scholarly journals Kinetics Study of Microwave-Assisted Brine Extraction of Lipid from the Microalgae Nannochloropsis sp.

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 784 ◽  
Author(s):  
Nour Zghaibi ◽  
Rozita Omar ◽  
Siti Mazlina Mustapa Kamal ◽  
Dayang Radiah Awang Biak ◽  
Razif Harun
Keyword(s):  
Mathematical Model ◽  
Lipid Analysis ◽  
Kinetic Modelling ◽  
Low Cost ◽  
Lipid Extraction ◽  
Positive Influence ◽  
Sem Analysis ◽  
Microwave Assisted ◽  
Lipid Mass ◽  
Kinetics Of

The kinetics of lipid extraction utilizing microwave-assisted extraction (MAE) from Nannochloropsis sp. microalgae were studied using a low cost and green solvent, namely brine (NaCl) solution. The kinetic modelling of the lipid extraction was performed to evaluate the mechanism of the lipid mass transfer using different extraction models, including Fick’s Law, First and Second-order Rate Law and the Patricelli mathematical model. The Patricelli mathematical model described the kinetics of lipid extraction well, with the highest average values of determination coefficient (R2 ≥ 0.952) and the lowest average values of mean relative percentage deviation (MRPD ≤ 8.666%). The lipid analysis indicated a positive influence of the microwave temperature and time on the quantity and quality of extracted lipids. SEM analysis of spent microalgae clearly shows an increase in the distorted cell with increase microwave temperature and time, which could be directly correlated to the mechanism of the MAE-brine technique.

scholarly journals Polychromatic-Light Irradiation Kinetics of Dacarbazine and Nifedipine. Application as New Reliable UVA-drug-actinometers.

2021 ◽  
Author(s):  
Mounir Maafi ◽  
Mohammed Ahmed Al-Qarni
Keyword(s):  
Mathematical Model ◽  
Kinetic Models ◽  
Present Method ◽  
Kinetic Modelling ◽  
Incident Light ◽  
Light Irradiation ◽  
Reactive System ◽  
Rate Laws ◽  
Polychromatic Light ◽  
Kinetics Of

Abstract The photokinetic behaviour of materials driven by polychromatic light is an area that has not received a lot of attention in the literature. Most often, such photokinetic data is treated by thermal kinetic models (i.e., the classical 0th -, 1st - or 2nd -order equations). Such models were not analytically derived from the rate-laws of the photodegradation reactions. Polychromatic light kinetic modelling is hence of importance, as a means to providing adequate toolkits and metrics. This paper aims at proposing two reliable drug-actinometers useful for polychromatic UVA range. The general actinometric methodology offered here is also useful for any drugs/materials obeying a primary photoprocess where both reactant and photoproduct absorb the incident light, of the \(AB{\left(1{\Phi }\right)}_{{\epsilon }_{B}\ne 0}\) type. The present method has been consolidated by the η-order kinetics, a mathematical model analytically derived from the photosystem’s rate-law. This represents the first ever equation in the literature, to model polychromatic light of this reactive system. This framework further demonstrated the lamp-specificity of actinometers. Overall, Dacarbazine and Nifedipine photodegradations obeyed η-order kinetics, and stand as effective actinometers that can be recommended for the ICH Q1b photostability testing.

scholarly journals Microwave-Assisted Brine Extraction for Enhancement of the Quantity and Quality of Lipid Production from Microalgae Nannochloropsis sp.

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3581 ◽  
Author(s):  
Zghaibi ◽  
Omar ◽  
Kamal ◽  
Biak ◽  
Harun
Keyword(s):  
Fatty Acids ◽  
Low Cost ◽  
Methyl Esters ◽  
Lipid Production ◽  
Lipid Extraction ◽  
Soxhlet Extraction ◽  
Solid Loading ◽  
Omega 3 ◽  
Microwave Assisted

Toward attaining a sustainability and eco-friendly process, a green and low-cost solvent—brine (NaCl solution) is proposed, as microwave-assisted extraction (MAE) technique solvent to extract lipids from microalgae Nannochloropsis sp. The effect of NaCl concentration on the quantity and quality of the extracted lipid was assessed, while MAE parameters were optimized using response surface methodology (RSM). The content of fatty acid methyl esters (FAMEs) in the lipid was analyzed by using a gas chromatography—flame ionization detector (GC/FID). The highest lipid yield (16.1%) was obtained using 10% (w/v) brine at optimum extraction parameters of 5% (w/v) solid loading, 100 °C, and 30 min. The lipid extraction yield via optimized MAE-brine technique was thrice better than that Soxhlet extraction did and only 2% less than Bligh and Dyer (B&D) lipid extraction, which utilized harmful solvents. The proposed MAE-brine technique offered better quality lipids containing the highest amount of polyunsaturated fatty acids (PUFA) (44.5%) and omega-3 fatty acids (FAs) (43%). Hence, the MAE-brine solvent technique appears to be a promising extraction method for cheaper, greener, and faster extraction of a high-quality lipid for specialty food applications.

