scholarly journals Application of Wasted Oolong Tea as a Biosorbent for the Adsorption of Methylene Blue

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yunfei Hu ◽  
Yue Zhang ◽  
Yuqun Hu ◽  
Chen-Yao Chu ◽  
Jinke Lin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Adsorption Efficiency ◽  
Order Model ◽  
Oolong Tea ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Second Order Model

Tea powder, a biosorbent prepared from wasted oolong tea, was collected as a prospective adsorbent for the adsorption of methylene blue (MB) from aqueous solution. The effect of factors on adsorption efficiency, isotherms, kinetics, and potential mechanism was carried out. Adsorption capacity of MB onto wasted tea powder increased with the MB concentration and contact time, whereas the increase in pH value and ion strength appeared to have a negative effect for the adsorption process. The adsorption efficiency increased rapidly and reached a stable state within 120 min. The optimal tea powder loading weight is suggested to be at 0.1 to 0.2 g, and the highest efficiency of 94.8% is achieved at 333 K. There were no significant changes in adsorption efficiency when the effect of temperature is considered. The Langmuir isotherm model was found to be the best isotherm models to elucidate the adsorption mechanism in this study. The maximum adsorption capacities calculated at different temperatures by the Langmuir model ranging from 312.5 to 333.3 mg·g−1 were much close to the experimental results. From the kinetic analysis, the pseudo--second-order model was found to be the best model to describe the adsorption behavior. The calculated adsorption capacities at different initial MB concentrations by the pseudo-second-order model ranging from 92.34 to 400 mg·g−1 were well close to the experimental data. The fitting results obtained from the intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step and some other mechanisms along with the intraparticle diffusion were probably involved. The intraparticle diffusion of MB molecules into pore structures of wasted tea powder is the rate-limiting step for the adsorption process in this study. The repetitive cycle experiments indicated that the wasted oolong tea powder was efficiently regenerated using NaOH and thus be used for many times.

scholarly journals Oyster Shell Waste (Crassostrea Gigas) as A Cheap Adsorbent for Adsorption Of Methylene Blue Dyes: Equilibrium and Kinetics Studies

2021 ◽  
Vol 1 (4) ◽  
pp. 95-102
Author(s):  
Muhammad Muhammad ◽  
Meriatna Meriatna ◽  
Nia Afriani ◽  
Rizka Mulyawan
Keyword(s):  
Methylene Blue ◽  
Correlation Coefficient ◽  
Crassostrea Gigas ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Oyster Shell ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Shell Powder

In this study, Oyster (Crassostrea gigas) shell powder which contains calcium carbonate (CaCO3) was converted into calcium oxide (CaO). The Oyster shell powder that had been activated was utilized for the adsorption of the methylene blue (MB) dyeing material, which is one of waste water concerns. Oyster shells were crushed and sieved into 100 mesh sized powder and then calcinated at a temperature of 600℃ and 800℃ both for 4 hours period. To determine the adsorption equilibrium, methylene blue (MB) solution was used with varying concentration from 10 to 50 mg/L in which the adsorbent weighing 3 g was put into a conical flash and shaken until the adsorption equilibrium was reached. As for the adsorption kinetics, 250 mL MB solution was used with initial concentrations of 10, 20 and 30 mg/L, with an adsorbent weight of 3 g and a solution at pH 11 for each concentration. The evaluation of the experimental data from the adsorption process is well explained by the Freundlich equation, with the correlation coefficient value (R2) found to be 0.9999, where the value of the adsorption intensity (n) is close to unity; this shows that the adsorption is multilayer or in other words the adsorption energy is heterogeneous. The kinetics study also shows that pseudo second-order model is the most applicable to the adsorption process. From the pseudo-second-order model, with the correlation coefficient between 0.9984 - 0.9999 can explain that the methylene blue (MB) adsorption process is chemically based sorption or in other words termed as chemisorption.

scholarly journals Tea Stem as a Sorbent for Removal of Methylene Blue from Aqueous Phase

