regeneration for the spent AC was 70.4% with 90°C water temperature and up to 95% when 5% NaOH was added into the regeneration solution. These findings are very important for developing efficient adsorbents for the removal of these newly emerging PFASs from wastewater and understanding their interfacial behaviour.

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Study of natural adsorbent chitosan and derivatives for the removal of caffeine from water

Water Quality Research Journal ◽

10.2166/wqrjc.2012.021 ◽

2012 ◽

Vol 47 (1) ◽

pp. 80-90 ◽

Cited By ~ 3

Author(s):

Serena Sanford ◽

Kripa S. Singh ◽

Sahil Chaini ◽

Gaetan LeClair

Keyword(s):

Hydrogen Peroxide ◽

Activated Carbon ◽

Adsorption Capacity ◽

Mesoporous Materials ◽

Isotherm Models ◽

Batch Adsorption ◽

Chemical Modifications ◽

High Affinity ◽

Natural Adsorbent ◽

Batch Tests

The adsorption of caffeine was evaluated using natural adsorbent chitosan and three derivates of the material. Raw, H2O2 pre-treated, and a chemically altered chitosan were compared to activated carbon. Activated carbon was found to have a high affinity for caffeine (98% removal) while raw chitosan performed poorly with an average adsorption of 15.9%. Batch tests in acidic and basic conditions as well as increasing dosage did not have an effect on the performance. Chemical modifications to chitosan included calcinated mesoporous materials and non-calcinated materials, both of which increased chitosan adsorption of caffeine to 29 and 40%, respectively. Hydrogen peroxide pre-treated chitosan performed best of chitosan-based adsorbents, and reached a 46% removal of caffeine in batch adsorption tests. The majority of the adsorbents had low correlation to the Langmuir, Freundlich, and Redlich–Peterson isotherm models. However, data were sufficient to compare adsorption capacity for caffeine among activated carbon, chitosan, and chitosan derivatives.

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Adsorption CO2 on Activated Carbon with Surface Modification

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.746 ◽

2013 ◽

Vol 634-638 ◽

pp. 746-750 ◽

Cited By ~ 5

Author(s):

Cheng Lin ◽

Hui Yun Zhang ◽

Xiao Ying Lin ◽

Yun Fei Feng

Keyword(s):

Surface Modification ◽

Activated Carbon ◽

Activate Carbon ◽

Adsorption Capacity ◽

Flue Gas ◽

Adsorption Process ◽

Low Cost ◽

Solid Sorbent ◽

Adsorption Capacities ◽

New Type

The success of CO2 capture from flue gas with solid sorbent is dependent of a low cost sorbent with high CO2 adsorption capacity and selectivity. Modifying surface texture of activated carbon with impregnating amines is expected to offer the benefits of liquid amines in the typical adsorption process routes. In this work, cocoanut activate carbon (AC) is firstly alkalified by KOH solution, then modified by impregnation of tetraethylenepentamine (TEPA), triethylenetetramine (TATA), and triethanolamine (TEA) to form a new type of sorbents. The effects of alkalifying treatment and temperature on CO2 adsorption capacities of the sorbents are investigated. Results indicate that the activate carbons modified by combining alkalification pretreatment firstly and then impregnated amines at low temperature are profitable for CO2 adsorption. The adsorption capacities of CO2 are enhanced with TEPA and TETA impregnation on the activate carbon pretreated by KOH solution. And CO2 adsorption capacity of new sorbents is stable after many adsorption and desorption cycles.

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Freundlich, Langmuir, Temkin, DR and Harkins-Jura Isotherm Studies on the Adsorption of CO2 on Various Porous Adsorbents

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2018-0134 ◽

2018 ◽

Vol 17 (5) ◽

Cited By ~ 4

Author(s):

Fatma Oguz Erdogan

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Low Cost ◽

Type A ◽

Isotherm Models ◽

Koh Activation ◽

Cornelian Cherry ◽

Cornus Mas ◽

Adsorption Capacities ◽

Mcm 41

Abstract The objective of the study was to prepare low-cost activated carbon from cornelian cherry stones (Cornus mas L.) and compare its adsorption capacities for CO2 with that of commercial multiwalled carbon nanotubes, activated carbon, MCM-41 and four zeolites (silver exchanged, 13X, faujasite type and linde type A). BET, t-plot and DFT methods were used for the characterization of all adsorbent samples based on N2 adsorption-desorption data obtained at 77 K. The produced activated carbon samples (KAC and NAC) were also characterized by scanning electron microscopy (SEM). The adsorption data were evaluated by several isotherm models such as Freundlich, Langmuir, Temkin, DR and Harkins-Jura isotherm models. Langmuir adsorption isotherms constants related to adsorption capacity, Wm were found as 11.496, 6.175, 4.189, 3.986 and 3.50 mmol/g for NAC, KAC, faujasite type zeolit, MCM-41 and AC, respectively. The CO2 adsorption capacities of the silver exchanged, 13X, faujasite type and linde type A zeolites were 10.814, 10.241, 14.608 and 13.343 wt%, respectively. Microporous zeolites showed higher CO2 adsorption capacities than the mesoporous MCM-41 and MWCNT. The CO2 adsorption capacity of commercial activated carbon (AC) was found to be 9.428 wt%, while the CO2 adsorption capacities of activated carbons obtained using NaOH and KOH were found to be 13.685 and 15.057 wt%, respectively. The highest CO2 adsorption capacity of 15.057 wt% was achieved with KAC. It could be confirmed that NaOH or KOH activation plays an important role to determine the porous structure and amount of CO2 adsorbed. Results showed that activated carbon produced from cornelian cherry stones is suitable for the adsorption of CO2 and could be used as a low cost effective adsorbent in the capture of CO2.

