scholarly journals Harnessing of Newly Tailored Poly (Acrylonitrile)-Starch Nanoparticle Graft Copolymer for Copper Ion Removal via Oximation Reaction

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.

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.


2011 ◽  
Vol 347-353 ◽  
pp. 281-284
Author(s):  
Peng Ge ◽  
Li Juan Wan ◽  
Ya Jing Xu

Among the investigated clays and minerals (kaolinite, natural zeolite, manual zeolite, bentonite, sepiolite, sepiolite amianthus, tremolite amianthus, vermiculite and baritite), the baritite clay was selected as the optimal adsorbent for aqueous Cr (VI). The Cr (VI) adsorption capacity on baritite clay reached as high as 39.01 mg∙g−1 at 20°C. Then the adsorption kinetics of Cr (VI) by the baritite clay were investigated in details. Results showed that the pseudo-second-order model was a suitable description for the adsorption kinetics and fitted well with the experimental data.


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.


2013 ◽  
Vol 726-731 ◽  
pp. 2191-2197 ◽  
Author(s):  
Su Yun He ◽  
Cai Yun Han ◽  
Su Fang He ◽  
Hua Wang ◽  
Chun Xia Liu ◽  
...  

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.


Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1141 ◽  
Author(s):  
Joanna Lach

The aim of the study was to evaluate the possibility of applying commercial activated carbons currently used in water treatment plants and modified carbon at 400 and 800 °C in the atmosphere of air, water vapour and carbon dioxide to remove chloramphenicol. Adsorption kinetics was examined for solutions with pH of 2–10. Adsorption kinetics were determined for the initial concentration of chloramphenicol of 161 mg/dm3 and the adsorption isotherm was determined for the concentrations of 161 to 1615 mg/dm3. Of the analysed activated carbons (F-300, F-100, WG-12, ROW 08 Supra and Picabiol), the highest adsorption capacity was obtained for the use of Picabiol (214 mg/g), characterized by the highest specific surface area and pore volume. The pH value of the solution has little effect on the adsorption of chloramphenicol (the highest adsorption was found for pH = 10, qm = 190 mg/g, whereas the lowest—for pH = 6, qm = 208 mg/g). Modification of activated carbon WG-12 at 800 °C caused an increase in adsorption capacity from 195 mg/g (unmodified carbon) to 343 mg/g. A high correlation coefficient was found between the capacity of activated carbons and the total volume of micropores and mesopores. Among the examined adsorption kinetics equations (pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion), the lowest values of the R2 correlation coefficient were obtained for the pseudo-first order equation. Other models with high correlation coefficient values described the adsorption kinetics. The adsorption results were modelled by means of the Freundlich, Langmuir, Temkin and Dubibin–Radushkevich adsorption isotherms. For all activated carbons and process conditions, the best match to the test results was obtained using the Langmuir model, whereas the lowest was found for the Dubibin–Radushkevich model.


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.


2013 ◽  
Vol 741 ◽  
pp. 55-58
Author(s):  
Wen Lian Luo

The removal of Cu2+ ions from aqueous solution was studied using pickled diatomite samples. The linear Langmuir and Freundlich adsorption equations were applied to describe the equilibrium isotherms. The pseudo-first-order and pseudo-second-order models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model.


Author(s):  
C.E. Muko-Okoro ◽  
I.A. Obiora-Okafo ◽  
J.N. Ndive

Phenol is a prevalent pollutant found in many industrial wastewaters, and it is paid singular attention because of its special features including high toxicity, carcinogenic properties, and vital cumulative ability that affects the health of humans and the environment. The current study investigated the removal of phenol from synthetic aqueous solutions using prepared Moringaoleifera seed shell as an adsorbent. The efficiency of phenol removal by Moringaoleifera seed shell was evaluated in a batch system, and different parameters such as initial concentration of phenol (100, 200, 300, 400 and 500 mg/L), contact time (10, 20, 30, 40, 50 and 60 min), and adsorbent dosage (0.2, 0.4, 0.6, 0.8, and 1.0 g) were studied. The results showed that the highest percentage of phenol removal by the ash occurred at 0.8 g dosage, contact time of 40 min, and initial concentration of 500 mg/L giving 87.2% phenol removal. The adsorption process was modeled with Langmuir and Freundlich isotherms and adsorption kinetics (pseudo-first order and pseudo-second order) at controlled temperatures. The results showed that the experimental data fitted the Langmuir (R2 = 0.8338) much better than the Freundlich model (R2 = 0.7314). For the analysis of the adsorption kinetics, the results showed that the experimental data fitted the pseudo-second order kinetics (R2 = 0.999) much better than the pseudo-first order kinetics (R2 = 0.5042). In general, the results of this study revealed that Moringaoleifera seed shell has suitable potential for use in removing phenol from aqueous solution on operation and practical scales due to its availability and organic nature.


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