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tzan-Chain Lee ◽  
Shumao Wang ◽  
Zonggui Huang ◽  
Zhongxing Mo ◽  
Gangxing Wang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Ionic Strength ◽  
Aqueous Phase ◽  
Removal Efficiency ◽  
Adsorption Mechanism ◽  
Second Order ◽  
Isotherm Models ◽  
Order Model ◽  
Pseudo Second Order ◽  
Second Order Model

The potentiality of tea stem for the adsorption of methylene blue (MB) from aqueous phase was investigated. A series of operating factors, including the initial MB concentration, contact time, pH of solution, dose of tea stem, and ionic strength of solution, were conducted to understand the effect of adsorption of MB onto tea stem. Adsorption isotherm, kinetic models, thermodynamic investigation, and regenerability of tea stem were systematically investigated in this study. The experiment results revealed that the removal efficiency decreased with MB concentration and the equilibrium time of adsorption at different initial MB concentrations was approximately at 60 min. The appropriate dose of tea stem powder was found to be 4 g/L. The pHzpc of tea stem was evaluated and was observed to be 6.0 ± 0.2. The removal efficiency increased with pH ranging from 3.0 to 5.0 and remained constantly at the pH range of 5.0–11.0. The pH affected the adsorption because of the repellent power between H+ and dye cation. The ionic strength was found to have a negligible effect on the adsorption. The Langmuir and Temkin isotherm models were found to be the best isotherm models to elucidate the adsorption mechanism between MB and tea stem powder. The maximum adsorption capacity of 103.09 mg/g derived from the Langmuir model was much close to the experimental result. From the kinetic analysis, the pseudo-second-order model was found to be the suitable model to describe the adsorption behavior. The calculated adsorption capacities at different temperatures derived from the pseudo-second-order model ranging from 68.91 to 69.8 mg/g were well close to the experimental data. The intraparticle diffusion of MB molecules into pore structures of tea stem powder is the rate-limiting step for the adsorption process in this study. Evaluation of thermodynamic parameters including changes in enthalpy, entropy, and Gibb’s free energy indicated the adsorption mechanism between MB and tea stem powder was a spontaneous and exothermic process. The regeneration/adsorption experiments indicated that the tea stem powder efficiently remained more than 97% after five cycles using NaOH as a desorbing agent and thus be used for many times. On the basis of experimental results obtained, it is concluded that the tea stem has a considerable potential as a low-cost sorbent for removing MB from the aqueous phase.

Use of papaya seeds as a biosorbent of methylene blue from aqueous solution

2013 ◽  
Vol 68 (2) ◽  
pp. 441-447 ◽  
Author(s):  
Diego S. Paz ◽  
Alexandre Baiotto ◽  
Marcio Schwaab ◽  
Marcio A. Mazutti ◽  
Mariana M. Bassaco ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Second Order ◽  
Adsorption Kinetic ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Papaya Seeds ◽  
Second Order Model

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2–12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin–Raduschkevich, Tempkin, Jovanovich, Redlich–Peterson, Sips, Toth and Radke–Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g–1. Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model.

Electrosorption of Methylene Blue from Aqueous Solution on Graphene-Titanium Electrode: Adsorption Kinetics Studies

2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Dan Wu ◽  
Yaxiu Zhao ◽  
Qiang Liu ◽  
Chein-Chi Chang ◽  
Wei Hou
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Kinetics ◽  
Graphene Film ◽  
Titanium Substrate ◽  
Second Order ◽  
Applied Potential ◽  
Order Model ◽  
Pseudo Second Order ◽  
Second Order Model

Abstract A graphene film deposited on titanium substrate was successfully prepared by a facile solution evaporation method, as electrode exhibiting superior electrosorption property toward methylene blue (MB) from aqueous solution. The fabricated graphene film on titanium substrate was characterized in detail by scanning electron microscopy (SEM) and FTIR techniques. As electrode (GTE) for electrosorption of MB, some experimental parameters, such as applied potential, concentration of electrolyte, solution initial pH and temperature, were systematically investigated and discussed. The experimental results demonstrated that the maximum adsorption capacity using GTE can reach 86.06 mg· g−1 under the optimized conditions of −600 mV of applied potential, pH of 7.5, 293 K and 0.01 mg· L−1 Na2SO4 solution, which is 1.40 times of that obtained under open circuit condition in 10 mg· L−1 MB solution. The adsorption isotherm of MB on GTE was analyzed with Langmuir and Freundlich isotherm equations, Pseudo-first-order model, pseudo-second-order model, and intra-particle diffusion model were applied to depict the adsorption kinetics process. The electrosorption of MB preferably fitted Langmuir isotherm, indicating a single-layer adsorption of MB molecules on graphene film followed pseudo-second-order model. Moreover the electrosorption of MB on GTE was found to be spontaneous and endothermic process. This work would be helpful to design and fabricate high performance carbon-based electrodes for high efficiency electrosorption treatment of dye wastewaters.

