Competitive coordination of iron(III) and copper(II) ions with amidoximated polyacrylonitrile nanofiber and the catalytic performance of the complex

2021 ◽  
pp. 152808372110639
Author(s):  
Fu Li ◽  
Pengfei Fei ◽  
Yongchun Dong ◽  
Man Zhang ◽  
Yu Feng ◽  
...  

This present work describes the competitive coordination of iron (III) and copper (II) ions with amidoximated polyacrylonitrile nanofiber and the catalytic performance of the resulting complex (Fe-Cu-AO- n-PAN). The coordination results showed that the increase of the initial concentration of metal ions was beneficial to the increase of the coordination amount. There were both competition and synergistic effects between the two metal ions. But AO- n-PAN was more inclined to coordinate with Fe3+ ions. The promotion effect of Cu2+ ions on iron coordination due to weak positive electric property and small ion radius increased with its initial concentration in the solution. The Langmuir-Freundlich isotherm model among of four selected isotherm models for binary system showed the best fit to the co-coordination reaction between AO- n-PAN and Fe3+-Cu2+ binary solution. Fe-Cu-AO- n-PAN as heterogeneous Fenton catalyst displayed improved catalytic performance than mono-metal complexes due to its better dye adsorption and the synergistic effect between Cu2+ and Fe3+ ions during degradation process, and both the alkali-resistant and the reusability of it were improved at the same time.

Author(s):  
N. O. Ilelaboye ◽  
A. A. Oderinde

Increased anthropogenic activities have led to serious environmental problems due to pollution caused by toxic materials such as heavy metals whose levels are rising in the environment. The inefficiency and high cost of conventional methods of waste treatment have prompted the investigation of environmentally friendly and cheaper methods of treatment using natural products. In this study, G. arborea leaves powder was investigated with a view of using it as cheap material for the biosorption of Pb2+ and Cd2+   from wastewater. The effects of operational parameters like pH, biosorbent dose [g/L], initial metal ions concentration [mg/L], contact time [minutes] and stirring speed [rpm] on the biosorption efficiency [%] were determined. The optimum solution pH for Pb2+ and Cd2+adsorption was 5.0 and peak adsorption of 91.33% and 82.53% for Pb2+ and Cd2+, respectively. 5 g/L Melina leaves were enough to achieve peak removal of both metal ions. The removal of the metal ions was comparatively quick, and stability was achieved after 30 minutes. The optimum stirring speed was 250 rpm for both metal ions. The uptake efficiency of the biosorbent was determined by Langmuir and Freundlich isotherm models. The value of Langmuir isotherm separation parameter [RL] of Pb2+ ion [0.0446 - 0.78125] and Cd2+ [0.1005- 0.9482] were within range of 0 -1 indicating favorable biosorption for both metal ions. The degree of non-linearity [n] values between Pb2+ [12.79] and Cd2+ [11.79] solution concentration and biosorption in Freundlich equation were greater than 1, indicating physical biosorption of Pb2+ and Cd2+ on to G. arborea leaves. G. arborea can serve as efficient biosorbent not only for Pb2+ and Cd2+ ions but also for other heavy metal ions in a wastewater stream


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0,enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1024 ◽  
Author(s):  
Gulzhian I. Dzhardimalieva ◽  
Rose K. Baimuratova ◽  
Evgeniya I. Knerelman ◽  
Galina I. Davydova ◽  
Sarkyt E. Kudaibergenov ◽  
...  

Several important synthesis pathways for metal-organic frameworks (MOFs) were applied to determine how the synthesis methods and conditions affect the structure and adsorption capacity of the resulting samples. In the present work, three different synthesis routes were used to obtain copper trimesinate coordination polymer: Slow evaporation (A), solvothermal synthesis using a polyethylene glycol (PEG-1500) modulator (B), and green synthesis in water (C). This MOF was characterized by elemental analysis, infrared spectrometry, X-ray diffraction, scanning electron microscopy, thermogravimetry and volumetric nitrogen adsorption/desorption. The samples have permanent porosity and a microporous structure with a large surface area corresponding to the adsorption type I. The obtained MOF was tested as a sorbent to remove organic dyes methylene blue (МВ), Congo red (CR) and methyl violet (MV) as examples. Dye adsorption followed pseudo-first-order kinetics. The equilibrium data were fitted to the Langmuir and Freundlich isotherm models, and the isotherm constants were determined. Thermodynamic parameters, such as changes in the free energy of adsorption (∆G0), enthalpy (∆H0), and entropy (∆S0), were calculated. Thermolysis of copper trimesinate leads to the formation of carbon materials Cu@C with a high purity.


