scholarly journals Pharmaceuticals Removal by Adsorption with Montmorillonite Nanoclay

2021 ◽  
Vol 22 (18) ◽  
pp. 9670
Author(s):  
Marina Kryuchkova ◽  
Svetlana Batasheva ◽  
Farida Akhatova ◽  
Vasily Babaev ◽  
Daina Buzyurova ◽  
...  
Keyword(s):  
Pharmaceutical Compounds ◽  
Adsorption Properties ◽  
Mass Ratio ◽  
Solution Ph ◽  
Freundlich Model ◽  
Chemical Pollutants ◽  
Natural Clays ◽  
Efficient Adsorbent ◽  
Continuous Accumulation ◽  
Better Than

The problem of purifying domestic and hospital wastewater from pharmaceutical compounds is becoming more and more urgent every year, because of the continuous accumulation of chemical pollutants in the environment and the limited availability of freshwater resources. Clay adsorbents have been repeatedly proposed as adsorbents for treatment purposes, but natural clays are hydrophilic and can be inefficient for catching hydrophobic pharmaceuticals. In this paper, a comparison of adsorption properties of pristine montmorillonite (MMT) and montmorillonite modified with stearyl trimethyl ammonium (hydrophobic MMT-STA) towards carbamazepine, ibuprofen, and paracetamol pharmaceuticals was performed. The efficiency of adsorption was investigated under varying solution pH, temperature, contact time, initial concentration of pharmaceuticals, and adsorbate/adsorbent mass ratio. MMT-STA was better than pristine MMT at removing all the pharmaceuticals studied. The adsorption capacity of hydrophobic montmorillonite to pharmaceuticals decreased in the following order: carbamazepine (97%) > ibuprofen (95%) > paracetamol (63–67%). Adsorption isotherms were best described by Freundlich model. Within the pharmaceutical concentration range of 10–50 µg/mL, the most optimal mass ratio of adsorbates to adsorbents was 1:300, pH 6, and a temperature of 25 °C. Thus, MMT-STA could be used as an efficient adsorbent for deconta×ating water of carbamazepine, ibuprofen, and paracetamol.

scholarly journals Removal of Cd(II) from Aquatic System UsingOscillatoriasp. Biosorbent

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Seyed Naser Azizi ◽  
Abasalt Hosseinzadeh Colagar ◽  
Seyede Maryam Hafeziyan
Keyword(s):  
Contact Time ◽  
Metal Ion ◽  
Biomass Concentration ◽  
Adsorption Properties ◽  
Langmuir Model ◽  
Ion Concentration ◽  
Solution Ph ◽  
Batch Mode ◽  
Freundlich Model ◽  
Biosorption Capacity

Biosorption of Cd(II) ions from aqueous solutions by native and driedOscillatoriasp. Cyanobacterium biomass was investigated in the batch mode. TheOscillatoriasp. was prepared from Molecular and Cell Laboratory of University of Mazandaran and grown in BG-11 medium. A comparison of Cd(II) adsorption properties of dried with nativeOscillatoriasp. biomass was made, the dried one showed a higher biosorption capacity and faster kinetic. The influence of solution pH, contact time, biomass concentration, initial metal ion concentration, and presence of coions using driedOscillatoriasp. biomass as well as pretreatment on the biosorption capacity of the biomass were studied. Various pretreatments ofOscillatoriasp. increased biosorption of Cd(II) at pH 7 in comparison with native biomass. However, heating at 100°C in a water bath showed significant improvement in Cd(II) biosorption capacity. The experimental biosorption data was well fitted to the Freundlich model compared to the Langmuir model, and the amount of Cd(II) removed from solution increased with increasing Cd(II) concentration. In addition, the dried biomass was investigated for Cd(II) removal from the simulated real sample containing about 14 mg/l Cd(II) at pH 7, under the same experimental condition.

Preparation of Graphene Oxide/Chitosan Pellets and Their Adsorption Properties for Congo Red

2019 ◽  
Vol 18 (05) ◽  
pp. 1850030 ◽  
Author(s):  
Qiuju Du ◽  
Yanhui Li ◽  
Jiabin Li ◽  
Zhao Zhang ◽  
Bin Qiao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Congo Red ◽  
Electrostatic Interactions ◽  
Kinetic Studies ◽  
Adsorption Properties ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Freundlich Model ◽  
Adsorption Data ◽  
Pseudo Second Order

A facile and easily separated adsorbent, graphene oxide (GO) pellets wrapped by chitosan (GOP) were prepared. Batch adsorption studies were carried out to study the adsorption properties of congo red onto GOP by varying the experimental parameters such as the contact time, the initial concentration of congo red, the solution pH, the adsorbent dose, and the temperature. The kinetic studies showed that the adsorption data fitted a pseudo-second-order model well. The isotherm analysis showed that the adsorption data fitted the Freundlich model well. The adsorption mechanism was mainly attributed to electrostatic interactions, [Formula: see text]–[Formula: see text] stacking interaction, hydrogen bond, and van der Waals force. Thermodynamic studies indicated that the adsorption process was endothermic and spontaneous.

