scholarly journals Micro-mesoporous modified activated carbon from corn husks for removal of hexavalent chromium ions

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Nabila S. Ammar ◽  
Nady A. Fathy ◽  
Hanan S. Ibrahim ◽  
Sahar M. Mousa
Keyword(s):  
Activated Carbon ◽  
Functional Groups ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Activated Carbons ◽  
Sorption Process ◽  
Modified Activated Carbon ◽  
Modeling Studies ◽  
Adsorption Of Nitrogen ◽  
Mesoporous Structures

AbstractModified activated carbon sorbents (ACP-Zn and ACP-Zn-Fe) had been prepared from the activation of corn husks precursor to increase the chemical activity of the resulting adsorbents by increasing the number of active functional groups and generation of micro-mesoporous structures. Fourier transform infrared (FTIR) assessed the acidic surface properties of the prepared activated carbons that is due to the presence acidic functional groups such as –OH and –COOH which improves the removal efficiency of the produced sorbents. Textural characteristics revealed the generation of micro-mesoporous structures in ACP–Zn and ACP-Zn-Fe. Thus the combination of H3PO4 with Zn or Zn–Fe could enhance the mesoporosity with a considerable decrease in the adsorption of nitrogen. However, the formation of mesopores might be attributed to the template-like effects of the obtained Zn- of Zn-Fe compounds inside the carbon structure. These structures were employed as sorbents for removal of hexavalent chromium Cr(VI) ions from its aqueous solutions, and the removal efficiency reached ~ 86% for ACP-Zn-Fe and ~ 82% for ACP-Zn. The kinetic modeling studies revealed that the sorption process follows the pseudo-second-order model which indicates that the mechanism of process is chemisorptions. Freundlich, Langmuir and Dubinin–Radushkevich (D–R) models were used to express the experimental data. The isotherm modeling studies revealed that the sorption process was fit with both Freundlich and Langmuir models with maximum capacity 24.8 and 30.3 mg/g for ACP-Zn and ACP-Zn-Fe, respectively.

scholarly journals Sequestration of hexavalent chromium from aqueous solutions by activated carbon derived from Macadamia nutshells

2016 ◽  
Vol 75 (1) ◽  
pp. 196-206 ◽  
Author(s):  
V. E. Pakade ◽  
O. B. Nchoe ◽  
L. Hlungwane ◽  
N. T. Tavengwa
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Hexavalent Chromium ◽  
Activated Carbons ◽  
Cost Effective ◽  
Sorption Process ◽  
Freundlich Model ◽  
Optimum Parameters ◽  
Effective Removal ◽  
Efficient Adsorbent

The purpose of this study was to investigate the feasibility of activated carbons prepared from Macadamia nutshells as an efficient adsorbent for the removal of hexavalent chromium (Cr(VI)) from aqueous solutions. The activated carbon was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), CHNS analyzer and Brunauer–Emmett–Teller (BET). For effective removal of Cr(VI), the optimum parameters found were pH 2, 120 min of contact time and 0.2 g of sorbent. The adsorption data fitted well into the Freundlich model, suggesting a multilayer sorption process. The results demonstrated that Macadamia activated carbon could be used as cost-effective biosorbent for the treatment of aqueous solutions contaminated by Cr(VI) with an adsorption capacity of 22.3 mg g−1. The mode of removal involved adsorption and reduction of Cr(VI) to Cr(III).

scholarly journals Post-treatment of coke wastewater on activated carbons

2018 ◽  
Vol 44 ◽  
pp. 00088 ◽  
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Magdalena Madeła ◽  
Magdalena Wrońska
Keyword(s):  
Activated Carbon ◽  
Sorption Capacity ◽  
Removal Efficiency ◽  
Vibration Amplitude ◽  
Activated Carbons ◽  
Sorption Process ◽  
Post Treatment ◽  
Sonication Time ◽  
Coke Wastewater ◽  
Static Conditions

