Optimizing adsorption of Cr(VI) from aqueous solutions by NiO nanoparticles using Taguchi and response surface methods

2015 ◽  
Vol 72 (5) ◽  
pp. 721-729 ◽  
Author(s):  
Nasim Ziaeifar ◽  
Morteza Khosravi ◽  
Mohammad A. Behnajady ◽  
Mahmood R. Sohrabi ◽  
Nasser Modirshahla
Keyword(s):  
Aqueous Solutions ◽  
Response Surface ◽  
Contact Time ◽  
Sol Gel ◽  
The Other ◽  
Nio Nanoparticles ◽  
Optimum Conditions ◽  
Nickel Oxide Nanoparticles ◽  
Response Surface Methods ◽  
Do So

In the present study, nickel oxide nanoparticles synthesized by the sol–gel method were used as an effective adsorbent for the removal of Cr(VI) from aqueous solutions. To do so, the effect of four parameters including the concentration of Cr(VI), the dosage of NiO, contact time, and pH on the removal of Cr(VI) by NiO nanoparticles were studied. In order to examine and describe the optimum conditions for each of the mentioned parameters, Taguchi and response surface methods were used. The results of the experiment using Taguchi and response surface methods indicated the greater effect of the NiO adsorbent parameter in comparison to the other parameters in the adsorption of Cr(VI) by NiO nanoparticles, and showed that the increase in contact time and pH does not affect the removal percentage of Cr(VI) significantly.

Exploring the characteristics of the nickel oxide nanoparticles via Sol - gel method

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Jothi M ◽  
Sowmiya K
Keyword(s):  
Nickel Oxide ◽  
Ph Value ◽  
Lattice Structure ◽  
Sol Gel ◽  
Systematic Change ◽  
Average Crystalline Size ◽  
Nio Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
X Ray ◽  
Vis Spectroscopy

Nickel Oxide (NiO) is an important transition metal oxide with cubic lattice structure. NiO is thermally stable that is suitable for tremendous applications in the field of optic, ceramic,glass, electro-chromic coatings, plastics, textiles, nanowires, nanofibers, electronics,energy technology, bio-medicine, magnetism and so on. In this present study, NiO nanoparticles were successfully synthesized by sol-gel technique. Nano-sols were prepared by dissolving Nickel-Chloride [NiCl2.6H2O] in NaOH solvent and were converted into nano structured gel on precipitation. A systematic change in preparation parameters like calcination temperature, time, pH value has been noticed in order to predict the influence on crystallite size. Then the prepared samples were characterized by the X-ray Diffraction Spectroscopic (XRD), UV-VIS Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). From XRD, the average crystalline-size has been calculated by Debye-Scherrer Equation and it was found to be 12.17 nm and the band gap energy of Nickel oxide (NiO) from UV studies reveals around 3.85 eV. Further, EDX and FTIR studies, confirm the presences of NiO nanoparticles. The SEM study exhibits the spherical like morphology of Nickel oxide (NiO). Further from PSA, the mean value of NiO nanoparticles has been determined.

Biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus

2012 ◽  
Vol 66 (8) ◽  
pp. 1699-1707 ◽  
Author(s):  
A. K. Giri ◽  
R. K. Patel ◽  
P. C. Mishra
Keyword(s):  
Aqueous Solutions ◽  
Bacillus Cereus ◽  
Contact Time ◽  
Living Cells ◽  
Optimum Conditions ◽  
Order Model ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Biomass Dosage ◽  
Batch Biosorption

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.

scholarly journals Evaluate the effectiveness of the UV/ persulfate process to remove catechol from solution aqueous

2021 ◽  
Keyword(s):  
Data Analysis ◽  
Aqueous Solutions ◽  
Uv Radiation ◽  
Removal Efficiency ◽  
Design Of Experiment ◽  
Contact Time ◽  
Batch Reactor ◽  
Acidic Ph ◽  
Optimum Conditions ◽  
Optimum Ph

<p>Catechol is used as an antioxidant, fungicide, and polymerization inhibitors in a variety of industries such as petrochemical. Catechol must be removed from effluents before it enters to environment. This study aimed to investigate combined UV radiation and persulfate process in removal of catechol from aqueous solutions. All experiments were performed in a batch reactor. Data analysis were done with Design of Experiment (DoE) software. The effects of various variables such as pH, initial persulfate concentration, and initial Catechol concentration were investigated. The findings indicated with increases in persulfate concentration and decrease in catechol concentrations, the removal efficiency increased. Acidic pH and UV radiation were the leading factors in removal of catechol. The optimum pH, persulfate concentration, and catechol concentration were obtained 7, 0.04 M, and 100 mg l-1, respectively. More removes of catechol was achieved in optimum conditions within contact time of 60 min. The synergic effects of UV and persulfate radical were about 88%. Approximately 60% of catechol was mineralized within contact time of 60 min. Persulfate radicals resulting from UV/S2O82- were the main effective oxidants in removal and mineralization of catechol. Owing to high removal efficiency of persulfate compounds which are, also, abundant and inexpensive, these can be applied in removal of persistent organic pollutants from aqueous solutions.</p>

