scholarly journals Synthesis of Poly(Ortho-Phenylenediamine) Fluffy Microspheres and Application for the Removal of Cr(VI)

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Zhoufeng Wang ◽  
Fang Liao
Keyword(s):  
Aqueous Solutions ◽  
Room Temperature ◽  
Average Diameter ◽  
Ammonium Persulfate ◽  
Solution Ph ◽  
Sem Images ◽  
Chemical Polymerization ◽  
Ph Values ◽  
Langmuir Isotherm Model ◽  
Adsorbent Materials

We reported the synthesis of fluffy poly(o-phenylenediamine) (PoPD) microspheres via chemical polymerization of oPD monomers by ammonium persulfate (APS) at room temperature. The SEM images showed that PoPD microspheres with an average diameter of 1.5 μm and their surfaces consist of highly oriented nanofibers. Furthermore, PoPD microspheres were used as adsorbent materials for the removal of Cr(VI) from aqueous solutions. The Cr(VI) adsorption behavior on the prepared PoPD microspheres was studied at different adsorption contact times, solution pH values, and amount of the adsorbent. Experimental isotherms of Cr(VI) ions were successfully fit to the Langmuir isotherm model. The results indicate that the PoPD fluffy microspheres are an effective adsorbent for the removal of Cr(VI) ions from aqueous solutions, and they could be useful in treatment of Cr(VI)-polluted wastewaters.

scholarly journals Ca2+ removal from water by the use of Na-palygorskite for potential water softening

2021 ◽  
Author(s):  
Gianni Eleni ◽  
Panagopoulos Georgios ◽  
Katsanou Konstantina ◽  
Biniaris Alexandros
Keyword(s):  
Linear Form ◽  
Water Samples ◽  
Room Temperature ◽  
Low Cost ◽  
Water Hardness ◽  
Water Softening ◽  
Initial Concentration ◽  
Ph Values ◽  
Langmuir Isotherm Model ◽  
Ft Ir

Abstract Sodium-treated palygorskite (Na-Pal) sample was investigated for the sorption of Ca2+ ions with the aim of treating water hardness. The effective modification of the mineral with Na+ was verified by XRD and FT-IR techniques. Batch kinetic experiments in standard solutions were performed proving that 30 g/L of Na-Pal were highly satisfactory as the Ca2+ removal reached the 85% for 100 mg/L Ca2+ initial concentration, which is very promising for the softening of moderate or hard waters. The Ca2+ removal found to be pH and temperature independent, with high removal rates at room temperature and common pH values of water samples (pH 4–12), rendering these circumstances ideal for the low-cost maintenance of the procedure that took place within the first 5 min. The linear form of the Langmuir isotherm model expressed better (R2 = 1) the Ca2+ sorption, which means that takes place at specific homogeneous sites of Na-Pal. Thermodynamic analysis proved the non-spontaneous (positive ΔG0), physical, and exothermic nature (ΔH0 = −10.8197 kJ/mol) of the reaction, while the kinetic models proved the chemisorption of Ca2+ by Na-Pal.

scholarly journals Fish (Labeo rohita) scales as a new biosorbent for removal of textile dyes from aqueous solutions

2012 ◽  
Vol 2 (3) ◽  
pp. 175-184 ◽  
Author(s):  
Sagnik Chakraborty ◽  
Shamik Chowdhury ◽  
Papita Das Saha
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Assessment ◽  
Arrhenius Equation ◽  
Textile Dyes ◽  
Fish Scale ◽  
Fish Scales ◽  
Solution Ph ◽  
Batch System ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The feasibility of utilizing fish scales as a new biosorbent for removal of textile dyes, namely crystal violet (CV) and methylene blue (MB), from their aqueous solutions was investigated in a batch system. Experiments were conducted as a function of initial solution pH (2–10), contact time (0–180 min), biosorbent dose (0.5–5 g) and temperature (293–313 K). The Langmuir isotherm model showed excellent fit to the equilibrium biosorption data of both CV and MB. The maximum dye biosorption capacity of fish scale was calculated as 74.39 and 58.67 mg g−1 for CV and MB, respectively, at 313 K. Biosorption phenomena of CV and MB by fish scales followed pseudo-second-order kinetics. Activation energy calculated by using the Arrhenius equation suggested the chemisorption nature of the biosorption processes. A thermodynamic assessment indicated the spontaneous and endothermic nature of biosorption of the textile dyes. It could be concluded that fish scales may be used as an inexpensive and effective biosorbent for removal of dyes from aqueous solutions.

