scholarly journals Activated Graphene Oxide-Calcium Alginate Beads for Adsorption of Methylene Blue and Pharmaceuticals

Author(s):  
Burcu Gunes ◽  
Yannick Jaquet ◽  
Laura Sánchez ◽  
Rebeca Pumarino ◽  
Declan McGlade ◽  
...  

The remarkable adsorption capacity of graphene derived materials has prompted their examination in composite materials suitable for deployment in treatment of contaminated waters. In this study, crosslinked calcium alginate – graphene oxide beads were prepared and activated by exposure to pH 4 by using 0.1M HCl. The activated beads were investigated as novel adsorbents for the removal of organic pollutants (Methylene Blue dye and the pharmaceuticals Famotidine and Diclofenac) with a range of physicochemical properties. Effects of initial pollutant concentration, temperature, pH and adsorbent dose were investigated and kinetic models were examined for fit to the data. Maximum adsorption capacities qmax obtained were 1334, 35.50 and 36.35 mg g-1 for the uptake of Methylene blue, Famotidine and Diclofenac respectively. The equilibrium adsorption had an alignment with Langmuir isotherms while the kinetics were most accurately modelled using a pseudo- first –order and second order models according to the regression analysis. Thermodynamic parameters such as ΔG◦, ΔH◦ and ΔS◦ were calculated and the adsorption process was determined to be exothermic and spontaneous.

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6343
Author(s):  
Burcu Gunes ◽  
Yannick Jaquet ◽  
Laura Sánchez ◽  
Rebecca Pumarino ◽  
Declan McGlade ◽  
...  

The remarkable adsorption capacity of graphene-derived materials has prompted their examination in composite materials suitable for deployment in treatment of contaminated waters. In this study, crosslinked calcium alginate–graphene oxide beads were prepared and activated by exposure to pH 4 by using 0.1M HCl. The activated beads were investigated as novel adsorbents for the removal of organic pollutants (methylene blue dye and the pharmaceuticals famotidine and diclofenac) with a range of physicochemical properties. The effects of initial pollutant concentration, temperature, pH, and adsorbent dose were investigated, and kinetic models were examined for fit to the data. The maximum adsorption capacities qmax obtained were 1334, 35.50 and 36.35 mg g−1 for the uptake of methylene blue, famotidine and diclofenac, respectively. The equilibrium adsorption had an alignment with Langmuir isotherms, while the kinetics were most accurately modelled using pseudo- first-order and second order models according to the regression analysis. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated and the adsorption process was determined to be exothermic and spontaneous.


2019 ◽  
Vol 487 ◽  
pp. 539-549 ◽  
Author(s):  
Mohamed Mokhtar Mohamed ◽  
Mohamed A. Ghanem ◽  
Mohamed Khairy ◽  
Eman Naguib ◽  
Nouf H. Alotaibi

2020 ◽  
Vol 309 ◽  
pp. 113171 ◽  
Author(s):  
Mehmet Harbi Calimli ◽  
Mehmet Salih Nas ◽  
Hakan Burhan ◽  
Sibel Demiroglu Mustafov ◽  
Özkan Demirbas ◽  
...  

2019 ◽  
Vol 04 ◽  
Author(s):  
Sachin Dev ◽  
Man Singh

Introduction: The Metal Sulfide Nanoparticles Doped Graphene Oxide Sheets Have Been Studied And Were Used To Adsorb Fluorescent Methylene Blue Dye. Such Mechanism Efficiently Reduces The Dyes And Their Fluorescent Pollutants Through The Positive And Negative Holes. The Metal Sulfide Doped Graphene Oxide Could Be A Most Potential Route To Reduce From Fluorescent To Non-Fluorescent Species To Prevent The Global Warming And Other Pollution Being Caused By Them. Objectives: This Study Has Been To Strengthen And Widen The Applications Of Negative And Positive Holes Quick Formation At A Negligible Energy Barrier. Metal Sulfide Nanoparticles Were Doped With Graphene Oxide To Further Strengthen The Semiconducting And To Fastened The Rate Of Adsorption Of Methylene Blue Dye. Methods: Graphite Flakes Were Oxidized To Graphite Oxide With High Yield. The Graphite Oxide Was Sonicated In Water To Obtain Graphene Oxide And Doped With Metal Sulfide Nanoparticles In Situ. The Samples Were Characterized With High End Instruments And Used For Adsorption. Results: The Metal Sulfide Nanoparticles Were Successfully Doped With Graphene Oxide. The Ftir And Xps Spectra Infer Doping Of Metal Sulfide Nanoparticle In Graphene Oxide. That Enhanced Methylene Blue Adsorption Upto 97%. Conclusion: The Common Adsorption Effect Of Methylene Blue With Bare Graphene Oxide And Metal Sulfide Nanoparticles Doped Graphene Oxide Were Studied In This Paper. The Methylene Blue Adsorption Was Maximum (97%) By Cadmium Sulfide Doped Graphene Oxide Compared To Bare Graphene Oxide (87%), Nickel Sulfide Doped Graphene Oxide (79%), And Zinc Sulfide Doped Graphene Oxide (89%). The Metal Sulfide Nanoparticles Have Successfully Enhanced A Semiconductor Mechanism Of Graphene Oxide Especially With 3d And 4d10 Of Cds.


2019 ◽  
Vol 4 (1-2) ◽  
pp. 1-6
Author(s):  
M. Mahadeva Swamy ◽  
B.M. Nagabhushana ◽  
Nagaraju Kottam

The present experiment explains the effectiveness of adsorption studies of methylene blue dye from aqueous solutions on activated carbon from Selenicereus grandiflorus (SG) treated with conc. sulfuric acid. The sulphuric acid-treated Selenicereus grandiflorus activated carbon (SGAC) was used as low-cost adsorbent for the removal of methylene blue dye from aqueous solution. It suggests an ideal alternative method to adsorption of dye compared to other expensive treatment options. The adsorption studies have been conducted at different experimental parameters, i.e., pH, contact time, adsorbent dose and initial dye concentration. The batch mode experiments were conducted by different adsorbent dose (0.03-0.150 g per 50 mL), pH of the solution (2-12), effect of time (3-18 min), initial dye concentration (10 mg/L), point of zero charge and regeneration of spent adsorbent studies. Langmuir model shows better fit to the equilibrium data (R2 = 0.966) than Freundlich model. The adsorption capacity (Qm) of SGAC increases with increasing dosage where Qm is 16.17 mg g-1.


2020 ◽  
Vol 23 (10) ◽  
pp. 370-376
Author(s):  
Thamrin Azis ◽  
La Ode Ahmad ◽  
Keke Awaliyah ◽  
Laode Abdul Kadir

Research on the equilibrium and adsorption kinetics of methylene blue dye using tannin gel from the Tingi tree (Ceriops tagal) has been carried out. This study aims to determine the capacity and adsorption kinetics of tannin gel against methylene blue dye. Several parameters, such as the effect of contact time, pH, and methylene blue dye concentration on adsorption, were also studied. Based on the research results, the optimum adsorption process is a contact time of 30 minutes and a pH of 7. The adsorption capacity increased to a concentration of 80 mg/L with a maximum adsorption capacity (qm) of 49.261 mg/g. The adsorption process follows the pseudo-second-order adsorption kinetics model and the Langmuir isotherm model.


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