scholarly journals Application of Recycled Zero-Valent Iron Nanoparticle to the Treatment of Wastewater Containing Nitrobenzene

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Heon Lee ◽  
Byung-Hoon Kim ◽  
Young-Kwon Park ◽  
Sun-Jae Kim ◽  
Sang-Chul Jung
Keyword(s):  
Particle Size ◽  
Biological Process ◽  
Film Formation ◽  
Dosage Level ◽  
Zero Valent Iron ◽  
Solution Ph ◽  
Steel Work ◽  
Iron Nanoparticle ◽  
Decreasing Ph ◽  
Pickling Line

Zero-valent iron (ZVI) was synthesized using iron oxide, a byproduct of pickling line at a steel work. ZVI with a mean particle size of 500 nm was synthesized. The reaction activity of the synthesized ZVI was much higher than commercial ZVI. When applied to the decomposition of nitrobenzene (NB), the ZVI particles underwent corrosion and passivation oxide film formation, resulting in particle size decrease. The NB decomposition rate increased with increasing ZVI dosage level and with decreasing pH. The solution pH increased monotonously with increasing reaction duration, whereas the aniline concentration showed a maximum at 50 min. Based on the GC/MS analysis, NB is presumed to be reduced into aniline via reductive intermediates such as azobenzene and azoxybenzene. When combined with a subsequent biological process, the synthesized ZVI will be able to decompose NB in wastewater effectively.

scholarly journals Chitosan Nanocarrier Entrapping Hydrophilic Drugs as Advanced Polymeric System for Dual Pharmaceutical and Cosmeceutical Application: A Comprehensive Analysis Using Box-Behnken Design

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 677
Author(s):  
Sara A. Abosabaa ◽  
Aliaa N. ElMeshad ◽  
Mona G. Arafa
Keyword(s):  
Particle Size ◽  
Sodium Tripolyphosphate ◽  
Chitosan Nanoparticles ◽  
Optimization Procedure ◽  
Entrapment Efficiency ◽  
Chitosan Solution ◽  
Polydispersity Index ◽  
Successful Implementation ◽  
Solution Ph ◽  
Box Behnken Design

The objective of the present research is to propose chitosan as a nanocarrier for caffeine—a commonly used drug in combating cellulite. Being a hydrophilic drug, caffeine suffers from insufficient topical penetration upon application on the skin. Chitosan nanoparticles loaded with caffeine were prepared via the ionic gelation technique and optimized according to a Box–Behnken design. The effect of (A) chitosan concentration, (B) chitosan solution pH, and (C) chitosan to sodium tripolyphosphate mass ratio on (Y1) entrapment efficiency percent, (Y2) particle size, (Y3) polydispersity index, and (Y4) zeta potential were studied. Subsequently, the desired constraints on responses were applied, and validation of the optimization procedure was confirmed by the parameters exhibited by the optimal formulation. A caffeine entrapment efficiency percent of 17.25 ± 1.48%, a particle size of 173.03 ± 4.32 nm, a polydispersity index of 0.278 ± 0.01, and a surface charge of 41.7 ± 3.0 mV were attained. Microscopical evaluation using transmission electron microscope revealed a typical spherical nature of the nanoparticles arranged in a network with a further confirmation of the formation of particles in the nano range. The results proved the successful implementation of the Box–Behnken design for optimization of chitosan-based nanoparticles in the field of advanced polymeric systems for pharmaceutical and cosmeceutical applications.

scholarly journals Ammoniacal System Mechanisms for Leaching Copper from Converter Slag

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Alvaro Aracena ◽  
Andrés Valencia ◽  
Oscar Jerez
Keyword(s):  
Particle Size ◽  
Converter Slag ◽  
Research Work ◽  
Ammonium Hydroxide ◽  
Copper Extraction ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Electron Microscopy Analysis ◽  
Leaching Solution ◽  
Conversion Stage

In pyrometallurgical processes refining copper, the main source of loss in the conversion stage is from slag. This paper reports on research work treating converter slag containing high percentages of copper (36 wt%) using ammonium hydroxide at room temperature. Variables analyzed are solution pH, agitation, temperature, NH4OH concentration and particle size. Results showed that the hydronium ion resulting from ammonium hydroxide dissociation was the main oxidant of copper compounds in slag, such as CuO, Cu2O and Cu, with the exception of CuFeO2. The particles contain a large amount of microcracks (porosity) in their refractory structure (analyzed by compositional image capture (BSE)). Thus, the diffusion of the leaching solution through the microcracks making contact with the copper oxides would be allowed. Leaching mechanisms were corroborated by X-ray diffraction and scanning electron microscopy analysis. Increasing temperature and NH4OH concentration while decreasing particle size obtained higher copper recoveries, reaching values of 84.8%. Under the same conditions, the main impurity (iron) was minimal (<2%). Solution pH also affected slag leaching. Agitation of the solution positively affected the rate of copper extraction. Leaching kinetics of the leaching solution through the porosity formed in the slag was analyzed under the intraparticle diffusion model. The reaction order was 1.2 with respect to the concentration of ammonium hydroxide and the model was inversely proportional to the square of the particle radius. The activation energy obtained was 42.3 kJ/mol for temperature range 283 to 333 K.

