scholarly journals Adsorptive removal of cationic and anionic dyes using graphene oxide

2018 ◽  
Vol 78 (4) ◽  
pp. 732-742 ◽  
Author(s):  
V. Sabna ◽  
Santosh G. Thampi ◽  
S. Chandrakaran
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Uv Spectroscopy ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Dye Molecules ◽  
Anionic Dyes ◽  
Batch Mode ◽  
Initial Concentration ◽  
Adsorptive Removal

Abstract This paper presents the results of comparative study on the application of graphene oxide (GO) for the adsorptive removal of crystal violet (CV) and methyl orange (MO) in batch mode. GO, synthesised from graphite, was characterised by field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, point of zero charge (pHPZC) and ultra violet (UV) spectroscopy. Dispersion of GO in water revealed the conversion of hydrophobic graphite into hydrophilic. Performance with regard to adsorption of CV and MO on GO was evaluated at different values of the operational parameters such as contact time between GO and the dye molecules, dosage of GO, and initial concentration and pH of the dye solution. Uptake and percentage removal of the dyes increased with increase in contact time and adsorbent dosage, but declined with increase in initial concentration of the dye. Experimental data on the uptake of dye molecules by GO showed good fit with the Freundlich isotherm model and the pseudo second order kinetic model. The maximum uptake by GO was higher for CV (207.4 mg/g) than that for MO (37.2 mg/g). Results indicate that GO is an effective adsorbent for the removal of CV but not for MO.

Adsorption of Congo Red Dye on HDTMA Surfactant-Modified Zeolite A Synthesized from Fly Ash

2018 ◽  
Vol 382 ◽  
pp. 307-311 ◽  
Author(s):  
Jumaeri ◽  
Sri Juari Santosa ◽  
Sutarno
Keyword(s):  
Fly Ash ◽  
Congo Red ◽  
Contact Time ◽  
Batch Reactor ◽  
Order Kinetic ◽  
Zeolite A ◽  
Adsorption Model ◽  
Anionic Dyes ◽  
Initial Concentration ◽  
Modified Zeolite

Adsorption of anionic dyes Congo Red (CR) on HDTMA surfactant-modified zeolite A has been studied. The zeolite A, which is synthesized from coal fly ash, was modified with surfactant hexdeciltrimethylammonium bromide (HDTMA-Br) as much as 200% cation exchange capacity (CEC) of the zeolite. The effect of pH, contact time and initial concentration on the CR adsorption has been evaluated.The adsorption was carried out in a batch reactor at various pH, contact time and initial concentration on the given temperature. The amount CR adsorption varies as a function of pH, contact time and initial concentration of solution. Adsorption model of Langmuir and Freundlich from empirical data is used for this experiment. The Langmuir isotherm is more suitable for this adsorption. The experimental data fulfilled pseudo second-order kinetic models. The surfactant-modified zeolite A is more effective than zeolite A without modified on the adsorption of CR in aqueous solution.

scholarly journals Removal of hexavalent chromium from graphene oxide supported on a cellulose acetate and polyacrylic acid membrane

2021 ◽  
pp. 1-8
Author(s):  
Juan SÁNCHEZ-MÁRQUEZ ◽  
Rosalba FUENTES-RAMÍREZ ◽  
Zeferino GAMIÑO-ARROYO
Keyword(s):  
Graphene Oxide ◽  
Cellulose Acetate ◽  
Hexavalent Chromium ◽  
Polyacrylic Acid ◽  
Contact Time ◽  
Polymeric Membrane ◽  
Point Of Zero Charge ◽  
Inversion Method ◽  
Initial Concentration ◽  
Phase Inversion Method

This work focused on the study of the hexavalent chromium removal process from graphene oxide supported on a cross-linked cellulose acetate and polyacrylic acid polymeric membrane. The membranes were synthesized by the phase inversion method and Graphene oxide was added in proportions of 1% by weight to the polymeric material. Graphene oxide was obtained from crystalline graphite (Electron Microscope Science, No. 70230). The graphite was oxidized using the improved method of Hummers. The characterization of polymer and graphene oxide was made by Raman spectroscopy. The surface charge and point of zero charge of the materials were evaluated using a potentiometric titration method proposed by Loskutov and Kuzin. The removal of Cr (VI) was studied as a function of contact time and of initial concentration of Cr (VI). The removal of Cr (VI) (~90%) mainly occurs in a contact time from 32 to 64 h when the initial concentration of Cr (VI) is 1 mg/L.

