scholarly journals Adsorption of methylene blue on corncob charcoal: Thermodynamic studies

2021 ◽  
Vol 23 (1) ◽  
pp. 131-144
Author(s):  
A.A. Fodeke ◽  
O.J. Ayejuyone
Keyword(s):  
Methylene Blue ◽  
Thermodynamic Properties ◽  
Isotherm Model ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Thermodynamic Quantities ◽  
Zero Charge ◽  
Temperature Isotherm ◽  
Single Temperature ◽  
Mb Adsorption

To obtain the thermodynamic properties of adsorption of methylene blue (MB) on corncob carbonaceous adsorbents - untreated (UCC) and acid treated (TCC) - their equilibrium adsorption was determined between 10 o– 40o C at different pH conditions. The adsorption isotherms were fitted to Freundlich, Langmuir and Temkin isotherm models. The point of zero charge of each of the adsorbents was also determined. The point of zero charge was 10.58 ±0.09 for TCC, and 7.55 ± 0.10 for UCC. Only Freundlich model could account for the observed thermodynamic properties of MB adsorption by the adsorbents, though Temkin and Langmuir models have higher correlation coefficients. MB adsorption by TCC was an entropically driven process which depends on pH;ΔSo at pH 10.5 < ΔSo at pH 8.0 <ΔSo at pH 12.0. The ΔHo of the endothermic process at pH 12 is > ΔHo at pH 8 > ΔHo at pH 10.5. The results suggest that MB adsorption by the adsorbents occur by physisorption and is optimum when the pH is around the point of zero charge. It is important to ensure that in addition to fitting and equilibrium adsoption data by an isotherm model, the fit of the relevant equilibrium parameter should also be good and give thermodynamic quantities that could satisfactorily account for the observed adsorption properties of the system.  Deciding the suitability of an isotherm model for fitting adsorption equilibrium experiment based on compared error function of the fitted curves or lines through single temperature isotherm could lead to erroneous conclusion. Keywords: adsorption, adsorbent; methylene blue; enthalpy; entropy; Freundlich

scholarly journals Microwave Enhanced Synthesis of Sulfonated Chitosan-montmorillonite for Effective Removal of Methylene Blue

2021 ◽  
Author(s):  
Nur Shazwani Abdul Mubarak ◽  
N.N. Bahrudin ◽  
Ali H. Jawad ◽  
B.H. Hameed ◽  
Sumiyyah Sabar
Keyword(s):  
Methylene Blue ◽  
Langmuir Isotherm ◽  
Cationic Dyes ◽  
Isotherm Model ◽  
Batch Adsorption ◽  
Sulfonate Group ◽  
Order Kinetic ◽  
Effective Removal ◽  
Langmuir Isotherm Model ◽  
Mb Adsorption

Abstract In this work, sulfonated chitosan montmorillonite composite (S-CS-MT) beads were synthesized using a microwave irradiation method designed to have a better saving-time procedure. The potency of S-CS-MT as an adsorbent was assessed for the removal of cationic dyes such as methylene blue (MB) from aqueous solution. The batch adsorption experiments indicated that MB adsorption onto S-CS-MT follows the Pseudo-second-order kinetic and Langmuir isotherm model. The maximum extent obtained from the Langmuir isotherm model for MB adsorption was 188.2 mg g− 1 at 303 K. The thermodynamic study indicated that the adsorption reaction is favorable and spontaneous. These findings indicated that montmorillonite chitosan grafted with the sulfonate group has the ability and efficacy as biohybrid adsorbent for the adsorption of cationic dyes.

scholarly journals Methylene blue removal using a low-cost activated carbon adsorbent from tobacco stems: kinetic and equilibrium studies

2017 ◽  
Vol 75 (10) ◽  
pp. 2390-2402 ◽  
Author(s):  
Bellington Mudyawabikwa ◽  
Henry H. Mungondori ◽  
Lilian Tichagwa ◽  
David M. Katwire
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Radiation Power ◽  
Low Cost ◽  
Carbon Adsorbent ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Equilibrium Studies ◽  
Mb Adsorption

The aim of this study was to prepare activated carbon from tobacco stalks using microwave heating. The prepared activated carbon was applied as an adsorbent in methylene blue (MB) removal from water. The optimum conditions for activated carbon preparation were a radiation power of 280 W for a period of 6 minutes after the impregnation of the precursor material with 30% ZnCl2 for 24 hours. The activated carbon yield and iodine number were 49.43% and 1,264.51 mg/g respectively. The activated carbon also had a point of zero charge of 5.81 with an adsorption capacity of 123.45 mg/g for MB. The optimum conditions for MB adsorption were a pH of 6.5 with an adsorbent dosage of 0.2 g/50 mL at 25 °C. The MB adsorption kinetics followed the pseudo second order kinetic model with the intra-particle diffusion model suggesting a two-step adsorption mechanism. The adsorption data also fitted well within the Langmuir adsorption isotherm model. Tobacco stalks can successfully be turned into an economically important product.

