Adsorption Behaviors of Hydroquinone onto Porous Adsorbents

2012 ◽  
Vol 610-613 ◽  
pp. 1971-1974
Author(s):  
Zeng Yin Zhu ◽  
Bing Li ◽  
Hai Suo Wu ◽  
Wei Liu ◽  
Jin Wei
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Molecular Species ◽  
Adsorption Kinetic ◽  
Adsorption Behaviors ◽  
Low Concentrations ◽  
Porous Adsorbents ◽  
Ph Dependent

As the toxicity even at low concentrations, pollution of phenolic compounds has become an issue of international concern. Adsorption has been proven to be the effective and widely used method for phenolic compounds removal. In this study, porous resins as adsorbents for the removal of hydroquinone from aqueous solutions were evaluated. Activated carbon F400D was employed for comparison. The faster adsorption kinetic was observed on the mesoporous XAD-4, while the higher adsorption capacity was obtained on the microporous NDA150, which had larger surface area. Despite the different surface properties and pore structures of the studied adsorbents, similar trends of pH-dependent adsorption were observed, implying the importance of the hydroquinone molecular species to the adsorption onto the porous adsorbents. This work provided an understanding of adsorption behavior of hydroquinone on porous adsorbents.

Activated carbon from avocado seeds for the removal of phenolic compounds from aqueous solutions

2017 ◽  
Vol 71 ◽  
pp. 168-181 ◽  
Author(s):  
Anderson J.B. Leite ◽  
Carmalin Sophia A. ◽  
Pascal S. Thue ◽  
Glaydson S. dos Reis ◽  
Silvio L.P Dias ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Aqueous Solutions

Adsorption of leather dye onto activated carbon prepared from bottle gourd: equilibrium, kinetic and mechanism studies

2013 ◽  
Vol 67 (1) ◽  
pp. 201-209 ◽  
Author(s):  
Edson Luiz Foletto ◽  
Caroline Trevisan Weber ◽  
Diego Silva Paz ◽  
Marcio Antonio Mazutti ◽  
Lucas Meili ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Adsorption Kinetic ◽  
Bottle Gourd ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Equilibrium Data

Activated carbon prepared from bottle gourd has been used as adsorbent for removal of leather dye (Direct Black 38) from aqueous solution. The activated carbon obtained showed a mesoporous texture, with surface area of 556.16 m2 g−1, and a surface free of organic functional groups. The initial dye concentration, contact time and pH significantly influenced the adsorption capacity. In the acid region (pH 2.5) the adsorption of dye was more favorable. The adsorption equilibrium was attained after 60 min. Equilibrium data were analyzed by the Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherm models. The equilibrium data were best described by the Langmuir isotherm, with maximum adsorption capacity of 94.9 mg g−1. Adsorption kinetic data were fitted using the pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models. The adsorption kinetic was best described by the second-order kinetic equation. The adsorption process was controlled by both external mass transfer and intraparticle diffusion. Activated carbon prepared from bottle gourd was shown to be a promising material for adsorption of Direct Black 38 from aqueous solution.

scholarly journals Adsorption of Crystal Violet Dye Using Activated Carbon of Lemon Wood and Activated Carbon/Fe3O4 Magnetic Nanocomposite from Aqueous Solutions: A Kinetic, Equilibrium and Thermodynamic Study

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2241
Author(s):  
Rauf Foroutan ◽  
Seyed Jamaleddin Peighambardoust ◽  
Seyed Hadi Peighambardoust ◽  
Mirian Pateiro ◽  
Jose M. Lorenzo
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Crystal Violet ◽  
Fe3o4 Nanoparticles ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Magnetic Nanocomposite ◽  
Maximum Adsorption Capacity ◽  
Adsorption Enthalpy

