Studies of adsorption kinetics and regeneration of aniline, phenol, 4-chlorophenol and 4-nitrophenol by activated carbon

The present paper reports kinetic studies of the adsorption of aniline (AN), phenol (P), 4-chlorophenol (CP) and 4-nitrophenol (NP) from aqueous solution onto granular activated carbon (GAC). In FTIR spectral analysis, the transmittance of the peaks gets increased after the loading of AN, P, CP and NP signifying the participation of these functional groups in the adsorption and it seems that the adsorption of AN, P, CP and NP is chemisorptive in nature. The rates of adsorption were found to obey a pseudo-second order model and that the dynamics of AN, P, CP and NP adsorption are controlled by a combination of surface and pore diffusion. The diffusion coefficient were of the order of 10-10 m2 s-1. Thermal desorption at 623 K was found to be more effective than solvent desorption. GAC performed well for at least five adsorption-desorption cycle, with continuous decrease in adsorption efficiency after each thermal desorption. Owing to its relative high heating value, the spent GAC can be used as co-fuel for the production of heat in a boiler or a furnace.

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Biocarbon Derived from Opuntia ficus indica for p-Nitrophenol Retention

Processes ◽

10.3390/pr8101242 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1242

Author(s):

Hanedi Elhleli ◽

Faten Mannai ◽

Mongi ben Mosbah ◽

Ramzi Khiari ◽

Younes Moussaoui

Keyword(s):

Activated Carbon ◽

Fourier Transforms ◽

Activated Carbons ◽

Removal Rate ◽

Order Model ◽

Opuntia Ficus Indica ◽

Effects Of Ph ◽

Pseudo Second Order ◽

Fourier Transforms Infrared Spectroscopy ◽

Adsorption Desorption

Activated carbon obtained from Opuntia ficus indica by sodium hydroxide activation was employed for the adsorption of p-nitrophenol from water. The activated carbons obtained were characterized by Fourier transforms infrared spectroscopy, sorption of nitrogen, scanning electron microscopy, and Boehm titration. Effects of pH, contact time, amount of adsorbent, and temperature on the adsorption of p-nitrophenol were studied. Adsorption isotherms were analyzed using Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich models, and the thermodynamic parameters have been determined. The adsorption of p-nitrophenol was spontaneous, exothermic, and propitious at 15 °C and adopted the pseudo-second order model, and the most credible isotherm was Langmuir’s one. The activated carbon used in this work has good p-nitrophenol adsorption characteristics, and the study of the desorption and reuse of this carbon shows that it retains a removal rate greater than 94% after five cycles of adsorption-desorption.

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Brasil nut mesocarp (Bertholletia excels) as a Biomass Source for Activated Carbon Production: Correlation Between Thermal Treatment and Adsorption Performance

Biointerface Research in Applied Chemistry ◽

10.33263/briac124.45844596 ◽

2021 ◽

Vol 12 (4) ◽

pp. 4584-4596

Keyword(s):

Activated Carbon ◽

Maximum Adsorption Capacity ◽

Brazil Nut ◽

Order Model ◽

X Ray ◽

Adsorption Performance ◽

Carbon Production ◽

Pseudo Second Order ◽

Adsorption Desorption ◽

Best Fit

The activated carbon investigated in this work was produced from the extractive residues of Brazil nut processing, more specifically from the mesocarp of the Amazonian fruit. The process was performed by muffle pyrolysis, with ZnCl2 impregnation, at 400 and 500 °C. All samples were characterized by X-ray diffractometry, thermogravimetry, CHNS elemental analysis, scanning electron microscopy, and adsorption/desorption of N2. The results were promissory, with 99% removal of methylene blue for the CA25 material, which has a surface area of 1236 m2 g-1, much higher than commercial coal (CAC, 618 m2 g-1). The adsorption kinetics best fit the pseudo-second-order model for all materials. The maximum adsorption capacity obtained was 195.3 mg g-1. Therefore, the extractive residue of Brazil nut has excellent potential for the development of activated carbon, which can be used effectively to mediate environmental contamination in a given aqueous medium.

