INVESTIGATION OF Cr (VI) IONS ADSORPTIVE REMOVAL FROM AQUEOUS SOLUTION ONTO TiO2-AC COMPOSITE: NON-LINEAR EQUILIBRIUM MODELING AND KINETICS.

2021 ◽  
Vol 10 (1) ◽  
pp. 41-54
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Solution Concentration ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Batch Mode ◽  
Non Linear

The present work dedicated to the removal of Cr(VI) ions in aqueous solution onto a synthetized TiO2-AC composite. Composite characterization was carried out by determining of the point of zero charge pHpzc, iodine number, methylene blue index and FT-IR spectra. Adsorption experiments were conducted in batch mode and the influences of composite quantity, contact time, Cr(VI) ions concentration, ionic strength, and pH were studied. The highest adsorption were obtained in acid medium, with lowest adsorbent quantity (0.01 g) and initial solution concentration of 10 ppm. The results of kinetic studies revealed that Cr(VI) adsorption process on TiO2-AC composite followed pseudo second-order kinetic model. Non-linear regression was applied to equilibrium data and Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models were used for evaluation of adsorption parameters. The best-fitting was estimated based on correlation coefficient R2 value and the calculation of error deviations between experimental and predicted equilibrium adsorption data, using non-linear analysis. The results showed that Freundlich model describing adsorption process the best. The isotherm parameters from Langmuir and Freundlich models revealed that Cr(VI) adsorption mechanism on the composite is linear, spontaneous, and endothermic follows chemisorption process.

scholarly journals ADSORPTION CHARACTERISTICS OF ZIZYPHUS JUJUBA SEED SHELL ACTIVATED NANO POROUS CARBON FOR REMOVING COPPER (II) IONS FROM WASTEWATER

2016 ◽  
Vol 4 (12) ◽  
pp. 226-241
Author(s):  
K Veeravelan ◽  
S Arivoli ◽  
V Marimuthu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Batch Mode ◽  
Zizyphus Jujuba ◽  
Pseudo Second Order ◽  
Nano Carbon

In the present study, adsorption of copper (II) ions from aqueous solution by Activated Zizyphus Jujuba shell Nano Carbon was investigated under batch mode. The influence of solution pH, sorbent dose, copper concentration, contact time and temperature was studied. The copper adsorption was favored with maximum adsorption at pH 6.5. Sorption equilibrium time was observed in 60 min. The equilibrium adsorption data were correlated with Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Hurkins-Jura, Halsay, Radlich-Peterson, Jovanovic and BET isotherm models. The kinetics of the adsorption process was tested by pseudo-first-order, pseudo-second order, Elovich and Intra-particle diffusion models. It was shown that adsorption of copper could be described by the pseudo-second order kinetic model. Thermodynamic parameters such as Gibbs free energy (ΔG0), the enthalpy (ΔH0) and the entropy change of sorption (ΔS0) have also been evaluated and it has been found that the adsorption process was spontaneous, feasible and endothermic in nature. The results indicated that Activated Zizyphus Jujuba shell Nano Carbon can be used as an effective and low-cost adsorbent to remove copper (II) from aqueous solution.

scholarly journals Characterization of Residual Biomasses and Its Application for the Removal of Lead Ions from Aqueous Solution

2019 ◽  
Vol 9 (21) ◽  
pp. 4486 ◽  
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Darío Gonzalez-Delgado ◽  
Angel Villabona-Ortiz
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Mesoporous Structure ◽  
Isotherm Models ◽  
Solution Ph ◽  
Batch Mode ◽  
Suitable Alternative

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

scholarly journals Magnetic/Polyetherimide-Acrylonitrile Composite Nanofibers for Nickel Ions Removal from Aqueous Solution

2020 ◽  
Author(s):  
Muhammaed O Aijaz ◽  
Mohammed R Karim ◽  
Hamad F. Alharbi ◽  
Nabeel H. Alharthi ◽  
Fahad Al-Mubaddel
Keyword(s):  
Aqueous Solution ◽  
Magnetic Nanoparticles ◽  
Aqueous Medium ◽  
Composite Nanofibers ◽  
Adsorption Process ◽  
Composite Membranes ◽  
Polymeric Membrane ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Nickel Ions