Activated carbon prepared from lemon (Citrus limon) wood (ACL) and ACL/Fe3O4 magnetic nanocomposite were effectively used to remove the cationic dye of crystal violet (CV) from aqueous solutions. The results showed that Fe3O4 nanoparticles were successfully placed in the structure of ACL and the produced nanocomposites showed superior magnetic properties. It was found that pH was the most effective parameter in the CV dye adsorption and pH of 9 gave the maximum adsorption efficiency of 93.5% and 98.3% for ACL and ACL/Fe3O4, respectively. The Dubinin–Radushkevich (D-R) and Langmuir models were selected to investigate the CV dye adsorption equilibrium behavior for ACL and ACL/Fe3O4, respectively. A maximum adsorption capacity of 23.6 and 35.3 mg/g was obtained for ACL and ACL/Fe3O4, respectively indicating superior adsorption capacity of Fe3O4 nanoparticles. The kinetic data of the adsorption process followed the pseudo-second order (PSO) kinetic model, indicating that chemical mechanisms may have an effect on the CV dye adsorption. The negative values obtained for Gibb’s free energy parameter (−20 < ΔG < 0 kJ/mol) showed that the adsorption process using both types of the adsorbents was physical. Moreover, the CV dye adsorption enthalpy (ΔH) values of −45.4 for ACL and −56.9 kJ/mol for ACL/Fe3O4 were obtained indicating that the adsorption process was exothermic. Overall, ACL and ACL/Fe3O4 magnetic nanocomposites provide a novel and effective type of adsorbents to remove CV dye from the aqueous solutions.

scholarly journals ADSORPTION OF FOOD COLORING ALLURA RED DYE (E129) FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON

2017 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Saad A Alkahtani ◽  
Samer S Abu-Alrub ◽  
Ashraf M Mahmoud
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Kinetic Models ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Allura Red

<p>The adsorption behavior of Allura red (E129)<strong> </strong>from aqueous solutions onto activated carbon was successfully investigated. All factors affecting the adsorption process were carefully studied and the conditions were optimized. Adsorption of E129 onto activated carbon was found to increase by decreasing the mass of activated carbon, pH and ionic strength of the solution and by increasing temperature. The adsorption capacity of the activated carbon for Allura red was relatively high. Under the optimum conditions, the maximum adsorption capacity for E129 dye was 72.85 mg/g. Three adsorption models; Langmuir, Freundlich and Temkin model were investigated regarding the adsorption of E129. The models’ parameters K<sub>L</sub>, qm, R2, (n) were determined and found to be 0.0222, 72.85 mg/g, 0.9057-0.9984, and 0.992, respectively. Also, pseudo first and second-order kinetic models were tested to determine the best-fit model to the adsorption of E129 dye onto activated carbon. The results showed that the adsorption of E129 onto activated carbon obeyed both the Freundlich isotherm and pseudo second-order kinetic models. Moreover, thermodynamic studies indicated that the adsorption of E129 dye onto the activated carbon was spontaneous. </p>

scholarly journals Removal of metoprolol from aqueous solutions by the activated carbon prepared from pine cones

2019 ◽  
Vol 6 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Dariush Naghipour ◽  
Abdoliman Amouei ◽  
Kamran Taher Ghasemi ◽  
Kamran Taghavi
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Contact Time ◽  
Wastewater Treatment Plants ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Pine Cones ◽  
Adsorbent Dose

Background: Metoprolol (MTP) with its low biodegradability is one of the most dominant micropollutant in the effluent of wastewater treatment plants. The aim of this study was to investigate the removal of metoprolol from aqueous solutions by the activated carbon prepared from pine cones. Methods: The pine cones were activated using thermal activation method. Characteristics of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). In this study, the influent of different parameters such as pH, contact time, initial concentrations of metoprolol, adsorbent dose, temperature, adsorption isotherms, and kinetics were investigated. Results: The maximum removal efficiency of MTP (89.2%) was obtained at pH=8.5, adsorbent dose=1.5 g, contact time=60 min, and initial concentration=50 mg/L. By increasing the adsorbent dose, the removal efficiency also increased, but the adsorption capacity decreased, however, by increasing the initial concentration, the removal efficiency decreased, but the adsorption capacity increased. The isotherm experimental data for metoprolol was best fitted using the Langmuir model, and kinetic data were better described by pseudo-second-order kinetic model. The thermodynamic study indicated that the adsorption of MTP by the adsorbent was feasible, spontaneous, and endothermic. Conclusion: MTP removal by the activated carbon prepared from pine cones showed that this natural adsorbent is appropriate for removal of metoprolol from aqueous solutions regarding cost, efficiency, and production method.

