Adsorption kinetics of 17α-ethinyl estradiol and bisphenol A on carbon nanomaterials. I. Several concerns regarding pseudo-first order and pseudo-second order models

2010 ◽  
Vol 10 (5) ◽  
pp. 838-844 ◽  
Author(s):  
Bo Pan ◽  
Baoshan Xing
2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2558 ◽  
Author(s):  
Zhansheng Wu ◽  
Xinhui Wei ◽  
Yongtao Xue ◽  
Xiufang He ◽  
Xia Yang

Activated carbons (ACs) based on apricot shells (AS), wood (W), and walnut shells (WS) were applied to adsorb atrazine in co-solutions. To study the effect of Bisphenol A (BPA) on the adsorption behavior of atrazine, the adsorption performance of ACs for BPA in single solution was studied. The results demonstrated that the adsorption kinetics of BPA fitted the pseudo-second-order model, the adsorption isotherms of BPA followed the Langmuir model. Meanwhile, the adsorption kinetics of atrazine fitted the pseudo-second-order kinetics model and the isotherm was consistent with the Freundlich model both in single solution and co-solution. In addition, competitive adsorption was observed when atrazine coexisted with BPA or humic acid. For the adsorption capacity, the adsorption amount of ASAC, WAC, and WSAC for atrazine obviously decreased by 18.0%, 30.0%, and 30.3% in the presence of BPA, respectively, which was due to the π−π interactions, hydrophobic interactions, and H-bonds, resulting in the competitive adsorption between atrazine and BPA. This study contributes to the further understanding of the adsorption behavior for atrazine in co-solution.


2021 ◽  
Author(s):  
Muhammad Yasir ◽  
Tomas Sopik ◽  
Lenka Lovecka ◽  
Dusan Kimmer ◽  
Vladimir Sedlarik

Abstract This study focuses on characterizing the adsorption kinetics of sex hormones (estrone, 17β-estradiol, 17α-ethinylestradiol, and estriol) on electrospun nanofibrous polymeric nanostructures based on cellulose acetate, polyamide, polyethersulfone, polyurethane, and polyacrylonitrile. The materials’ structure possessed fibers of average diameter in the range 174-330 nm, while its specific surface area equaled 10.2 to 20.9 m2/g. The adsorption-desorption process was investigated in four cycles to determine the reusability of the sorption systems. A one-step high-performance liquid chromatography technique was developed to detect concurrently each hormone present in the solution. Experimental data was applied to gauge adsorption kinetics with the aid of pseudo-first-order, pseudo-second-order, and intraparticle diffusion models; findings showed that estrone, estradiol, and ethinylestradiol followed pseudo-second-order kinetics, while estriol followed pseudo-first-order kinetics. It was observed that polyurethane had maximum adsorption capacities of 0.801, 0.590, 0.736, and 0.382 mg/g for estrone, 17β-estradiol, 17α-ethinylestradiol, and estriol, respectively. The results revealed that polyurethane had the highest percentage efficiency of estrogens removal at ~58.9% and lowest for polyacrylonitrile at ~35.1%. Consecutive adsorption-desorption cycles demonstrated that polyurethane maintained high efficiency, even after being used four times compared with the other polymers. The findings indicate the studied nanostructures have the potential to be effective sorbents for eradicating these estrogens concurrently from the environment.


2020 ◽  
Vol 1 (1) ◽  
pp. 11717
Author(s):  
Lívia Katia Dos Santos Lima ◽  
Antônio Vilas Boas Quintiliano Júnior ◽  
André Henrique Zeferino ◽  
Ana Paula Duarte

The textile industry stands out for generating effluents with high levels of dyes, which have a high polluting potential. Among these dyes, the Remazol Brilliant Blue R azo dye, is one of the most used for dyeing wool and cotton, being released in excess on these effluents. Intended for the carcinogenic and mutagenic potential of this type of dyes, several researches are developed in search of economical technologies for their removal. An adsorption is a viable technique, since several materials can be used for this purpose. Bovine bone activated carbon, as it is a residue from the livestock industry that is easily obtained, has been studied as an adsorbent material in the removal of dyes. Therefore, the objective of this project was to evaluate the performance of the adsorption kinetics of the Remazol Brilliant Blue R dye from the effluents using bovine bone activated carbon. The experiments were carried out in batches, with solutions concentrations of 20, 50 and 100 ppm, and the mathematical models of pseudo-first order, pseudo-second order and intraparticle diffusion were adjusted to the experimental data. For concentrations of 20 and 50 ppm, the model that best fits was the pseudo-first order, while for the concentration of 100 ppm the pseudo-second order model obtained the best result with R2 of 0.992. The intraparticle diffusion model showed that the higher the concentration of the dye in solution, the greater the thickness of the boundary layer and that the intraparticle diffusion does not control the adsorption process in any of the study criteria.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hien Thi Dinh ◽  
Nam Trung Tran ◽  
Dai Xuan Trinh

In this work, the adsorptive removal of methylene blue and methyl orange by UiO-66-NO2 nanoparticles was studied. The influence of pH on the adsorption capacity was assessed. The kinetics of the adsorption process were investigated and compared with pseudo-first-order, pseudo-second-order, Elovich, and intraparticle models. The kinetics of the adsorption fits moderately with the pseudo-first-order, but perfectly fits with pseudo-second-order models, and has a very good fit with the Elovich and intraparticle models. The adsorption isotherms were measured and compared with the Langmuir and Freundlich models. The adsorption capacity of methyl orange (MO) on UiO-66-NO2 nanoparticles (142.9 mg/g) was over three times higher than that of methylene blue (MB) on the nanoparticles (41.7 mg/g). The discrepancy between these capacities was attributed to the presence of the -NO2 functional group, which caused a strong negative mesomeric effect in the metal-organic framework structure.


2019 ◽  
Vol 287 ◽  
pp. 69-74 ◽  
Author(s):  
Suntree Sangjan ◽  
Khanittha Ponsanti

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.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.


2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.


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