Use of natural and effective mandarin peel in the elimination of malachite green from the aqueous media: adsorption properties, kinetics and thermodynamics

2020 ◽  
Vol 177 ◽  
pp. 176-185
Author(s):  
Gizem Müjde Yalvaç ◽  
Bahar Bayrak
Keyword(s):  
Malachite Green ◽  
Aqueous Media ◽  
Adsorption Properties ◽  
Kinetics And Thermodynamics ◽  
Mandarin Peel

scholarly journals Effective Removal of Malachite Green from Aqueous Solutions Using Magnetic Nanocomposite: Synthesis, Characterization, and Equilibrium Study

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Q. Alorabi
Keyword(s):  
Surface Area ◽  
Malachite Green ◽  
Chemical Activation ◽  
Aqueous Media ◽  
Kinetic Studies ◽  
Cost Effective ◽  
Magnetic Nanocomposite ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Order Kinetic

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.

Xerogel activated diatoms as an effective hybrid adsorbent for the efficient removal of malachite green

2019 ◽  
Vol 43 (9) ◽  
pp. 3810-3820 ◽  
Author(s):  
Ganesan Sriram ◽  
U. T. Uthappa ◽  
Madhuprasad Kigga ◽  
Ho-Young Jung ◽  
Tariq Altalhi ◽  
...  
Keyword(s):  
Malachite Green ◽  
Aqueous Media ◽  
Efficient Removal

The surface of a naturally available diatom was modified using a xerogel for the enhanced removal of malachite green from aqueous media.

scholarly journals Uptake of Methylene Blue from Aqueous Solution by Pectin–Chitosan Binary Composites

2020 ◽  
Vol 4 (3) ◽  
pp. 95
Author(s):  
Dexu Kong ◽  
Lee D. Wilson
Keyword(s):  
Methylene Blue ◽  
Aqueous Media ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Point Of Zero Charge ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Adsorption Sites ◽  
Biopolymer Composites

To address the need to develop improved hybrid biopolymer composites, we report on the preparation of composites that contain chitosan and pectin biopolymers with tunable adsorption properties. Binary biopolymer composites were prepared at variable pectin–chitosan composition in a solvent directed synthesis, dimethyl sulfoxide (DMSO) versus water. The materials were characterized using complementary methods (infrared spectroscopy, thermal gravimetric analysis, pH at the point-of-zero charge, and dye-based adsorption isotherms). Pectin and chitosan composites prepared in DMSO yielded a covalent biopolymer framework (CBF), whereas a polyelectrolyte complex (PEC) was formed in water. The materials characterization provided support that cross-linking occurs between amine groups of chitosan and the –COOH groups of pectin. CBF-based composites had a greater uptake of methylene blue (MB) dye over the PEC-based composites. Composites prepared in DMSO were inferred to have secondary adsorption sites for enhanced MB uptake, as evidenced by a monolayer uptake capacity that exceeded the pectin–chitosan PECs by 1.5-fold. This work provides insight on the role of solvent-dependent cross-linking of pectin and chitosan biopolymers. Sonication-assisted reactions in DMSO favor CBFs, while cross-linking in water yields PECs. Herein, composites with tunable structures and variable physicochemical properties are demonstrated by their unique dye adsorption properties in aqueous media.

Scrutinizing the substituent effect on Mo-based electrocatalysts for molecular hydrogen release through axial–equatorial decomposition: a DFT study

2019 ◽  
Vol 21 (30) ◽  
pp. 16601-16614 ◽  
Author(s):  
Diana Yepes ◽  
Pablo Jaque ◽  
Jorge I. Martínez-Araya
Keyword(s):  
Substituent Effect ◽  
Molecular Hydrogen ◽  
Aqueous Media ◽  
Hydrogen Release ◽  
Dft Study ◽  
Kinetics And Thermodynamics

The effect of electron-donating and -withdrawing groups is studied in terms of axial and equatorial locations at the p-pyridine rings in the [(PY5Me2)MoO]2+ for the H2 release in aqueous media. It opens a way to modify its kinetics and thermodynamics.

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