scholarly journals γ-Induced Graft Copolymerization onto Cellulosic Fabric Waste for Cationic Dye Removal

2005 ◽  
Vol 23 (6) ◽  
pp. 455-466 ◽  
Author(s):  
A. Hashem ◽  
H.H. Sokker ◽  
E.S. Abdel Halim ◽  
A. Gamal

Radiation grafting of itaconic acid (IA) onto cellulosic fabric in the presence of dimethylformamide (DMF) as a solvent by the mutual method is discussed. Factors affecting the radiation graft copolymerization were investigated. These factors include the radiation dosage, the monomer concentration and the solvent. The grafted samples were characterized using FT-IR spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Utilization of the grafted cellulosic fabric waste in the removal of Methylene Blue (MB) from aqueous solution was examined. The adsorption data showed that the maximum adsorption capacity of Methylene Blue onto grafted cellulosic fabric waste was 38 mg/g. The adsorption data also obeyed the Langmuir and Freundlich isotherms.

2009 ◽  
Vol 27 (4) ◽  
pp. 363-382 ◽  
Author(s):  
A.A. Khalil ◽  
H.H. Sokker ◽  
A. Al-Anwar ◽  
A. Abd El-Zaher ◽  
A. Hashem

Radiation grafting by the mutual method of methacrylic acid/acrylonitrile (MAA/AN) onto Alhagi residues in the presence of dimethylformamide (DMF) as a solvent is discussed. The factors affecting the radiation graft copolymerization were investigated. These included radiation dose, co-monomer composition and concentration. The grafted samples were characterized using FT-IR spectroscopy and scanning electron microscopy (SEM), as well as by the estimation of their nitrogen and carboxyl group contents. The grafted samples were then amidoximated by treatment with hydroxylamine hydrochloride in an alkaline medium. Such amidoximated poly(MAA/AN)-grafted Alhagi residues were utilized for the removal of Zn(II) ions from aqueous solution by adsorption and the factors affecting such adsorption processes were studied. These factors were the pH of the adsorbate solution, the adsorbent dosage, the contact time and the adsorption temperature. The adsorption data obeyed the Langmuir and Freundlich isotherms. The Langmuir adsorption capacity (Qmax) of the amidoximated poly(MAA/AN)-grafted Alhagi residues towards Zn(II) ions was found to be 212.76 and 344.8 mg/g at 30 °C and 50 °C, respectively. Similarly, the Freundlich constants, KF and 1/n, at 30 °C were found to be 21.47 and 0.3489, respectively. The study showed that amidoximated poly(MAA/AN)-grafted Alhagi residues were effective in the adsorption of Zn(II) ions from aqueous solutions. The thermodynamics parameters of the adsorption process, viz. ΔH0, ΔG0 and ΔS0, were evaluated. The results showed that the adsorption of Zn(II) ions onto amidoximated poly(MAA/AN)-grafted Alhagi residues was endothermic and spontaneous. The adsorption data followed second-order kinetics.


2008 ◽  
Vol 26 (8) ◽  
pp. 563-579 ◽  
Author(s):  
A. Hashem ◽  
F. Ahmad ◽  
R. Fahad

Three types of starch hydrogels were prepared via the graft polymerization of acrylonitrile, AN, onto maize starch using ceric ammonium nitrate, CAN, as the initiator, followed by saponification with sodium hydroxide. The prepared hydrogel samples were characterized by estimating their nitrogen and carboxy group contents, and by the application of FT-IR spectroscopy, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM); in addition, their water retention values, WRVs, were also determined. The feasibility of using these hydrogels to remove Hg(II) ions from aqueous solutions was examined. Factors affecting the adsorption of Hg(II) ions onto the starch hydrogels were studied, including the pH value of the solution, the contact time and the concentrations of the adsorbent and adsorbate. The present study has shown that the prepared hydrogels could be used effectively for the adsorption of Hg(II) ions from aqueous solutions. The adsorption data obtained obeyed the Langmuir and Freundlich isotherms. The adsorption of Hg(II) ions onto the starch hydrogels followed second-order kinetics. An examination was made of the mechanism for the adsorption of Hg(II) ions onto the starch hydrogels.