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Fabrication of Mesoporous NaZrP Cation-Exchanger for U(VI) Ions Separation from Uranyl Leach Liquors

Colloids and Interfaces ◽

10.3390/colloids3040061 ◽

2019 ◽

Vol 3 (4) ◽

pp. 61 ◽

Cited By ~ 2

Author(s):

Alhindawy ◽

Elshehy ◽

El-Khouly ◽

Abdel-Monem ◽

Atrees

Keyword(s):

Kinetic Studies ◽

Electricity Production ◽

X Ray Diffraction ◽

Order Model ◽

Extraction And Separation ◽

Inorganic Cation ◽

Cation Exchangers ◽

Pseudo Second Order ◽

Uptake Process ◽

Adsorption Desorption

As the demand for uranium production-based energy worldwide has been increasing in the last decades to maintain nuclear growth for electricity production, there are great efforts towards developing an easy and inexpensive method for uranium extraction and separation from its ores. For this purpose, mesoporous inorganic cation exchangers provide an efficient separation technology that can help streamline production and lower overall cost. This study describes the development of nano-structured mesoporous sodium zirconium phosphate (NaZrP-CEX) for separation and extraction of uranyl ions from real samples. The fabricated NaZrP-CEX was well characterized by various techniques such as X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), N2 adsorption/desorption, Dynamic light scattering (DLS) and zeta potential). The kinetics/thermodynamic behaviors of uranyl ion adsorption into NaZrP-CEX from an aqueous solution were minutely studied. The kinetic studies showed that the pseudo-second order model gave a better description for the uptake process. The negative value of ΔG indicate high feasibility and spontaneity of adsorption. Finally, mesoporous NaZrP-CEX can be regenerated using both of HNO3 (0.05 M) or HCl (1 M) up to seven cycles of operation.

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Pectin/Activated Carbon-Based Porous Microsphere for Pb2+ Adsorption: Characterization and Adsorption Behaviour

Polymers ◽

10.3390/polym13152453 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2453

Author(s):

Ri-si Wang ◽

Ya Li ◽

Xi-xiang Shuai ◽

Rui-hong Liang ◽

Jun Chen ◽

...

Keyword(s):

Activated Carbon ◽

Profile Analysis ◽

Removal Rate ◽

Physical Adsorption ◽

Kinetic Studies ◽

Maximum Adsorption Capacity ◽

Texture Profile ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Adsorption Desorption

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+ and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.

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Effect of Sodium Benzenesulfonate on SO42− Removal from Water by Polypyrrole-Modified Activated Carbon

Advances in Materials Science and Engineering ◽

10.1155/2021/1442506 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Feng Zhang ◽

Dong-Sheng Wang ◽

Fan Yang ◽

Tian-Yu Li ◽

Hong-Yan Li ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Granular Activated Carbon ◽

Langmuir Model ◽

Sulfate Adsorption ◽

Modified Activated Carbon ◽

Pseudo Second Order ◽

Acidic Conditions ◽

Adsorption Desorption ◽

Desorption Cycle

Sodium benzenesulfonate was doped into polypyrrole-modified granular activated carbon (pyrrole-FeCl3·(6H2O)-sodium benzenesulfonate-granular activated carbon; PFB-GAC) with the goal of improving the modified GAC’s ability to adsorb sulfate from aqueous solutions. At a GAC dosage of 2.5 g and a pyrrole concentration of 1 mol L−1, the adsorption capacity of PFB-GAC prepared using a pyrrole:FeCl3·(6H2O):sodium benzenesulfonate ratio of 1000 : 1500 : 1 reached 23.05 mg g−1, which was eight times higher than that for GAC and two times higher than that for polypyrrole-modified GAC without sodium benzenesulfonate. Adsorption was favored under acidic conditions and high initial sulfate concentrations. Doping with sodium benzenesulfonate facilitated polymerization to give polypyrrole. Sodium benzenesulfonate introduced more imino groups to the polypyrrole coating, and the N+ sites improved ion exchange of Cl− and SO42− and increased the adsorption capacity of sulfate. Adsorption to the PFB-GAC followed pseudo-second-order kinetics. The adsorption isotherm conformed to the Langmuir model, and adsorption was exothermic. Regeneration using a weak alkali (NH3·H2O), which released OH− slowly, caused less damage to the polypyrrole than using a strong alkali (NaOH) as the regeneration reagent. NH3·H2O at a concentration of 12 mol L−1 (with the same OH− concentration as 2 mol L−1 NaOH) released 85% of the sorbed sulfate in the first adsorption-desorption cycle, and the adsorption capacity remained >6 mg g−1after five adsorption-desorption cycles.

