Synergetic Performance of Graphene Oxide and Chitosan on the Removal of Direct Red 7

2019 ◽  
Vol 35 (6) ◽  
pp. 1789-1798
Author(s):  
Sumathi Ganesan ◽  
Gurumallesh Prabu Halliah

Graphene oxide/Chitosan (GOCH) composite was synthesized by hydrothermal method and structurally characterized by FT-IR, RAMAN, XRD and BET analyses which provide support for graphene oxide and chitosan incorporation. The synthesized composite was employed for the removal of direct red 7 (DR7) by batch adsorption process. Langmuir, Freundlich, Temkin, Dubinin-Radushkevic, Harkin-Jura, Scatchard plot analysis and Hasley isotherms were used to elucidate adsorption mechanism. The value of R2 revealed that isotherm was well explained by Langmuir model. The extent of monolayer adsorption capacity of GOCH was calculated as 34.2 mg/g. The pseudo first order kinetic studies were in agreement with experimental data. Thermodynamic parameters such as activation energy (Ea = 8.405 KJ/mol), enthalpy (ΔH = 89.417 KJ/mol), free energy change (ΔG) and entropy (ΔS = 0.2971 KJ/mol) were calculated. It propounded that the adsorption of DR7 on GOCH was favorable, spontaneous and an endothermic process.

2015 ◽  
Vol 71 (11) ◽  
pp. 1611-1619 ◽  
Author(s):  
Jun Liu ◽  
Hongyan Du ◽  
Shaowei Yuan ◽  
Wanxia He ◽  
Pengju Yan ◽  
...  

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.


2019 ◽  
Vol 801 ◽  
pp. 304-310
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Elaine Nicole O. Cañeba ◽  
Karl Michael V. Edquila ◽  
Joel Ian C. Espita ◽  
Jem Valerie D. Perez

Nanocomposite beads containing 2% chitosan (CS), 2% polyethyleneimine (PEI), and 1,500 ppm graphene oxide (GO) were synthesized for the removal of methyl orange (MO) from water. Characterization of the CS-PEI-GO beads using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) showed favorable adsorbent properties as given by the presence of numerous surface functional groups and a porous structure. Effects of different parameters such as pH, contact time, and initial concentration on the percentage removal of MO and adsorption capacity of the beads were investigated by performing batch adsorption experiments. MO removal of more than 85% was achieved by the beads across a wide pH range. Kinetic studies were performed and a pseudo-second order kinetic equation with R2 of 0.9999 was obtained. Furthermore, adsorption equilibrium data for MO were best described by the Toth isotherm model (R2 = 0.9644), suggesting multilayer adsorption on heterogeneous adsorption sites with a maximum adsorption capacity of 421.51 mg/g. Finally, FTIR and SEM analyses after adsorption confirmed the presence of MO on the surface of the beads and revealed an intact and stable structure. Overall, the excellent adsorption capability and multi-functionality demonstrated in this study show great potential of the synthesized material for wastewater treatment applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Y. El maguana ◽  
N. Elhadiri ◽  
M. Benchanaa ◽  
R. Chikri

In the present study, batch adsorption experiments were carried out to investigate the removal of methyl orange (MO) from aqueous solution using sugar scum powder as an effective inorganic adsorbent which is a cheap precursor and abundant. The characteristics of this material were determined using XRD, SEM/EDX, and FTIR. The adsorption performance of sugar scum powder was evaluated using MO as the model adsorbate. Effects of various parameters such as initial dye concentration, contact time, and adsorbent dose were studied. The adsorption process can be best described by the pseudo-second-order kinetic and Langmuir adsorption isotherm models. Maximum monolayer adsorption capacity for MO removal was found to be 15.24 mg/g at temperature 22°C and pH 7.2. Moreover, thermodynamic parameters suggested that the adsorption of MO onto sugar scum powder was a spontaneous and exothermic process. The results demonstrated that sugar scum is a suitable precursor for the preparation of efficient adsorbent for dye removal from wastewater.


