scholarly journals Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sivarama Krishna Lakkaboyana ◽  
Khantong Soontarapa ◽  
Nabel Kalel Asmel ◽  
Vinay Kumar ◽  
Ravi Kumar Marella ◽  
...  

AbstractThe present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)2-NWs-PVA-AC). The obtained Cu(OH)2-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution pH, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir–Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94–98.5% with a span of 10 min. and decent adsorption of about 98.5% at a pH of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (− 44.11 to − 48.86 kJ/mol) and a low negative value of ΔH° (− 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.

2021 ◽  
Author(s):  
Ahmed A. Oun ◽  
Kholod H. Kamal ◽  
Khaled Farroh ◽  
Esmat F. Ali ◽  
Mohamed A. Hassan

Abstract Cellulose, oxidized-fibers, and oxidized-nanocellulose were isolated from sponge-gourd fibers (Luffa cylindrica). Isolated materials showed different morphology (shape and size), chemical, crystalline properties, and removal efficiency against methylene blue (MB) and lead ions (Pb2+). The cellulosic materials showed high efficiency in removing MB more than Pb2+. So, different luffa forms/hydroxyapatite (HAp) composites were prepared and used as adsorbents for removal of both MB and Pb2+ from aqueous solutions. The effect of sorbent type, contact time, and initial MB and Pb2+ concentrations were studied. HAp was successfully synthesized on the surface of luffa with an average length of 40–56 nm and width of 14–19 nm. Kinetic and adsorption studies of MB and Pb2+ ions were well fitted with the pseudo-second-order model and Langmuir model. The maximum adsorption capacity of MB was 25.2 mg/g, 30.8 mg/g, and 36.2 mg/g for oxidized-fibers/HAp, oxidized-fibers, and cellulose, respectively, and for Pb2+ was 625 mg/g, 714 mg/g, and 714.5 mg/g for oxidized-fibers/HAp, oxidized-nanocellulose/HAp, and cellulose/HAp, respectively. Also, more than 85% of MB (25 mg/L) and 95% of lead (500 mg/L) were removed within the first 5 min. Oxidize-fibers/HAp composite showed effective adsorption with both MB and Pb2+ in a very short time.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sivarama Krishna Lakkaboyana ◽  
Khantong Soontarapa ◽  
Nabel Kalel Asmel ◽  
Vinay Kumar ◽  
Ravi Kumar Marella ◽  
...  

Author(s):  
Vahab Ghalehkhondabi ◽  
Alireza Fazlali ◽  
Keyhan Ketabi

Abstract Methylene blue (MB) is the cationic dye that is widely used for coloring cotton, wool, and silk. Since MB is harmful to human beings and toxic to microorganisms, there is the need to find cheap and efficient methods for removal of MB from wastewater prior to disposal into natural waters. In the present study, MB adsorption potential of MgO/AC prepared using a sol–gel-thermal deep-coating method was compared with the activated carbon (AC). The central composite design (CCD) as a method of the response surface methodology (RSM) was applied to minimize the number of runs and process optimization. The characterization of the microporous MgO/AC composite showed that the magnesium oxide nanoparticles were successfully coated on the AC and the BET specific surface area of AC and MgO/AC were 1,540 and 1,246 m2/g, respectively. The MB removal efficiency and the maximum adsorption capacity of AC and MgO/AC were 89.6, 97.5% and 571.7, 642.3 mg/g, respectively under optimum operational conditions of initial dye concentration of 100.9 mg/L, the adsorbent dosage of 69.4 mg/100 mL, pH of 10.2 and contact time of 149.1 min. According to an analysis of variance (ANOVA), the initial dye concentration and its interaction with the other effective factors have a large impact on adsorption efficiency. Furthermore, the mechanism of adsorption followed the Langmuir isotherm (R2 = 0.9935, Δqe = 2.9%) and adsorption kinetics fitted by the pseudo-second-order model (R2 = 0.9967, Δqe = 6.6%). Finally, our results suggest that the prepared MgO/AC is an efficient and promising material for dye wastewater treatment.