Fabrication of a Novel Electrospun Polyacrylonitrile/Giant Ball {Mo132} Composite Nanofibrous Mats in Adsorption of 2-CEES

2019 ◽  
Vol 3 (2) ◽  
pp. 130-138
Author(s):  
Reza Haddad ◽  
Mehdi Dusti Telgerd ◽  
Hojjatalla Hadi ◽  
Mohammad Sadeghinia
Keyword(s):  
Room Temperature ◽  
Composite Nanofibers ◽  
Sulfur Mustard ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Heterogeneous Structure ◽  
Adsorption Ability ◽  
Sem Images ◽  
Electrospinning Technique ◽  
Good Ability

Background: Polyacrylonitrile/Mo132 composite nanofibers mats was synthesized by an electrospinning technique using PAN and giant ball nano-polyoxomolybdateMo132. The nanocluster Mo132 was mixed with PAN solution and then electrospun to produce bead-free nanofibers. The aim of this study is to evaluate the adsorption ability of electrospun composite nanofibers against sulfur mustard stimulants and assess the possibility of using the electrospun nanofibers as protective membranes in chemical masks and warfare clothing. Adsorption of sulfur mustard stimulants was investigated on the surface of PAN nanofibers embedded with keplerate nano-polyoxomolybdate. Methods: In order to study the 2-CEES adsorption ability, the prepared PAN/Mo132 nanofibers composite was further prepared and exposed to 2-CEES solution. The surface morphology and other properties of the PAN/Mo132 nanofibers composite were characterized by various techniques, including SEM, TEM, FT-IR, UV-Vis. SEM images which showed that the average diameter of the fibers was found to be between 100-120 nm. Results: The adsorption efficiency of PAN/Mo132 composite in adsorption of 2-CEES was obtained 89% after 7h at room temperature. The results showed that composite nanofibers PAN/Mo132 will have a good ability as protective clothing and chemical masks against chemical warfare agents. Conclusion: PAN/Mo132 nanofibers were prepared by electrospinning method. The leaching of Mo132 from the nanofibers was not observed, meaning that the catalyst had excellent stability and could be used as a heterogeneous structure against the adsorption of sulfur mustard stimulant at room temperature. This composite nanofibers membrane exhibited good performance to adsorb 2-CEES in comparison with pure PAN. The adsorption rate of 2-CEES increases with increasing the amount of Mo132 embedded in the PAN nanofibers.

scholarly journals Adsorption of Cu(II) Ions on Adsorbent Materials Obtained from Marine Red Algae Callithamnion corymbosum sp.

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 372 ◽  
Author(s):  
Alina Roxana Lucaci ◽  
Dumitru Bulgariu ◽  
Maria-Cristina Popescu ◽  
Laura Bulgariu
Keyword(s):  
Red Algae ◽  
Aqueous Media ◽  
Maximum Adsorption Capacity ◽  
Waste Biomass ◽  
Solution Ph ◽  
Sem Images ◽  
Hno3 Solution ◽  
Algae Biomass ◽  
Aqueous Effluents ◽  
Adsorbent Materials

In recent years, studies on the more efficient use of natural materials in adsorption processes have increased significantly. Thus, obtaining new adsorbents from marine algae biomass with higher adsorptive performance will ensure a better use of these renewable resources. In this study, the adsorption of Cu(II) ions from aqueous solution was done using three types of adsorbent materials obtained from marine red algae biomass (Callithamnion corymbosum sp.), namely: alginate (Alg), algae waste biomass resulted after alginate extraction (AWB) and iron nanoparticles functionalized with alginate (Fe-NPs-Alg), compared to raw marine red algae biomass (RAB). FTIR spectra and SEM images recorded for each type of adsorbent indicate a porous structure and the presence of various superficial functional groups who may be involved in the retention of Cu(II) ions. The biosorption experiments were performed in a batch system, at different initial Cu(II) ion concentrations and contact times, maintaining a constant initial solution pH (4.4), adsorbent dose (2.0 g/L), and temperature (25 ± 1 °C). The obtained results indicate that the retention of Cu(II) ions requires a maximum of 60 min to reach equilibrium, and the maximum adsorption capacity increases in order: RAB (47.62 mg/g) < Fe-NPs-Alg (52.63 mg/g) < AWB (83.33 mg/g) < Alg (166.66 mg/g). The quantitative removal of Cu(II) ions from aqueous effluents can be done in two successive adsorption stages, using AWB (in the first stage) and Fe-NPs-Alg (in the second stage), when the treated solution has a Cu(II) ions concentration below the maximum permissible limit. The quantitative recovery of retained Cu(II) ions (over 97%) can be done by treating these exhausted adsorbent materials with 0.1 N HNO3 solution. Therefore, the extraction of alginate from marine red algae biomass could be a viable solution to obtain efficient adsorbent materials for Cu(II) ions removal from aqueous media, and allow for a better valorisation of marine red algae biomass.

