scholarly journals Adsorptive Performance of Polypyrrole-Based KOH-Activated Carbon for the Cationic Dye Crystal Violet: Kinetic and Equilibrium Studies

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Abdel-Basit Al-Odayni ◽  
Naaser A. Y. Abduh ◽  
Safiah A. Alramadhan ◽  
Mashael T. Aljboar ◽  
...  

The aim of this work was to investigate the adsorptive performance of the polypyrrole-based KOH-activated carbon (PACK) in the removal of the basic dye crystal violet (CV) using a batch adsorption system. The equilibrium data, obtained at different initial CV concentrations ( C 0 = 50 – 500   mg / L ) and temperatures (25–45°C), were interpreted using the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms, with the Langmuir model providing a better fit ( R 2 ≥ 0.9997 ) and a maximum adsorption capacity of 497.51 mg/g at 45°C. Under the examined conditions, the values of the thermodynamic parameters free energy, enthalpy, and entropy indicate a spontaneous, endothermic, and physisorption adsorption process. The kinetic data of the adsorption process were very well described by a pseudo-second-order model ( R 2 ≥ 0.9996 ). However, surface diffusion seems to be the main rate-controlling step. Thus, we concluded that PACK shows commercial potential for the removal of cationic dyes such as CV from industrial effluent.

Author(s):  
Md. Shahin Azad ◽  
Syaza Azhari ◽  
Mohd Sukri Hassan

The utilization of biopolymer derived from Moringa oleifera bark using ZnCl2 and H2SO4 as activating agents for eliminating Methylene blue, Escherichia coli and Pseudomonas aeruginosa from producing wastewater. In this study, Methylene blue and both bacteria were effectively adsorbed by activated carbon with lowest dosage. The activated carbon was prepared from natural-by product of Moringa oleifera bark by pyrolysis in a furnace at 700°C for 1 h. The characteristics of activated carbon have been determined using Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), pHzpc (zero point charge), and FTIR spectroscopy. The obtained result were closely fitted with Freundlich isotherm model and adsorption kinetics follow the pseudo-second order model with the highest value of correlation coefficient (R2~1). Adsorption quantity was dose dependent and bacteria were maximum adsorbed using 10 mg of activated carbon as well as 25mg for methylene blue. The maximum adsorption capacity showed within 1 hour. The bacterial load was reduced by 98% for E. coli, 96% for P. aeruginosa as well as methylene blue reduced 94.2% from aqueous solution using batch adsorption methods. Adsorption process controlled by film diffusion mechanism. These result proposed that the activated carbon of Moringa oleifera can be used as a good adsorbent for the removal of Methylene blue, E. coli and P. aeruginosa.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2218 ◽  
Author(s):  
Carlos Grande-Tovar ◽  
William Vallejo ◽  
Fabio Zuluaga

In this work, we synthesized chitosan grafted-polyacrylic acid (CS-g-PA) through surface-initiated atom transfer radical polymerization (SI-ATRP). We also studied the adsorption process of copper and lead ions onto the CS-g-PA surface. Adsorption equilibrium studies indicated that pH 4.0 was the best pH for the adsorption process and the maximum adsorption capacity over CS-g-PA for Pb2+ ions was 98 mg·g−1 and for Cu2+ it was 164 mg·g−1, while for chitosan alone (CS), the Pb2+ adsorption capacity was only 14.8 mg·g−1 and for Cu2+ it was 140 mg·g−1. Furthermore, the adsorption studies indicated that Langmuir model describes all the experimental data and besides, pseudo-second-order model was suitable to describe kinetic results for the adsorption process, demonstrating a larger kinetic constant of the process was larger for Pb2+ than Cu2+. Compared to other adsorbents reported, CS-g-PA had comparable or even superior adsorbent capacity and besides, all these results suggest that the new CS-g-PA polymers had potential as an adsorbent for hazardous and toxic metal ions produced by different industries.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1003 ◽  
Author(s):  
Ainoa Murcia-Salvador ◽  
José A. Pellicer ◽  
María I. Fortea ◽  
Vicente M. Gómez-López ◽  
María I. Rodríguez-López ◽  
...  