scholarly journals Study on Adsorption of Cu and Ba from Aqueous Solutions Using Nanoparticles of Origanum (OR) and Lavandula (LV)

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ghadah M. Al-Senani ◽  
Foziah F. Al-Fawzan
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Free Energy ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Solution Ph ◽  
Environment Friendly ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Langmuir And Freundlich Models

Wild herbs (Origanum (OR) and Lavandula (LV)) were used as environment-friendly adsorbents in this study. The adsorbents were used for adsorption of Cu and Ba from water. The adsorption of heavy metals onto OR and LV was dependent on particle size, dose, and solution pH. The diameter of adsorbent particles was less than 282.8 nm. The adsorption follows second-order kinetics. Langmuir and Freundlich models have been applied to describe the equilibrium data, and the thermodynamic parameters, the Gibbs free energy, ∆G°, enthalpy, ∆H°, and entropy, ∆S°, have been determined. The positive value of ∆H° suggests that the adsorption of heavy metals by the wild herbs is endothermic. The negative values of ∆G° at all the studied temperatures indicate that the adsorption is a spontaneous process. It can be concluded that OR and LV are promising adsorbents for the removal of heavy metals from aqueous solutions over a range of concentrations.

Efficient removal of uranium from aqueous solution by zero-valent iron nanoparticle and its graphene composite

2015 ◽  
Vol 290 ◽  
pp. 26-33 ◽  
Author(s):  
Zi-Jie Li ◽  
Lin Wang ◽  
Li-Yong Yuan ◽  
Cheng-Liang Xiao ◽  
Lei Mei ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Zero Valent Iron ◽  
Efficient Removal ◽  
Iron Nanoparticle ◽  
Graphene Composite

scholarly journals Effect of Kaolin particle size on the removal of Pb(II) from aqueous solutions by Kaolin-supported nanoscale zero-valent iron

2020 ◽  
Vol 7 (4) ◽  
pp. 045002
Author(s):  
Shang-Qun Li ◽  
Chuang Yu ◽  
Ze-Xiang Wu ◽  
Xiao-Qing Cai ◽  
Fu-Sheng Zha
Keyword(s):  
Particle Size ◽  
Aqueous Solutions ◽  
Zero Valent Iron ◽  
Nanoscale Zero Valent Iron

Removal of diazo dye Direct Red 23 from aqueous solution using zero-valent iron nanoparticles immobilized on multi-walled carbon nanotubes

2015 ◽  
Vol 71 (9) ◽  
pp. 1367-1374 ◽  
Author(s):  
Mahmoud Reza Sohrabi ◽  
Nafiseh Mansouriieh ◽  
Morteza Khosravi ◽  
Mohsen Zolghadr
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Zero Valent Iron ◽  
Mass Ratio ◽  
Solution Ph ◽  
Operational Conditions ◽  
Multi Walled Carbon Nanotubes ◽  
Diazo Dye ◽  
Zero Valent Iron Nanoparticles ◽  
Walled Carbon Nanotubes

The present study immobilized nanoscale zero-valent iron (nZVI) on multi-walled carbon nanotubes (MWCNTs) to enhance the reactivity of nZVI and prevent its aggregation. This novel composite (nZVI/MWCNT) was characterized by scanning electron microscopy and X-ray diffraction. The results showed that nZVI particles dispersed on the surface of the MWCNTs. The composite was used to remove the diazo dye Direct Red 23 from aqueous solution. The effects of nZVI to MWCNT mass ratio, nanocomposite content, solution pH, initial dye concentration and temperature were studied. The optimum nZVI/MWCNT mass ratio was 1:3. Batch experiments suggest that degradation efficiency decreased as the initial dye concentration increased and increased as the nanocomposite content increased, decreasing the pH from 8 to 4. The reaction followed a pseudo-first-order model under the operational conditions investigated in this study.

Electroacoustic determination of size and zeta potential of casein micelles in skim milk

1996 ◽  
Vol 63 (3) ◽  
pp. 387-404 ◽  
Author(s):  
Theresa Wade ◽  
James K. Beattie ◽  
William N. Rowlands ◽  
Mary-Ann Augustin
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Skim Milk ◽  
Median Particle Size ◽  
Casein Micelles ◽  
Median Particle ◽  
Decreasing Ph ◽  
Good Agreement

SummaryMeasurements of the zeta potential and particle size of casein micelles in skim milk suspensions at natural and lower pH have been made using the technique of electroacoustics. This technique requires no dilution or change of environment of the casein micelles. The zeta potential obtained at natural pH for a commercial skim milk suspension was −18 mV; it became less negative with decreasing pH. The median particle size observed at natural pH for a commercial skim milk suspension was 0·2 εm, in good agreement with previously reported values. The particle size increased as the pH was decreased.

Sign in / Sign up

Export Citation Format

Share Document