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Analisis Variasi Temperatur Aktivasi Terhadap Daya Serap Arang Aktif Tandan Aren (Arenga Pinnata Merr) Dengan Agen Aktivasi Potassium Silicate(K2SiO3)

Jurnal Penelitian Pendidikan Fisika ◽

10.36709/jipfi.v5i3.13803 ◽

2020 ◽

Vol 5 (3) ◽

pp. 221

Author(s):

Muhammad Azam ◽

Muhammad Anas ◽

Erniwati Erniwati

Keyword(s):

Methylene Blue ◽

Activated Carbon ◽

Adsorption Capacity ◽

Temperature Variation ◽

Chemical Activation ◽

Weight Ratio ◽

Potassium Silicate ◽

Physical Activation ◽

Activation Temperature ◽

Pyrolysis Reactor

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.

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Electroadsorption of Bromide from Natural Water in Granular Activated Carbon

Water ◽

10.3390/w13050598 ◽

2021 ◽

Vol 13 (5) ◽

pp. 598

Author(s):

David Ribes ◽

Emilia Morallón ◽

Diego Cazorla-Amorós ◽

Francisco Osorio ◽

María J. García-Ruiz

Keyword(s):

Activated Carbon ◽

Electric Field ◽

Adsorption Capacity ◽

Natural Water ◽

Granular Activated Carbon ◽

Open Circuit ◽

Filter Press ◽

Anodic Treatment ◽

Positive Polarization ◽

Two Stages

The adsorption and electroadsorption of bromide from natural water has been studied in a filter-press electrochemical cell using a commercial granular activated carbon as the adsorbent. During electroadsorption experiments, different voltages were applied (2 V, 3 V and 4 V) under anodic conditions. The presence of the electric field improves the adsorption capacity of the activated carbon. The decrease in bromide concentration observed at high potentials (3 V or 4 V) may be due to the electrochemical transformation of bromide to Br2. The anodic treatment produces a higher decrease in the concentration of bromide in the case of cathodic electroadsorption. Moreover, in this anodic electroadsorption, if the system is again put under open circuit conditions, no desorption of the bromide is produced. In the case of anodic treatment in the following adsorption process after 24 h of treatment at 3 V, a new decrease in the bromide concentration is observed as a consequence of the decrease in bromide concentration after the electrochemical stage. It can be concluded that the electroadsorption process is effective against the elimination of bromide and total bromine in water, with a content of 345 and 470 µg L−1, respectively, reaching elimination values of 46% in a single-stage electroadsorption process in bromide and total bromine. The application of the electric field to the activated carbon with a positive polarization (anodic electroadsorption) increases the adsorption capacity of the activated carbon significantly, achieving a reduction of up to 220 µg L−1 after 1 h of contact with water. The two stage process in which a previous electrochemical oxidation is incorporated before the electroadsorption stage significantly increased the efficiency from 46% in a single electroadsorption step at 3 V, to 59% in two stages.

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TiO2-Powdered Activated Carbon (TiO2/PAC) for Removal and Photocatalytic Properties of 2-Methylisoborneol (2-MIB) in Water

Water ◽

10.3390/w13121622 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1622

Author(s):

Xiao-Pin Guo ◽

Peng Zang ◽

Yong-Mei Li ◽

Dong-Su Bi

Keyword(s):

Activated Carbon ◽

Natural Organic Matter ◽

Uv Light ◽

Sol Gel ◽

Light Irradiation ◽

Nano Tio2 ◽

Uv Light Irradiation ◽

Adsorption Capacities ◽

Taste And Odor ◽

Composite Photocatalysts

2-methylisoborneol (2-MIB) is a common taste and odor compound caused by off-flavor secondary metabolites, which represents one of the greatest challenges for drinking water utilities worldwide. A TiO2-coated activated carbon (TiO2/PAC) has been synthesized using the sol-gel method. A new TiO2/PAC photocatalyst has been successfully employed in photodegradation of 2-MIB under UV light irradiation. In addition, the combined results of XRD, SEM-EDX, FTIR and UV-Vis suggested that the nano-TiO2 had been successfully loaded on the surface of PAC. Experimental results of 2-MIB removal indicated that the adsorption capacities of PAC for 2-MIB were higher than that of TiO2/PAC. However, in the natural organic matter (NOM) bearing water, the removal efficiency of 2-MIB by TiO2/PAC and PAC were 97.8% and 65.4%, respectively, under UV light irradiation. Moreover, it was shown that the presence of NOMs had a distinct effect on the removal of MIB by TiO2/PAC and PAC. In addition, a simplified equivalent background compound (SEBC) model could not only be used to describe the competitive adsorption of MIB and NOM, but also represent the photocatalytic process. In comparison to other related studies, there are a few novel composite photocatalysts that could efficiently and rapidly remove MIB by the combination of adsorption and photocatalysis.

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