Triazole, Benzotriazole, and Naphthotriazole as Corrosion Inhibitors for Brass

CORROSION ◽  
1976 ◽  
Vol 32 (10) ◽  
pp. 414-417 ◽  
Author(s):  
R. WALKER
Keyword(s):  
Corrosion Inhibitors ◽  
Lower Cost ◽  
Solution Ph ◽  
Inhibitor Efficiency ◽  
Wide Range ◽  
Better Than

Abstract The use of triazole, benzotriazole, and naphthotriazole as corrosion inhibitors for brass is briefly reviewed. The corrosion of 70/30 brass immersed in a wide range of solutions is reported both with and without the inhibitors. The inhibitor efficiency of benzotriazole is given as a function of the solution pH and the concentration used. Triazole was only effective in mildly corrosive solutions and benzotriazole and naphthotriazole were much better. Generally naphthotriazole was better than benzotriazole but is much more expensive and a higher concentration of benzotriazole can give the same protection as naphthotriazole at a much lower cost.

scholarly journals Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  
Keyword(s):  
Reaction Time ◽  
Color Removal ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Fenton Process ◽  
Solution Ph ◽  
Leachate Treatment ◽  
First Order ◽  
Order Kinetic Model ◽  
Better Than

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

Synthesis, Characterization and Adsorption Studies of a Graphene Oxide/Polyacrylic Acid Nanocomposite Hydrogel

2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim
Keyword(s):  
Industrial Effluents ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Nanocomposite Hydrogel ◽  
Adsorption System ◽  
Order Model ◽  
Solution Ph ◽  
Freundlich Model ◽  
Dye Sorption ◽  
Pseudo Second Order

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.

Compression and consolidation characteristics of structured natural clay

2004 ◽  
Vol 41 (6) ◽  
pp. 1250-1258 ◽  
Author(s):  
J -C Chai ◽  
N Miura ◽  
H -H Zhu ◽  
Yudhbir
Keyword(s):  
Numerical Analysis ◽  
Void Ratio ◽  
Natural Clay ◽  
Hardening Law ◽  
Modified Cam Clay ◽  
Calculated Load ◽  
Natural Clays ◽  
Consolidation Behavior ◽  
Better Than ◽  
Cam Clay

The compression and consolidation behavior of some structured natural clays are discussed. It is shown that for some structured natural clays, the relation between void ratio (e) and mean effective stress (p′) is more linear in a ln(e + ec) – ln(p′) plot (where ec is a soil parameter) than in an e – ln(p′) plot. It is proposed that for structured natural clay with a sensitivity value greater than 4, a linear ln(e + ec) – ln(p′) relation can be used in settlement and consolidation calculation. The effect of introducing a linear ln(e + ec) – ln(p′) relation on the calculated load–settlement curve and consolidation behavior of structured clays is discussed. The linear ln(e + ec) – ln(p′) relation was incorporated into the modified Cam–clay model by modifying the hardening law of the model. It is shown that using the linear ln(e + ec) – ln(p′) relation simulated the consolidation behavior of the structured natural clays better than using the linear e – ln(p′) relation.Key words: structured natural clay, compression, consolidation, constitutive model, numerical analysis.

scholarly journals Discovery of alliin as a putative inhibitor of the main protease of SARS-CoV-2 by molecular docking

BioTechniques ◽  
2020 ◽  
Vol 69 (2) ◽  
pp. 108-112 ◽  
Author(s):  
Bijun Cheng ◽  
Tianjiao Li
Keyword(s):  
Molecular Docking ◽  
Pharmaceutical Compounds ◽  
The Novel ◽  
Important Target ◽  
Main Protease ◽  
Docking Method ◽  
Life Threatening ◽  
Novel Coronavirus ◽  
Better Than ◽  
Molecular Docking Method

The outbreak of viral pneumonia caused by the novel coronavirus SARS-CoV-2 that began in December 2019 caused high mortality. It has been suggested that the main protease (Mpro) of SARS-CoV-2 may be an important target to discover pharmaceutical compounds for the therapy of this life-threatening disease. Remdesivir, ritonavir and chloroquine have all been reported to play a role in suppressing SARS-CoV-2. Here, we applied a molecular docking method to study the binding stability of these drugs with SARS-CoV-2 Mpro. It appeared that the ligand–protein binding stability of the alliin and SARS-CoV-2 Mpro complex was better than others. The results suggested that alliin may serve as a good candidate as an inhibitor of SARS-CoV-2 Mpro. Therefore, the present research may provide some meaningful guidance for the prevention and treatment of SARS-CoV-2.