2016 ◽  
Vol 75 (5) ◽  
pp. 1138-1147 ◽  
Author(s):  
Manash Deep Dey ◽  
Minhaz Ahmed ◽  
Ranjana Singh ◽  
Ratan Boruah ◽  
Rupak Mukhopadhyay

Fresh water streams contaminated with synthetic dye-containing effluents pose a threat to aquatic and human life either by preventing aquatic photosynthesis or by entering into the food chain. Adsorptive removal of such dyes with potent biosorbents is an important technique to reduce bioaccumulation and biomagnifications of the dyes in human life. We report use of betel nut (BN) husk and banana peel (BP), two most abundant ligno-cellulosic wastes, as efficient adsorbents for the removal of the basic dye methylene blue (MB). The adsorption by BN and BP was consistently high over wide ranges of pH and temperature, suggesting their dye removal potential in diverse conditions. Physico-chemical studies, e.g. scanning electron microscopy and Fourier transform-infrared spectroscopy studies, revealed changes in surface topology and functional moieties of BN and BP post adsorption, implying dye interaction with the biomass surface. The dye adsorption in both cases followed pseudo-second-order kinetics. While adsorption of MB by BN was better fitted with the Temkin isotherm model, adsorption with BP followed both Langmuir and Freundlich isotherm models. Our studies concluded that both adsorbents efficiently remove MB from its aqueous solution with BP proved to be marginally superior to BN.


2013 ◽  
Vol 69 (1) ◽  
pp. 195-201 ◽  
Author(s):  
Rupa Chakraborty ◽  
Sukalpa Karmakar ◽  
Somnath Mukherjee ◽  
Sunil Kumar

An investigation was performed to evaluate the uptake capacity of Pistia in living condition for adsorptive removal of chromium(VI) from spiked solution for examining a remedial measure for disposal of chrome-laden wastewater in an urban wetland system. Kinetics results show about 78% removal was achieved for 3 mg/L initial concentration of Cr(VI). Experimental data showed that the root portion absorbed more Cr(VI) (28.54 μg/g) compared to accumulation in leaf (5.73 μg/g). It was also noted that the plant could effectively remove Cr(VI) from the solution with minor damage up to an initial Cr(VI) concentration of 3 mg/L, for which the adsorption isotherm studies were conducted. The maximum uptake capacity of the plant was recorded as 0.05 mg/g of Cr(VI) at the equilibrium level after a contact period of 7 days for an initial concentration of 8 mg /L, although severe physiological damage occurred. The experimental results were plotted in Langmuir and Freundlich isotherm models and both were found to be well fitted (r2 = 0.979 and r2 = 0.974 respectively). The high value of n (2.16) reveals a strong bond between the plant root and dissolved Cr(VI), which favours the adsorption process. The order of the reaction was also examined on the basis of uptake capacity and it was found that the second order model fitted best.


2019 ◽  
Vol 31 (12) ◽  
pp. 3035-3040
Author(s):  
Sazmal Effendi Arshad ◽  
Zarina Amin ◽  
Perng Yang Puah ◽  
Mohd Sani Sarjadi ◽  
Baba Musta ◽  
...  

Organic-inorganic hybrid polymers have been demonstrated to be an efficient technique for the adsorption of pollutants present in water. Silica gel adsorbent has been applied in this field due to promising characters, such as thermally stable, reusability and high metal ion adsorption capacities. Here, silica gel supported acrylonitrile functional group (silica-APTS-DPN) was reacted with hydroxylamine to yield silica gel supported amidoxime ligand (SBA). All the functionalized silica gel adsorbents were characterized by FTIR. In terms of metal ions adsorption, SBA revealed good absorption capacities towards both copper (Cu2+) (172 mg g-1) and iron (Fe3+) (168 mg g-1) ions at pH 6 and followed the order of Cu2+ > Fe3+. Increased pH condition was beneficial for both metal ions adsorption. The adsorption kinetics of both ions followed the pseudo-first-order model within 0-60 min of adsorption time. Langmuir and Freundlich isotherm models were both applied to study the adsorption behaviour, Freundlich isotherm model (R2 > 0.99) proved to be a better fit, which propose that multilayer adsorption occurred on the silica gel grafted with amidoxime ligand. Finally, this study proved that the silica gel supported amidoxime ligand was successfully applied as an absorbent for the removal of both copper and iron from aqueous media.


