scholarly journals ZnO Nanoparticles for Photocatalytic Application in Alkali-Activated Materials

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5519
Author(s):  
Hector R. Guzmán-Carrillo ◽  
Alejandro Manzano-Ramírez ◽  
Ines Garcia Lodeiro ◽  
Ana Fernández-Jiménez
Keyword(s):  
Zinc Oxide Nanoparticles ◽  
Second Order ◽  
Order Kinetic ◽  
Order Model ◽  
First Order ◽  
Photocatalytic Application ◽  
Vis Spectroscopy ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Alkali Activated

This paper reports an Alkali-Activated Materials (AAM) using two different precursors, metakaolin and a metallurgical slag with photocatalytic zinc oxide nanoparticles, as novel photocatalytic composites. The photodegradation performance of the composites using methylene blue (MB) dye as a wastewater model was investigated by ultraviolet radiations (UV-vis) spectroscopy. Adsorption in dark conditions and photodegradation under UV irradiation are the mechanisms for removing MB dye. The pseudo-first-order kinetic and pseudo-second-order kinetic models were employed, and the experimental data agreed with the pseudo-second-order model in both cases with UV and without UV irradiations. As new photocatalytic materials, these composites offer an alternative for environmental applications.

scholarly journals Adsorption of Cu (II) and Ni (II) Ions from Solution onto Calcium Alginate Beads

2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu
Keyword(s):  
Contact Time ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Second Order ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Calcium Alginate Beads ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order

scholarly journals Adsorption of Estrogenic Hormones in Aqueous Solution Using Electrospun Nanofibers From Waste Cigarette Butts: Kinetics, Mechanism, and Reusability

2021 ◽  
Author(s):  
Muhammad Yasir ◽  
Tomáš Šopík ◽  
Rahul Patwa ◽  
Dušan Kimmer ◽  
Vladimír Sedlařík
Keyword(s):  
Fractional Power ◽  
Small Diameter ◽  
Electrospun Nanofibers ◽  
Second Order ◽  
Order Kinetic ◽  
Suitable Alternative ◽  
First Order ◽  
Estrogenic Hormones ◽  
Pseudo Second Order ◽  
Pseudo First Order

Abstract This study emphasizes rapid and simultaneous adsorptive removal of estrogenic hormones (EHs): estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and estriol (E3) from wastewater using recycled waste cigarette electrospun nanofibers (WCENFs). The nanofibers exhibited a small diameter (196±65 nm) and large surface area (18.05 m 2 /g), along with a strong affinity towards all EHs by adsorption due to abundant hydrogen bonding interactions. A one-step high-performance liquid chromatography technique was developed to detect each EH present in the solution simultaneously. The adsorption kinetics helps select optimum conditions for the large-scale removal process, so experimental data using pseudo-first-order, pseudo-second-order, intra-particle diffusion, Elovich, and fractional power models were fitted. It was found that E1, E2, and EE2 followed pseudo-second-order kinetics while E3 followed pseudo-first-order kinetic models. The total adsorption capacity on WCENFs was determined to be 2.14 mg/g, whereas the individual adsorption capacities of E1, E2, EE2, and E3 were found to be 0.551, 0.532, 0.687, and 0.369 mg/g, respectively. The percentage efficiency of WCENFs was highest with EE2 ~64.3% and least with E3 ~34.6%. Adsorption-desorption studies revealed that WCENFs could repeatedly be used four times. The reported results indicate a significant potential of WCENFs to be an effective sorbent and portable filter for simultaneous estrogenic hormone removal. WCENFs filter is a suitable alternative to commercial Cellulose acetate filters.