Kinetic and isotherm studies on adsorption of methylene blue using polyacrylonitrile/hydroxyl group functionalized multiwall carbon nanotube multilayered nanofibrous composite

2020 ◽  
pp. 009524431989728
Author(s):  
S Swaminathan ◽  
NM Imayathamizhan ◽  
A Muthumanickkam
Keyword(s):  
Methylene Blue ◽  
Kinetic Study ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Hydroxyl Group ◽  
Isotherm Models ◽  
Multiwall Carbon Nanotube ◽  
Methylene Blue Adsorption ◽  
Multiwall Carbon

Nanofibrous composite mat was prepared using polyacrylonitrile hard yarn waste and hydroxyl group functionalized multiwall carbon nanotubes (MWCNTs-OH) by electrospinning technique and exploit for methylene blue dye adsorption from aqueous solution. The nanofibrous composite mat was characterized by Fourier transform (FT) infrared spectroscopy, FT-Raman, scanning electron microscopy, X-ray diffractometer and thermogravimetric analyser. The adsorption experiments were studied to investigate the effect of MWCNT-OH weight percentage, initial solution pH, contact time and initial dye concentration on the adsorption. The higher percentage of methylene blue adsorption was found to be 80.05% under optimal condition. The adsorption equilibrium data were studied with Langmuir and Freundlich isotherm models. The R2 value was found to be higher in the Freundlich isotherm model which was clearly indicated that the Freundlich isotherm model is most suitable for the adsorption of methylene blue on nanofibrous composite mat. The kinetic study was carried out to explain the adsorption rate of methylene blue on nanofibrous composite. The kinetic study of methylene blue adsorption was favourable to the pseudo second-order equation.

scholarly journals Isotherm Studies of Adsorption of Methylene Blue by Palm Kernel Shell

2018 ◽  
pp. 1-9
Author(s):  
Oladokun Benjamen Niran ◽  
Salaudeen Abdulwasiu Olawale ◽  
Utam John Ushie
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Palm Kernel ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Suitable Model ◽  
Palm Kernel Shell ◽  
Freundlich Adsorption Isotherm ◽  
Langmuir And Freundlich Models ◽  
Mb Adsorption

The main aim of this work is determine the feasibility of palm kernel shell (PKS) with phosphoric acid impregnation to biosorb methylene blue (MB) from aqueous solution by carrying out isotherm studies of the process. The influence of various factors such as contact time, initial dye concentration, adsorbent dosage, pH of dye solution and temperature were investigated in a batch adsorption technique. Result showed that adsorption of methylene blue (MB) dye was favourable at acidic pH. The percentage adsorption was found to increase with time of agitation, temperature, and mass of adsorbent but decreased with increase in initial MB concentration. In order to obtain a suitable model for the MB adsorption process, obtained data were fitted into different isotherm models like Langmuir and Freundlich models. Results showed that Freundlich adsorption isotherm model best describe MB adsorption onto palm kernel shell (PKS).

scholarly journals Modification of the surface chemistry of activated carbon and its influence on methylene blue adsorption

2018 ◽  
Vol 5 (1) ◽  
pp. 374
Author(s):  
David Wibowo ◽  
Lanny Setyadhi ◽  
Suryadi Ismadji
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Surface Chemistry ◽  
Activated Carbons ◽  
Surface Acidity ◽  
Carbon Surface ◽  
Point Of Zero Charge ◽  
Titration Method ◽  
Zero Charge ◽  
Boehm Titration