Preparation, Characterization and Hemostatic Properties of Chitosan Caffeates

2019 ◽  
Vol 814 ◽  
pp. 365-371
Author(s):  
Si Tong Lu ◽  
Dong Ying Zhang ◽  
Zhang Hu ◽  
Si Dong Li ◽  
Pu Wang Li
Keyword(s):  
Caffeic Acid ◽  
Freeze Drying ◽  
Water Solubility ◽  
Crystal Form ◽  
Positive Control ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yunnan Baiyao ◽  
Better Than

In this paper, chitosan and caffeic acid were used as starting materials to prepare chitosan caffeates by reflux-heating and freeze-drying. The structures of chitosan caffeates were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and potentiometric titration. At the same time, the physical properties of chitosan caffeates were tested and the hemostatic properties were evaluated. The results showed that four chitosan caffeates with different mass ratios of chitosan and caffeic acid (1:1, 1:2, 1:4, 1:6) had been successfully prepared, which enhanced the water solubility. FTIR analysis demonstrated that caffeic acid had been successfully grafted onto chitosan chains. XRD showed that the crystal form of chitosan changed to some extent and the chain had some regularity in some directions, but its crystallinity reduced. Chitosan caffeates, particularly mass ratio of 1:1, showed excellent hemostatic properties and even better than chitosan and the positive control (Yunnan Baiyao), which were expected to be developed as an effective biomaterial for hemostasis.

Adsorption and stabilization of nickel ions on fly ash/lime mixing

2000 ◽  
Vol 42 (5-6) ◽  
pp. 79-85 ◽  
Author(s):  
P. Ricou-Hoeffer ◽  
V. Héquet ◽  
I. Lécuyer ◽  
P. Le Cloirec
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Influential Factors ◽  
Metallic Ions ◽  
Mass Ratio ◽  
Solution Ph ◽  
Nickel Ions ◽  
Experimental Design Methodology ◽  
By Products ◽  
Lime Addition

Experimental design methodology was used to define conditions for the adsorption and the stabilization of nickel ions (initial concentration of 500 mg.L-1) on coal fly ash/lime sorbent. This type of sorbent allows the reuse of by-products and increases the stabilization of metallic ions by lime addition. It was shown that the solution pH, the metal/adsorbent mass ratio, the type of fly ash used as sorbent, and the fly ash/lime mass ratio are the most influential factors. A set of parameters was finally obtained (pH 5, metal/adsorbent ratio of 0.01 g.g-1, fly ash/lime ratio of 4 g.g-1, fly ash with the lowest content of iron oxide) for which the removal of Ni2+ is 96% and the leaching 0.03% by permuted water and 0.2% by acid solution of pH 2.

scholarly journals Removal of Cefdinir from Aqueous Solution Using Nanostructure Adsorbents of TiO2, SiO2 and TiO2/SiO2

2019 ◽  
Vol 33 (2) ◽  
pp. 235-248
Author(s):  
H. Banu Yener
Keyword(s):  
Rice Husk Ash ◽  
Control Mechanism ◽  
Reaction Model ◽  
Solution Temperature ◽  
Solution Ph ◽  
Freundlich Model ◽  
Adsorbent Surface ◽  
Adsorbate Concentration ◽  
Langmuir Isotherm Model ◽  
Spontaneous Occurrence

The adsorptive removal of cefdinir, an antibiotic, from aqueous solutions on TiO2, SiO2 and TiO2/SiO2 nanostructures was studied by batch experiments. The SiO2 particles were obtained from rice husk ash. Investigated were the effects of the solution pH, adsorbent dosage, initial adsorbate concentration, and solution temperature on both cefdinir uptake and removal. The studies suggest that the adsorption of cefdinir on the nanostructures was mainly due to the electrostatic interaction between the ionic adsorbate molecules and charged adsorbent surface sites. The adsorption isotherm data of TiO2 and SiO2 fit well to the Langmuir isotherm model and the Freundlich model for TiO2/SiO2. The thermodynamic studies indicated favorable and spontaneous occurrence of adsorption. The kinetic data of TiO2 fitted best with PSO reaction model equation, and was described well by Weber-Morris diffusion model with dominating control mechanism of intraparticle diffusion and limited contribution of internal film diffusion.

Sign in / Sign up

Export Citation Format

Share Document