2014 ◽  
Vol 609-610 ◽  
pp. 26-31
Author(s):  
Chun Lei Li ◽  
Hui Xu ◽  
Jun Long Zhang ◽  
Wei Wang ◽  
Jing Tang ◽  
...  

A removal of Cu (II) ions from aqueous solutions onto PAM/ATP has been investigated using batch adsorption technique, including the effect of pH, contact time, initial metal ion concentration, adsorption thermodynamics and kinetics. PAM/ATP was characterized with Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The equilibrium data were analyzed using Langmuir and Freundlich isotherms and the best interpretation was given by Langmuir. The maximum adsorption capacity was found to be 212 mg/g after 60 min when pH =3. Regeneration experiments showed that the investigated PAM/ATP could be reused without significant adsorption losses even after five adsorption-desorption cycles.


2021 ◽  
Vol 43 (4) ◽  
pp. 436-436
Author(s):  
Nida Shams Jalbani Nida Shams Jalbani ◽  
Amber R Solangi Amber R Solangi ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Ranjhan Junejo Ranjhan Junejo ◽  
Asif Ali Bhatti Asif Ali Bhatti

In current study, the diphenylaminomethylcalix[4]arene (3) was synthesized and immobilized onto silica surface to prepare a selective, regenerable and stable resin-4. The synthesized resin-4 has been characterized by FT-IR spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. To check the adsorption capacity of resin-4, the batch and column adsorption methodology were applied and it has observed that the resin-4 was selectively removed Hg2+ ions under the optimized parameters. The maximum adsorption capacity was obtained at pH 9 using 25 mg/L of resin-4. Under the optimal conditions, different equilibrium, kinetic and thermodynamic models were applied to experimental data. The results show that adsorption mechanism is chemical in nature following Langmuir model with good correlation coefficient (R2=0.999) and having 712.098 (mmol/g) adsorption capacity. The energy of calculated from D-R model suggests the ion exchange nature of the adsorption phenomenon. Dynamic adsorption experiments were conducted using Thomas model. The maximum solid phase concentration (qo) was 7.5 and rate constant was found to be 0.176 with (R2=0.938) for Hg2+ ions. The kinetic study describes that the adsorption mechanism follows pseudo second order (R2=0.999). The thermodynamic parameters such as ∆H (0.032 KJ/mol) and ∆S (0.127 KJ/mol /K) and ∆G (-5.747,-6.306, -7.027 KJ/mol) shows that the adsorption of Hg2+ ion is endothermic and spontaneous. The reusability of resin-4 was also checked and it has observed that the after 15 cycle only 1.2 % adsorption reduces. Moreover, the resin-4 was applied on real wastewater samples obtained from local industrial zone of Karachi, Sindh-Pakistan.


2020 ◽  
Vol 10 (8) ◽  
pp. 2726 ◽  
Author(s):  
Roxana Nicola ◽  
Otilia Costişor ◽  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Radu Lazău ◽  
...  

Magnetic iron oxide-silica shell nanocomposites with different iron oxide/silica ratio were synthesized and structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), small-angle neutron scattering, magnetic and N2-sorption studies. The composite that resulted with the best properties in terms of contact surface area and saturation of magnetization was selected for Pb2+ adsorption studies from aqueous media. The material presented good absorption capacity (maximum adsorption capacity 14.9 mg·g−1) comparable with similar materials presented in literature. Its chemico-physical stability and adsorption capacity recommend the nanocomposite as a cheap adsorbent material for lead.


2021 ◽  
Vol 11 (5) ◽  
pp. 13130-13140

Our study aims to evaluate the efficiency of dissolved iron (III) retention in synthetic solutions by adsorption on treated natural phosphate collected in the Khouribga region. This research focused on the valorization of phosphate, a naturally occurring resource that is abundant in Morocco. The resulting products were analyzed by various methods, including FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). In this work, we studied the effect of several parameters such as adsorbent amount, contact time, solution pH, and initial concentration of iron (III) on the adsorption process. The results of the adsorption of iron (III) indicate that the efficiency was achieved after 5 minutes, and the maximum adsorption capacity calculated from the Langmuir model was 26.18 mg g-1. The regeneration and reuse of synthesized adsorbent are effective for five cycles of adsorption-desorption cycles without reducing adsorption capacity.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1734 ◽  
Author(s):  
Abel Adekanmi Adeyi ◽  
Siti Nurul Ain Md Jamil ◽  
Luqman Chuah Abdullah ◽  
Thomas Shean Yaw Choong ◽  
Kia Li Lau ◽  
...  