scholarly journals Comparison of Rhodotorula sp. and Bacillus megaterium in the removal of cadmium ions from liquid effluents

2018 ◽  
Vol 7 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Mihaela Roşca ◽  
Raluca-Maria Hlihor ◽  
Petronela Cozma ◽  
Elena Niculina Drăgoi ◽  
Mariana Diaconu ◽  
...  
Keyword(s):  
Bacillus Megaterium ◽  
Contact Time ◽  
Point Of Zero Charge ◽  
Operating Parameters ◽  
Order Kinetic ◽  
Cadmium Ions ◽  
X Ray ◽  
Freundlich Isotherms ◽  
Accuracy And Precision ◽  
Pseudo Second Order

AbstractThis study compares the capacity ofRhodotorulasp. andBacillus megateriumfor Cd(II) removal considering the influence of operating parameters (pH, biosorbent dosage, contact time, temperature, initial metal concentration in solution). The highest Cd(II) uptake of 14.2 mg/g byRhodotorulasp. was exhibited at 30°C, when working at pH 6 and with 5 g/l biosorbent dosage, after 48 h of contact time. In these conditions, a removal efficiency of 85% was obtained. Similar outcomes were obtained forB. megaterium(15.1 mg/g, 90%) at 35°C, pH 4 and 3 g/l biosorbent dosage, considered as the optimum set of parameters, equilibrium being achieved for a contact time of 20 min. The possible interaction mechanisms between the biosorbents and Cd(II) were evaluated through point of zero charge (pHpzc), Fourier transform infrared (FTIR), spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Data were modeled using pseudo-first and pseudo-second order kinetic models and Langmuir and Freundlich isotherms models. Further studies considered a modeling approach based on linear regression with Durbin-Watson statistics, while the accuracy and precision of experiments were evaluated by ANOVA.

scholarly journals Use of sweet ‘Pêra’ peel as an adsorbent in the treatment of textile effluents

2019 ◽  
Vol 23 (9) ◽  
pp. 716-722
Author(s):  
Ketyla K. R. do Nascimento ◽  
Fernando F. Vieira ◽  
Marcello M. de Almeida ◽  
Josué da S. Buriti ◽  
Aldre J. M. Barros ◽  
...  
Keyword(s):  
Contact Time ◽  
Exponential Model ◽  
Point Of Zero Charge ◽  
Infrared Analysis ◽  
Hydroxyl Groups ◽  
Solution Ph ◽  
Initial Concentration ◽  
Zero Charge ◽  
Adsorbed Quantity ◽  
Air Circulation

ABSTRACT The disposal of industrial wastewater into aquatic bodies without proper treatment can cause severe damage to the environment and human health. The objective of this study was to perform the drying of the sweet orange (Citrus sinensis L. Osbeck) peel cultivar Pêra and evaluate the viability of its use as biosorbent in the removal of a direct dye. Drying was carried out in an oven with air circulation at temperatures of 60 and 80 ºC. The mathematical models of Page, Henderson and Pabis, Logarithmic, Midilli and Two-term exponential were fitted to the moisture data as a function of time. The material was characterized by scanning electron microscopy, point of zero charge, and infrared spectroscopy. In the adsorption study, a complete 24 factorial design was used to analyze the influence of mass, initial concentration, solution pH and contact time on adsorbed quantity (qt) and removal percentage of the dye (R%). In the drying, the two-term exponential model fitted best to the experimental data. The characterization of the material indicated that the adsorbent has zero charge point of 3.5 and porous structure, and the infrared analysis indicated the presence of carboxylic and hydroxyl groups. In the adsorption, the adsorbed quantity of the dye increased under conditions of lower pH and biosorbent mass and higher initial concentration and contact time. The removal percentage of dye increases with higher biosorbent mass. The biosorbent used is a promising waste for the adsorption of the burgundy-16 dye.

scholarly journals Glyphosate adsorption by Eucalyptus camaldulensis bark-mediated char and optimization through response surface modeling

2019 ◽  
Vol 9 (7) ◽  
Author(s):  
Kamalesh Sen ◽  
Jayanta Kumar Datta ◽  
Naba Kumar Mondal
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Low Cost ◽  
Eucalyptus Camaldulensis ◽  
Zero Point ◽  
Isotherm Models ◽  
Multilayer Adsorption ◽  
Batch Mode ◽  
Initial Concentration ◽  
Glyphosate Herbicide

