scholarly journals Facile Method by Bentonite Treated with Heat and Acid to Enhance Pesticide Adsorption

2021 ◽  
Vol 11 (11) ◽  
pp. 5147
Author(s):  
Chutima Pluangklang ◽  
Kunwadee Rangsriwatananon
Keyword(s):  
Aqueous Solution ◽  
Particle Size Analysis ◽  
Single Step ◽  
Size Analysis ◽  
Atrazine Concentration ◽  
27Al Mas Nmr ◽  
Pesticide Adsorption ◽  
Endothermic Process ◽  
Pseudo Second Order ◽  
Ph Range

In this work, simple conditions were applied to modify bentonite for the removal of pesticides from aqueous solution. Bentonite was modified in a single step as BA0.5 (with HCl 0.5 M) and BC500 (calcined at 500 °C) and combined steps with different sequences (BA0.5C500 and BC500A0.5). These adsorbents were characterised by XRD, XRF, FT-IR, 27Al MAS NMR, BET, NH3-TPD, TGA, HPLC, particle size analysis and zeta potential. Single-component adsorption with atrazine, diuron, 2,4-D and paraquat was used in aqueous solution at various pesticide concentrations, contact times and pH levels. It was found that the sequence of the treatment significantly affected atrazine adsorption. BC500A0.5 exhibited the highest efficiency for atrazine adsorption in a broad pH range of 3.0–9.0. Its adsorption at pH 6.0 was about 12 times greater than that of other adsorbents with an initial atrazine concentration of 50 mg L−1, which indicates BC500A0.5 specifically for the adsorption of atrazine. In addition, for the simultaneous adsorption of all four pesticides, BC500A0.5 was found to remove the maximum total amount of the pesticides, indicating that it could be used as a good multifunctional adsorbent. All modified bentonites showed similar diuron adsorption better than that of unmodified bentonite. The greatest adsorption of 2,4-D prefers BA0.5C500, occurring at pH 2–4. In the case of paraquat adsorption, all adsorbents are good at absorbing paraquat, but bentonite had the highest rate of paraquat removal, whereas BA0.5C500 was found to have the lowest, and the adsorption increased with increasing pH. Furthermore, the adsorption process on the adsorbents fits well with the Langmuir isotherm and pseudo-second-order kinetics models, as the thermodynamic parameters showed a spontaneous and endothermic process.

scholarly journals The Performance and Adsorption Mechanism of a Novel Collector, Dodecyl Dimethyl Betaine (BS-12), for the Flotation Separation of Ilmenite and Titanaugite

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 116 ◽  
Author(s):  
Pan Chen ◽  
Xujian Chai ◽  
Mengjie Tian ◽  
Wei Chen ◽  
Si Wan ◽  
...  
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Adsorption Mechanism ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Xps Analysis ◽  
Spectroscopy Analysis ◽  
Ft Ir ◽  
Ph Range

In this paper, a novel collector, dodecyl dimethyl betaine (BS-12), was used in the selective separation of ilmenite from titanaugite. The flotation performance and associated adsorption mechanism were studied by micro-flotation experiments, particle size analysis, Fourier-transform infrared (FT-IR) spectroscopy analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The micro-flotation results indicated that BS-12 exhibited a stronger collecting ability towards ilmenite than titanaugite within an acidic pH range, and that the recovery of ilmenite was about 50% higher than that of titanaugite under the optimum flotation conditions. Particle size analysis demonstrated that BS-12 could selectively agglomerate ilmenite to a certain extent and then contribute to the flotation difference between ilmenite and titanaugite. FT-IR results showed some characteristic bands of BS-12 on treated ilmenite, and on titanaugite with BS-12. The XPS analysis further confirmed that BS-12 chemisorbed onto ilmenite and titanaugite in a similar way, but the limited active sites on titanaugite in comparison with ilmenite accounted for their differences in flotation.

scholarly journals Zeta-potential and Particle Size Analysis of Human Amelogenins

2009 ◽  
Vol 89 (2) ◽  
pp. 149-153 ◽  
Author(s):  
V. Uskoković ◽  
Z. Castiglione ◽  
P. Cubas ◽  
L. Zhu ◽  
W. Li ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Particle Size Analysis ◽  
Full Length ◽  
Spherical Particles ◽  
Size Analysis ◽  
Hierarchical Assembly ◽  
Ph Range

The developing enamel matrix is a highly dynamic system mainly composed of the full-length amelogenin and its proteolytic cleavage products. In this study, size, zeta-potential, and the isoelectric points of nanoparticles of the recombinant full-length human amelogenin (rH174) and two proteolytic products (rH163 and rH146) were analyzed by dynamic light-scattering and electrokinetic measurements. We tested the hypothesis that zeta-potential may be used as a control parameter in directing the self-assembly of amelogenins. Extensive aggregation of amelogenin molecules with the particle size reaching about one micron occurred at a mildly acidic to neutral pH, and coincided with the red shift of the internal fluorescence. Zeta-potential was between ± 15 mV in the same pH range, indicating that amelogenin aggregation occurred when surface potentials were minimal. This suggests that electrostatic interactions may be another crucial factor, aside from hydrophobic interaction, in the aggregation and hierarchical assembly of spherical particles of amelogenins into supramolecular structures of a higher order.

