scholarly journals Batch equilibrium and kinetics of mercury removal from aqueous solutions using polythiophene/graphene oxide nanocomposite

2017 ◽  
Vol 75 (12) ◽  
pp. 2841-2851 ◽  
Author(s):  
Anthony M. Muliwa ◽  
Maurice S. Onyango ◽  
Arjun Maity ◽  
Aoyi Ochieng
Keyword(s):  
Graphene Oxide ◽  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Significant Loss ◽  
Mercury Removal ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Equilibrium Studies ◽  
Mercury Uptake

Polythiophene/graphene oxide (PTh/GO) nanocomposite (NC) was prepared through polymerisation of thiophene in the presence of GO and was used for mercury ions (Hg2+) adsorption in aqueous solutions. Equilibrium studies showed that mercury removal was strongly influenced by solution pH and GO composition in the NC. The equilibrium data were well described by both Langmuir and Freundlich isotherm models, with a Langmuir maximum adsorption capacity of 113.6 mg/g. Adsorption kinetics were rapid and correlated well with the pseudo-second-order model. The thermodynamic studies indicated that the adsorption was spontaneous and endothermic in nature, and occurred through a physicochemical mechanism. Desorption studies revealed that PTh/GO NC could be used repeatedly for three adsorption-desorption cycles without a significant loss in its capacity. Competing ions reduced mercury uptake although considerable values were still attained. The findings of this study suggest that PTh/GO NC is a potential adsorbent for Hg2+ removal from aqueous solutions.

scholarly journals Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

2020 ◽  
Vol 10 (5) ◽  
pp. 1738
Author(s):  
Kay Thwe Aung ◽  
Seung-Hee Hong ◽  
Seong-Jik Park ◽  
Chang-Gu Lee
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Naoh Solution ◽  
Surface Modified ◽  
Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

Adsorptive Removal of Drimarene Brilliant Blue by Thermo Stable, Eco-friendly Graphene Oxide Reinforced Polyvinyl Alcohols Hydrogels With High Reusability Potential

2021 ◽  
Author(s):  
Adeel Mustafa ◽  
Nazia Yaqoob ◽  
Maheen Almas ◽  
Shagufta Kamal ◽  
Khalid Mahmood Zia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Thermo Gravimetric Analysis ◽  
Freundlich Isotherm ◽  
Brilliant Blue ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Pseudo Second Order

Abstract In this study graphene oxide (GO) reinforced polyvinyl alcohol (PVA) composites hydrogels were synthesized and used as efficient adsorbents for Drimarene Brilliant Blue K-4BL. GO nanoparticles (NPs) were synthesized by modified Hummer’s method. The composites were characterized by Fourier transform infrared spectroscopy (FT-IR), Thermo-gravimetric analysis (TGA), Scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed homogeneous dispersion of reinforcement in the synthesized composites. Moreover thermal stability of the composites was significantly enhanced by the addition of graphene oxide nanoparticles. The synthesized composites were used for the removal of Drimarene brilliant Blue from model waste water. The effect of pH, content of GONPs and initial concentration of Drimarene Brilliant Blue K-4BL on the adsorption capacity of synthesized GO/PVA composites were investigated. The equilibrium isothermal data were studied by applying Langmuir and Freundlich isotherm models. Results demonstrated that the adsorption process is well described by the Langmuir adsorption isotherm. According to the Langmuir model, maximum adsorption capacity i.e. 32mg/g was obtained at 0.7% GO/PVA composite. From the kinetic study it was concluded that pseudo-second-order model is the best fitted. Synthesized composites showed excellent reusability (almost 95 %) for the adsorption of Drimarene Brilliant Blue K-4BL after four successive cycles of adsorption and desorption. Thus, the GO/PVA composites demonstrated a great potential in terms of cost effectiveness, efficiency and reusability for the removal of Drimarene Brilliant Blue K-4BL dye.

scholarly journals Single and Binary Equilibrium Studies for Ni2+ and Zn2+ Biosorption onto Lemna gibba from Aqueous Solutions

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1089
Author(s):  
Liliana Morales-Barrera ◽  
César Mateo Flores-Ortiz ◽  
Eliseo Cristiani-Urbina
Keyword(s):  
Optimal Solution ◽  
Freundlich Isotherm ◽  
Lemna Gibba ◽  
Isotherm Models ◽  
Solution Ph ◽  
Equilibrium Studies ◽  
Metal Concentrations ◽  
Binary Metal ◽  
Batch Systems ◽  
Equilibrium Data