Abstract In this study, orthophosphoric acid-modified activated char was prepared from Eucalyptus camaldulensis bark (EBAC), and used for removing traces of [N-(phosphonomethyl)glycine] (glyphosate) herbicide from aqueous solution. The adsorption capacity was characterized by zero-point-charge pH, surface analysis, and Fourier transform infrared spectroscopy. Batch mode experiments were conducted to observe the effects of selected variables, namely dose, contact time, pH, temperature, and initial concentration, on adsorption capacity. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models were generated to describe the mechanisms involved in the multilayer adsorption process. The results show that high temperature enhanced the adsorption capacity of EBAC, with a temperature of 373 K yielding adsorption capacity (qmax) and Freundlich parameter (KF) of 66.76 mg g−1 and 9.64 (mg g−1) (L mg−1)−n, respectively. The thermodynamics study revealed entropy and enthalpy of −5281.3 J mol−1 and −20.416 J mol−1, respectively. Finally, glyphosate adsorption was optimized by the Box–Behnken model, and optimal conditions were recorded as initial concentration of 20.28 mg L−1, pH 10.18, adsorbent dose of 199.92 mg/50 mL, temperature of 303.23 K, and contact time of 78.42 min, with removal efficiency of 98%. Therefore, it can be suggested that EBAC could be used as an efficient, low-cost adsorbent for removal of glyphosate from aqueous solutions.

Removal of Malachite Green from Aqueous Solutions by Perlite

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Vijayakumar Govindasamy ◽  
Renganathan Sahadevan ◽  
Sivanesan Subramanian ◽  
Dharmendira Kumar Mahendradas
Keyword(s):  
Malachite Green ◽  
Contact Time ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Order Kinetic ◽  
Batch Mode ◽  
Adsorption Mechanisms

Perlite was utilized as an adsorbent for the removal of malachite green from their aqueous solution. The effects of the initial dye concentration, contact time, adsorbent dose, pH, and temperature were studied for the adsorption of malachite green in batch mode. The dye adsorption equilibrium was rapidly attained after 40 min of contact time. Adsorbent was characterized by FTIR, XRD and SEM. The Langmuir and Freundlich isotherm described the adsorption data over the concentration range (20 – 100 mg/L). The rate parameters of the intra particle diffusion were calculated and compared to identify the adsorption mechanisms. The thermodynamic parameters such as entropy change, enthalpy change, and energy of adsorption were calculated to know the nature of adsorption. The negative values of energy of adsorption and the positive values of enthalpy change suggested that the adsorption process is spontaneous and exothermic. Kinetic studies showed that the adsorption process obeyed the pseudo first-order kinetic model.

scholarly journals Adsorption of an anionic dye (Congo red) from aqueous solutions by pine bark

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Khaoula Litefti ◽  
M. Sonia Freire ◽  
Mostafa Stitou ◽  
Julia González-Álvarez
Keyword(s):  
Congo Red ◽  
Low Cost ◽  
Pine Bark ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Batch Mode ◽  
Adsorbent Dosage ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Cr Concentration

Abstract Pinus pinaster bark, an abundant by-product from the timber industry, has been studied as a potential low-cost adsorbent for the removal of Congo red (CR) dye from wastewaters. Surface morphological and physico-chemical characteristics of pine bark were analysed using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), determination of the point of zero charge (pHPZC) and elemental analysis. Assays were performed to determine the wavelength for the maximum absorbance and the stability with time of CR solutions depending on concentration and/or pH, which resulted to be a very significant parameter. Adsorption studies were conducted on batch mode to study the effect of contact time (till 7 days), pH (2–9), adsorbent dosage (1–10 g L−1) and temperature (25–60 °C). The bark adsorption capacity at equilibrium varied between 0.3 and 1.6 mg g−1 and the equilibrium adsorption percentage between 23.4 and 100% depending on adsorbent dosage, temperature and pH at an initial CR concentration of 5 mg L−1. Kinetic data for the removal of CR by pine bark were best fitted by the pseudo-second-order kinetic model. The equilibrium data fitted well with the Freundlich model. Thermodynamic analysis indicated that the adsorption process is exothermic and spontaneous.

scholarly journals Benzene Removal by Iron Oxide Nanoparticles Decorated Carbon Nanotubes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Aamir Abbas ◽  
Basim Ahmed Abussaud ◽  
Ihsanullah ◽  
Nadhir A. H. Al-Baghli ◽  
Marwan Khraisheh ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Contact Time ◽  
Batch Adsorption ◽  
Oxide Nanoparticles ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Benzene Removal