scholarly journals Adsorptive Removal of Acid Blue 80 Dye from Aqueous Solutions by Cu-TiO2

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Ingrid Johanna Puentes-Cárdenas ◽  
Griselda Ma. Chávez-Camarillo ◽  
César Mateo Flores-Ortiz ◽  
María del Carmen Cristiani-Urbina ◽  
Alma Rosa Netzahuatl-Muñoz ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Isotherm Models ◽  
Solution Ph ◽  
Operating Variables ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Modeling Of Adsorption ◽  
Adsorption Equilibrium Data ◽  
Acid Blue

The adsorption performance of a Cu-TiO2composite for removing acid blue 80 (AB80) dye from aqueous solutions was investigated in terms of kinetics, equilibrium, and thermodynamics. The effect of operating variables, such as solution pH, initial dye concentration, contact time, and temperature, on AB80 adsorption was studied in batch experiments. AB80 adsorption increased with increasing contact time, initial dye concentration, and temperature and with decreasing solution pH. Modeling of adsorption kinetics showed good agreement of experimental data with the pseudo-second-order kinetics model. The experimental equilibrium data for AB80 adsorption were evaluated for compliance with different two-parameter, three-parameter, and four-parameter isotherm models. The Langmuir isotherm model best described the AB80 adsorption equilibrium data. The thermodynamic data revealed that the AB80 adsorption process was endothermic and nonspontaneous. Kinetics, equilibrium, and thermodynamic results indicate that Cu-TiO2adsorbs AB80 by a chemical sorption reaction.

scholarly journals Removal of the Hypoglycaemic Drug Gliclazide From Aqueous Solutions by Carbon-Based Magnetic Materials

2021 ◽  
Author(s):  
Ferda Civan Çavuşoğlu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Monolayer Adsorption ◽  
Langmuir Isotherm Model ◽  
Carbon Based

Abstract Adsorption of gliclazide from aqueous solutions with carbon-based adsorbents is the aim of this study. For this purpose, magnetic, versatile, and inexpensive magnetic activated carbon (MAC) and magnetic multi-walled carbon nanotube (MMWCNT) adsorbents have been developed. MAC and MMWCNT characterization were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA) techniques. In order to find the optimum conditions in batch adsorption experiments, the effects of parameters such as adsorbent dose, gliclazide solution pH, contact time, temperature and presence of foreign ions were investigated. Parameters were calculated for adsorption isotherms using Langmuir and Freundlich models. The adsorption studies of MAC and MMWCNT materials with gliclazide were in accordance with the nonlinear Langmuir and Freundlich isotherm models for all temperatures (298, 308, 318 K). The correlation coefficients of the Langmuir isotherm model are slightly higher than the Freundlich model. MAC adsorbent has maximum monolayer adsorption capacity at T=298 K (qmax=101.66 mg/g, R2=0.88) while MMWCNT has maximum monolayer adsorption capacity at T=308 K (qmax=71.59 mg/g, R2=0.90). For MAC and MMWCNT - Gliclazide adsorption systems, pseudo-first and secondorder kinetic models were examined and found to be more appropriate to the pseudo-secondorder kinetic model. The results showed that the MAC and MMWCNT could be could be promising adsorbents for gliclazide removal.

scholarly journals Adsorption Isotherms of Phenol Onto Adsorbents Derived from Egg Shell and Palm-Oil Shell

2012 ◽  
Vol 13 (3) ◽  
pp. 276
Author(s):  
Rayandra Asyhar
Keyword(s):  
Experimental Data ◽  
Adsorption Isotherms ◽  
Contact Time ◽  
Room Temperature ◽  
Adsorption Equilibrium ◽  
Solution Ph ◽  
Adsorption Models ◽  
Ph Values ◽  
Temperature And Pressure ◽  
Egg Shell

The adsorption isotherms of phenol from aqueous solution onto adsorbents obtained from egg shell (ESA) andpalm shell (PSA) were investigated. The objectives of the investigation were to understand the effect of bothadsorbents on solution pH and to study the adsorption equilibrium of phenol onto the adsorbents. The effect ofadsorbent on pH of solution was studied by shaking the adsorbent of 0.1 to 1.5 g with 100 ml of acidic aqueoussolution for 30 min at room temperature. The adsorption experiments were performed by stirring appropriateamount of adsorbent with 100 ml of 50 mg/l concentration of phenol at constant temperature and pressure. TheLangmuir and Fraundlich adsorption models were applied to experimental data and the isotherm constants werecalculated using linier regression analysis. The results showed that the adsorption capacity of the adsorbentsincreases with increasing of dosage and contact time. Also, pH of solution affected the adsorption isotherm ofphenol, where maximum adsorption was observed at pH values lower than 9.