scholarly journals Kinetic, equilibrium and thermodynamic studies of Ni(II) ions sorption on sulfuric acid treated Lagenaria vulgaris shell

2016 ◽  
Vol 22 (3) ◽  
pp. 235-247 ◽  
Author(s):  
Danijela Bojic ◽  
Goran Nikolic ◽  
Jelena Mitrovic ◽  
Miljana Radovic ◽  
Milica Petrovic ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Significant Loss ◽  
Isotherm Models ◽  
Pseudo Second Order ◽  
Na Ions ◽  
Ph Range ◽  
Rate Limiting ◽  
Lagenaria Vulgaris

Chemically modified Lagenaria vulgaris shell (ccLVB) was tested as a new sorbent for the removal of Ni(II) from aqueous solution, in batch conditions. The sorption process was very fast reaching equilibrium in about 20 min. Ni(II) sorption is almost invariant in the pH range from 3 to 6. Sorption kinetics followed pseudo-second order, intraparticle diffusion and Chrastil?s models, which suggest that both surface reaction and diffusion were the rate-limiting steps. Equilibria experimental results are well fitted by Langmuir and Temkin sorption isotherm models, indicating mixed adsorption process. The maximum biosorption capacity of ccLVB for Ni(II) was found to be 84.51 mg g-1. The calculated thermodynamic parameters showed that the biosorption of nickel on ccLVB was feasible, spontaneous and exothermic at 25-45?C. The desorption experiments showed that the ccLVB could be reused for five cycles without significant loss in sorption capacity. Release of Na+ ions from the biosorbent during sorption of Ni(II) reveals that the main sorption mechanism is ion exchange. Presented study suggests that ccLVB can be used effectively for the removal of Ni(II) ions from aqueous solution.

scholarly journals Novel Ag/Kaolin Nanocomposite as Adsorbent for Removal of Acid Cyanine 5R from Aqueous Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Saeedeh Hashemian ◽  
Mohammad Reza Shahedi
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Alkaline Condition ◽  
Order Kinetic ◽  
Nano Composite ◽  
Order Kinetic Model ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Ag/kaolin nanocomposite was prepared by reduction of Ag+ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50 nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409 m2 g−1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60 min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo-second-order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution.

Phosphate Removal from Aqueous Solution Using Fly Ash Modified with Magnetic Fe-Zn Bimetal Oxide

2012 ◽  
Vol 621 ◽  
pp. 296-302
Author(s):  
Ke Xu ◽  
Tong Deng ◽  
Chun Guang Li ◽  
Jun Ling Niu
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Langmuir Isotherm ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Order Model ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Modified Fly Ash

In this work the adsorption of phosphate using the magnetic Fe-Zn bimetal oxide modified fly ash was studied. The experimental results showed that the effective pH range for the adsorption of phosphate was between 3.0 and 9.0. The removal percentage of phosphate reached maximum at pH 8.0. Kinetic study showed that the phosphate adsorption was well described by pseudo second order model. The removal efficiency of phosphate increased with the increase of adsorbent dosage and the decrease of the initial concentration. The adsorption of phosphate could be described well by Langmuir isotherm, the Langmuir constant Q0 was 24.15mg/g.

scholarly journals PROCESSING PARACETAMOL-5-NITROISOPHTHALIC ACID COCRYSTAL USING SUPERCRITICAL CO2 AS AN ANTI-SOLVENT

2019 ◽  
pp. 194-199 ◽  
Author(s):  
RAYMOND R. TJANDRAWINATA ◽  
STEVANUS HIENDRAWAN ◽  
BAMBANG VERIANSYAH
Keyword(s):  
Polarized Light ◽  
Particle Size Analysis ◽  
Solvent Evaporation ◽  
Single Step ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Mean Diameter ◽  
Carbon Dioxide Co2 ◽  
The Individual

Objective: A new method of cocrystallization based on the use of supercritical carbon dioxide (CO2) as an anti-solvent was explored. In the present study, we investigate and analyze paracetamol (PCA)-5-nitroisophthalic acid (5NIP) cocrystal produced using supercritical anti-solvent (SAS) process. Methods: PCA-5NIP cocrystals prepared by SAS cocrystallization were compared to those produced using traditional solvent evaporation by rapid evaporation (RE) process. The cocrystals produced were characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarized light microscopy (PLM), Fourier Transform Infrared (FTIR) spectroscopy, particle size analysis and scanning electron microscopy (SEM). Results: The products obtained from SAS and RE process exhibited identical PXRD spectra and were distinguishable from the individual compounds, indicating the formation of a new phase. DSC analysis revealed that PCA-5NIP cocrystals from each method possess similar melting point which lies between the melting points of the parent compounds. Cocrystal particles with a mean diameter of 4.66 µm were produced from SAS process, which was smaller than those produced by traditional solvent evaporation method with a mean diameter of 38.09 μm. Conclusion: This study demonstrates the ability of SAS process to produce the submicron size of PCA-5NIP cocrystal with altered physicochemical properties in a single step process.