The dyeing industry is one of the most polluting in the world. The adsorption of dyes by polymeric matrixes can be used to minimize the discharge of dyes into the environment. In the present study, chitosan-NaOH and β-cyclodextrin-epichlorohydrin polymers were used to remove the dye Direct Blue 78 from a wastewater model. To understand the adsorption behavior of Direct Blue 78 onto the polymers, adsorption rate and maximum adsorption capacity were calculated using kinetic tests and isotherm curves respectively. The kinetic data and mechanism of the adsorption process were analyzed by three models and the equilibrium data by three adsorption isotherms; also the different thermodynamic parameters were calculated. Results showed that the adsorption process follows pseudo-second-order kinetics in both polymers and the Langmuir isotherm best-fitted data for chitosan-NaOH polymer and the Freundlich isotherm for the β-CDs-EPI polymer. The adsorption process is exothermic in both cases and spontaneous for the β-CDs-EPI polymer to a certain temperature and not spontaneous for the chitosan-NaOH polymer and β-CDs-EPI polymer at higher temperatures. The complementary action of an advanced oxidation process eliminated >99% of the dye from water. The coupled process seems to be suitable for reducing the environmental impact of the dyeing industry.


2015 ◽  
Vol 71 (11) ◽  
pp. 1611-1619 ◽  
Author(s):  
Jun Liu ◽  
Hongyan Du ◽  
Shaowei Yuan ◽  
Wanxia He ◽  
Pengju Yan ◽  
...  

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.


2015 ◽  
Vol 72 (6) ◽  
pp. 983-989 ◽  
Author(s):  
Zheng-ji Yi ◽  
Jun Yao ◽  
Yun-fei Kuang ◽  
Hui-lun Chen ◽  
Fei Wang ◽  
...  

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mashael Alshabanat ◽  
Ghadah Alsenani ◽  
Rasmiah Almufarij

The adsorption of crystal violet (CV) onto date palm fibers (DPFs) was examined in aqueous solution at 25°C. The experimental maximum adsorption capacity value was0.66×10−6. Langmuir, Freundlich, Elovich and Temkin models were applied to describe the equilibrium isotherms. The influence of pH and temperature on dye removal was evaluated. The percentage removal of CV dye by adsorption onto DPF at different pH and temperatures showed that these factors play a role in the adsorption process. Thermodynamic analysis was performed, and the Gibbs free energyΔGο, enthalpy changeΔHο, and entropyΔSοwere calculated. The negative values ofΔGοindicate spontaneous adsorption. The negative value ofΔHοindicates that the interaction between CV and DPF is exothermic, and the positive value ofΔSοindicates good affinity between DPF and CV. The kinetic data were fitted to a pseudo-second-order model.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Swarup Biswas ◽  
Umesh Mishra

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

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.


2021 ◽  
Vol 920 (1) ◽  
pp. 012010
Author(s):  
F Fadzail ◽  
M Hasan ◽  
Z Mokhtar ◽  
N Ibrahim ◽  
O S An ◽  
...  

Abstract Removal of ketoprofen using Dillenia Indica peel activated carbon was investigated using batch adsorption at a laboratory scale. Chemical activation method with the aid of phosphoric acid was utilised in preparing the activated carbon. The adsorption experiments were evaluated using various factors which, are initial concentration, adsorbent dosage, and pH of ketoprofen. The optimum condition was determined to be at pH 6 and adsorbent dosage of 0.4 g with a most KTP uptake of 8.354 mg/g. The experimental findings showed that adsorption is favorable at lower pH. Isotherm studies were conducted and the data indicated that Langmuir isotherm was well fitted to the adsorption process and the pseudo-second-order model was more preferable in simulating the kinetic process. In essence, Dillenia Indica peel activated carbon was proven as being a favourable adsorbent for the uptake of ketoprofen in batch mode.


2022 ◽  
Author(s):  
Mahboobeh Monjezi ◽  
Vahid Javanbakht

Abstract Geopolymers as sustainable and environmentally friendly “green materials”, can be synthesized by utilizing waste material and by-products. A porous geopolymer foam adsorbent based on ZSM-5 zeolite was prepared using templating emulsion/chemical foaming method in different conditions and used for dye removal in batch and continuous systems. The parameters affecting the dye adsorption including temperature, concentration, and pH, kinetics, isotherm, and thermodynamics of the process were investigated. The results of the geopolymer foam synthesis showed that thermal pretreatment of the zeolite has a positive effect on the strength and adsorption capacity. Moreover, the increase in sodium silicate more than the stoichiometric reduces the strength and adsorption capacity. The findings obtained from the batch adsorption process showed that the adsorption kinetics of the pseudo-second-order model and the adsorption isotherm of the Temkin model is adjusted with the experimental data. Thermodynamic results indicated that the process of dye adsorption with geopolymer foam is exothermic. The results from continuous experiments indicated more compatibility of the adsorption process with the models of Thomas and Bohart-Adams. The maximum adsorption capacity of methylene blue in batch and continuous processes was 9.82 and 8.17 mg/g. The adsorbent reduction was performed successfully by chemical and thermal processes.


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