The aim of this research was to determine the effect the ozonation and sonification processes for post-treatment of coke wastewaters using activated carbons. The tests were carried out in three systems ie. I-AC (activated carbon), II-O3+AC (ozonation + activated carbon) and III-US+AC (ultrasound + activated carbon). In the experiment were used a three types of activated carbons: WG-12, ROW 08 Supra and Picabiol. The sorption process was carried out in static conditions at contact for 24h time of the wastewater with activated carbons. Coke wastewater was oxidized through ozonation at a constant ozone dose of 10 mg/dm3. Sonication of coke wastewater was conducted at vibration amplitude was 61.5 μm, with sonication time of 8 min. Results of removing of COD were estimated on the base of sorption capacity and COD removal efficiency. The second system was the most effective (O3+AC) for carbons WG-12 and ROW 08 Supra, whereas in the case of carbon Picabiol, the best efficiency was found for system I (AC). The lowest efficiency of removal of COD from coke wastewater was the systems III (US+AC) for all three activated carbons.

scholarly journals Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review

2012 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
W.D.P Rengga ◽  
M. Sudibandriyo ◽  
M Nasikin
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Energy ◽  
Hydrogen Gas ◽  
Agricultural Product ◽  
Adsorption Method ◽  
Modified Activated Carbon ◽  
Nano Size ◽  
Formaldehyde Adsorption

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy. Keywords: adsorption; bamboo; formaldehyde; modified activated carbon; nano size particles

Attachment and Growth of Biomass on Surface-Modified Activated Carbon Fibers

1992 ◽  
Vol 26 (3-4) ◽  
pp. 665-671 ◽  
Author(s):  
K. Kutics ◽  
M. Suzuki
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Calculated Data ◽  
Bacterial Biomass ◽  
Activated Carbon Fiber ◽  
Continuous Stirred Tank Reactor ◽  
Modified Activated Carbon ◽  
Start Up ◽  
Surface Modified

Activated carbon fiber (ACF) was used as a model of commercial activated carbons to examine the effect of surface chemistry on the attachment behavior of bacterial biomass. Surface acidity was found to enhance the biomass-ACF interaction. When ACFs were applied as biomass support media in a continuous stirred tank reactor, surface acidity of the carbon resulted in faster biomass growth in the start-up phase. The start-up phase was simulated by a simple biomass attachment kinetics model. Experimental and calculated data show a reasonable agreement, with the exception of the hydrogenated specimen, which was interpreted by assuming that the hydrogen-reduced surface is highly reactive and then may undergo oxidation in the initial phase of operation so that the adsorption characteristics are altered.

Modification of Activated Carbon and its Application on Adsorption of UDMH Gas

2013 ◽  
Vol 634-638 ◽  
pp. 1026-1030 ◽  
Author(s):  
Huan Chun Wang ◽  
Xiao Li Gou ◽  
Xiao Meng Lv
Keyword(s):  
Activated Carbon ◽  
High Temperature ◽  
Transition Metal ◽  
Surface Structure ◽  
Functional Groups ◽  
Room Temperature ◽  
Activated Carbons ◽  
Metal Solution ◽  
Modified Activated Carbons

Two kinds of modified activated carbons were prepared by dipping with Zn(NO3)2 solution and by reducing in the atmosphere of N2 at high temperature respectively, which were characterized by FTIR,DSC,SEM and EDS. The surface structure was strongly changed in the process, along with the changes of chemical functional groups. The results of adsorption experiments revealed that the adsorbent capacities of UDMH gas at room temperature were enhanced obviously by modification compared with the raw activated carbon, especially dipped by transition metal solution. The mechanism probably involved was also discussed.