2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Sabarish Radoor ◽  
Jasila Karayil ◽  
Aswathy Jayakumar ◽  
Jyotishkumar Parameswaranpillai ◽  
Suchart Siengchin

AbstractIn the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDAX) and N2 adsorption–desorption isotherm (BET). XRD and FT-IR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30 ℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption–desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.


2011 ◽  
Vol 413 ◽  
pp. 148-153 ◽  
Author(s):  
Xue Na Hu ◽  
Ya Han ◽  
Jia Yan Li ◽  
Jun Yan Wu ◽  
Jian Rong Chen ◽  
...  

Thiol-functionalized MCM-48 (SH-MCM-48) was synthesized by co-condensation method, with co-templates of cetyltrimethylammonium bromide (CTAB) and nonionic poly (ethylene oxide)–poly (propylene oxide)–poly (ethylene oxide) triblock copolymer (Pluronic P123). The resulting material was characterized by XRD and FT-IR spectrum. The potential of SH-MCM-48 for adsorption Zn (II) from aqueous solution was examined. Batch adsorption studies were carried out to investigate the effect of experimental parameters including pH, metal ions concentration and adsorption time. The maximum adsorption capacities of Zn (II) onto SH-MCM-48 were 30.12, 34.01 and 38.02 mg g-1 at the temperature of 303, 313 and 323K, respectively. The adsorption kinetics data were found to follow the pseudo-second-order kinetic model, and adsorption isotherms were fitted well with Langmuir and Freundlich models. Moreover, the adsorption thermodynamic parameters (△G0, △H0 and △S0) were measured, and indicated that the adsorption was an exothermic and spontaneous process.


Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3890
Author(s):  
Chenlu Jiao ◽  
Die Liu ◽  
Nana Wei ◽  
Jiannan Gao ◽  
Fan Fu ◽  
...  

Porous sustainable cellulose/gelatin/sepiolite gel beads were fabricated via an efficient ‘hydrophilic assembly–floating droplet’ two-step method to remove Congo red (CR) from wastewater. The beads comprised microcrystalline cellulose and gelatin, forming a dual network framework, and sepiolite, which acted as a functional component to reinforce the network. The as-prepared gel beads were characterized using FTIR, SEM, XRD, and TGA, with the results indicating a highly porous structure that was also thermally stable. A batch adsorption experiment for CR was performed and evaluated as a function of pH, sepiolite addition, contact time, temperature, and initial concentration. The kinetics and isotherm data obtained were in agreement with the pseudo-second-order kinetic model and the Langmuir isotherm, with a maximum monolayer capacity of 279.3 mg·g−1 for CR at 303 K. Moreover, thermodynamic analysis demonstrated the spontaneous and endothermic nature of the dye uptake. Importantly, even when subjected to five regeneration cycles, the gel beads retained 87% of their original adsorption value, suggesting their suitability as an efficient and reusable material for dye wastewater treatments.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3427
Author(s):  
Rachid El Kaim Billah ◽  
Moonis Ali Khan ◽  
Young-Kwon Park ◽  
Amira AM ◽  
Hicham Majdoubi ◽  
...  

Chitosan (Cs)-based composites were developed by incorporating silica (Cs–Si), and both silica and hydroxyapatite (Cs–Si–Hap), comparatively tested to sequester hexavalent (Cr(VI)) ions from water. XRD and FT-IR data affirmed the formation of Cs–Si and Cs–Si–Hap composite. Morphological images exhibits homogeneous Cs–Si surface, decorated with SiO2 nanoparticles, while the Cs–Si–Hap surface was non-homogeneous with microstructures, having SiO2 and Hap nanoparticles. Thermal analysis data revealed excellent thermal stability of the developed composites. Significant influence of pH, adsorbent dose, contact time, temperature, and coexisting anions on Cr(VI) adsorption onto composites was observed. Maximum Cr(VI) uptakes on Cs and developed composites were observed at pH 3. The equilibration time for Cr(VI) adsorption on Cs–Si–Hap was 10 min, comparatively better than Cs and Cs–Si. The adsorption data was fitted to pseudo-second-order kinetic and Langmuir isotherm models with respective maximum monolayer adsorption capacities (qm) of 55.5, 64.4, and 212.8 mg/g for Cs, Cs–Si, and Cs–Si–Hap. Regeneration studies showed that composites could be used for three consecutive cycles without losing their adsorption potential.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5408
Author(s):  
Yichao Gong ◽  
Jianbing Su ◽  
Muyuan Li ◽  
Aixue Zhu ◽  
Guisui Liu ◽  
...  