Effects of Inorganic Orthophosphate and Pyrophosphate on Dissolution of Calcium Fluoride in Water

1988 ◽  
Vol 67 (2) ◽  
pp. 447-449 ◽  
Author(s):  
F. Lagerlöf ◽  
E. Saxegaard ◽  
P. Barkvoll ◽  
G. Rølla
Keyword(s):  
Aqueous Solutions ◽  
Calcium Fluoride ◽  
Clinical Studies ◽  
Slow Release ◽  
Dental Enamel ◽  
Fluoride Release ◽  
Ph Values ◽  
Rate Of Dissolution ◽  
Low Concentrations ◽  
Ph Dependent

Calcium and fluoride release from excess solid calcium fluoride was monitored for 15-30 min in aqueous solutions containing various concentrations of inorganic orthophosphate and pyrophosphate. Low concentrations of these ions (1-10 μmol/L) considerably inhibited the rate of dissolution of calcium fluoride. This inhibition was pH-dependent, being reduced at pH values below 5. It is suggested that a reduced calcium fluoride dissolution rate, in the presence of phosphate, can account for the relatively slow loss of calcium fluoride from dental enamel observed in recent clinical studies. It also appears that calcium fluoride coated with phosphate may provide a pH-controlled slow release of fluoride that may be of clinical significance and a major component of the cariostatic mechanism of topically applied fluoride.

scholarly journals Behavior of bentonite in an aqueous electrolytic solution – evaluation of electrolytic aggregation for adsorption capacity of Cd2+ ions onto bentonite

2018 ◽  
Vol 77 (12) ◽  
pp. 2841-2850
Author(s):  
Ekanayaka Achchillage Ayesha Dilrukshi ◽  
Takeshi Fujino ◽  
Shun Motegi
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Current Density ◽  
Electrolytic Solution ◽  
Clay Particles ◽  
Adsorption Behaviors ◽  
Adsorption Capacities ◽  
Current Densities ◽  
Submerged Area ◽  
Hydrolysis Of

Abstract In this study, we used aqueous solutions containing 1 mg/L of Cd2+ for electrolysis while varying the current density (CD), amount of bentonite added and the effective submerged area to investigate the adsorption capacity of Cd2+ ions onto bentonite by electrolytic aggregation. The adsorption of Cd2+ ions increased with increasing amount of bentonite added to the electrolytic solution. The addition of bentonite also regulated the pH of the electrolytic solution during the electrolysis process in addition to the hydrolysis of water. The maximum adsorption capacities at equilibrium (qe) for current densities of 3.14 and 7.49 mA/cm2 (i.e. for 2 and 1 L electrolytic solutions) with 0.2 g of bentonite were 4.54 and 2.92 mg/g, respectively. The removal of Cd2+ (RCd) clearly depended on the pH of the electrolytic solution. Moreover, qe decreased with increasing amount of bentonite used for electrolytic aggregation. The findings of this study will be useful for understanding the aggregation of clay particles under electrolysis and their adsorption behaviors.

scholarly journals ADSORPTION OF PHENOL COMPOUNDS BY ACTIVATED CARBON FORMED DURING CARBONIZATION OF BROWN COAL WITH POTASSIUM HYDROXIDE

2021 ◽  
Vol 2 ◽  
pp. 21-32
Author(s):  
Ju.V. Таmarkina ◽  
I.B. Frolova ◽  
O.O. Velichko ◽  
V.O. Кucherenko
Keyword(s):  
Activated Carbon ◽  
Phenolic Compounds ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Brown Coal ◽  
Potassium Hydroxide ◽  
Carbonization Temperature ◽  
Equilibrium Concentrations

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]

scholarly journals Carbaryl Sorption by Porogen-Treated Banana Pith Carbon

2008 ◽  
Vol 26 (9) ◽  
pp. 679-686 ◽  
Author(s):  
M. Sathishkumar ◽  
J.G. Choi ◽  
C.S. Ku ◽  
K. Vijayaraghavan ◽  
A.R. Binupriya ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Kinetic Data ◽  
Maximum Adsorption Capacity ◽  
Adsorption Ability ◽  
Ph Dependent ◽  
Langmuir And Freundlich Models

This paper reports the adsorption ability of banana pith activated carbon, with ZnCl2 as the porogen, towards carbaryl (1-naphthyl- N-methylcarbamate) from aqueous solution. The pH-edge experiments revealed that carbaryl adsorption onto ZnCl2-treated banana pith activated carbon (ZTC) was a pH-dependent process with maximum adsorption occurring at pH 11. The adsorption isotherm obtained at pH 11 revealed that ZTC possessed a maximum adsorption capacity of 45.9 mg/g. The adsorption isotherms were well described by the Langmuir and Freundlich models. The kinetic data obtained at different initial carbaryl concentrations were modelled using pseudo-first- and -second-order models. Acetone successfully desorbed carbaryl with a 99.8% elution efficiency.

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