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.

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.

scholarly journals Crystal Violet Dye Adsorption from Aqueous Solution using Activated Chickpea Husk (Cicer arientum)

2021 ◽  
Vol 34 (1) ◽  
pp. 104-110
Author(s):  
Sonia Rani ◽  
Sudesh Chaudhary
Keyword(s):  
Crystal Violet ◽  
Adsorption Mechanism ◽  
Dye Adsorption ◽  
Second Order ◽  
Order Model ◽  
Batch Mode ◽  
After Effects ◽  
Crystal Violet Dye ◽  
Pseudo Second Order ◽  
Second Order Model

The chickpea husk (Cicer arientum) were activated by chemical modification with sulphuric acid, for its application as biosorbent for the remediation of crystal violet dye from wastewater. Activated chickpea husk (ACH) was characterized for its chemical structure and morphology using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The after effects of leading affecting parameters like dose of adsorbent, time of contact, pH and concentration were studied by commencing experiments in batch mode. Adsorption mechanism and sorption efficiency of ACH was examined using variety of isotherms (Langmuir & Freundlich) and kinetic models (pseudo first order and pseudo second order). Experimental data for adsorption rate was in good harmony with the results obtained using pseudo second order model. The adsorption capacity determined using Langmuir isotherm and pseudo second order model was found to be 142.85 mg/g.

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 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 Kinetics and equilibriums adsorption of Cu (II) ion by chitosan and cross-linked chitosan-bentonite

REAKTOR ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 117-124
Author(s):  
Hargono Hargono ◽  
Angga Mei Sarah ◽  
Feninda Nevrita ◽  
Bakti Jos
Keyword(s):  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Order Model ◽  
Equilibrium Studies ◽  
Test Parameters ◽  
Constant Rate ◽  
Pseudo Second Order ◽  
The Impact ◽  
Second Order Model

The sorption of Cu (II) particle from aqueous solution onto chitosan and cross-connected chitosan-bentonite (CTS-BTN) as adsorbent were conducted in batch conditions. The impact of different test parameters: starting pH, sorption time was assessed. Equilibrium studies have been completed to decide the limit of chitosan and CTS-BTN for Cu (II) particle. The Langmuir and Freundlich isotherm models were used in the examination of the trial information as linearized conditions. It was discovered that the isotherm information were all around portrayed by the Langmuir isotherm. Chitosan and CTS-BTN showed an adsorption capacity of 125 mg/g and 142.86 mg/g, respectively. The constant of adsorption rate was investigation utilizing a pseudo first order and a pseudo second order model. The pseudo second order model brought about the best fit with test information (R2= 0,991 for CTS and R2= 0,995 for CTS-BTN), additionally giving a constant rate k2, ads= 8.85 x 10-5 g/mg min for CTS and 3.72 x 10-4 g/mg min for CTS-BTN. Recommending that this model could be used in design and applications.Keywords:  adsorption; Cu(II) ion; chitosan; cross-linked; isotherm; kinetics

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.

scholarly journals Molybdenum Trioxide: Efficient Nanosorbent for Removal of Methylene Blue Dye from Aqueous Solutions

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Molybdenum Trioxide ◽  
Second Order ◽  
Blue Dye ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Removal Capacity ◽  
Pseudo Second Order

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.

scholarly journals The Equilibrium, Kinetics, and Thermodynamics Studies of the Sorption of Methylene Blue from Aqueous Solution Using Pulverized Raw Macadamia Nut Shells

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joshua N. Edokpayi ◽  
Samson O. Alayande ◽  
Ahmed Adetoro ◽  
John O. Odiyo
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Surface Area ◽  
Low Cost ◽  
Aqueous Media ◽  
Group Analysis ◽  
Second Order ◽  
Isotherm Models ◽  
Macadamia Nut ◽  
Pseudo Second Order

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (−ΔG0=28.72−31.77 kJ/mol) and endothermic in nature (ΔH0=17.45 kJ/mol). The positive value of ΔS0 (0.15 kJ/molK) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution.

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