A novel magnetic composite material, Fe3O4@SiO2/chitosan/graphene oxide/β-cyclodextrin (MCGC), was prepared by multi-step methods. Various methods were used to systematically characterize the morphology, composition, structure, and magnetic properties of MCGC. The results obtained show that the composite material has good morphology and crystal structure and can be separated quickly by an external magnetic field. The operation is relatively easy, and the raw materials used to prepare this material are economical, easy to obtain, and environmentally friendly. The performance and adsorption mechanism for using this material as an adsorbent to remove bisphenol A (BPA) and bisphenol F (BPF) from water were studied. The adsorption parameters were optimized. Under optimal conditions, MCGC was found to remove more than 90% of BPA and BPF in a mixed solution (20 mg/L, 50 mL); the adsorption process for BPA and BPF on MCGC was found to follow a Redlich–Peterson isotherm model and Pseudo-second-order kinetic model. The adsorption mechanism for MCGC may involve a combination of various forces. Recycling experiments showed that after five uses, MCGC retained a more than 80% removal effect for BPA and BPF, and through real sample verification, MCGC can be used for wastewater treatment. Therefore, MCGC is economical, environmentally friendly, and easy to separate and collect, and has suitable stability and broad application prospects.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tamirat Dula ◽  
Khalid Siraj ◽  
Shimeles Addisu Kitte

This study reports on the adsorption of Hexavalent Chromium from aqueous solutions using activated carbon prepared from bamboo (Oxytenanthera abyssinica) waste by KOH activation heating in an electrical furnace at 1073 K for 3 hrs. Batch adsorption experiments were also carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo-second-order kinetic model. Thermodynamic parameters showed that adsorption on the surface of BWAC was feasible, spontaneous in nature, and exothermic between temperatures of 298 and 318 K. The equilibrium data better fitted the Freundlich isotherm model for studying the adsorption behavior of Hexavalent Chromium by BWAC. IR spectrum for loaded and unloaded BWAC was obtained using FT-IR spectrophotometer. Adsorption efficiency and capacity of Hexavalent Chromium were found to be 98.28% at pH 2 and 59.23 mg/g at 300 K.


2019 ◽  
Vol 10 (1) ◽  
pp. 4706-4713

Clean water is an essential element for the survival of humans and nature. However, the tremendous growth in industrialization has degraded the water quality by introducing pollutants such as dyes into the main water bodies such as rivers. In this research, the locally collected agricultural wastes such as watermelon peel (Citrullus lanatus) and corn peel (Zea Mays) were tested on two types of synthetics dyes such Remazol Brilliant Violet 5R (RBV5) and Remazol Brilliant Blue R (RBBR). From the screening test, the watermelon peel achieved the highest color removal percentage with 44.8% and followed by corn’s peel with 18.89%. Both adsorbents were selected for the batch adsorption test by varying the parameters. Based on the results achieved from the batch adsorption test, the optimum removal of dye particles was achieved at the lowest concentration of dye solutions. The optimum pH value to achieve a high percentage of color removal is at pH3, which is acidic. In this case, the 3 g of adsorbent dosage achieved the highest percentage of color removal compared to 5 g. This could due to insufficient contact time. In addition, the chemical and physical characteristics of the adsorbents were analyzed using FESEM and FTIR respectively. By analyzing the surface texture and functional group, differences in the adsorbents before and after adsorption were noticed. Besides that, based on the obtained R2 values from the linear plotting, the Temkin isotherm model and pseudo-second-order kinetic model fitted well compared to other isotherm and kinetic models. In conclusion, the watermelon peel and corn peel are capable of removing dye particles in the industrial effluent under selective conditions with low cost while being environmentally friendly.


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