scholarly journals Radiation Induced Silver Nanoparticles in Ionically Crosslinked Alginate Beads for Efficient Catalytic Degradation of Basic Dye

2021 ◽  
Author(s):  
Manal F. abou Taleb ◽  
Faten Ismail Abou El Fadl ◽  
Hanan Albalwi ◽  
Mohamed M. Ibrahim
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Calcium Alginate ◽  
Degradation Kinetics ◽  
Visible Spectrum ◽  
Catalytic Degradation ◽  
Second Order ◽  
Blue Dye ◽  
Ag Nps ◽  
Pseudo Second Order

Abstract Silver nanoparticles (Ag NPs) are widely used as engineered nanomaterials in many advanced nanotechnologies, due to their versatile, easy and cheap preparations combined with peculiar chemical-physical properties. Their increased production and integration in environmental applications including water treatment raise concerns for their impact on humans and the environment. In this study, gamma radiation dose of 20 kGy was utilized to induce the synthesis silver nanoparticles (Ag NPs) in the alginate micro beads to prepare calcium Alginate/Ag (Ca-ALG/Ag) nanocomposite beads. These beads were then used to degrade toxic basic dyes in waste water. Initially, Ca-ALG /Ag nanocomposite beads were synthesized and characterized using Ultra Violet-visible spectrum (UV-Vis), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) for confirming the formation of Ag NPs and morphological study. The catalytic efficiency of the resulting Ca-ALG/Ag nanocomposite beads is evaluated for the degradation of dyes such sandocryl blue dye in the presence of NaBH4. The catalytic degradation of sandocryl blue dye was very fast in the present conditions: 0.1 g of catalyst 5 ml NaBH4 and the optimum time for complete reduction was 30 min. The pseudo-first order, pseudo second order and intra particle diffusion model used to evaluate the kinetic models and the mechanism of the degradation. Results showed that the degradation kinetics best fit the pseudo-second-order model and Langmuir isotherm model. The Biopolymer-based nanocomposite beads of calcium alginate, and Ag NPs can be applied to reduce dyestuff, where it is economically viable and environmentally friendly.

scholarly journals Green Synthesis of Silver Nanoparticles Using Flower Extract of Hemigraphis colorata as Reducing Agent and its Biological Activity

2021 ◽  
Vol 10 (4) ◽  
pp. 2646-2654
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Green Synthesis ◽  
Visible Spectrum ◽  
Spherical Shape ◽  
Ag Nps ◽  
Surface Plasma Resonance ◽  
Flower Extract ◽  
Uv Visible ◽  
Average Size

Green synthesis of silver nanoparticles (Ag NPs) was performed using flower extract of Hemigraphis colorata (H. Colorata). Synthesized nanoparticles were characterized by UV-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM-SAED). , The crystalline nature of the sample was examined by an X-ray diffraction study (XRD). The UV-Visible spectrum showed surface plasma resonance (SPR) at 360 nm revealed the formation of nanoparticles, SEM and TEM exhibited spherical shape particles with an average size between 10-20 nm. The valuation of the antibacterial and antifungal study revealed its efficiency in killing bacteria and fungi.

scholarly journals Molybdenum Trioxide: Efficient Nanosorbent for Removal of Methylene Blue Dye from Aqueous Solutions

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Molybdenum Trioxide ◽  
Second Order ◽  
Blue Dye ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Removal Capacity ◽  
Pseudo Second Order

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.

scholarly journals Adsorption of Cu (II) and Ni (II) Ions from Solution onto Calcium Alginate Beads

2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu
Keyword(s):  
Contact Time ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Second Order ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Calcium Alginate Beads ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order

scholarly journals Methylene Blue Dye Removal from Aqueous Media Using Activated Carbon Prepared by Lotus Leaves: Kinetic, Equilibrium and Thermodynamic Study

2021 ◽  
Vol 68 (2) ◽  
pp. 363-373
Author(s):  
Roya Salahshour ◽  
Mehdi Shanbedi ◽  
Hossein Esmaeili
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Sorption Process ◽  
Second Order ◽  
Blue Dye ◽  
Order Kinetic ◽  
Methylene Blue Dye ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Lotus Leaves