Study of the Cu(II) removal from aqueous solutions by adsorption on titania

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Toxic Metals ◽  
Low Cost ◽  
Lateral Interaction ◽  
Tio2 Surface ◽  
High Toxicity ◽  
Removal Of Heavy Metals ◽  
Solution Parameters ◽  
Kinetics Of

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.

scholarly journals Preparation of Zn-MOFs by microwave-assisted ball milling for removal of tetracycline hydrochloride and Congo red from wastewater

2021 ◽  
Vol 10 (1) ◽  
pp. 125-133
Author(s):  
Qinhui Ren ◽  
Fuhua Wei ◽  
Hongliang Chen ◽  
Ding Chen ◽  
Bo Ding
Keyword(s):  
Ball Milling ◽  
Congo Red ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Tetracycline Hydrochloride ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Wastewater Purification ◽  
Microwave Assisted ◽  
Metal Organic

Abstract In this study, we prepared Zn-MOFs as an ordinary, low-cost, and efficiency method taking advantage of zinc(ii) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were measured via scanning electron microscopy, infrared spectrometry, X-ray diffraction, and thermogravimetry. We explored its use as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid. Therefore, our findings indicate that Zn-MOFs have broad application vista in wastewater purification.

Kinetic modelling of reactions for the synthesis of 2-methyl-5-ethyl pyridine

2021 ◽  
Author(s):  
Emanuele Moioli ◽  
Leo Schmid ◽  
Peter Wasserscheid ◽  
Hannsjoerg Freund
Keyword(s):  
Kinetic Modelling ◽  
Acid Catalyst ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Kinetics Of

The kinetics of the acid catalyzed reactions of acetaldehyde ammonia trimer (AAT) and paraldehyde (para) to 2-methyl-5-ethyl pyridine (MEP) in the presence of an acid catalyst were investigated systematically. A...

scholarly journals The Effect of Al on the Formation of a CrTaO4 Layer in Refractory High Entropy Alloys Ta-Mo-Cr-Ti-xAl

2021 ◽  
Author(s):  
S. Schellert ◽  
B. Gorr ◽  
H.- J. Christ ◽  
C. Pritzel ◽  
S. Laube ◽  
...  
Keyword(s):  
Mass Gain ◽  
Positive Influence ◽  
High Entropy Alloys ◽  
Oxide Scales ◽  
Temperature Oxidation ◽  
Internal Corrosion ◽  
High Entropy ◽  
Continuous Mass ◽  
Oxide Substrate ◽  
Kinetics Of

AbstractIn this study, the effect of Al on the high temperature oxidation of Al-containing refractory high entropy alloys (RHEAs) Ta-Mo-Cr-Ti-xAl (x = 5; 10; 15; 20 at%) was examined. Oxidation experiments were performed in air for 24 h at 1200 °C. The oxidation kinetics of the alloy with 5 at% Al is notably affected by the formation of gaseous MoO3 and CrO3, while continuous mass gain was detected for alloys with the higher Al concentrations. The alloys with 15 and 20 at% Al form relatively thin oxide scales and a zone of internal corrosion due to the formation of dense CrTaO4 scales at the interface oxide/substrate. The alloys with 5 and 10 at% Al exhibit, on the contrary, thick and porous oxide scales because of fast growing Ta2O5. The positive influence of Al on the formation of Cr2O3 followed by the growth of CrTaO4 to yield a compact scale is explained by getter and nucleation effects.

scholarly journals Kinetic modelling of NO heterogeneous radiation-catalytic oxidation on the TiO2 surface in humid air under the electron beam irradiation

Nukleonika ◽  
2017 ◽  
Vol 62 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Henrietta Nichipor ◽  
Yongxia Sun ◽  
Andrzej G. Chmielewski
Keyword(s):  
Electron Beam ◽  
Catalytic Oxidation ◽  
Removal Efficiency ◽  
Electron Beam Irradiation ◽  
Kinetic Modelling ◽  
Water Concentration ◽  
Beam Irradiation ◽  
Humid Air ◽  
Kinetics Of ◽  
Influential Parameters

Abstract Theoretical study of NOx removal from humid air by a hybrid system (catalyst combined with electron beam) was carried out. The purpose of this work is to study the possibility to decrease energy consumption for NOx removal. The kinetics of radiation catalytic oxidation of NO on the catalyst TiO2 surface under electron beam irradiation was elaborated. Program Scilab 5.3.0 was used for numerical simulations. Influential parameters such as inlet NO concentration, dose, gas fl ow rate, water concentration and catalyst contents that can affect NOx removal efficiency were studied. The results of calculation show that the removal efficiency of NOx might be increased by 8-16% with the presence of a catalyst in the gas irradiated field.

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