Adsorption of methyl orange dye onto biochar adsorbent prepared from chicken manure

2018 ◽  
Vol 77 (5) ◽  
pp. 1303-1312 ◽  
Author(s):  
Jiangang Yu ◽  
Xingwen Zhang ◽  
Dong Wang ◽  
Ping Li
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Chicken Manure ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Equilibrium Data ◽  
Intra Particle Diffusion ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract In this work, the biochar adsorbent carboxymethyl cellulose (CMC), was prepared from the pyrolysis (600 °C, 120 min) of chicken manure for the removal of methyl orange (MO) from aqueous solution, and its physicochemical properties were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). The experimental parameters including agitation speed, initial solution pH, biochar dosage and contact time on the adsorption properties of MO from aqueous solution onto CMC were investigated in batch experiments. The kinetic adsorption of different initial concentration could be accurately described by the pseudo-second-order model and the overall rate process was apparently influenced by external mass transfer and intra-particle diffusion. Furthermore, the Langmuir isotherm model showed a better fit with equilibrium data (R2 > 0.99), with the maximum adsorption capacity of 39.47 mg·g−1 at 25 °C. Moreover, the thermodynamic parameters indicated that the adsorption of MO onto CMC was a spontaneous and endothermic process. The results of this study indicated that CMC could be used as a promising biomass adsorbent material for aqueous solutions containing MO.

Removal of Methyl Red from Aqueous Solution by Adsorption onto Mg-Al HTLc

2013 ◽  
Vol 750-752 ◽  
pp. 1426-1429
Author(s):  
Yun Bo Zang
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Adsorption Process ◽  
Bulk Solution ◽  
Methyl Red ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Percent Removal

In this study, removal of Methyl Red from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, pH and temperature. It is found that HTlc could reduced Methyl Red concentration effectively. The kinetic process which reached equilibrium at about 2h can be fitted by pseudo-second order kinetics. The percent removal of MR by the HTlc was dependent on the initial pH of bulk solution. There was no much changes in amount of adsorption in the initial pH range of 6-8, while it reached maxium at about of 9. The adsorption process was endothermic.

Preparation of Mg-Fe HTLCs and Study on the Adsorption Performance

2014 ◽  
Vol 675-677 ◽  
pp. 647-653
Author(s):  
Hong Bin Lv ◽  
Yao Li ◽  
Wan You Zhang ◽  
Li Juan Xi
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Order Kinetic ◽  
Sulfate Ions ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ph Range ◽  
Synthesized Materials

Mg-Fe hydrotalcite-like compounds (Mg-Fe-HTLCs) were synthesized via hydrothermal method, and characterized by XRD and FT-IR. The roasted products were used to remove sulfate ions by the adsorptive ability from aqueous solution. The effects of adsorbent dosage, initial pH and temperature on the sulfate ions removal were fully investigated, and the adsorption kinetics and adsorption isotherms were also studied. Results showed that the synthesized materials with CO32- as the interlayer anions had fine crystallinity. The materials of Mg-Fe hydrotalcite-like compounds had a very good adsorption capacity for aqueous solution with the initial sulfate ions concentration was 500mg/L, pH range from 4 to 8 and temperature of 35°C. Moreover, the adsorption equilibrium was about 90 min under the optical condition. The experimental data showed a good compliance with the pseudo-second-order kinetic model, and the adsorption isotherm data met Langmuir models well. It was found that the maximal adsorption capacity reached 151.51mg/g.

Adsorption of Congo Red from Aqueous Solution Using La/MFA Composite as Adsorbent

2019 ◽  
Vol 944 ◽  
pp. 1117-1122
Author(s):  
Bei Gang Li ◽  
Xiao Hong Lin
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Congo Red ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
High Concentration ◽  
Composite Adsorbent ◽  
Different Temperatures

A novel lanthanum/modified fly ash (La/MFA) composite adsorbent prepared by simple solution reaction was used for the adsorption of Congo Red (CR) dye from aqueous solution. The morphology and particle size distribution of the composite were characterized, and the equilibrium adsorption was researched. The results show that the adsorption of CR onto La/MFA can reach equilibrium in 30 minutes. The entire adsorption process can be well described by pseudo-second-order kinetic equation at different temperatures. The value of apparent adsorption activation energy is 16.2kJ/mol. The isothermal data conform to the Langmuir model with the maximum adsorption capacity of 714 mg/g at 298K. According to the negative values of Gibbs free energy change (ΔG°) and enthalpy change (ΔH°), and reduction of Langmuir adsorption coefficient with the increase of temperature, the adsorption system from 298K to 328K is confirmed to be of spontaneous and exothermic nature. The results of SEM and particle size analysis indicate that the particle sizes and specific surface of La/MFA are smaller and coarser than those of FA. As a low-value composite adsorbent, La/MFA is especially effective for the removal of high concentration CR.

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