Within the study, magnetic/polyetherimide-acrylonitrile composite nanofibers membrane with effective adsorption of nickel ions in aqueous solution were established, through a simple electrospinning method. Iron oxide nanoparticles were stirred and ultrasonically dispersed into polyetherimide-acrylonitrile solution for homogenous suspension. Afterwards, the polyetherimide-acrylonitrile solution with uniform suspension of iron nanoparticles was used in electrospinning machine to produce uniform and smooth nanofibers composite membrane. The confirmation of nanoparticles incorporation into polymeric membrane were characterized by SEM, EDX, FTIR, XRD and nanoparticles aqueous stability through leach out test. The high adsorption capability of the composite membranes on nickel ions was mainly attributed to the combination of magnetic nanoparticles, polyetherimide-acrylonitrile matrix and nano-sized structure of membrane. Membrane containing magnetic nanoparticles demonstrate the maximum adsorption capabilities (102 mg/g) for nickel ions from aqueous solution. Different kinetics and isotherm models were applied to understand the adsorption behavior during adsorption process, amongst them pseudo second order kinetic and Langmuir isotherm model were well fitted. Additionally, EDX, FTIR and XRD results confirmed the presence of nickel ions onto membrane after adsorption process. Polyetherimide-acrylonitrile composite nanofibers membranes containing magnetic nanoparticles may use as an environmentally-friendly and non-toxic adsorbent for the removal of nickel ions in aqueous medium due to its ease of preparation, easy to use and stability in aqueous medium by retaining the nanoparticles inside the nanofibers membranes.

scholarly journals Sorption of Bivalent Ions by Cymbopogon citratus: Characterisation and Investigation of Biosorptive Capacity and Mechanism

2018 ◽  
Vol 4 (3) ◽  
pp. 297-302
Author(s):  
S. Jayashree ◽  
Jeyavathana Samuel ◽  
R. Vashantha
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Adsorption Process ◽  
Low Cost ◽  
Kinetic Studies ◽  
Solution Temperature ◽  
Isotherm Models ◽  
Physical Parameters ◽  
Cymbopogon Citratus ◽  
Equilibrium Data

The main objective of this study was to investigate the removal of cadmium(II) ions from aqueous solution using raw Cymbopogon citratus as an adsorbent. It was characterized by FT-IR, XRD, SEM-EDAX and its physical parameters were analyzed. Different factors such as pH, contact time, initial concentration and temperature were studied. Maximum adsorption was taken place at the optimum pH of 6 and the equilibrium data were analyzed by Langmuir, Freundlich and Temkin Isotherm models. Among those isotherm models Langmuir and Temkin were fitted well with good correlation coefficient (R2). The negative values of ΔG⁰ for all temperature shows the adsorption process for cadmium(II) ion was spontaneous in nature and feasible. The negative value of enthalpy change ΔH⁰ shows the adsorption process is exothermic and the positive value of ΔS⁰ indicates the disorderness or randomness process of adsorption. The positive value of Ea indicates the higher solution temperature favors the adsorption of metal ion onto RCC. The experimental data were analyzed by kinetic studies such as pseudo-first order, pseudo-second order and intra-particle diffusion models. Desorption was also studied and the recovery of the adsorbent was found to be 10%. Thus on the basis of these investigations the present study concludes that the raw Cymbopogon citratus (RCC) was found to be highly effective, nontoxic, environmental friendly and low cost adsorbent for the removal of toxic Cd(II) ions from aqueous solution.

Removal of Hexavalent Chromium by Adsorption on Microwave Assisted Activated Carbon Prepared from Stems of Leucas Aspera

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
A. Shanmugalingam ◽  
A. Murugesan
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Batch Mode ◽  
Microwave Assisted ◽  
Leucas Aspera ◽  
Order Kinetic Model ◽  
Impregnation Time

Abstract This study reports adsorption of Cr(VI) ions from aqueous solution using activated carbon that was prepared from stems of Leucas aspera. Eight hundred and fifty watts power of microwave radiation, 12 min of radiation time, 60% of ZnCl2 solution and 24 h of impregnation time are the optimal parameters to prepare efficient carbon effective activated carbon. It was designated as MWLAC (Microwave assisted Zinc chloride activated Leucas aspera carbon). Various adsorption characteristics such as dose of the adsorbent, agitation time, initial Cr(VI) ion concentration, pH of the solution and temperature on adsorption were studied for removal of Cr(VI) ions from aqueous solution by batch mode. Also the equilibrium adsorption was analyzed by the Langmuir, Freundlich, Tempkin and D-R isotherm models. The order of best describing isotherms was given based on R2 value. The pseudo-second-order kinetic model best fitted with the Cr(VI) adsorption data. Thermodynamic parameters were also determined and results suggest that the adsorption process is a spontaneous, endothermic and proceeded with increased randomness.