Rice Husk Active Carbon as a Potential Low-Cost Adsorbent for TNT Wastewater

2011 ◽  
Vol 356-360 ◽  
pp. 1289-1292
Author(s):  
Dan Fu ◽  
Yi He Zhang ◽  
He Li Wang ◽  
Feng Zhu Lv
Keyword(s):  
Rice Husk ◽  
Active Carbon ◽  
Low Cost ◽  
Adsorption Properties ◽  
Second Order ◽  
Order Model ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
And Diffusion

In this paper, the adsorption properties of TNT on Rice husk active carbon (RHAC) were investigated. The effects of contact time was examined. Kinetic data obtained at different concentrations were conducted using Lagergren’s pseudo first-order, pseudo second-order and diffusion models. The regression results showed that the adsorption kinetics was more accurately represented by pseudo second-order model. The study indicates that there is significant potential for RHAC as an adsorbent material for TNT removal from wastewater.

scholarly journals The Application of Monkey Cola Pericarp (Cola lepidota) in the Removal of Toluene from Aqueous Medium

2020 ◽  
pp. 53-67
Author(s):  
C. Obi ◽  
N. C. Ngobiri ◽  
L. C. Agbaka ◽  
M. U. Ibezim-Ezeani
Keyword(s):  
Aqueous Medium ◽  
Contact Time ◽  
Second Order ◽  
Phytochemical Screening ◽  
Order Model ◽  
Initial Concentration ◽  
First Order ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Pseudo First Order

The study focused on the investigation of the effectiveness of the pericarp of monkey kola (Cola lepidota) biomass (CLPB) in the removal of toluene from aqueous system. X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and phytochemical screening methods were used for characterizing the biosorbent. The effects of contact time, pH, and concentration on biosorption process were studied. The phytochemical screening showed the presence of alkaloids, flavonoids, tannins, carbohydrate, saponins and steroids. Carboxylic, alkene and alcohol groups were found to be the principal functional groups. The highest percentage removal was 99.63% at toluene initial concentration of 40 mg/L and 98.30% at pH 8. The contact time 30 minutes gave better removal efficiency of 99.89%. Among the biosorption isotherm models tested (Langmuir, Freundlich, Dubinin Radushkevich and Temkin, respectively), the Langmuir model equation gave a better fit of the equilibrium data with a correlation coefficient (R2) of 0.99. The equilibrium data was tested with pseudo-first order and pseudo-second order models and pseudo-second order model (R² = 0.99) fitted more than the pseudo-first order model (R² = 0.85). This study has revealed that Cola lepidota is a potential biosorbent for the removal of toluene from aqueous medium under the operating conditions of contact time of 30 minutes, pH of 8 and initial concentration of 40 mg/g.

scholarly journals Kinetic study on the removal of heavy metals by Cajanus Cajan husk

2019 ◽  
pp. 206-229
Author(s):  
Mallappa A. Mallappa A. Devania, Mallappa A. Devania ◽  
Basudeb Munshi
Keyword(s):  
Heavy Metals ◽  
Kinetic Model ◽  
Kinetic Models ◽  
Cajanus Cajan ◽  
Second Order ◽  
Order Model ◽  
First Order ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Pseudo First Order

The removal of heavy metals from wastewater has become crucial to meet safe discharge standards. Development of more economic process has been strived owing to high cost of adsorbents. Thus, biosorption process has become the area of interest to researchers and engineers. The present study has carried out the transient removal of heavy metals from wastewater by both physically treated and chemically modified Cajanus cajan (Pigeon pea) husk (CCH) as novel biosorbents. Work includes five different models such as first order, second order, nth order, first order reversible and second order reversible under the heading of prediction of transient concentration of metal in the solution are used, and under the heading of prediction of transient metal uptake capacity; fractional power, pseudo first order, pseudo second order, second order reversible, Elovich, intra-particle diffusion and film diffusion models are used to analyse the kinetic data. For a metal at any particular initial concentration the best kinetic model with the least RMSE is identified. Pictorial comparison between experimental and pseudo second order and pseudo first order model predictive data of Cd(II) and Cu(II) transient biosorption, respectively onto CCH are illustrated. The trend of the results shows a successful prediction capability of all the kinetic models used in the present work. According to RMSE data, it can be concluded that the best kinetic models are pseudo second order for Cd(II) and pseudo first order for Cu(II). It has been found that the required equilibrium time is always less for the chemically activated than the physically activated sorbent. At 100 mg/L initial metal concentration, pseudo-first-order model has been identified as the best kinetic model for the transient Cu(II) and the best kinetic model for fitting the transient sorption of Cd(II) on CCH is pseudo-second-order. At initial metal concentration of 150 mg/L, initial biosorption rate of 9.7038 for Cd(II) on CCH(N) is greater than 1.4553 for Cu(II) on CCH(N). These indicate that Cd(II) undergoes faster adsorption rate than Cu(II) onto CCH.