The adsorption behavior of activated carbons is determined not only by their porous structures but also by the chemical nature of its surface. The surface chemistry of activated carbons can be selectively modified in order to improve their adsorption capacity. In this study, a NORIT granular activated carbon was treated by oxidant (HNO3) and non-oxidant acid (HCI) at different concentrations and temperatures. The surface chemistries of the materials were characterized by Boehm titration method and by the determination of the point of zero charge (pHPZC).The adsorption properties of the selected samples were studied by adsorption of methylene blue, which is one of the important dyes and found in many textile effluents. In addition, the pore structures of the modified carbons were also studied by argon adsorption at 87.29 K. As results, it was observed that both HN03 and HCI treatments could increase the surface acidity of activated carbons. Activated carbons modified by HCI gave the best performance on the adsorption of methylene blue.Keywords: Activated Carbon, Surface Chemistry, Chemical Treatment, Boehm Titration Method, Adsorption AbstrakKemampuan adsorpsi karbon akti.ftidak hanya ditentukan oleh struktur pori tetapijuga dipengaruhi oleh sifat kimia dari permukaannya. Sifat kimia permukaan karbon aktif dapat secara selektif dimodifikasi dengan tujuan untuk lebih meningkatkan kapasitas adsorpsinya. Pada penelitian ini, karbon aktif NORIT granular ditreatment dengan menggunakan asam oksidator (HNO) dan non-oksidator (HCI) pada berbagai konsentrasi dan suhu. Sifat kimia permukaan karbon aktif dikarakterisasi dengan menggunakan metode titrasi Boehm serta dengan penentuan point of zero charge (pHPZC). Kemampuan adsorpsinya diuji dengan mengadsorp larutan methylene blue, dimana methylene blue merupakan salah satu komponen dalam limbah tekstil. Sedangkan struktur pori karbon aktif dianalisa dengan adsorpsi Ar pada suhu 87,29 K. Penelitian ini menunjukkan bahwa baik treatment dengan HNO3 maupun HCI dapat mengakibatkan terjadinya peningkatan sifat asam pada permukaan karbon aktif. Karbon aktif yang diberi perlalatan dengan HCI memberikan kemampuan adsorpsi yang paling baik dalam adsorpsi larutan methylen biru.Kata Kunci: Karbon Aktif, Sifat Kimia Permukaan, Perlakuan dengan Larutan Kimia, Metode Titrasi Boehm, Adsorpsi

scholarly journals Biosorption of Acid Dye in Single and Multidye Systems onto Sawdust of Locust Bean (Parkia biglobosa) Tree

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Abdur-Rahim Adebisi Giwa ◽  
Khadijat Ayanpeju Abdulsalam ◽  
Francois Wewers ◽  
Mary Adelaide Oladipo
Keyword(s):  
Methylene Blue ◽  
Rhodamine B ◽  
Synergetic Effect ◽  
Ternary Systems ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Parkia Biglobosa ◽  
Adsorption Processes ◽  
Acid Blue

Properties of raw sawdust ofParkia biglobosa, as a biosorbent for the removal of Acid Blue 161 dye in single, binary, and ternary dye systems with Rhodamine B and Methylene Blue dyes in aqueous solution, were investigated. The sawdust was characterized using Scanning Electron Microscopy, Fourier Transform Infrared spectrophotometry, X-ray diffraction, and pH point of zero charge. Batch adsorption experiments were carried out to determine the equilibrium characteristics, thermodynamics, and kinetics of the sorption processes. The data obtained were subjected to various isotherm and kinetics equations. The results showed that the adsorption processes were described by different isotherm models depending on the composition of the system; they were all spontaneous (ΔGranges from −0.72 to −5.36 kJ/mol) and endothermic (range ofΔHis 11.37–26.31 kJ/mol) and with increased randomness withΔSvalues of 55.55 and 98.78 J·mol/K for single and ternary systems, respectively. Pseudo-second-order kinetics model gave better fit for all the sorption systems studied irrespective of the differences in composition, with the initial and overall rate constants higher for the mixtures than for the single system (6.76 g·mg−1min−1). The presence of Rhodamine B and Methylene Blue had a synergetic effect on the maximum monolayer capacity of the adsorbent for Acid Blue 161 dye.

Adsorptive Removal of Methylene Blue Using Magnetic Biochar Derived from Agricultural Waste Biomass: Equilibrium, Isotherm, Kinetic Study

2018 ◽  
Vol 17 (05) ◽  
pp. 1850002 ◽  
Author(s):  
M. Ruthiraan ◽  
E. C. Abdullah ◽  
N. M. Mubarak ◽  
Sabzoi Nizamuddin
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Agricultural Waste ◽  
Research Work ◽  
Equilibrium Adsorption ◽  
Isotherm Model ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Magnetic Biochar ◽  
Equilibrium Adsorption Capacity

Wastewater discharge from textile industries contribute much to water pollution and threaten the aqua ecosystem balance. Synthesis of agriculture waste based adsorbent is a smart move toward overcoming the critical environmental issues as well as a good waste management process implied. This research work describes the adsorption of methylene blue dye from aqueous solution on nickel oxide attached magnetic biochar derived from mangosteen peel. A series of characterization methods was employed such as FTIR, FESEM analysis and BET surface area analyzer to understand the adsorbent behavior produced at a heating temperature of 800[Formula: see text]C for 20[Formula: see text]min duration. The adsorbate pH value was varied to investigate the adsorption kinetic trend and the isotherm models were developed by determining the equilibrium adsorption capacity at varied adsorbate initial concentration. Equilibrium adsorption isotherm models were measured for single component system and the calculated data were analyzed by using Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich isotherm equations. The Langmuir, Freundlich and Tempkin isotherm model exhibit a promising R2-correlation value of more than 0.95 for all three isotherm models. The Langmuir isotherm model reflectsan equilibrium adsorption capacity of 22.883[Formula: see text]mg[Formula: see text]g[Formula: see text].