scholarly journals Kinetic modeling of heavy metal sorption by vinyl pyridine based copolymer

2012 ◽  
Vol 66 (6) ◽  
pp. 795-804 ◽  
Author(s):  
Danijela Maksin ◽  
Sladjana Kljajevic ◽  
Maja Djolic ◽  
Jelena Markovic ◽  
Bojana Ekmescic ◽  
...  
Keyword(s):  
Room Temperature ◽  
Mercury Porosimetry ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Metal Sorption ◽  
Order Model ◽  
Heavy Metal Sorption ◽  
Pseudo Second Order ◽  
Maximal Capacity ◽  
Second Order Model

Commercial macroporous poly(4-vinylpyridine-co-divinylbenzene) [P4VPD], known as REILLEX-425 was characterized by mercury porosimetry, nitrogen physisorption, Fourier transformed infrared (FTIR) spectroscopy and elemental analysis. Sorption rates of P4VPD for Cu(II), Co(II) and Cr(VI) ions were determined in static non-competitive experiments, at room temperature (298 K). Rapid sorption was observed, especially for Co(II), with half time, t1/2, of 1.5 min and high experimental maximal capacity, Qmax, of 3.08 mmol g-1. Four kinetic models (pseudo-first and pseudo-second order model, intraparticle diffusion and Boyd model) were used for analyzing metal sorption by P4VPD. Metal ions sorption is well represented by the pseudo-second-order model, with definite influence of pore and film diffusion on sorption rates.

scholarly journals Adsorption of cationic dye onto Moroccan natural rock

2019 ◽  
Vol 9 (1) ◽  
pp. 37-44
Author(s):  
Amira AM ◽  
Fatima Ouzidan ◽  
Tarik Ainane ◽  
Mohamed Talbi ◽  
M'hammed El Kouali
Keyword(s):  
Adsorption Kinetics ◽  
Diffusion Mechanism ◽  
Elimination Rate ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Natural Rock ◽  
Pseudo Second Order ◽  
Second Order Model

This paper evaluates the ability of a natural rock found in Morocco to remove the pollutant properties of methylene blue (MB) dye. In this regard, the experiments were conceived to test the hypothesis that the rock native of the country’s region of Khenifra can be used as a new abundant adsorbent to remove cationic dyes from water through the adsorption technique in order to avoid extra cost and contribute to the valorization of this material. For this, several factors such as pH of the solution, granulometry, mass of adsorbent, initial dye concentration and stirring rate were tested. The adsorption kinetics process was tested through three models, namely, the pseudo-first-order model, pseudo-second-order model and the intraparticle diffusion model, to predict which type of adsorption is best suited in the removal of dye pollution. The batch study proves that only the granulometry (G ≤ 63µm = 91%, G ≤ 80µm = 88.4% and G ≤ 100µm=70.7%) and the adsorbent mass (the more the mass of the adsorbent increases the more the elimination is achieved) can influence the elimination rate of our rock. Meanwhile, the data of the adsorption kinetics test show that the experimental adsorption could be described by the mechanism of the pseudo-second-order model (correlation coefficients near the unit ‘R 2 = 0.99’ ), confirming chemical sorption as a rate-limiting step of the intraparticle diffusion mechanism. According to the results of this study, the rock collected from the area of Khenifra can be used as a new and efficient adsorbent in the field of wastewater treatment.

