scholarly journals Sorptive behaviour of chromium on polyethylene microbeads in artificial seawater

2018 ◽  
Vol 250 ◽  
pp. 06001 ◽  
Author(s):  
Nur Farhan Zon ◽  
Ammar Iskendar ◽  
Shamila Azman ◽  
Shazani Sarijan ◽  
Razali Ismail
Keyword(s):  
Potential Role ◽  
Adsorption Process ◽  
Artificial Seawater ◽  
Order Kinetic ◽  
Heavy Metal Adsorption ◽  
First Order ◽  
Pseudo First Order ◽  
Aquatic Food ◽  
Good Agreement

This study investigates the interactions between chromium (Cr) and microplastic under controlled laboratory conditions using low density polyethylene microbeads as plastic particles. Chromium was added to suspensions of in artificial seawater to investigate heavy metal adsorption on microbeads surface. Polyethylene microbeads proved to have affinity in providing surface area for chromium. It served as an effective sorption surface thus lowering amounts of chromium in seawater through adsorption process. The best percentage of heavy metals adsorbed to microbeads and adsorption capacity was 1.7 µg/g and 8.5 % at 1.0 µg/mL respectively. The maximum adsorption was monitored for 180 hours. Kinetic study was performed and fitted well in pseudo-first-order kinetic. In term of isotherm, dataset was in good agreement with both Langmuir and Freundlich with correlation at 0.977 and 0.9606 respectively. Adsorption of chromium to polyethylene microbeads had important implications for the potential role of microplastics, in this case microbeadschromium contaminated act as a quantified link in aquatic food webs.

scholarly journals Ganglioside incorporation and release by the isolated perfused rat liver

1991 ◽  
Vol 274 (2) ◽  
pp. 581-585 ◽  
Author(s):  
S C Kivatinitz ◽  
A Miglio ◽  
R Ghidoni
Keyword(s):  
Rat Liver ◽  
The Other ◽  
Regulatory Role ◽  
Isolated Perfused Rat Liver ◽  
Order Kinetic ◽  
Perfused Rat Liver ◽  
Ganglioside Gm1 ◽  
First Order ◽  
Pseudo First Order

The fate of exogenous ganglioside GM1 labelled in the sphingosine moiety, [Sph-3H]GM1, administered as a pulse, in the isolated perfused rat liver was investigated. When a non-recirculating protocol was employed, the amount of radioactivity in the liver and perfusates was found to be dependent on the presence of BSA in the perfusion liquid and on the time elapsed after the administration of the ganglioside. When BSA was added to the perfusion liquid, less radioactivity was found in the liver and more in the perfusate at each time tested, for up to 1 h. The recovery of radioactivity in the perfusates followed a complex course which can be described by three pseudo-first-order kinetic constants. The constants, in order of decreasing velocity, are interpreted as: (a) the dilution of the labelled GM1 by the constant influx of perfusion liquid; (b) the washing off of GM1 loosely bound to the surface of liver cells; (c) the release of gangliosides from the liver. Process (b) was found to be faster in the presence of BSA, probably owing to the ability of BSA to bind gangliosides. The [Sph-3H]GM1 in the liver underwent metabolism, leading to the appearance of products of anabolic (GD1a, GD1b) and catabolic (GM2, GM3) origin; GD1a appeared before GM2 and GM3 but, at times longer than 10 min, GM2 and GM3 showed more radioactivity than GD1a. At a given time the distribution of the radioactivity in the perfusates was quite different from that of the liver. In fact, after 60 min GD1a was the only metabolite present in any amount, the other being GM3, the quantity of which was small. This indicates that the liver is able to release newly synthesized gangliosides quite specifically. When a recirculating protocol was used, there were more catabolites and less GD1a than with the non-recirculating protocol. A possible regulatory role of ganglioside re-internalization on their own metabolism in the liver is postulated.

scholarly journals Removal of Iron(II) Using Ni/Al Layered Double Hydroxide Intercalated with Keggin Ion

Molekul ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 149
Author(s):  
Aldes Lesbani Lesbani ◽  
Normah Normah ◽  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Roy Andreas ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Layered Double Hydroxide ◽  
Adsorption Process ◽  
Order Kinetic ◽  
Adsorption Time ◽  
Keggin Ion ◽  
First Order ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
Double Hydroxide