The biosorption ability of Lemna gibba for removing Ni2+ and Zn2+ ions in aqueous batch systems, both individually and simultaneously, was examined. The influences of solution pH and initial single and binary metal concentrations on equilibrium Ni2+ and Zn2+ biosorption was explored. The optimal solution pH for Ni2+ and Zn2+ biosorption was 6.0, for both the single and binary metal systems. Ni2+ and Zn2+ biosorption capacities increased with increasing initial metal concentrations. The presence of Zn2+ ions more adversely affected the biosorption of Ni2+ ions in the binary metal systems than vice versa. The single and binary biosorption isotherms of Ni2+ and Zn2+ revealed that L. gibba’s affinity for Zn2+ ions was higher than that for Ni2+ ions. The Redlich–Peterson and Freundlich isotherm models fit well to the experimental equilibrium data of Ni2+ ions, whereas Redlich–Peterson and Langmuir models better described the equilibrium data of Zn2+ ions in single metal systems. The modified Sips isotherm model best fit the competitive biosorption data of Ni2+-Zn2+ on L. gibba. FTIR analyses suggest the involvement of hemicellulose and cellulose in the biosorption of Ni2+ and Zn2+. The presence of Ni2+ and Zn2+ on the L.gibba surface was validated by SEM-EDX.

Adsorption of Cobalt Ions onto Mycobacterium phlei from Wastewaters

2011 ◽  
Vol 71-78 ◽  
pp. 2249-2252 ◽  
Author(s):  
Yan Xing
Keyword(s):  
Practical Implication ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Cobalt Ions ◽  
Mycobacterium Phlei ◽  
Order Kinetic Model ◽  
Economic Technology

This fundamental work deals with the biosorption removal of Co(II) using a Mycobacterium phlei strain. Several variables that have an effect on the capacity of cobalt biosorption from aqueous solution by Mycobacterium phlei were studied. particularly the effects of solution pH, initial Co(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Co(II) was 68.22 mg/g. The best correlation was provided by the second-order kinetic model, implying that chemical sorption was the rate-limiting step. The practical implication of this study is the development of an effective and economic technology for Co(II) removal from wastewaters.

scholarly journals Activated carbon from mustard stalk biomass: Synthesis, characterization and application in wastewater treatment

2021 ◽  
pp. 10-10
Author(s):  
Kalpana Patidar ◽  
Manish Vashishtha
Keyword(s):  
Activated Carbon ◽  
Chemical Activation ◽  
Total Pore Volume ◽  
Freundlich Isotherm ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Isotherm Study ◽  
Adsorption Rates

Present work is focused on the preparation of mustard stalk activated carbon (MSAC) using chemical activation with H3PO4 and exploring its properties for its use in dye removal from wastewater. Adsorption variable (dosage, contact time, and solution pH), pore structure, morphology, surface functional groups, equilibrium kinetics, and isotherm study for removal of methylene blue (MB) using MSAC were investigated. The present study showed that an adsorption dosage of 0.2 g L-1 and pH 8 can be considered as optimum for the MB removal. SEM result showed that pore of MSAC was larger than the pore of the mustard stalk (MS). BET surface area and total pore volume of MSAC were found as 510 m2 g-1 and 0.33 cm3 g-1, respectively. Equilibrium adsorption data were examined by Langmuir and Freundlich isotherm models. Better correspondence to the Langmuir model with a maximum adsorption capacity of 212.76 mg g-1 (MB onto MSAC) was obtained. Dimensionless factor, RL revealed favourable nature of the sorption in the MSAC - MB system. Adsorption rates were found to conform to the pseudo-second-order kinetics with good correlation. These results show that the MSAC could be used as a renewable and economical alternative to commercial AC in the removal of MB dye from wastewater.

scholarly journals Adsorptive Removal of Malachite Green Dye onto Coal-Associated Soil and Conditions Optimization

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
T. R. Sundararaman ◽  
A. Saravanan ◽  
P. Senthil Kumar ◽  
M. Millicent Mabel ◽  
R. V. Hemavathy ◽  
...  
Keyword(s):  
Malachite Green ◽  
Nonlinear Models ◽  
Water Environment ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Best Fit