scholarly journals Synthesis, Characterization and Kinetic Studies of Chelate Polymer Derived from 3-Nonyl Benzene and its Use for the Removal of Some Heavy Metals from Aqueous Solutions

2021 ◽  
pp. 3336-3349
Author(s):  
Qadoori Zidan Khalaf ◽  
Hamid Mohammed Saleh Al-Jubori ◽  
Kareem Jumaah Al-salihi
Keyword(s):  
Condensation Reaction ◽  
Polymer Surface ◽  
Second Order ◽  
Order Kinetic ◽  
First Order ◽  
Lead And Cadmium ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Chelate Polymer ◽  
Kinetic Equilibrium

    A new chelate polymer (2-5-hydroxy-3-methyl-2- (3-nonyl benzene) imino) methyl) benzyl) 4-6-dimethyphenol] (K4) was prepared by using the condensation reaction method and identified by several techniques, including FT-IR, NMR, and atomic absorption spectroscopy, as well as TG-DTA thermal analysis. The kinetic equilibrium for the sorption of lead and cadmium ions on the chelate polymer surface was also investigated. The results showed that the sorption of both ions followed the pseudo-first-order and pseudo-second-order kinetic equilibrium. The rate constant values of pseudo-first-order reaction  were equal to 0.062 and 0.057 min-1  , while the values of pseudo-second-order were 0.0103 and 0.053 L.mg-1 min-1) for the sorption of Pb (II) and Cd (II) on chelate polymer, respectively. Thermodynamic parameters were also investigated and the sorption values for Pb+2 were achieved at 25 oC, ΔG = 0.436 KJ/mole, ΔH = 10.55 KJ/mole, and ΔS= 0.08 KJ/mole, , whereas those for Cd+2 were 25 oC , ΔG = -2.345 KJ/mole, ΔH = 4.378 KJ/mole, and ΔS= 0.09 KJ/mole. The results showed that the sorption process was spontaneous and endothermic in nature for the sorption of each of Pb+2 and Cd+2 on polymer surface.

REMOVAL OF ORANGE G FROM AQUEOUS SOLUTIONS BY POLYSTYRENE-MODIFIED CHITIN

2017 ◽  
Vol 79 (7) ◽  
Author(s):  
Abdulganiyu Umar ◽  
Mohd Marsin Sanagi ◽  
Ahmedy Abu Naim ◽  
Wan Nazihah Wan Ibrahim ◽  
Aemi Syazwani Abdul Keyon ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Absorption Capacity ◽  
Second Order ◽  
Batch Adsorption ◽  
Order Model ◽  
First Order ◽  
Orange G ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
First Time

