Adsorptive removal of methylene blue (MB) and malachite green (MG) dyes from aqueous solutions using graphene oxide (GO)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Raja Babu Chilakapati ◽  
S. Hemanth Kumar ◽  
Suggala V. Satyanarayana ◽  
Dilip Kumar Behara

Abstract Graphene oxide (GO) synthesized via modified Hummers method was studied for adsorption of methylene blue (MB) and malachite green (MG) dyes from aqueous solutions. It is hypothesized that electrostatic interactions between dye molecules and surface of GO will facilitate charge carrier movements and degrade the dye in an efficient way. The as synthesized GO was characterized using various characterization techniques such as XRD, Raman, FTIR, UV–Vis, SEM and EDAX. The experimental results suggest that dye removal percentage will increase with increase in adsorbent dosage, time as well as solution pH and the process was exothermic in nature. The adsorption data at 293 K could be fitted by Langmuir equation with a maximum adsorption amount of 119.04, 102.4 mg/g and Langmuir adsorption equilibrium constant of 1.58, 0.867 L/mg for MB and MG dyes, respectively. The outcomes of present article will help not only to understand the adsorption characteristics of GO on MB and MG dyes but also paves path towards development of highly oxidized GO surface for degradation of complex dyes.

2019 ◽  
Vol 18 (05) ◽  
pp. 1850030 ◽  
Author(s):  
Qiuju Du ◽  
Yanhui Li ◽  
Jiabin Li ◽  
Zhao Zhang ◽  
Bin Qiao ◽  
...  

A facile and easily separated adsorbent, graphene oxide (GO) pellets wrapped by chitosan (GOP) were prepared. Batch adsorption studies were carried out to study the adsorption properties of congo red onto GOP by varying the experimental parameters such as the contact time, the initial concentration of congo red, the solution pH, the adsorbent dose, and the temperature. The kinetic studies showed that the adsorption data fitted a pseudo-second-order model well. The isotherm analysis showed that the adsorption data fitted the Freundlich model well. The adsorption mechanism was mainly attributed to electrostatic interactions, [Formula: see text]–[Formula: see text] stacking interaction, hydrogen bond, and van der Waals force. Thermodynamic studies indicated that the adsorption process was endothermic and spontaneous.


2003 ◽  
Vol 21 (2) ◽  
pp. 189-198
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Rana Saeidi ◽  
Salam Abu Zaid

As in Part I, non-activated (natural) and chemically activated oak shells were evaluated for their ability to remove phenol and Methylene Blue (as a typical dye component) from aqueous solutions. Batch adsorption experiments were conducted to investigate the effect of contact time, sorbent concentration, phenol concentration and the pH of the solution on the sorption process. Activated oak shells adsorbed more phenol than natural oak shells under the same conditions. A decrease in sorbent concentration or an increase in phenol concentration or solution pH resulted in an increase in phenol uptake by the oak shells. The uptake of Methylene Blue increased with decreasing sorbent concentration and with an increase in the dye concentration, but decreased significantly with solution pH. According to the fractional factorial design technique, the sorbent type employed (natural or activated) had the most significant influence on phenol or Methylene Blue uptake followed by sorbent concentration and then sorbate concentration. Interaction amongst the different operating variables played an important role in the uptake of phenol or Methylene Blue dye by the adsorbent considered.


NANO ◽  
2017 ◽  
Vol 12 (03) ◽  
pp. 1750032 ◽  
Author(s):  
H.-Y. He

Reduced graphene oxide-SnSe (rGO-SnSe) nanohybrids were synthesized with a solution chemical reaction at room temperature. The nanohybrids were characterized by various techniques for their microstructural and photocatalytic activities in photodegradation of alkaline dye malachite green in the water. The effects of rGO/SnSe ratio, initial solution pH, and H2O2 concentration on the photodegradation efficiency were studied. The SnSe nanocrystallines with nanoscale size and narrow bandgap were formed and uniformly adhered on the rGO surface. Raman analysis confirmed the reduction of GO. The experimental results indicated that the nanohybrids showed excellent sunlight-excited photocatalytic activity in degrading malachite green in the water. Significantly, the nanohybrids showed remarkable photo-Fenton-like catalytic activity. The photodegradation rates of the hybrids were greater than that of SnSe nanoparticles, increased with increasing rGO/SnSe ratio, and related to operation parameters. High photocatalytic activities were ascribed to the efficiency interface effect that was confirmed by the calculations of band energy level and photoconductivity. The TOC measurement further verified the photodegradation results. The nanoparticles and nanohybrids also showed excellent reusability.


RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26532-26536 ◽  
Author(s):  
Cressa Ria P. Fulong ◽  
Timothy R. Cook

A Co(ii) coordination polymer acts as a sponge for organic dye molecules, removing them from aqueous solutions.


2017 ◽  
Vol 2 (2) ◽  
pp. 697-701 ◽  
Author(s):  
Yunus Yildiz ◽  
Tugba Onal Okyay ◽  
Betül Sen ◽  
Bahdisen Gezer ◽  
Sultan Kuzu ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.


2016 ◽  
Vol 9 (2) ◽  
pp. 102-108
Author(s):  
Yash Mishra ◽  
V. Sowmya ◽  
S. Shanthakumar

In this study, the adsorption potential of Teak (Tectona grandis) leaf powder (TLP) to remove Methylene blue (MB) and Malachite Green (MG) dye molecules from aqueous solution was investigated. Batch experiments were conducted to evaluate the influence of operational parameters such as, pH (2-9), adsorbent dosage (1-7 g/L), contact time (15-150 minutes) and initial dye concentration (20-120 mg/L) at stirring speed of 150 rpm, on the adsorption of MB and MG on TLP. The maximum removal efficiency of 98.4% and 95.1% was achieved for MB and MG dye, respectively. The experimental equilibrium data were analyzed using Langmuir, Freundlich and Temkin isotherms and it was found that it fitted well to the Freundlich Isotherm model. The surface structure and morphology of the adsorbent was characterized using Scanning electron microscopy (SEM) and the presence of functional groups and its interaction with the dye molecules were analyzed using Fourier transform infrared (FTIR). Based on the investigation, it has been demonstrated that the teak leaf powder has good potential for effective adsorption of Methylene blue and Malachite green dye.


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