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

Polymers ◽  
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+.

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

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.

scholarly journals Adsorption of Tea Polyphenols using Microporous Starch: A Study of Kinetics, Equilibrium and Thermodynamics

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1449 ◽  
Author(s):  
Xianchun Hu ◽  
Xianfeng Du
Keyword(s):  
Physical Adsorption ◽  
Tea Polyphenols ◽  
Adsorptive Capacity ◽  
Partial Hydrolysis ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Long Term Storage ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

Microporous starch (MPS) granules were formed by the partial hydrolysis of starch using α–amylase and glucoamylase. Due to its biodegradability and safety, MPS was employed to adsorb tea polyphenols (TPS) based on their microporous characteristics. The influences of solution pH, time, initial concentration and temperature on the adsorptive capacity were investigated. The adsorption kinetics data conformed to the pseudo second–order kinetics model, and the equilibrium adsorption data were well described by the Langmuir isotherm model. According to the fitting of the adsorption isotherm formula, the maximum adsorption capacity of TPS onto MPS at pH 6.7 and T = 293 K was approximately 63.1 mg/g. The thermodynamic parameters suggested that the adsorption of TPS onto MPS was spontaneous and exothermic. Fourier transform infrared (FT–IR) analysis and the thermodynamics data were consistent with a physical adsorption mechanism. In addition, MPS-loaded TPS had better stability during long-term storage at ambient temperature.

Removal of Pb(II) by adsorption onto Chinese walnut shell activated carbon

2015 ◽  
Vol 72 (6) ◽  
pp. 983-989 ◽  
Author(s):  
Zheng-ji Yi ◽  
Jun Yao ◽  
Yun-fei Kuang ◽  
Hui-lun Chen ◽  
Fei Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Walnut Shell ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Chinese Walnut ◽  
Maximum Removal

The excessive discharge of Pb(II) into the environment has increasingly aroused great concern. Adsorption is considered as the most effective method for heavy metal removal. Chinese walnut shell activated carbon (CWSAC) was used as an adsorbent for the removal of Pb(II) from aqueous solution. Batch experiments were conducted by varying contact time, temperature, pH, adsorbent dose and initial Pb(II) concentration. Adsorption equilibrium was established within 150 min. Although temperature effect was insignificant, the Pb(II) adsorption was strongly pH dependent and the maximum removal was observed at pH 5.5. The Pb(II) removal efficiency increased with increasing CWSAC dosage up to 2.0 g/L and reached a maximum of 94.12%. Langmuir and Freundlich adsorption isotherms were employed to fit the adsorption data. The results suggested that the equilibrium data could be well described by the Langmuir isotherm model, with a maximum adsorption capacity of 81.96 mg/g. Adsorption kinetics data were fitted by pseudo-first- and pseudo-second-order models. The result indicated that the pseudo-first-order model best describes the adsorption kinetic data. In summary, CWSAC could be a promising material for the removal of Pb(II) from wastewater.

Equilibrium and Kinetic Studies of Benzene and Toluene Adsorption onto Microwave Irradiated-Coconut Shell Activated Carbon

2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Kinetic Studies ◽  
Coconut Shell ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Volatile Organic ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Coconut Shell Activated Carbon

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.

scholarly journals STUDY ON THE ADSORPTION CHARACTERISTICS OF CONGO RED BY SYCAMORE BARK ACTIVATED CARBON

2017 ◽  
Vol 1 ◽  
pp. 64 ◽  
Author(s):  
Li Cong ◽  
Lingling Feng ◽  
Xinlai Wei ◽  
Jie Jin ◽  
Ke Wu
Keyword(s):  
Activated Carbon ◽  
Congo Red ◽  
Room Temperature ◽  
Adsorption Process ◽  
Removal Rate ◽  
Adsorption Properties ◽  
Adsorption Efficiency ◽  
Adsorbent Dosage ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The activated carbon was prepared from sycamore bark by activation of zinc chloride. The absorbing effect of activated carbon on Congo red wastewater is studied. The characteristics of sycamore bark activated carbon were characterized by SEM and BET. The effects of adsorbent dosage, time, and shaking speed on the adsorption properties of Congo red by sycamore bark activated carbon were studied. The isotherm, kinetics, and thermodynamics of adsorption were explored. The results revealed that the activated carbon contain a large apparent mesopores. Adsorption efficiency was increased with enhancing the adsorption dosage and time. The removal rate of Conge red reached to 98.2% under room temperature with adsorbent dosage of 3.0 g/L, adsorption time of 120 min, shaking speed of 60r/min. The adsorption of Congo red on sycamore bark activated carbon was followed Langmuir isotherm model and Lagergren pseudo-second order kinetics model. The adsorption was spontaneous, endothermic, and the entropy was increasing in the adsorption process.