In the present work, methylene blue was eliminated from aqueous solution using activated carbon prepared by lotus leaves. To perform the experiments, batch method was applied. Also, several analyses such as SEM, FTIR, EDAX and BET were done to determine the surface properties of the activated carbon. The results showed that the maximum sorption efficiency of 97.59% was obtained in initial dye concentration of 10 mg/L, pH of 9, adsorbent dosage of 4 g/L, temperature of 25 °C, contact time of 60 min and mixture speed of 400 rpm. Furthermore, the maximum adsorption capacity was determined 80 mg/g, which was a significant value. The experimental data was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, which the results showed that the pseudo-second order kinetic model could better describe the kinetic behavior of the sorption process. Also, the constant rate of the pseudo-second order kinetic model was obtained in the range of 0.0218–0.0345 g/mg.min. Moreover, the adsorption equilibrium was well described using Freundlich isotherm model. Furthermore, the thermodynamic studies indicated that the sorption process of methylene blue dye using the activated carbon was spontaneous and exothermic.

scholarly journals Dye removal from artificial wastewater using heterogeneous bio-fenton system

2017 ◽  
Vol 23 (4) ◽  
pp. 447-456
Author(s):  
Rahim Shojaat ◽  
Afzal Karimi ◽  
Naghi Saadatjoo ◽  
Soheil Aber
Keyword(s):  
Kinetic Models ◽  
Calcium Alginate ◽  
Correlation Coefficients ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Fenton System

In the present study, GOx/MnFe2O4/calcium alginate nano-composite was prepared by the trapping enzyme/nanoparticles in calcium alginate. The prepared absorbent was applied for decolorization of artificial dye wastewater of acid red 14 (AR14) by heterogeneous bio-Fenton system. Kinetic and isotherm studies were carried out. The decolorization of acid red 14 followed the Michaelis- Menten, pseudo-first order and pseudo-second order kinetic models. Good correlation coefficients were obtained by fitting the experimental data to Michaelis- Menten and pseudo-second order kinetic models. The adsorption isotherms were described by Langmuir, Freundlich and Temkin isotherms. Among the three isotherm models, the Freundlich model was fitted with the equilibrium data obtained from adsorption of AR14 onto MnFe2O4/calcium alginate; while Temkin isotherm gave the best correlation for adsorption on MnFe2O4 nanoparticles. The effect of various parameters such as initial pH of solution, initial dye concentration, and contact time on the adsorption of AR14 on MnFe2O4 and MnFe2O4/ /calcium alginate as well as dye enzymatic decomposition was studied. The decolorization of AR14 with initial concentration of 10 mg.L?1 by using GOx/ /MnFe2O4/calcium alginate was 60.17%.

Modified Carbon Nanostructures Obtained From Sugarcane Bagasse Hydrochar for Treating Chromium-Polluted Water

2020 ◽  
Vol 16 ◽  
Author(s):  
Nady A. Fathy ◽  
Sahar M. El-Khouly ◽  
Ola I. El-Shafey
Keyword(s):  
Electron Microscope ◽  
Surface Area ◽  
Functional Groups ◽  
Sugarcane Bagasse ◽  
Carbon Nanostructures ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Polluted Water ◽  
Initial Concentration ◽  
Pseudo Second Order