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Highly Effective Adsorption of Caffeine by a Novel Activated Carbon Prepared From Coconut Leaf

10.21203/rs.3.rs-901559/v1 ◽

2021 ◽

Author(s):

Elvio N. Oliveira ◽

Alex T. Meneses ◽

Samara F. de Melo ◽

Franciele M. R. Dias ◽

Maisa T. B. Perazzini ◽

...

Keyword(s):

Activated Carbon ◽

Activated Carbons ◽

Physical Adsorption ◽

Average Pore Size ◽

Kinetic Studies ◽

Amorphous Structure ◽

Operating Conditions ◽

Average Pore ◽

Pseudo Second Order ◽

Adsorption Desorption

Abstract The disposal of coconut wastes is costly and damaging to the environment, but its uses are advantageous activated carbons production. Coconut leaves waste were used for activated carbon production by pyrolysis at 500º C and activation with potassium carbonate. The activated carbon was used for caffeine removal from aqueous solution. The coconut leaves activated carbon showed a predominantly amorphous structure from X-ray diffraction analysis and a pH at the zero charge point of 7.9. From the N2 adsorption/desorption method, the adsorbent showed a predominance of mesopores, with average pore size of 45.48 ηm and a surface area of 678.03 m2/g. From kinetic studies the data followed the pseudo-second order, where the intraparticle diffusion can be neglected. The adsorption isotherms were satisfactorily adjusted for the Redlich-Peterson model and a type curve L was identified. The thermodynamic parameters showed that adsorption occurred spontaneously, was exothermic and governed by physical adsorption. The artificial neural networks developed were capable of predicting both kinetics and equilibrium adsorption data under different operating conditions and was comparable to the traditional models available in literature in the training experiments, encouraging its use for data generalization when an efficient dataset is used. In conclusion, coconut leaves waste showed to be a promising feedstock to produce activated carbon aiming caffeine removal from water and wastewater.

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Adsorption of Nitrate onto ZnCl2-Modified Coconut Granular Activated Carbon: Kinetics, Characteristics, and Adsorption Dynamics

Advances in Materials Science and Engineering ◽

10.1155/2018/1939032 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Lingjie Liu ◽

Min Ji ◽

Fen Wang

Keyword(s):

Activated Carbon ◽

Granular Activated Carbon ◽

Kinetic Studies ◽

Surface Characteristics ◽

Electrostatic Attraction ◽

Batch Adsorption ◽

Dynamic Adsorption ◽

Batch Experiments ◽

Nitrate Adsorption ◽

Pseudo Second Order

Coconut granular activated carbon (CGAC) was modified by impregnating with ZnCl2solution to remove nitrate from aqueous solutions. Sorption isotherm and kinetic studies were carried out in a series of batch experiments. Nitrate adsorption of both ZnCl2-modified CGAC and CGAC fitted the Langmuir and Freundlich models. Batch adsorption isotherms indicated that the maximum adsorption capacities of ZnCl2-modified CGAC and CGAC were calculated as 14.01 mgN·g−1and 0.28 mgN·g−1, respectively. The kinetic data obtained from batch experiments were well described by pseudo-second-order model. The column study was used to analyze the dynamic adsorption process. The highest bed adsorption capacity of 1.76 mgN·g−1was obtained by 50 mgN·L−1inlet nitrate concentration, 20 g adsorbents, and 10 ml·min−1flow rate. The dynamic adsorption data were fitted well to the Thomas and Yoon–Nelson models with coefficients of correlationR2 > 0.834 at different conditions. Surface characteristics and pore structures of CGAC and ZnCl2-modified CGAC were performed by SEM and EDAX and BET and indicated that ZnCl2had adhered to the surface of GAC after modified. Zeta potential, Raman spectra, and FTIR suggested the electrostatic attraction between the nitrate ions and positive charge. The results revealed that the mechanism of adsorption nitrate mainly depended on electrostatic attraction almost without any chemical interactions.