In this work, polystyrene modified-chitin was evaluated for the first time as adsorbent for the removal of Orange G from aqueous solutions. Its absorption capacity was compared to that of chitin. BET and FESEM results showed that the polystyrene-modified chitin has higher surface area (12.47 m2/g) compared to chitin (4.92 m²/g). Batch adsorption experiments on the removal of Orange G from aqueous solutions were conducted. The results showed that the polystyrene-modified chitin has improved adsorption capacity compared to chitin. The maximum adsorption of orange G by chitin occurred at pH 2, while that of the polystyrene-modified chitin occurred at pH 6. At an initial concentration of 20 mg/L, the percentages of dye removal were 65.16% and 81.20% for raw chitin (RCH) and polystyrene-modified chitin (MCH), respectively. Kinetics studies for the adsorbents were conducted using pseudo-first-order and pseudo-second-order models. The pseudo-first-order model gives poor fittings for both adsorbents, with low coefficients of determination (R2). The pseudo-second-order model fits the experimental data well, with R2 close to unity. Langmuir and Freundlich models were used to interpret the adsorption isotherms. It was found that Langmuir isotherm conformed better than Freundlich model in the adsorption of selected dye on chitin and the polystyrene-modified chitin, with R2 nearly unity.

Kinetic Study of Arsenic(V) Absorption with Al2O3 Functionalized SBA-15

2013 ◽  
Vol 726-731 ◽  
pp. 2191-2197 ◽  
Author(s):  
Su Yun He ◽  
Cai Yun Han ◽  
Su Fang He ◽  
Hua Wang ◽  
Chun Xia Liu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Second Order ◽  
Particle Diffusion ◽  
Order Model ◽  
Surface Absorption ◽  
Arsenic Uptake ◽  
First Order ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Pseudo First Order

This research presented the kinetic performance of arsenic absorption by mesostructure SBA-15 functionalized with Al2O3. The SBA-15 was previously synthesised and subsequently functionalized via impregnation of alumina oxides. The absorption of arsenic(V) was studied as a function of absorbent dosage and contact time. The experimental data were fitted to kinetic pseudo-first order, pseudo-second order and the intra-particle diffusion model. The pseudo-second order model presented the best correlation with the experimental data. Both surface absorption and intra-particle diffusion were acting during arsenic uptake, except for absorbent dosage of 0.1g, which was mainly controlled by the intra-particle diffusion.

Adsorption and Photocatalytic Kinetic of Wastewater Treatment by Photocatalyst - Alginate/Polyvinyl Alcohol Composite Beads

2019 ◽  
Vol 287 ◽  
pp. 69-74 ◽  
Author(s):  
Suntree Sangjan ◽  
Khanittha Ponsanti
Keyword(s):  
Photocatalytic Activity ◽  
Polyvinyl Alcohol ◽  
Adsorption Kinetics ◽  
Second Order ◽  
First Order ◽  
Order Rate ◽  
Composite Beads ◽  
Vis Spectroscopy ◽  
Pseudo Second Order ◽  
Pseudo First Order

Photocatalyst composite beads were applied as adsorbent substances in the waste water treatment process. The beads were synthesised using different photocatalyst types in sodium alginate-polyvinyl alcohol matrix (SA-PVA) as commercial ZnO (ZnO/SA-PVA), synthesised ZnO (ZnO(syn)/SA-PVA), and synthesised ZnO-graphene oxide (ZnO(syn)-GO/SA-PVA). The morphology and photocatalytic activity of the composite beads were studied utilising X-ray diffractometry, Fourier transform infrared spectroscopy and UV-vis spectroscopy. Photocatalytic activity was studied by methylene blue removal, pseudo-first order rate (k1), pseudo-second order rate (k2), the kinetics of adsorption at equilibrium (qe), pseudo-first (K1) and pseudo-second (K2) order adsorption kinetics. The results confirmed that photocatalytic activity was enhanced by the addition of GO in the photocatalyst composite beads. The results confirmed that the MB removal efficiency of ZnO(syn)-GO/SA-PVA composite bead was the best for all conditions described by k1, k2 and qt at around 0.0139 min-1, 0.0302 L.mg-1min-1 and 8.818 mg.g-1, respectively, under visible irradiation. In addition, the adsorption kinetics system was considered by the pseudo-first order and pseudo-second order adsorption kinetics, in which ZnO(syn)-GO/SA-PVA composite beads were around 0.0259 min-1 and 0.232 g.mg-1min-1, respectively.

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