Effects of pH Value on the Structures and Optical Properties of Bi2S3 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 397-399
Author(s):  
Jian Feng Huang ◽  
Yan Wang ◽  
Li Yun Cao ◽  
Hui Zhu ◽  
Xie Rong Zeng
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Room Temperature ◽  
Light Emission ◽  
Ph Value ◽  
Solution Ph ◽  
Oriented Growth ◽  
Cathodic Electrodeposition ◽  
Ph Values ◽  
Effects Of Ph

Bismuth sulfide (Bi2S3) is an important semiconductor material, which has wide applications in thermoelectricity, electronics, photoelectricity and infrared spectroscopy. Bi2S3 thin films have been deposited on ITO substrates through a cathodic electrodeposition approach at room temperature. The as-deposited thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and photoluminescence spectrum (PL). The effects of solution pH values on the structures and optical properties of the thin films were particularly investigated. Results show that uniform Bi2S3 thin films with oriented growth along (240) direction can be obtained at the solution pH value range from 4.5 to 6.5. The as-prepared thin films exhibit stable blue-green photoluminescence properties under the ultraviolet light excitation at room temperature. With the increase of the solution pH values, the crystallization of the Bi2S3 thin films improves while the grain size of the obtained thin films decreases and the light emission intensity of the thin films decreases.

scholarly journals Clean one-pot multicomponent synthesis of pyrans using a green and magnetically recyclable heterogeneous nanocatalyst

SynOpen ◽  
2021 ◽  
Author(s):  
Mina Ghassemi ◽  
Ali Maleki
Keyword(s):  
Room Temperature ◽  
Significant Loss ◽  
Copper Ferrite ◽  
Multicomponent Synthesis ◽  
Thermo Gravimetric ◽  
Sem Images ◽  
One Pot ◽  
Three Component Reaction ◽  
Ft Ir ◽  
The One

Copper ferrite (CuFe2O4) magnetic nanoparticles (MNPs) were synthesized via thermal decomposition method and applied as a reusable and green catalyst in the synthesis of functionalized 4H-pyran derivatives using malononitrile, an aromatic aldehyde and a β-ketoester in ethanol at room temperature. Then it was characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) analysis, scanning electron microscopy (SEM) images, thermo gravimetric and differential thermo gravimetric (TGA/DTG) analysis. The catalyst was recovered from the reaction mixture by applying an external magnet and decanting the mixture. Recycled catalyst was reused for several times without significant loss in its activity. Running the one-pot three-component reaction at room temperature, no use of eternal energy source and using a green solvent provide benign, mild, and environmentally friendly reaction conditions; as well, ease of catalyst recovering, catalyst recyclability, no use of column chromatography and good to excellent yields are extra advantages of this work.

scholarly journals Enhanced Oil Removal by a Non-Toxic Biosurfactant Formulation

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 467
Author(s):  
Emília Mendes da Silva Santos ◽  
Isabela Regina Alvares da Silva Lira ◽  
Hugo Moraes Meira ◽  
Jaciana dos Santos Aguiar ◽  
Raquel Diniz Rufino ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Cost ◽  
Aeration Rate ◽  
Oil Removal ◽  
Central Composite Rotatable Design ◽  
Chemical Methods ◽  
Ph Values ◽  
Spectroscopic Analyses ◽  
New Formulation ◽  
Central Composite

In this study, a new formulation of low-cost, biodegradable, and non-toxic biosurfactant by Candida sphaerica UCP 0995 was investigated. The study was conducted in a bioreactor on an industrial waste-based medium, and a central composite rotatable design was used for optimization. The best results, namely a 25.22 mN/m reduction in surface tension, a biosurfactant yield of 10.0 g/L, and a critical micelle concentration of 0.2 g/L, were achieved in 132 h at an agitation speed of 175 rpm and an aeration rate of 1.5 vvm. Compositional and spectroscopic analyses of the purified biosurfactant by chemical methods, Fourier transform infrared spectroscopy, and nuclear magnetic resonance suggested that it is a glycolipid-type biosurfactant, and it showed no cytotoxicity in the MTT assay. The biosurfactant, submitted to different formulation methods as a commercial additive, remained stable for 120 days at room temperature. Tensioactive properties and stability were evaluated at different pH values, temperatures, and salt concentrations. The biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to wide ranges of pH, temperature and salinity, enabling application under extreme environmental conditions. Bioremediation tests were performed to check the efficacy of the isolated biosurfactant and the selected microbial species in removing oil from soil. The results demonstrated that the biosurfactant produced has promising properties as an agent for the bioremediation of contaminated soil.

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