Layered double hydroxide (LDH) Ni/Al-NO3 was synthesized using a coprecipitation method under base condition following with intercalation using Keggin ion [a-SiW12O40]4- to form Ni/Al-[a-SiW12O40] LDH. The LDHs were characterized using XRD, FTIR, BET, and pHpzc analyses. Furthermore, LDHs were applied as adsorbent of iron(II) from aqueous solution. The adsorption process was studied through the effect of adsorption time, the concentration of iron(II), and temperature adsorption. The results show the interlayer distance of LDHs was increased from 7.408 Å to 10.533 Å after intercalation process. The adsorption of iron(II) on LDHs showed that adsorption of iron(II) on both LDHs follows pseudo first-order kinetic model with R2 value is close to one. The adsorption process was spontaneous, with adsorption capacity up to 36.496 mg g-1.

scholarly journals Study on the adsorption of MnO4- ions onto GO/PVA/Fe3O4 composite

2021 ◽  
Vol 10 (2) ◽  
pp. 104-108
Author(s):  
Thu Le Dieu ◽  
Hoang Tran Vinh
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Sorption Process ◽  
Order Kinetic ◽  
Influence Of Temperature ◽  
First Order ◽  
Pseudo First Order

In this study, MnO4- ions are adsorbed onto GO/PVA/Fe3O4 composite. Results showed that after 18 hours, the adsorption process gets equilibrium with the adsorption capacity is 187.8 mg.g-1, the mass of adsorbent is 0.005 g in 10 mL of 200 mg.L-1 MnO4- ions solution. The influence of temperature was also investigated and with the increasing of temperature, the adsorption capacity also increases, so the adsorption is endothermic. The sorption process obeys pseudo-first-order kinetic.

Experimental Study on Adsorption Mechanism of U(VI) by Modified CMC

2013 ◽  
Vol 650 ◽  
pp. 231-237
Author(s):  
Shu Kui Zhou ◽  
Guang Ming Zeng ◽  
Ying Jiu Liu ◽  
Hai Yang Jiang
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Ph Value ◽  
Physical Adsorption ◽  
Order Kinetic ◽  
Freundlich Model ◽  
First Order ◽  
Batch System ◽  
Order Kinetic Model ◽  
Pseudo First Order

The modified carboxymethyl cellulose(CMC) was prepared and explored to adsorb uranium(Ⅵ) ions from aqueous solution in a batch system. The experimental results showed that on the condition of reaction temperature 70~80°C, CMC 30%-35% (w/w), CMC to AA (w/w) of 10:2.5 and reaction time 3.5-4 h, the modification effect was the best. High removal efficient of U(Ⅵ) was obtained 97.1% at temperature of 25°C, pH value of 5.0, dosage of modified CMC 0.1 g/L and contact time of 60 min. It was found that the adsorption process was best described by Freundlich model and pseudo-first-order kinetic model (R2=0.9618), indicating that the adsorption is mainly on the surface of the modified CMC. Thermodynamics parameters of negative value of ΔG0 and positive value of ΔH0 revealed the spontaneity and endothermic nature of the adsorption. The adsorption is primarily due to physical adsorption.

scholarly journals U(VI) adsorption in water by sodium alginate modified Bacillus megaterium

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Dianxin Li ◽  
Yiqing Yang ◽  
Peng Zhang ◽  
Jiangang Liu ◽  
Tao Li ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Bacillus Megaterium ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order

The surface of Bacillus megaterium was modified by coating sodium alginate. The modified B. megaterium before and after adsorption were characterized by SEM, FTIR and XPS. The effects of pH, reaction time, initial U(VI) concentration and adsorbent dosage on the adsorption of U(VI) by the modified B. megaterium were studied by batch adsorption experiments. The adsorption process was studied by pseudo-first-order kinetics and pseudo-second-order kinetic models, Langmuir and Freundlich isotherms. The results showed that the maximum adsorption capacity of U(VI) was 74.61 mg g −1 under the conditions of pH 5.0, adsorbent 0.2 g l −1 , 30°C and initial U(VI) concentration of 15 mg l −1 . The adsorption process accords with pseudo-first-order kinetics and Langmuir isotherm. The adsorption capacity of U(VI) by the modified B. megaterium was still higher than 80% after five times of desorption and reuse experiments. In conclusion, the sodium alginate modified B. megaterium was an ideal material for U(VI) biosorption.