scholarly journals Activated biomass of the green microalga Chlamydomonas variabilis as an efficient biosorbent to remove methylene blue dye from aqueous solutions

Water SA ◽  
2019 ◽  
Vol 45 (1 January) ◽  
Author(s):  
Reda M Moghazy
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Model Fit ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Blue Dye ◽  
Maximum Adsorption Capacity ◽  
Green Microalga ◽  
Pseudo Second Order ◽  
Activated Biomass

The raw and activated biomass of a green microalga, Chlamydomonas variabilis, were investigated as adsorbents for the removal of methylene blue (MB) dye from aqueous solutions. Chlamydomonas variabilis was isolated and cultivated to obtain a sufficient algal biomass. The collected biomass was first oven-dried and then activated by H2SO4. The results obtained showed that the optimum adsorption of MB occurred over 30 min of contact time at pH 7 and an biosorbent dose of 1.5 and 1.0 g·L−1 of dried biomass and activated biosorbent, respectively. Point of zero charge (pHpzc) was recorded at pH 6.8 and 6.9 for dried and activated biomass, respectively. The activated biomass was a more effective biosorbent than was the dried biomass: At a MB concentration of 82.4 mg·L−1, the minimum removal was greater than 98% using 1 g·L−1 activated biomass with a maximum adsorption capacity (qmax) of 115 mg·g−1, whereas at a MB concentration of 56.4 mg·L−1, the maximum removal did not exceed 80.8% using 1.5 g·L−1 raw biomass with a qmax of 18.3 mg·g−1. Furthermore, the Freundlich and Langmuir isotherm models of adsorption showed a better model fit when using activated biomass than when using raw biomass, with the former yielding R2 values greater than 0.9. The kinetic data suggest that the adsorption of MB follows the pseudo-second-order equation better than the pseudo-first-order one. This study demonstrates that the activated biomass of Chlamydomonas variabilis can be used as an effective biosorbent for the treatment of dye-containing wastewater streams. 

scholarly journals Influence of Alginate Encapsulation on Point of Zero Charge (pHpzc) and Thermodynamic Properties of the Natural and Fe(III) - Modified Zeolite

2019 ◽  
Vol 32 ◽  
pp. 286-293 ◽  
Author(s):  
Milan Kragović ◽  
Marija Stojmenović ◽  
Jelena Petrović ◽  
Jorge Loredo ◽  
Snežana Pašalić ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Point Of Zero Charge ◽  
Modified Zeolite ◽  
Alginate Encapsulation ◽  
Zero Charge

Comparative Analysis of the Adsorption of Methylene Blue Using Magnetised and Non-Magnetised Coconut Shell Biochar

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
A Musa
Keyword(s):  
Methylene Blue ◽  
Nonlinear Regression ◽  
Error Function ◽  
Coconut Shell ◽  
Isotherm Models ◽  
P Value ◽  
Regression Methods ◽  
Best Fit ◽  
Coconut Shell Biochar ◽  
Mb Adsorption

It is envisaged that magnetisation might alter the sorption behaviours of magnetised biochars due to some variation in the physicochemical properties from their precursor. This study evaluated the adsorption behaviours of a coconut shell biochar produced at 600 °C, CSB600, and its magnetised pair, MCSB600, in the adsorption of methylene blue (MB) from aqueous solutions. Langmuir, Freundlich and Redlich-Peterson isotherm models were used to describe the experimental isotherm using linear and nonlinear regression methods to determine the best fit for MB adsorption from the batch experiments conducted. The Langmuir model proved to be the best fit to explain the experimental data as it had the highest R2 (0.9684 and 0.9855) from linear regression and the lowest hybrid fractional error function, HYBRID (4.58, 1.145) and marquardt’s percent standard deviation, MPSD (10.61, 5.04) error function values from the nonlinear regression methods with maximum monolayer adsorption capacities of 5.590 and 5.229 mg/g for CSB600 and MCSB600 respectively. The magnetised biochar exhibited similar adsorption characteristics to what was observed for the non-magnetised biochar and only about 6.46% lower MB adsorption capacity was recorded. A p-value of 0.088 obtained suggested the isotherms were similar and therefore, magnetisation did not affect the adsorption of MB.

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