Background: Application of nanotechnology in wastewater treatment is the solving key to cope with the conflict between people’s increasing demand for water and the world-wide water shortage. The main goal of this study is to prepare modified carbon nanostructures (CNSs) from sugarcane bagasse waste (SCB) as effective adsorbents for removing toxic Cr(VI) ions from their aqueous solutions. Methods: The preparation of CNSs was performed via catalytic hydrothermal/carbonization of SCB. The resultant CNSs sample was oxidized by oxidation with HNO3/H2O2 (O-CNSs) and then followed by coating with diethylenetriamine (N-CNSs). Transmission electron microscope (TEM), scanning electron microscope attached to energy-dispersive X-ray (SEM/EDX), fourier transform infrared (FTIR) and nitrogen adsorption analyses were used to determine the morphology and surface properties of CNSs. Adsorption and desorption studies of Cr(VI) ions onto these modified CNSs were investigated. Effects of initial concentration of Cr(VI), pH of solution and temperature in batch mode were estimated. Adsorption studies were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich models. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were undertaken to follow the adsorption mechanism. Results: The prepared samples composed of carbon nanotubes and graphene sheets as evident by TEM and SEM. The adsorption of Cr(VI) is exothermic in nature, well-fitted with Langmuir, described by pseudo-second order kinetic model and then is uncontrolled by intraparticle diffusion step. It was found that the adsorption of Cr(VI) was higher uptake over O-CNSs (56 mg/g) than that by N-CNSs (44 mg/g). This was ascribed to that the first sample is enriched with acidic O-functional groups and possessed higher specific surface area (188 m2/g). Desorption studies were achieved by HNO3 and NaOH reagents for recovering the Cr(VI) from O-CNSs. Results revealed that about 90% of Cr(VI) can be recovered by HNO3 more than that by NaOH till the third run. Conclusions: Two modified CNSs samples were successfully prepared from SCB. Adsorption of Cr(VI) is highly relied on initial concentration of Cr(VI), pH and temperature. The main factors controlling the adsorption behavior of Cr(VI) are the acidic functional groups and the accessible surface area on O-CNSs. Furthermore, the O-CNSs attained high stability in recycling tests for Cr(VI) removal.

scholarly journals Effectiveness of Alkali-Acid Treatment in Enhancement the Adsorption Capacity for Rice Straw: The Removal of Methylene Blue Dye

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Nady A. Fathy ◽  
Ola I. El-Shafey ◽  
Laila B. Khalil
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Rice Straw ◽  
Acid Treatment ◽  
Low Cost ◽  
Second Order ◽  
Isotherm Models ◽  
Blue Dye ◽  
Acid Modification ◽  
Pseudo Second Order

The effectiveness of alkali-acid modification in enhancement the adsorption capacity of rice straw (RS) for removing a basic dye was studied. The obtained adsorbents were characterized by slurry pH, pHPZC, iodine number, methylene blue number, FTIR, and SEM analyses. Adsorption of methylene blue (MB) was described by the Langmuir, Freundlich, Tempkin, and Redlich-Peterson isotherm models. Effects of contact time, initial concentration of MB dye, pH of solution, adsorbent dose, salt concentration of NaCl, and desorbing agents on the removal of MB were reported. Kinetic studies were analyzed using the pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models and were found to follow closely the pseudo-second-order model. Equilibrium data were best represented by the Langmuir and Redlich-Peterson isotherms. The adsorption capacities were varied between 32.6 and 131.5 mg/g for untreated and treated RS samples with NaOH-1M citric acid (ARS-1C), respectively. Adsorption behavior of the ARS-1C sample was experimented in a binary mixture containing methylene blue (basic) and reactive blue 19 (acidic) dyes which showed its ability to remove MB higher than RB19. Overall, the results indicate that the alkali-acid treatment proved to be potential modification for producing effective low-cost adsorbents for the removal of the basic dyes from wastewater.

scholarly journals Catalytic degradation of methylene blue in aqueous solutions over Ni- and Co- oxide systems

2011 ◽  
Vol 9 (6) ◽  
pp. 1000-1007 ◽  
Author(s):  
Maria Stoyanova ◽  
Stoyanka Christoskova
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Degradation Kinetics ◽  
Oxidative Degradation ◽  
Oxide System ◽  
Catalytic Degradation ◽  
Blue Dye ◽  
Oxide Systems ◽  
First Order Kinetics ◽  
Degradation Reaction

AbstractThe oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative destruction of methytlene blue dye in wastewaters.

scholarly journals Bioremoval of PVP coated silver nanoparticles using Aspergillus niger: the role of exopolysaccharides

2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Alrshim ◽  
Anindya Chanda
Keyword(s):  
Silver Nanoparticles ◽  
Aspergillus Niger ◽  
Wastewater Treatment Plants ◽  
Aqueous Media ◽  
Visible Spectrum ◽  
Ag Nps ◽  
Characteristic Peak ◽  
Uv Visible

Abstract The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. PVP-Ag-PVP resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.

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