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 Synthesis and characterization of activated carbon from sugar beet residue for the adsorption of hexavalent chromium in aqueous solutions

RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 8025-8032
Author(s):  
Jiaming Zhao ◽  
Lihua Yu ◽  
Feng Zhou ◽  
Huixia Ma ◽  
Kongyan Yang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Sugar Beet ◽  
Aqueous Solutions ◽  
Hexavalent Chromium ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Synthesis And Characterization ◽  
Step Method ◽  
Characterization Of Activated Carbon

A series of micro–mesoporous activated carbons (ACs) were prepared from sugar beet residue by a two-step method including KOH chemical activation and were used for Cr(vi) removal from aqueous solutions.

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

Energies ◽  
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.

scholarly journals Removal of Hexavalent Chromium Ions from Aqueous Solutions by an Anion-Exchange Resin

2008 ◽  
Vol 26 (9) ◽  
pp. 693-703 ◽  
Author(s):  
P. Senthil Kumar ◽  
K. Kirthika ◽  
K. Sathish Kumar
Keyword(s):  
Aqueous Solutions ◽  
Anion Exchange ◽  
Hexavalent Chromium ◽  
Exchange Resin ◽  
Ph Value ◽  
Anion Exchange Resin ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Isotherm Models ◽  
Exchange Resins

The removal of hexavalent chromium, Cr(VI), from aqueous solutions under different conditions using an anion-exchange resin (AXR) as an adsorbent was investigated under batch conditions. Such studies indicated that the percentage adsorption decreased with increasing initial Cr(VI) concentration, with the maximum removal of such ions occurred at a pH value of ca. 2.0. Both the Langmuir and Freundlich isotherm models were capable of reproducing the isotherms obtained experimentally. The sorption process was rapid during the first 20 min with equilibrium being attained within 30 min. The process followed first-order kinetics. The results demonstrate that such anion-exchange resins can be used for the efficient removal of Cr(VI) ions from water and wastewater.

Elaboration of novel polyaniline@Almond shell biocomposite for effective removal of hexavalent chromium ions and Orange G dye from aqueous solutions

2020 ◽  
Vol 27 (13) ◽  
pp. 15245-15258 ◽  
Author(s):  
Abdelghani Hsini ◽  
Abdelilah Essekri ◽  
Nouh Aarab ◽  
Mohamed Laabd ◽  
Abdelaziz Ait Addi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hexavalent Chromium ◽  
Almond Shell ◽  
Chromium Ions ◽  
Effective Removal ◽  
Orange G

scholarly journals Adsorption of Polycyclic Aromatic Hydrocarbons (PAHS) from Aqueous Solutions on Different Sorbents

2014 ◽  
Vol 13 (2) ◽  
pp. 87-96 ◽  
Author(s):  
Marzena Smol ◽  
Maria Włodarczyk-Makuła ◽  
Dariusz Włóka
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Aqueous Solutions ◽  
Aromatic Hydrocarbons ◽  
Environmental Samples ◽  
Sorption Process ◽  
Mineral Sorbent ◽  
Polycyclic Aromatic ◽  
Individual Hydrocarbons ◽  
Treatment Procedures

Abstract This paper presents the results of the possibility and effectiveness of PAHs removal from a model aqueous solution, during the sorption on the selected sorbents. Six PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene) listed by EPA for the analysis in the environmental samples were determined. Model aqueous solution was prepared with RESTEK 610 mix PAHs standard. After the sorption process, decrease in the concentration of individual hydrocarbons was observed. The removal percentage was dependent on the type of sorbent (quartz sand, mineral sorbent, activated carbon). The highest efficiency (98.1%) was observed for activated carbon.. The results shows that the sorption processes can be used in aqueous solutions treatment procedures.

Metal–organic framework@silica as a stationary phase sorbent for rapid and cost-effective removal of hexavalent chromium

2018 ◽  
Vol 6 (6) ◽  
pp. 2742-2751 ◽  
Author(s):  
Worood A. El-Mehalmey ◽  
Ahmed H. Ibrahim ◽  
Arwa A. Abugable ◽  
Mohamed H. Hassan ◽  
Rana R. Haikal ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Hexavalent Chromium ◽  
Metal Organic Framework ◽  
Cost Effective ◽  
Amino Derivative ◽  
Solid Sorbent ◽  
One Pot ◽  
Effective Removal ◽  
Metal Organic ◽  
Organic Framework

A one-pot synthesis is described to construct a composite of the amino-derivative Zr carboxylate metal–organic framework and silica gel (UiO-66-NH2@silica) as an efficient solid sorbent for hexavalent chromium.

Sign in / Sign up

Export Citation Format

Share Document