In this paper, carbon nanotubes (CNTs) impregnated with iron oxide nanoparticles were employed for the removal of benzene from water. The adsorbents were characterized using scanning electron microscope, X-ray diffraction, BET surface area, and thermogravimetric analysis. Batch adsorption experiments were carried out to study the adsorptive removal of benzene and the effect of parameters such as pH, contact time, and adsorbent dosage. The maximum removal of benzene was 61% with iron oxide impregnated CNTs at an adsorbent dosage 100 mg, shaking speed 200 rpm, contact time 2 hours, initial concentration 1 ppm, and pH 6. However, raw CNTs showed only 53% removal under same experimental conditions. Pseudo-first-order kinetic model was found well to describe the obtained data on benzene removal from water. Initial concentration was varied from 1 to 200 mg/L for isotherms study. Langmuir isotherm model was observed to best describe the adsorption data. The maximum adsorption capacities were 987.58 mg/g and 517.27 mg/g for iron oxide impregnated CNTs and raw CNTs, respectively. Experimental results revealed that impregnation with iron oxide nanoparticles significantly increased the removal efficiency of CNTs.

scholarly journals Optimizing the Biosorption Behavior of Ludwigia stolonifera in the Removal of Lead and Chromium Metal Ions from Synthetic Wastewater

2021 ◽  
Vol 13 (11) ◽  
pp. 6390
Author(s):  
Yasser A. El-Amier ◽  
Ashraf Elsayed ◽  
Mohamed A. El-Esawi ◽  
Ahmed Noureldeen ◽  
Hadeer Darwish ◽  
...  
Keyword(s):  
Experimental Data ◽  
Metal Ions ◽  
Contact Time ◽  
Static Condition ◽  
Sorption Process ◽  
Ion Concentration ◽  
Synthetic Wastewater ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Batch Mode

In this study, a natural low-coast, efficient, and eco- bio-sorbent plant material (Ludwigia stolonifera), with both parts of the root and shoot, were studied for the removal of the cationic metal ions, lead Pb2+ and chromium Cr6+, via batch mode experiments to evaluate their maximum adsorption capacity, and held a comparison between the used bio-sorbent roots and shoots, based on the highest bio-sorption potential. Optimization of the bio-sorption parameters, such as contact time, pH, bio-sorbent (root and shoot) dosage, and initial ion concentration was conducted. The results indicated that 1.6 g of the used bio-sorbent shoot material removed 81.4% of Pb2+, and 77% of Cr6+ metal ions from liquid media under the conditions of 100 ppm of initial metal ions concentration at room temperature for 60 min of contact time with the static condition. Different isotherms and kinetic models were fit to the experimental data to understand the nature of the bio-sorption process. The experimental data were best fit by the pseudo-second-order kinetic model with a high correlation coefficient (R2 = 0.999), which reveals the chemisorption nature of the bio-sorption process. The chemical and structural analysis of the used bio-sorbent, before and after Cr6+ and Pb2+ bio-sorption, were performed using different techniques of characterization, such as Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The used bio-sorbent proved to be a low-cost, efficient, and eco-friendly material to remove heavy metal ions from aqueous solutions.

scholarly journals Adsorption Study of Rhodamine B and Methylene Blue Dyes with ZSM-5 Directly Synthesized from Bangka Kaolin without Organic Template

2019 ◽  
Vol 20 (1) ◽  
pp. 130 ◽  
Author(s):  
Ani Iryani ◽  
Hadi Nur ◽  
Mardi Santoso ◽  
Djoko Hartanto
Keyword(s):  
Methylene Blue ◽  
Rhodamine B ◽  
Contact Time ◽  
Adsorption Process ◽  
Dye Adsorption ◽  
Standard Entropy ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Initial Concentration

Rhodamine B (RB) and Methylene Blue (MB) dyes adsorption using adsorbent ZSM-5 synthesized from Bangka kaolin were investigated in this study. The effects of the initial concentration, contact time and temperature on the adsorption process were also analyzed. The effect of the initial concentration and contact time played an important role in the adsorption process; however, the effect differs significantly in both dyes. The temperature plays little role in the dye adsorption process. The results showed the adsorption process occurred in ZSM-5 adhere to Langmuir isothermal adsorption model showing that the adsorption process occurred to be monolayer. Based on the kinetics studies, the pseudo-first-order kinetic model represents the adsorption kinetics that occurs for both dyes onto the synthesized ZSM-5. Thermodynamic parameters namely Gibbs free energy (ΔG°), standard entropy changes (ΔS°) and standard enthalpy (ΔH°) reveal that the adsorption process onto ZSM-5 for both dyes was spontaneous and exothermic.

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