NiO nanoparticles prepared by the sol-gel method for a dye sensitized solar cell applications

2018 ◽  
Vol 1 (92) ◽  
pp. 15-21
Author(s):  
M. Szindler ◽  
M.M Szindler ◽  
L.A. Dobrzański ◽  
T. Jung
Keyword(s):  
Solar Cell ◽  
Nickel Oxide ◽  
Sol Gel ◽  
Dye Sensitized Solar Cell ◽  
Nio Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
Gel Method ◽  
Sol Gel Method ◽  
Dye Sensitized ◽  
Harvesting Efficiency

Purpose: The purpose of this article is to synthesized NiO nanostructures by sol-gel method and characterized them for use in dye sensitized solar cells. For this purpose, a paste prepared from nanoparticles was prepared and screen printed on a glass substrate with the FTO layer. Design/methodology/approach: Nickel oxide nanoparticles was synthesized with participation of nickel (II) nitrate hexahydrate and citric acid. The prepared nanopowder has been subjected to structural analysis using a transmission electron microscope (TEM). Scanning Electron Microscopic (SEM) images were taken with a Zeiss Supra 35. Qualitative studies of chemical composition were also performed using the Energy Dispersive Spectrometer (EDS). The structure of nickel oxide was investigated by X-ray crystallography. An average crystallite size were calculated using Scherrer method and Williamson-Hall analysis. Light harvesting efficiency LHE was calculated from measured absorbance. Findings: The uniform nickel oxide nanoparticles with spherical shape were successfully produced by sol-gel method. The diameter of the as prepared nanoparticles does not exceed 25 nm which is confirmed by the XRD and TEM analysis. The light harvesting efficiency of the electrode in the entire studied range it’s over 90%. Therefore the NiO can be an attractive alternative to the most commonly used TiO2. Research limitations/implications: The next step in the research will be to investigate the ZnO/NiO composite on the properties of the photoelectrode of dye sensitized solar cell. Practical implications: The unique properties of produced NiO nanostructural materials have caused their interest in such fields as medicine, transparent electronics and photovoltaics. Originality/value: The NiO nanoparticles were prepared using sol-gel method and then effectively used in the photoanode of dye sensitized solar cell.

scholarly journals Response surface methodology, modeling to improve mercury removal from aqueous solutions using L-Cysteine functionalized Multi-walled Carbon Nanotubes

2019 ◽  
Vol 21 (1) ◽  
pp. 64-69
Keyword(s):  
Carbon Nanotubes ◽  
Response Surface Methodology ◽  
Aqueous Solutions ◽  
Response Surface ◽  
Removal Efficiency ◽  
Mercury Concentration ◽  
Contact Time ◽  
Mercury Removal ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

<p>The aim of this study was to evaluate the mercury removal from aqueous solutions by using L-Cysteine functionalized Multi-walled Carbon Nanotubes. The effect of pH, adsorbent dose, contact time and mercury concentration in removal efficiency was evaluated. Multi -walled carbon nanotubes were functionalized with L-cysteine. The Response Surface Methodology (RSM) was used to find the optimum process parameters. The results showed that an increase in contact time, pH and adsorbent dosage resulted in an increase of the adsorption rate. However, removal efficiency decreases by increasing mercury concentration. The highest and lowest removal efficiencies of mercury were 89% and 17%, respectively. The maximum adsorption rate was occurring at 120 min. It is concluded that L-Cysteine functionalized multi-walled carbon nanotubes is an effective adsorbent for removal from aqueous solutions.</p>

Response Surface Methodology as a Tool to Study the Removal of Amido Black Dye from Aqueous Solution using Anionic Clay Hydrotalcite

2010 ◽  
Vol 7 (1) ◽  
pp. 51
Author(s):  
Yamin Yasin ◽  
Nur Syahirah Abdul Latif ◽  
Abdul Hafiz Abdul Malik
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Interactive Effects ◽  
Optimum Conditions ◽  
Solution Ph ◽  
Adsorbent Dosage ◽  
Anionic Clay ◽  
Amido Black ◽  
Optimization Parameters

Anionic clay hydrotalcite was used as an adsorbent to remove amido black dye from aqueous solutions. Response surface methodology (RSM) based on a five-level, four-variable Central Composite Rotatable Design (CCRD) was employed to evaluate the interactive effects of various optimization parameters. The parameters were contact time (6-10 hrs), solution pH (4-8), adsorbent dosage (200-600 mg) and dye concentration (50-100 mg/I). Simultaneously increasing contact time, initial concentration and amount of adsorbent dosage increased the quantity of amido black dye removed. The optimum conditions derived via RSM for the reaction were a reaction time of 8.48 hrs, a concentration of 58. 09 mg/I, an adsorbent dosage of 431. 2 4 mg/L and a solution pH of 6.27. The experimental percentage removal was 85.55 % under optimum conditions, which compares well with the maximum predicted value of 87.95 %.