The paper evaluates the adsorptive potential of thiourea-modified poly(acrylonitrile-co-acrylic acid), (TA-poly(AN-co-AA)) for the uptake of cationic methylene blue (MB) from aquatic environments via a batch system. TA-poly(AN-co-AA) polymer was synthesized through redox polymerization and modified with thiourea (TA) where thioamide groups were introduced to the surface. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), CHNS and Zetasizer were used to characterize the physico-chemical and morphological properties of prepared TA-poly(AN-co-AA). Afterwards, it was confirmed that incorporation of thioamide groups was successful. The adsorption kinetics and equilibrium adsorption data were best described, respectively, by a pseudo-second-order model and Freundlich model. Thermodynamic analysis showed the exothermic and spontaneous nature of MB uptake by TA-poly(AN-co-AA). The developed TA-poly(AN-co-AA) polymer demonstrated efficient separation of MB dye from the aqueous solution and maintained maximum adsorption capacity after five regeneration cycles. The findings of this study suggested that synthesized TA-poly(AN-co-AA) can be applied successfully to remove cationic dyes from aquatic environments.


2015 ◽  
Vol 6 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Jixiang Zhang ◽  
Guangxia Zhang ◽  
Qiuxiang Zhou ◽  
Lailiang Ou

Calcium alginate (CA) was used as an adsorbent to remove methylene blue (MB) from aqueous solution. The effect of initial dye concentration, contact time, temperature and solution pH on the adsorption of MB onto CA was investigated by batch experiments. The percentage removal of MB decreased with increasing temperature. Comparatively high adsorption capacities were shown over a wide pH range (pH 2–11). More than 93% of MB removal was obtained within 30 min for an initial dye concentration of 1,000 mg/L at an adsorbent dose of 4 g/L. The adsorption equilibrium was investigated by the Langmuir and Freundlich isotherms. The maximum adsorption capacity was 2,355.4 mg/g on the basis of the Langmuir isotherm. Thermodynamic parameters were evaluated, and revealed that the adsorption process was a spontaneous, exothermic and entropy-reduced process. Pseudo-first, pseudo-second and intra-particle diffusion kinetic models were applied to the experimental data, and the results showed that the adsorption was in good agreement with the pseudo-second order kinetic model. Desorption studies implied that CA could be a useful adsorbent for the removal of MB from aqueous solution.


Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 30
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Saeed Al-Meer ◽  
Khalid A. Al-Saad

Non-magnetic and magnetic low-cost biochar (BC) from date pits (DP) were applied to remove tigecycline (TIGC) from TIGC-artificially contaminated water samples. Pristine biochar from DP (BCDP) and magnetite-decorated biochar (MBC-DP) were therefore prepared. Morphologies and surface chemistries of BCDP and MBC-DP were explored using FT-IR, Raman, SEM, EDX, TEM, and BET analyses. The obtained IR and Raman spectra confirmed the presence of magnetite on the surface of the MBC-DP. SEM results showed mesoporous surface for both adsorbents. BET analysis indicated higher amount of mesopores in MBC-DP. Box–Behnken (BB) design was utilized to optimize the treatment variables (pH, dose of the adsorbent (AD), concentration of TIGC [TIGC], and the contact time (CT)) and maximize the adsorptive power of both adsorbents. Higher % removal (%R), hitting 99.91%, was observed using MBC-DP compared to BCDP (77.31%). Maximum removal of TIGC (99.91%) was obtained using 120 mg/15 mL of MBC-DP for 10 min at pH 10. Equilibrium studies showed that Langmuir and Freundlich isotherms could best describe the adsorption of TIGC onto BCDP and MBC-DP, respectively, with a maximum adsorption capacity (qmax) of 57.14 mg/g using MBC-DP. Kinetics investigation showed that adsorption of TIGC onto both adsorbents could be best-fitted to a pseudo-second-order (PSO) model.


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