2015 ◽  
Vol 72 (6) ◽  
pp. 896-907 ◽  
Author(s):  
S. M. Anisuzzaman ◽  
Collin G. Joseph ◽  
D. Krishnaiah ◽  
A. Bono ◽  
L. C. Ooi

In this study, durian (Durio zibethinus Murray) skin was examined for its ability to remove methylene blue (MB) dye from simulated textile wastewater. Adsorption equilibrium and kinetics of MB removal from aqueous solutions at different parametric conditions such as different initial concentrations (2–10 mg/L), biosorbent dosages (0.3–0.7 g) and pH solution (4–9) onto durian skin were studied using batch adsorption. The amount of MB adsorbed increased from 3.45 to 17.31 mg/g with the increase in initial concentration of MB dye; whereas biosorbent dosage increased from 1.08 to 2.47 mg/g. Maximum dye adsorption capacity of the durian skin was found to increase from 3.78 to 6.40 mg/g, with increasing solution pH. Equilibrium isotherm data were analyzed according to Langmuir and Freundlich isotherm models. The sorption equilibrium was best described by the Freundlich isotherm model with maximum adsorption capacity of 7.23 mg/g and this was due to the heterogeneous nature of the durian skin surface. Kinetic studies indicated that the sorption of MB dye tended to follow the pseudo second-order kinetic model with promising correlation of 0.9836 &lt; R2 &lt; 0.9918.


2020 ◽  
Vol 10 (6) ◽  
pp. 1925 ◽  
Author(s):  
Loris Pietrelli ◽  
Iolanda Francolini ◽  
Antonella Piozzi ◽  
Maria Sighicelli ◽  
Ilaria Silvestro ◽  
...  

Chitosan is very effective in removing metal ions through their adsorption. A preliminary investigation of the adsorption of chromium(III) by chitosan was carried out by means of batch tests as a function of contact time, pH, ion competition, and initial chromium(III) concentration. The rate of adsorption was rather rapid (t1/2 < 18 min) and influenced by the presence of other metal ions. The obtained data were tested using the Langmuir and Freundlich isotherm models and, based on R2 values, the former appeared better applicable than the latter. Chitosan was found to have an excellent loading capacity for chromium(III), namely 138.0 mg Cr per g of chitosan at pH = 3.8, but metal ions adsorption was strongly influenced by the pH. About 76% of the recovered chromium was then removed simply by washing the used chitosan with 0.1 M EDTA (Ethylenediaminetetraacetic acid) solution. This study demonstrates that chitosan has the potential to become an effective and low-cost agent for wastewater treatment (e.g., tannery waste) and in situ environmental remediation.


2017 ◽  
Vol 19 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Sławomir Wierzba

Abstract This study examined the biosorption process of Ni(II) and Zn(II) from an aqueous solution by dead biomass of Yarrowia lipolytica. Optimum biosorption conditions were determined as a function of pH, biomass dosage, contact time, and temperature. The biosorbent was characterized by FTIR, which indicated the participation of hydroxyl, carboxyl, amide and amine groups in the process of binding the metal ions. The results showed that the biosorption processes of both metal ions closely followed pseudo-second order kinetics. The equilibrium data of Ni(II) and Zn(II) ions at 20, 30 and 40°C fitted the Langmuir and Freundlich isotherm models. Langmuir isotherm provided a better fit to the equilibrium data, with a maximum biosorption capacity of the Y. lipolytica biomass for Ni(II) and Zn(II) of 30.12 and 44.44 mg/g respectively. The calculated thermodynamic parameters demonstrated that the biosorption of Ni(II) and Zn(II) ions onto the Y. lipolytica was feasible, spontaneous and endothermic.


2017 ◽  
Vol 76 (10) ◽  
pp. 2776-2784 ◽  
Author(s):  
Deniz Akın Şahbaz ◽  
Caglayan Acikgoz

Abstract Cross-linked chitosan(C)/marble powder (M) composites with different weight ratio percentage (C100M0, C70M30, C50M50, and C30M70) were prepared from marble powder and chitosan and cross-linked using glutaraldehyde. The morphology and the surface area of the chitosan/marble powder composites were also characterized with a scanning electron microscope (SEM) and Micromeritics (ASAP 2020) BET (Brunauer, Emmett and Teller) instrument, respectively. To evaluate the adsorption behaviour of the chitosan/marble powder composites, 0.1 g adsorbent was added into 50 mL Diamozol Blue BRF %150 (C.I. Reactive Blue 221) solution with fixed concentrations (60 mg/L). At equilibrium, the adsorption capacity of C100M0, C70M30 and C50M50 for Dimozol Blue was about 27 mg/g and significantly greater than that of C30M70. C50M50 composite was more economical than C100M0 and C70M30 due to the higher marble powder content, and hence was selected as an adsorbent for the removal of Dimozol Blue from aqueous solution. The adsorption kinetics and equilibrium isotherms of Dimozol Blue onto the chitosan/marble powder composites from aqueous solution were investigated. The studies revealed that Dimozol Blue dye adsorption was described well by the pseudo-second-order and Freundlich isotherm models. The results of this study indicated the applicability of the chitosan/marble powder composites for removing industrial dyes from aqueous solution.


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