scholarly journals Study of the Equilibrium, Kinetics, and Thermodynamics of Boron Removal from Waters with Commercial Magnesium Oxide

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Javier Paul Montalvo Andia ◽  
Lidia Yokoyama ◽  
Luiz Alberto Cesar Teixeira
Keyword(s):  
Kinetic Model ◽  
Magnesium Oxide ◽  
Adsorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Boron Removal ◽  
First Order ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Pseudo First Order

In the present work, the equilibrium, thermodynamics, and kinetics of boron removal from aqueous solutions by the adsorption on commercial magnesium oxide powder were studied in a batch reactor. The adsorption efficiency of boron removal increases with temperature from 25°C to 50°C. The experimental results were fitted to the Langmuir, Freundlich, and Dubinin–Radushkevich (DR) adsorption isotherm models. The Freundlich model provided the best fitting, and the maximum monolayer adsorption capacity of MgO was 36.11 mg·g−1. In addition, experimental kinetic data interpretations were attempted for the pseudo-first-order kinetic model and pseudo-second-order kinetic model. The results show that the pseudo-second-order kinetic model provides the best fit. Such result suggests that the adsorption process seems to occur in two stages due to the two straight slopes obtained through the application of the pseudo-first-order kinetic model, which is confirmed by the adjustment of the results to the pseudo-second-order model. The calculated activation energy (Ea) was 45.5 kJ·mol−1, and the values calculated for ∆G°, ∆H°, and ∆S° were −4.16 kJ·mol−1, 21.7 kJ·mol−1, and 87.3 kJ·mol−1, respectively. These values confirm the spontaneous and endothermic nature of the adsorption process and indicated that the disorder increased at the solid-liquid interface. The results indicate that the controlling step of boron adsorption process on MgO is of a physical nature.

Photodegradation of some Furocoumarins in Ethanol under UV Irradiation

2016 ◽  
Vol 683 ◽  
pp. 402-405
Author(s):  
Natalya G. Bryantseva ◽  
Olga N. Tchaikovskaya ◽  
Vlada S. Kraiukhina ◽  
Maria Gómez ◽  
Jose Luis Gómez
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Kinetic Model ◽  
Kinetic Parameter ◽  
Bulk Solution ◽  
Order Kinetic ◽  
First Order ◽  
Operational Variables ◽  
Pseudo First Order ◽  
Good Agreement

Photodegradation of 5-Methoxypsoralen (5-MOP), 4', 5'-dimethyl-3,4-cyclogeksilpsoralen (KC5) and 4'-methyl-3,4 cycloheptylpsoralen (KC4) has been carried out in an XeBr exilamps, both in the presence of H2O2, and a kinetic model, which explains the dependence of the pseudo-first order kinetic parameter on the substrate concentration and other operational variables, has been developed. In the development of the model, mass transfer of 5-MOP, KC5 and KC4from the bulk solution to the wall of the vessel was assumed as the step determining the rate of the photodegradation process, which successfully explains some singularities observed in the experimental results.By fitting the experimental data to the model, a detailed study of the influence of all operational variables on the pseudo-first order kinetic parameter has been done, in good agreement with the model hypotheses.

scholarly journals Enhanced photocatalytic activity of wool-ball-like TiO2 microspheres on carbon fabric and FTO substrates

2018 ◽  
Vol 38 ◽  
pp. 02014
Author(s):  
Yu Zhang ◽  
Jian Gu ◽  
Mengqi Zhang
Keyword(s):  
Hydrothermal Method ◽  
Order Kinetic ◽  
Carbon Fabric ◽  
Facile Hydrothermal Method ◽  
Sem Images ◽  
First Order ◽  
Good Crystallinity ◽  
Degradation Rate Constant ◽  
Order Kinetic Model ◽  
Pseudo First Order