2019 ◽  
Vol 41 (1) ◽  
pp. 62-62
Author(s):  
Farida Bouremmad Farida Bouremmad ◽  
Abdennour Bouchair Abdennour Bouchair ◽  
Sorour Semsari Parapari Sorour Semsari Parapari ◽  
Shalima Shawuti and Mehmet Ali Gulgun Shalima Shawuti and Mehmet Ali Gulgun

Biosorbents can be an alternative to activated carbon. They are derived from agricultural by-products or aquatic biomass. They are low cost and they may have comparable performances to those of activated carbon. The present study focuses on the characterization of the Corallina Elongata (CE) alga and its adsorption performance for Methylene Blue (MB), this alga is found in abundance at the Mediterranean coast of the city of Jijel in eastern Algeria. The dried alga was characterized using various characterization techniques such as DTA, TG, FTIR, XRD, SEM and EDX, which showed that the material consists essentially of a calcite containing magnesium. Batch adsorption studies were carried out and the effect of experimental parameters Such as pH, initial dye concentration, temperature, adsorbent dose and contact time, on the adsorption of MB was studied. The kinetic experimental data were found to conform to the pseudo-second-order model with good correlation and equilibrium data were best fitted to The Langmuir model, with a maximum adsorption capacity of 34.4 mg/g. The adsorption isotherms at various temperatures allowed the determination of certain thermodynamic parameters (ΔG, ΔH and ΔS). Finally, the adsorption results showed a good affinity between CE and MB with a high adsorption capacity.


2015 ◽  
Vol 6 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Jixiang Zhang ◽  
Guangxia Zhang ◽  
Qiuxiang Zhou ◽  
Lailiang Ou

Calcium alginate (CA) was used as an adsorbent to remove methylene blue (MB) from aqueous solution. The effect of initial dye concentration, contact time, temperature and solution pH on the adsorption of MB onto CA was investigated by batch experiments. The percentage removal of MB decreased with increasing temperature. Comparatively high adsorption capacities were shown over a wide pH range (pH 2–11). More than 93% of MB removal was obtained within 30 min for an initial dye concentration of 1,000 mg/L at an adsorbent dose of 4 g/L. The adsorption equilibrium was investigated by the Langmuir and Freundlich isotherms. The maximum adsorption capacity was 2,355.4 mg/g on the basis of the Langmuir isotherm. Thermodynamic parameters were evaluated, and revealed that the adsorption process was a spontaneous, exothermic and entropy-reduced process. Pseudo-first, pseudo-second and intra-particle diffusion kinetic models were applied to the experimental data, and the results showed that the adsorption was in good agreement with the pseudo-second order kinetic model. Desorption studies implied that CA could be a useful adsorbent for the removal of MB from aqueous solution.


2018 ◽  
Vol 12 (1) ◽  
pp. 178-187
Author(s):  
Baghdad Science Journal

A new copolymer (MFA) was prepared from condensation of melamine (M) with p- methyl – anisole (A) in the presence of condensation agent like 37% (w/v) of formaldehyde. The new copolymer was characterized by elemental, IR and HNMR spectra. The chelating ion-exchange property of this polymer was studied for methylene blue dye in aqueous solution in 100-200ppm concentrations. The adsorption study was carried out over a wide range of pH, shaking time and in media of various kinetic parameters models. Thermal parameters like enthalpy, entropy and Gibbs free energy of adsorption process of methylene blue on surface of MFA resin were determined on the basis of kinetic parameters at different temperatures. To describe the equilibrium of adsorption, the Langmuir, Freundlich and Temkin isotherms were used. The Langmuir isotherm correlation (R2=0.987) was the best fitted for experimental data with maximum adsorption capacity of 200 ppm. A higher correlation value of the kinetic's model was observed close to pseudo first order, second order and Temkin kinetic models values of correlation R2 lie in the range (0.983-0.987) in comparing to other kinetic models.