The present research was investigated to eliminate the cationic dye (malachite green (MG)) from the water environment using coal-associated soil. The adsorbent material was characterized using scanning electron microscopy (SEM) and Fourier Transform Infrared Spectrophotometer (FTIR) analyses. Batch experiments were performed to investigate the different factors which affect the adsorption study. The maximum percentage removal of MG dye was attained as follows: adsorbent dose of 1.0 g/L (0.2 to 1.6 g/L), solution pH of 6.0 (2.0 to 9.0), temperature of 30°C (30 to 60°C), time contact of 60min (10 to 90 min), and dye’s concentration of 25 mg/L (25 to 150 mg/L). The adsorption isotherm was studied with four different isotherm models and results showed that the Freundlich isotherm model gave the best fit than the other nonlinear models to designate the isotherm behaviours with R 2 value of 0.9568, and the maximum adsorption capacity of coal-associated soil for MG dye adsorption is 89.97 mg/g. The evaluation of kinetic studies was performed by using three different kinetic models, where it exposed that pseudofirst order providing the best fit with R 2 value of 0.96 (25 to 150 mg/L). The thermodynamic parameters Gibbs free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) were endorsing that the present adsorption system was exothermic. Thus, the experimental results state that coal-associated soil could be an alternative material for the exclusion of dyes from water.

scholarly journals Evaluation of Pb (II) Adsorption from Aqueous Solutions Using Brassica nigra as a Biosorbent

2019 ◽  
Vol 13 (1) ◽  
pp. 77-92 ◽  
Author(s):  
Warren Reátegui-Romero ◽  
Walter J. Cadenas-Vásquez ◽  
María E. King-Santos ◽  
Walter F. Zaldivar Alvarez ◽  
Ricardo A. Y. Posadas
Keyword(s):  
Particle Size ◽  
Aqueous Solutions ◽  
Freundlich Isotherm ◽  
Brassica Nigra ◽  
Second Order ◽  
Lead Ion ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Operating Variables

Objectives: The Pb non-biodegradability results in bioaccumulation in living organisms causing serious health disorders. The present study aimed to investigate the capacity of Pb (II) adsorption in aqueous solutions using the Brassica nigra species as biosorbent. Methods: The present study was conducted using a synthetic solution with three Pb (II) concentrations (5, 15, and 30 ppm). The B. nigra was suitably treated until it became dry particles. After sifting it, three ranges of grain sizes were obtained. Samples of dry particles were analyzed before and after the biosorption to analyze their topography (SEM), as well as the elements on their surface (EDS). The influence of different operating variables on the biosorption of Pb (II) were analyzed. Kinetics of Pb (II) biosorption was analyzed with pseudo first and second order models. The biosorption in the equilibrium was studied with the Langmuir isotherm and Freundlich isotherm models. Results: The biosorbent B. nigra showed to be efficient for the adsorption of Pb (II). The most influential variables in the adsorption were pH, particle size, and biosorbent/solution ratio. The optimum pH for the adsorption of lead was 5 and removed 82.10% of lead from solution at 5 ppm, 82.24% at 15 ppm and 57.95% at 30 ppm. The results for the particle size between 177 and 297 μm were 82.65% for 5 ppm, 73.71% for 15 ppm, and 53.54% for 30 ppm. The biosorbent/solution ratio of 0.6 mg/mL or the 30 mg dose of biosorbent removed 80.26% for 5 ppm, 79.32% for 15 ppm, and 59.87% for 30 ppm. Biosorption isothermal data could be well interpreted by the Langmuir model with a maximum adsorption capacity of 53.476 mg/g of lead ion on B. nigra stem and roots biomass. The kinetic experimental data was properly correlated with the second-order kinetic model (R2 = 0.9997). Thus, the best desorbing agent was HNO3 (0.1N) for Pb (II) desorption. Conclusion: Our study showed that the herb B. nigra, without any chemical treatment, can be used to remove heavy metals such as Pb (II) from water and aqueous solution.

Box–Behnken Design for Optimizing the Synthesis Condition and Adsorption Capability of Covalently Crosslinked Chitosan/coal Fly Ash Composite

2021 ◽  
Author(s):  
Ibrahim Awad Mohammed ◽  
Nurul Najwa Abd Malek ◽  
Ali H. Jawad ◽  
Mohd Sufri Mastuli ◽  
Zeid A. Al-Othman
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Freundlich Isotherm ◽  
Polluted Water ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Box Behnken Design ◽  
Crosslinked Chitosan ◽  
Adsorbent Dose