The Study of Copper (II) Removal from Aqueous Solutions by Adsorption Using Corn Stalk Material

2012 ◽  
Vol 610-613 ◽  
pp. 1950-1953
Author(s):  
Zheng Jun Gong ◽  
Wenbo Zhou ◽  
Zhong Ping Qiu
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Corn Stalk ◽  
Absorption Process ◽  
Optimum Conditions ◽  
Batch Mode ◽  
Langmuir Adsorption ◽  
Initial Ph

In this study, removal of copper(Ⅱ) from aqueous solutions was examined using corn stalk. In the batch mode adsorption studies, the effects of initial pH and contact time on the copper(Ⅱ) adsorption by the corn stalk have been studied. The results show that: the pH 6.0 and contact time 8 hrs is optimum conditions of this absorption process when the dosage of corn stalk is 0.1g. In the isotherm studies, the Langmuir and Freundlich isotherm models were applied. The R2 of the Langmuir and Freundlich isotherm are 0.981 and 0.944 respectively. The Langmuir adsorption capacity Qmax is 54.05 mg/g. The goodness of fitness was obtained with the Langmuir and Freundlich adsorption isotherms.

scholarly journals Optimization of biosorption of nickel(II) and cadmium(II) by indigenous seaweed Enteromorpha using response surface methodology

2015 ◽  
Vol 50 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Gholamreza Tolian ◽  
Seyed Ali Jafari ◽  
Saeid Zarei
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Contact Time ◽  
Biomass Concentration ◽  
Langmuir Model ◽  
Optimum Conditions ◽  
Box Behnken Design ◽  
Biosorption Capacity ◽  
Independent Variables ◽  
Maximum Sorption

In the present paper, the biosorption capacity of an indigenous seaweed Enteromorpha sp. was assessed and compared for nickel(II) and cadmium(II) removal from aqueous solution. Response surface methodology based on Box–Behnken design was employed to achieve the optimum removal conditions as well as investigating the effects of some independent variables on the process performance. It was found that the maximum nickel(II) removal achieved was 87.16% under optimum conditions of pH 4.79, biomass concentration of 1,000 mg/L, contact time 70 min and temperature of 25 °C. For cadmium the optimum conditions were defined as pH 4.88, biomass concentration of 1,000 mg/L, contact time 50 min and temperature fixed at 65 °C which resulted in a maximum 75.16% removal. Equilibrium isotherm studies revealed that Freundlich and Langmuir models were more successful for describing nickel(II) and cadmium(II) biosorption data, respectively. The maximum sorption capacities of biomass, qmax, for nickel(II) and cadmium(II) were predicted as 250 and 167 mg/g, respectively, by the Langmuir model. The results suggest Enteromorpha seaweed as an eco-friendly and suitable biosorbent for nickel(II) and cadmium(II) removal from aqueous solutions.

Removal of trace thorium(IV) from aqueous solutions using a pseudo-polyrotaxane

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Huijun Liu ◽  
Shanxia Deng ◽  
Lanlin Lei ◽  
Zhiyuan Feng ◽  
Caixia Qi ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Thermodynamic Parameters ◽  
Contact Time ◽  
Experimental Results ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Optimum Conditions ◽  
Dose Concentration ◽  
Adsorbent Dose

Abstract The adsorption of thorium(IV) was studied using a pseudo-polyrotaxane, which was obtained by the reaction of poly(propyleneglycol) (PPG) and 6-OTs-β-CD. The adsorption of thorium(IV) was examined as a function of the contact time, pH of the solution, adsorbent dose, concentration of thorium(IV) and temperature using batch adsorption experiments. The experimental results suggested that the optimum conditions were found to be at pH 3.5, contact time 40 min, 10 mg adsorbent doses, 20 mg L−1 thorium(IV) concentration and 298 K. The maximum adsorption capacity was found to be 15.366 mg g−1. The thermodynamic parameters (ΔG0<0, ΔH0<0) were calculated, the result showed that the adsorption of thorium(IV) was exothermic and spontaneous process.

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