Characteristics of Activated Carbon Modified with Nitric Acid and its Performance in Catalytic Ozonation of Acid Red 3R

2013 ◽  
Vol 726-731 ◽  
pp. 1687-1690
Author(s):  
Jing Zhang ◽  
Jian Song Liu ◽  
Chun Liu ◽  
Jing Liang Yang ◽  
Lei Zhang
Keyword(s):  
Activated Carbon ◽  
Nitric Acid ◽  
Adsorption Capacity ◽  
Functional Groups ◽  
Chemical Properties ◽  
Catalytic Ozonation ◽  
Alkaline Condition ◽  
Ozone Decomposition ◽  
Acid Modification ◽  
Modified Activated Carbon

The structure and surface chemical properties of activated carbon after nitric acid modification and their influences on adsorption and catalytic ozonation of acid red 3R were investigated. The results showed that both specific surface area and micropore volume of activated carbon decreased, but mesopore volume increased after nitric acid modification. The adsorption capacity and catalytic ozonation performance of modified activated carbon were influenced due to the increased surface acidic functional groups. The adsorption capacity of modified activated carbon was enhanced under acidic condition due to dispersion interaction between increased surface acidic functional groups and acid red 3R. The increase in surface acidic functional groups of activated carbon was also considered to be responsible for improvement of the catalytic ozonation of acid red 3R under alkaline condition, because of their participation in the ozone decomposition and OH generation.

scholarly journals Adsorption of Polydisperse Polyvinyl Alcohol Molecules on the Surface of Activated Carbons

2003 ◽  
Vol 21 (5) ◽  
pp. 463-473
Author(s):  
J. Barkauskas ◽  
A. Vinslovaite
Keyword(s):  
Activated Carbon ◽  
Polyvinyl Alcohol ◽  
Functional Groups ◽  
Adsorption Process ◽  
Activated Carbons ◽  
Surface Heterogeneity ◽  
Raw Material ◽  
Carbon Substrate ◽  
Gel Chromatography ◽  
Graphene Layers

The adsorption of polyvinyl alcohol (PVA) on activated carbons was studied in aqueous solutions. Each batch of activated carbon produced was obtained via a definite number of technological operations using wood as the raw material. The adsorption process was studied using a gel chromatography technique with potentiometric titrations being employed for evaluating the chemical composition of the activated carbons produced. The data obtained from the various activated carbon samples were compared to ascertain the adsorption mechanism. It was concluded that water molecules had a limited influence on the competitive process of polymer adsorption. A rather pronounced negative correlation between the number of phenol functional groups and PVA adsorption capacity was observed, indicating that these groups hindered the adsorption process. Assumptions concerning the role of phenol functional groups were made, taking into account not only the surface heterogeneity but also changes in the electron density of the graphene layers in the carbon substrate.

scholarly journals Removal of Zinc by Bitter Orange Peels Activated Carbon and Commercially Activated Carbon, a Comparison Study.

2017 ◽  
Vol 5 (1) ◽  
pp. 120-131
Author(s):  
Laith Hamdan Hawal
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Treatment Time ◽  
Activated Carbons ◽  
Bitter Orange ◽  
Orange Peels ◽  
Effects Of Ph ◽  
Zinc Concentrations ◽  
Adsorbent Materials

 In this study, a comparison between using activated carbon prepared from bitter orange peels (BOAC) and a common commercially activated carbon (CAC), which is brought from the market, as adsorbent materials. This study was designed to find out which of these two activated carbons is more effective in the removal of zinc from waste water. This work examines the use of bitter orange peels, which are available as waste in local markets and in household garbage as an alternative presage to prepare an activated carbon by using (H2SO4) as activating reagent. The effects of pH, initial zinc concentrations, treatment time, adsorbent media bed height and the flow rate of simulated synthetic aqueous solution (SSAS) on the removal efficiency of zinc were all studied under 24oC The results indicated that the removal efficiency of zinc increases with decreasing in pH of SSAS. When the initial concentration of zinc increases in SSAS, the removal efficiency of zinc was decreased. The study proved that the increasing of contact time leads to greater removal efficiency. When the height of adsorbent media in fixed column increases, the removal efficiency was increased. The experiments also showed that the removal efficiency of zinc from the SSAS increased, when the flow rate decreased. It could be concluded from this work that (BOAC) is better than (CAC) as an adsorbent materials in the removal of zinc; with a removal efficiency of (90%, 86%), respectively

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