scholarly journals Synthesize and characterization of sawdust/MnFe2O4 nano composite for removal of indigo carmine from aqueous solutions

2014 ◽  
Vol 30 (4) ◽  
pp. 1753-1762 ◽  
Author(s):  
Saeedeh Hashemian ◽  
Motaharah Hidarian
Keyword(s):  
Aqueous Solutions ◽  
Indigo Carmine ◽  
Nano Composite

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

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 ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Kinetic Models ◽  
Batch Reactor ◽  
Maximum Adsorption Capacity ◽  
Nano Composite ◽  
Adsorption Processes ◽  
Intra Particle Diffusion ◽  
Short Time ◽  
Efficient Adsorbent

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.

Synthesis and Characterization of Chitosan/Fluorapatite Composites for the Removal of Cr (VI) from Aqueous Solutions and Optimized Parameters

2020 ◽  
Vol 231 (4) ◽  
Author(s):  
Rachid El Kaim Billah ◽  
Youness Abdellaoui ◽  
Zakaria Anfar ◽  
Germán Giácoman-Vallejos ◽  
Mahfoud Agunaou ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Synthesis And Characterization

Characterization of Structural Changes of Poly(vinyl methyl ether) γ-Irradiated in Diluted Aqueous Solutions

Langmuir ◽  
2004 ◽  
Vol 20 (7) ◽  
pp. 2883-2889 ◽  
Author(s):  
Claudia Querner ◽  
Thomas Schmidt ◽  
Karl-Friedrich Arndt
Keyword(s):  
Aqueous Solutions ◽  
Methyl Ether ◽  
Structural Changes ◽  
Vinyl Methyl ◽  
Vinyl Methyl Ether

scholarly journals Über Isopolywolframatfeststoffe und deren Beziehung zu Isopolywolframationen in wäßriger Lösun / Concerning Solid Isopolytungstates and their Relation to Isopolytungstate Ions in Aqueous Solutio

1975 ◽  
Vol 30 (11-12) ◽  
pp. 834-841 ◽  
Author(s):  
Vasile Cordis ◽  
Karl-Heinz Tytko ◽  
Oskar Glemser
Keyword(s):  
Aqueous Solutions ◽  
Reaction Scheme

A classification and characterization of the solid isopolytungstates obtainable from acidified aqueous solutions is given and the relation of the solid isopolytungstates to the isopolytungstate ions in the corresponding solutions is studied. As distinguished from the molybdate system all the polytungstate ions forming a solid exist in solution as well. The reasons for the non-occurrence of insoluble solids of species absent from solution are discussed. For setting up a reaction scheme on the polytungstates only very few of the large number of papers on this subject give evidentiary informations.

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