2020 ◽  
Vol 24 (7) ◽  
pp. 1229-1243
Author(s):  
A.H. Alabi ◽  
E.O. Oladele ◽  
A.J.O. Adeleke ◽  
F.C. Oni ◽  
C.A. Olanrewaju

Methylene Blue (MB) was adsorbed from aqueous solution using Baobab (Adansonia digitata L.) fruit pod and its goethite modified form. Adsorbents were characterized using Fourier Transform-Infra Red (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Batch experiments were conducted at room temperature (26.8 °C) and the adsorption data were fitted using Langmuir, Freundlich, Temkin and Dubinin- Radushkevich isotherms. Also, kinetic data was fitted using Pseudo-first order, pseudo-second order, Elovich and intra-particle diffusion models. Goethite modified baobab (GMB) appeared to have a coarse microporous surface with smoother surface and larger pore volumes compared to unmodified baobab (UB). The –C=O band was observed at 1631 and 1636 cm-1 for UB and GMB. The –OH band was observed at 3447.00 cm-1 and 3442 cm-1 for UB andGMB respectively. Langmuir model was suitable for describing the adsorption data of UB with R2 of 0.9293 while Temkin model was best for fitting adsorption data of MB on GMB with R2 of 0.9691. However, maximum adsorption capacity was obtained with Freundlich adsorption isotherm (15.4253 and 43.1301 mg/g for UB and GMB respectively). The maximum biosorption were 8.98 mg/g and 9.86 mg/g for UB and GMB respectively at pH 10. Pseudo-second-order kinetic model best fitted the kinetic data with R2 values of 0.9968 and 0.9993 for UB and GMB, ΔHo values were 83.123 KJ/mol and 361.094 KJ/mol for UB and GMB, while ΔSo values were 3.084 J/mol/ K and 1.765 J/mol/K for UB and GMB respectively. GMB adsorbed more of MB than UB and the process was endothermic. Keywords: Biosorption, Goethite, Baobab, Isotherms, Methylene blue.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1338
Author(s):  
Adrián Fernández-Lodeiro ◽  
Jamila Djafari ◽  
Javier Fernández-Lodeiro ◽  
Maria Paula Duarte ◽  
Elisabete Muchagato Mauricio ◽  
...  

In this work, the successful preparation and characterization of gold nanorods (AuNRs) coated with a mesoporous silica shell (AuNRs@Simes) was achieved. Conjugation with methylene blue (MB) as a model drug using ultrasound-stimulated loading has been explored for further application in light-mediated antibacterial studies. Lyophilization of this conjugated nanosystem was analyzed using trehalose (TRH) as a cryogenic protector. The obtained stable dry formulation shows potent antimicrobial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria after a simple post-treatment irradiation method with a red laser during a short time period.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2473
Author(s):  
Huiping Zeng ◽  
Wei Qi ◽  
Longxue Zhai ◽  
Fanshuo Wang ◽  
Jie Zhang ◽  
...  

The development of low-cost adsorbent is an urgent need in the field of wastewater treatment. In this study, sludge-based magnetic biochar (SMB) was prepared by pyrolysis of sewage sludge and backwashing iron mud without any chemical agents. The samples were characterized by TGA, XRD, ICP, Organic element analysis, SEM, TEM, VSM and BET. Characterization analysis indicated that the magnetic substance in SMB was Fe3O4, and the saturation magnetization was 25.60 emu·g−1, after the adsorption experiment, SMB could be separated from the solution by a magnet. The batch adsorption experiment of methylene blue (MB) adsorption showed that the adsorption capacities of SMB at 298 K, 308 K and 318 K were 47.44 mg·L−1, 39.35 mg·L−1, and 25.85 mg·L−1, respectively. After one regeneration with hydrochloric acid, the maximum adsorption capacity of the product reached 296.52 mg·g−1. Besides, the adsorption kinetic described well by the pseudo-second order model revealed that the intraparticle diffusion was not just the only rate controlling step in adsorption process. This study gives a reasonable reference for the treatment of sewage sludge and backwashing iron mud. The product could be used as a low-cost adsorbent for MB removal.


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