Characteristics of Cu2+ Adsorption by Modified Rice Straw

2013 ◽  
Vol 726-731 ◽  
pp. 2622-2628
Author(s):  
Ming Da Liu ◽  
Lei Guo ◽  
Jun Yang ◽  
Yao Jing Wang
Keyword(s):  
Rice Straw ◽  
Ph Value ◽  
Removal Rate ◽  
Maximum Adsorption Capacity ◽  
Static State ◽  
Metal Biosorption ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Sorption Time

In this paper, modified rice straw was investigated for its Cu2+removal ability from aqueous solution. The effects of environmental factors on metal biosorption were studied under static state, including initial concentration of metal ions, sorption time, initial pH value and adsordent dosage. In addition, the relevant equilibrium, kinetics were discussed. The results showed that the rice straw which was modified by NaOH had been improved greatly in its Cu2+removal ability. The rice straw had good effects on adsorption of low concentration of Cu2+solution. The adsorption data fit Langmuir isotherm model well, the maximum adsorption capacity for Cu2+reached 8.48 mg·g-1. The adsorption of Cu2+on the modified rice straw was a very rapid process, the kinetics fit a pseudo-second-order equation well. The pH value had prominent effect on the removal rate of Cu2+, adsorption efficient could reach over 92% when pH value was between 5 and 6.5. With increasing adsordent dosage, the removal rate of Cu2+increased.

scholarly journals Adsorption of Cu(II) by Poly-γ-glutamate/Apatite Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng
Keyword(s):  
Adsorption Capacity ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
Solution Ph ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Initial Adsorption ◽  
Adsorption Equilibrium Data

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.

Feasibility of Ceria Nanocrystal Adsorbent for Amoxicillin Removal from Water

2020 ◽  
Vol 860 ◽  
pp. 338-344
Author(s):  
Iis Nurhasanah ◽  
Kadarisman ◽  
Vincensius Gunawan ◽  
Heri Sutanto
Keyword(s):  
Average Crystallite Size ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
Adsorption Experiment ◽  
Adsorptive Property ◽  
Xrd Pattern ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Amoxicillin Removal ◽  
Adsorption Desorption

This study explored adsorptive property of ceria nanocrystal as an adsorbent for amoxicillin removal from water. Ceria nanocrystal was synthesized by employing precipitation method and characterized by using XRD and N2 adsorption-desorption analysis. The adsorption experiment was performed by managing amoxicillin in natural condition. Then, parameters in the adsorption experiment, such as adsorbent dosage, contact time, temperature and initial concentration of amoxicillin are varied. The XRD pattern illustrated that the average crystallite size of ceria nanocrystal formation was 13.08 nm. N2 adsorption-desorption analysis showed that ceria nanocrystal was mesoporous with specific surface area of ​​65.26 m2/g. The amoxicillin adsorption of ceria nanocrystal adsorbent was described by Langmuir isotherm model with maximum adsorption capacity of 37.17 mg/g. The adsorption kinetic of ceria nanocrystal corresponded to the pseudo-second order model. Removal efficiency of amoxicillin by ceria nanocrystal was approximately 80% within 60 minutes over temperature range 303-323K. Those parameter results are described that ceria nanocrystal adsorbent is feasible as a rapid amoxicillin removal from water.

scholarly journals Biocarbon Derived from Opuntia ficus indica for p-Nitrophenol Retention

Processes ◽  
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.

scholarly journals Hydrazinolyzed cellulose-g-polymethyl acrylate as adsorbent for efficient removal of Cd(II) and Pb(II) ions from aqueous solution

2016 ◽  
Vol 75 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Qiujin Jia ◽  
Wanting Zhang ◽  
Dongping Li ◽  
Yulong Liu ◽  
Yuju Che ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Physical Adsorption ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Efficient Adsorbent

Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ), an efficient adsorbent for removal of Cd(II) and Pb(II) from aqueous solution, has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis. The influences of initial pH, contact time, and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were examined in detail. As for Cd(II) adsorption, kinetic adsorption can be explained by pseudo-second-order, while adsorption isotherm fits well with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 235.85 mg g−1 at 28 °C. Further thermodynamic investigation indicated that adsorption of Cd(II) by adsorbent Cell-g-PMA-HZ is endothermic and spontaneous under studied conditions. On the other hand, isotherm of Pb(II) adsorption fits well with Freundlich isotherm model and is more likely to be a physical-adsorption-dominated process. Consecutive adsorption–desorption experiments showed that Cell-g-PMA-HZ is reusable with satisfactory adsorption capacity.

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