Abstract The growing concern regarding the environmental protection has encouraged researchers to focus their efforts on developing better and more effective possibilities of removing pollutants. In this research, a biocomposite adsorbent of covalently crosslinked chitosan-epichlorohydrin/coal fly ash (CHT-ECH/CFA) was synthesized and applied for reactive red 120 dye (RR120) removal. The CHT-ECH/CFA was characterized by BET, pH potentiometric, pHpzc, XRD, FTIR and SEM-EDX. Box–Behnken Design (BBD) was employed to assess the effects of the adsorption key parameters such as CFA loading into CTH-ECH matrix, adsorbent dose, solution pH, working temperature and contact time. The optimized CFA loading, adsorbent dose, temperature, time, and pH were observed to be 50 %, 0.07 g, 45 °C, 60 min, and pH 4 respectively. From BBD, the highest removal of RR120 removal at optimum conditions was found to be 90.2%. The results showed that adsorption performance can be modelled perfectly by both Langmuir and Freundlich isotherm models with maximum adsorption capacity of 237.7 mg/g at 45 °C. Moreover, the adsorption kinetics were well fitted to the pseudo-second order model. Based on the findings from the experiments conducted, the hybrid biocomposite adsorbent offers adequate potential for the treatment of anionic dye-polluted water.

MAGNETIC GRAPHENE OXIDE AS ADSORBENT FOR THE REMOVAL OF LEAD(II) FROM WATER SAMPLES

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Hamid Rashidi Nodeh ◽  
Wan Aini Wan Ibrahim ◽  
Mohd Marsin Sanagi
Keyword(s):  
Graphene Oxide ◽  
Adsorption Isotherm ◽  
Water Samples ◽  
Freundlich Isotherm ◽  
Environmental Water ◽  
Environmental Water Samples ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Magnetic Graphene Oxide ◽  
Flame Atomic Absorption

Magnetic Fe3O4 nanoparticles were prepared on graphene oxide (Fe3O4/GO) in situ in a one step process. The obtained Fe3O4/GO was used as an adsorbent for the removal for Pb(II) from environmental water samples prior to flame atomic absorption spectroscopy measurement. The adsorption procedure was optimized as follows: 60 min adsorption time, 50 mL sample volume, solution pH 4.5, and 25 mg adsorbent dosage. Under the optimum conditions, the adsorption efficiency obtained was greater than 75% (C = 50 mg L-1). The adsorption isotherm of Fe3O4@GO magnetic adsorbent was studied for Pb(II) adsorption using two isotherm adsorption models namely Langmuir and Freundlich. The adsorption isotherm data fits well with Langmuir isotherm (R2 = 0.9988) rather than with Freundlich isotherm. The maximum adsorption capacity (qm) obtained was 86.2 mg g-1. The results signified that the prepared Fe3O4/GO nanocomposite has a great adsorptive ability towards the Pb(II) from environmental water samples.

scholarly journals Removal of the Hypoglycaemic Drug Gliclazide From Aqueous Solutions by Carbon-Based Magnetic Materials

2021 ◽  
Author(s):  
Ferda Civan Çavuşoğlu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Monolayer Adsorption ◽  
Langmuir Isotherm Model ◽  
Carbon Based

Abstract Adsorption of gliclazide from aqueous solutions with carbon-based adsorbents is the aim of this study. For this purpose, magnetic, versatile, and inexpensive magnetic activated carbon (MAC) and magnetic multi-walled carbon nanotube (MMWCNT) adsorbents have been developed. MAC and MMWCNT characterization were analyzed using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA) techniques. In order to find the optimum conditions in batch adsorption experiments, the effects of parameters such as adsorbent dose, gliclazide solution pH, contact time, temperature and presence of foreign ions were investigated. Parameters were calculated for adsorption isotherms using Langmuir and Freundlich models. The adsorption studies of MAC and MMWCNT materials with gliclazide were in accordance with the nonlinear Langmuir and Freundlich isotherm models for all temperatures (298, 308, 318 K). The correlation coefficients of the Langmuir isotherm model are slightly higher than the Freundlich model. MAC adsorbent has maximum monolayer adsorption capacity at T=298 K (qmax=101.66 mg/g, R2=0.88) while MMWCNT has maximum monolayer adsorption capacity at T=308 K (qmax=71.59 mg/g, R2=0.90). For MAC and MMWCNT - Gliclazide adsorption systems, pseudo-first and secondorder kinetic models were examined and found to be more appropriate to the pseudo-secondorder kinetic model. The results showed that the MAC and MMWCNT could be could be promising adsorbents for gliclazide removal.

Sign in / Sign up

Export Citation Format

Share Document