Adsorption Kinetics of Pb2+ Ions Using Chitosan Nanoparticles

2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu
Keyword(s):  
Adsorption Kinetics ◽  
Chitosan Nanoparticles ◽  
Second Order ◽  
Isotherm Model ◽  
Order Model ◽  
Adsorption Characteristics ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Model

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.

Polyaniline/ZnO nanocomposites for the removal of methyl orange dye from waste water

2018 ◽  
Vol 32 (19) ◽  
pp. 1840085 ◽  
Author(s):  
Neha V. Nerkar ◽  
Subhash B. Kondawar ◽  
Snehal Kargirwar Brahme ◽  
Yun Hae Kim
Keyword(s):  
Waste Water ◽  
Methyl Orange ◽  
Adsorption Mechanism ◽  
Second Order ◽  
Pure Pani ◽  
Time Interval ◽  
Order Model ◽  
Vis Spectroscopy ◽  
Pseudo Second Order ◽  
Second Order Model

In this paper, we report the safe removal of methyl orange (MO) dye from aqueous solution using chemical interaction of dye molecule with polyaniline/zinc oxide (PANI/ZnO) nanocomposite. PANI/ZnO nanocomposite has been prepared by in situ polymerization. PANI/ZnO nanocomposite was found to be the best promising candidate for adsorption of dyes due to more porosities compared to that of pure PANI. In the present investigation, PANI/ZnO nanocomposite was mixed in a solution of MO dye and used for adsorption process. Color removal was studied using UV-Vis spectroscopy and the spectra were recorded for specific time interval and validation of kinetic model has been applied. Absorbance of PANI/ZnO nanocomposite was found to be increased as compared to that of pure ZnO nanoparticles and pure PANI due to synergistic effect. Comparatively, the removal of dye was also found to be more by using PANI/ZnO nanocomposites. In order to evaluate kinetic mechanism the pseudo-first-order model, pseudo-second-order model and intraparticle diffusion models were verified by the linear equation analysis. Adsorption mechanism of pseudo-second-order model was systematically explained for removal of dye using PANI/ZnO nanocomposite. The results clearly demonstrated that the adsorption mechanism gives very novel and green method of removal of hazardous dyes from waste water.

The Adsorption of Copper Ions Using Cyclodextrin Cross-Linked Magnetic Chitosan Microsphere

2012 ◽  
Vol 209-211 ◽  
pp. 1929-1934
Author(s):  
Jin Song Wang ◽  
Hui Yan Mo ◽  
Qing Wei Guo ◽  
Zhen Cheng Xu
Keyword(s):  
Copper Ions ◽  
Influence Factors ◽  
Second Order ◽  
Kinetic Properties ◽  
Order Model ◽  
Magnetic Chitosan ◽  
Pseudo Second Order ◽  
Percentage Removal ◽  
C 50 ◽  
Second Order Model

In this experiment, cyclodextrin cross-linked magnetic chitosan（CCMC ）microsphere was prepared, glutaraldehyde was chosen as crosslinker, Cyclodextrin and chitosan was synthezied. To observe the influence factors of adsorption and obtain the optimum condition, the adsorption of copper ions by CCMC was explored under the different pH, initial concentration, temperature, reaction time and so on. The results indicated that CCMC had a high percentage removal of Cu2+, optimum adsorption was observed at pH 5.0. The adsorption rate of Cu2+ on CCMC was quick and the percentage removal reached beyond 90% after 30min, indicating that the adsorption equilibrium could be established within 30 min. The kinetic and thermodynamic properties of CCMC was also explored, under the concentration of Cu2+ of 50mg/L, 100mg/L, 150mg/L, 200mg/L, 300mg/L, 500mg/L on the temperature of 25°C, 35°C, 45°C, 50°C. Freunlich isothermal to Langmuir isothermal was used to fit the data of adsorption capacity of Cu2+, which showed that the adsorption process of Cu2+ was better described by Freunlich isothermal than Langmuir isothermal. As to the kinetic properties, the experimental data of Cu2+ adsorption onto CCMC fitted to the pseudo-first order model and pseudo-second order model, but the adsorption of Cu2+ onto CCMC conformed to pseudo-second order model, the R2 reached above 0.999.

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