The wool-ball-like TiO2 microspheres on carbon fabric (TiO2-CF) and FTO substrates (TiO2-FTO) have been synthesized by a facile hydrothermal method in alkali environment, using commercial TiO2 (P25) as precursors. The XRD results indicate that the as-prepared TiO2 have good crystallinity. And the SEM images show that the wool-ball-like TiO2 microspheres with a diameter of 2-3 μm are composed of TiO2 nanowires, which have a diameter of ~50 nm. The photocatalytic behavior of the wool-ball-like TiO2 microspheres, TiO2-CF and TiO2-FTO under ultraviolet light was investigated by a pseudo first-order kinetic model, using methyl orange (MO) as pollutant. The wool-ball-like TiO2 microspheres obtained a degradation rate constant (Kap) of 6.91×10-3 min-1 . The Kap values of TiO2-FTO and TiO2-CF reach 13.97×10-3 min-1 and 11.80×10-3 min-1, which are 2.0 and 1.7 times higher than that of pristine wool-ball-like TiO2 microspheres due to the “sum effect” between TiO2 and substrates. This study offers a facile hydrothermal method to prepare wool-ball-like TiO2 microspheres on CF and FTO substrates, which will improve the recyclability of phtocatalysts and can be extended to other fields.

scholarly journals Photocatalytic degradation of indigo carmine by ZnO photocatalyst under visible light irradiation

2017 ◽  
Vol 14 (3) ◽  
pp. 582-587
Author(s):  
Baghdad Science Journal
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Degradation ◽  
Indigo Carmine ◽  
Catalyst Loading ◽  
Order Kinetic ◽  
Kinetic Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
The Relationship ◽  
Influential Parameters

In this work, the photocatalytic degradation of indigo carmine (IC) using zinc oxide suspension was studied. The effect of influential parameters such as initial indigo carmine concentration and catalyst loading were studied with the effect of Vis irradiation in the presence of reused ZnO was also investigated. The increased in initial dye concentration decreased the photodegradation and the increased catalyst loading increased the degradation percentage and the reused-ZnO exhibits lower photocatalytic activity than the ZnO catalyst. It has been found that the photocatalytic degradation of indigo carmine obeyed the pseudo-first-order kinetic reaction in presence of zinc oxide. This was found from plotting the relationship between ln (C0/Ct) and irradiation the rate constant of the process.UV- spectrophotometer was used to study the indigo carmine photodegradation.

Degradation of 4-nitrophenol using the Fenton process

2000 ◽  
Vol 42 (3-4) ◽  
pp. 155-160 ◽  
Author(s):  
Y.-S. Ma ◽  
S.-T. Huang ◽  
J.-G. Lin
Keyword(s):  
Kinetic Equation ◽  
Nitrogen Concentration ◽  
Order Kinetic ◽  
Fenton Process ◽  
Nitrogenous Compounds ◽  
First Order ◽  
Degradation Rate Constant ◽  
Before And After ◽  
Pseudo First Order ◽  
Order Kinetic Equation

In this study, The Fenton process was applied as a pretreatment method to treat industrial wastewater containing 4-nitrophenol (4-NP). The effect of oxidant dosages on the decomposition of 4-NP and the reaction kinetics were investigated. More than 99% of 4-NP was readily decomposed when the reaction was carried out at oxidant concentrations of 5 mM H2O2 and 5 mg/L Fe2+ for 2 hours. The total nitrogenous compounds and the nitrogen gas evolved, accounted for 88% of the initial nitrogen concentration. However, the maximum DOC removal efficiency was 30.6%; and only 1/3 of 4-NP was mineralized to carbon dioxide by the Fenton process. 4-NP degradation profiles fitted well into a pseudo first-order kinetic equation; degradation rate constant (min-1) of 4-NP increased from 4.3×10-3 to 66.1×10-3 with increasing dosages of H2O2 and Fe2+. In addition, the t value was calculated for studying the significance of simulation by the t-test. It was found that the t value was greater than the value for 99% confidence. This result suggested that the 4-NP decomposition profile could be described by the pseudo first-order kinetic equation. Biodegradability of 4-NP before and after the reaction was 0.018 and 0.594, respectively.

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