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Removal of Methylene Blue Dye by Using Eggshell Powder

Jurnal Teknologi ◽

10.11113/jt.v65.1648 ◽

2013 ◽

Vol 65 (1) ◽

Author(s):

Norzita Ngadi ◽

Chin Chiek Ee ◽

Nor Aida Yusoff

Keyword(s):

Methylene Blue ◽

Textile Industry ◽

Low Cost ◽

Kinetic Studies ◽

Operating Conditions ◽

Blue Dye ◽

Dye Wastewater ◽

Order Model ◽

Aquatic Life ◽

Pseudo Second Order

Dyes contain carcinogenic materials which can cause serious hazards to aquatic life and the users of water. Textile industry is the main source of dye wastewater which results in environmental pollution. Many studies have been conducted to investigate the use of low cost adsorbent as an alternative technique for the adsorption of dye. The objective of this study is to determine the potential of eggshell powder as an adsorbent for methylene blue removal and find out the best operating conditions for the color adsorption at laboratory scale. The adsorption of cationic methylene blue from aqueous solution onto the eggshell powder was carried out by varying the operating parameters which were contact time, pH, dosage of eggshell powder and temperature in order to study their effect in adsorption capacity of eggshell powder. The results obtained showed that the best operating condition for removal of methylene blue was at pH 10 (78.98 %) and temperature 50°C (47.37 %) by using 2 g of eggshell powder (57.03 %) with 30 minutes equilibrium time (41.36 %). The kinetic studies indicated that pseudo-second-order model best described the adsorption process.

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ADSORPTION AND KINETIC STUDIES OF A NATURAL DYE FROM CURCUMA LONGA L., ONTO BAMBOO YARN

Journal of Chemical Engineering and Industrial Biotechnology ◽

10.15282/jceib.v2i1.3802 ◽

2017 ◽

Vol 2 (1) ◽

pp. 13-26

Author(s):

Tengku Khamanur Azma Tg. Mohd Zamri ◽

Mimi Sakinah Abd Munaim ◽

Zularisam Ab Wahid

Keyword(s):

Adsorption Process ◽

Regression Coefficient ◽

Curcuma Longa ◽

Freundlich Isotherm ◽

Kinetic Studies ◽

Natural Dye ◽

Isotherm Models ◽

Order Model ◽

Dyeing Process ◽

Pseudo Second Order

Natural dye extracted from the rhizome of Curcuma longa L. were applied to bamboo yarns using exhaustion dyeing process. This study investigates the dyeing behaviour of Curcumin; the major color component isolated from rhizomes of Curcuma longa L.on bamboo yarn. Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich isotherm models were used to test the adsorption process of curcumin on bamboo yarn. Comparison of regression coefficient value indicated that the Freundlich isotherm most fitted to the adsorption of curcumin onto bamboo yarn. Furthermore, the kinetics study on this research fitted the pseudo-second order model which indicates that the basis of interaction was chemical adsorption.

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Recovery of phosphate from aqueous solution by magnetically recycled modified polishing powder composites

Water Science & Technology ◽

10.2166/wst.2019.381 ◽

2019 ◽

Vol 80 (7) ◽

pp. 1357-1366

Author(s):

Jianming Liu ◽

Runying Bai ◽

Junfeng Hao ◽

Bowen Song ◽

Yu Zhang ◽

...

Keyword(s):

Adsorption Capacity ◽

Ligand Exchange ◽

Adsorption Process ◽

High Adsorption ◽

Order Model ◽

Powder Composites ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Ph Level ◽

Adsorption Desorption

Abstract This study investigated a magnetically recycled modified polishing powder (CMIO@PP) as an adsorbent of phosphate; the CMIO@PP was synthesized by combining the modified La/Ce-containing waste polishing powder with CaO2-modified Fe3O4 (CMIO). Results indicate that the CMIO@PP nanocomposite presents a crystal structure comprising La (OH)3, Ce (OH)3, and Fe3O4, and that CMIO is uniformly dispersed in the modified polishing powder. The CMIO@PP (1:3) is a suitable choice considering its magnetism and adsorption capacity. The magnetic adsorbent exhibits a high adsorption capacity of 53.72 mg/g, a short equilibrium time of 60 min, and superior selectivity for phosphate. Moreover, the adsorbent strongly depends on the pH during the adsorption process and maintains a large adsorption capacity when the pH level is between 2 and 6. The adsorption of phosphate by the CMIO@PP (1:3) accords with the Langmuir isotherm model, and the adsorption process follows the pseudo-second order model. Meanwhile, adsorption–desorption experiments show that the adsorbent could be recycled a few times and that a high removal efficiency of phosphate from civil wastewater was achieved. Finally, mechanisms show that the adsorption of phosphate by the CMIO@PP (1:3) is mainly caused by electrostatic attraction and ligand exchange.

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