scholarly journals Removal of Methylene Blue from Aqueous Solution by Bone Char

2018 ◽  
Vol 8 (10) ◽  
pp. 1903 ◽  
Author(s):  
Puqi Jia ◽  
Hongwei Tan ◽  
Kuiren Liu ◽  
Wei Gao
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Particle Size ◽  
Adsorption Process ◽  
Removal Rate ◽  
Isotherm Models ◽  
Equilibration Time ◽  
Bovine Bone ◽  
Order Kinetic ◽  
Bone Char

Bone char was prepared from bovine bone for the removal of methylene blue from aqueous solution. The effects of particle size, contact time, and adsorption temperature on the removal rate of methylene blue were investigated. It was found that bone char particle size had an insignificant effect. The equilibration time was found at approximately 80 min. The removal rate decreased with an increase in temperature. The intraparticle diffusion was the main rate-limiting step. The experimental data was analyzed by kinetic, isotherm, and thermodynamic equations. The results show that the pseudo-second-order kinetic model and Freundlich, Temkin, and Dubinin–Kaganer–Radushkevich isotherm models are true of the adsorption process. The spontaneous and exothermic ion-exchange adsorption process was certified by the negative values of free energy change and enthalpy change, and 13.29 kJ mol−1 of adsorption energy.

scholarly journals Adsorptive removal of malachite green dye from aqueous solution onto activated carbon of Catha edulis stem as a low cost bio-adsorbent

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Gietu Yirga Abate ◽  
Adugna Nigatu Alene ◽  
Adere Tarekegne Habte ◽  
Desiew Mekuanint Getahun
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Low Cost ◽  
Aqueous System ◽  
Point Of Zero Charge ◽  
Isotherm Models ◽  
Synthetic Dyes ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Catha Edulis

Abstract Background The release of hazardous synthetic dyes into industrial effluents has emerged as an environmental problem requiring remediation. The present study focused on the preparation of a new and environmentally-friendly material (adsorbent) for the remediation of hazardous dyes from aqueous solution. The low cost adsorbent was prepared from locally available khat (Catha edulis) stem which considered as waste and accumulated on waste disposal areas of Woldia town, Ethiopia. Comprehensive characterization studies were carried out on the bio-adsorbent such as proximate analyses, specific surface area, point of zero charge and FT-IR analysis. Results The proximate analysis shows the prepared adsorbent has very high fixed carbon content (83.65%), which refers to high quality of the adsorbent. The adsorption performance of the prepared activated carbon was optimized by varying operational parameters such as initial dye concentration (10 mg/L), pH (10), dosage (0.5 g), and contact time (60 min). The maximum removal efficiency of the prepared adsorbent at those optimum conditions was 98.8%. The experimental data was tested by most common kinetics and isotherm models. It was observed that the pseudo-second-order kinetic model fits better with good correlation coefficient and the equilibrium data fitted well with the Freundlich isotherm model. Conclusion In summery this study demonstrated that the waste bio sorbent could be employed as an effective and eco-friendly alternative for the cleanup of dye-polluted aqueous system.

scholarly journals Removal of nitrobenzene from aqueous solution by adsorption onto carbonized sugarcane bagasse

2018 ◽  
Vol 36 (5-6) ◽  
pp. 1366-1385 ◽  
Author(s):  
Dunqiu Wang ◽  
Huijun Shan ◽  
Xiaojie Sun ◽  
Hongxia Zhang ◽  
Yanhua Wu
Keyword(s):  
Aqueous Solution ◽  
Functional Groups ◽  
Sugarcane Bagasse ◽  
Adsorption Process ◽  
Fourier Transforms ◽  
Adsorption Equilibrium ◽  
Physical Adsorption ◽  
Operating Conditions ◽  
Isotherm Models ◽  
Order Kinetic

A sorbent was prepared by charring sugarcane bagasse (SCB) and used to remove nitrobenzene from aqueous solution. The surface area, morphology, and functional groups of the adsorbent were characterized by Brunauer–Emmett–Teller method, scanning electron microscopy, and Fourier transforms infrared spectroscopy. Analysis indicated that oxygen-containing functional groups, such as C = O, –OH, –COOH, and C–O–C, may be involved in the adsorption process. The adsorption of nitrobenzene was investigated under different operating conditions, including adsorbent dosage, initial nitrobenzene concentration, pH, and contact duration. Four kinetic models were applied to describe the adsorption process. Results revealed that the optimal sorbent mass was 0.3 g/50 mL at pH 5.8 and 25°C. The kinetic data obeyed the pseudo-second-order kinetic model ( R2 > 0.9965). In addition, Langmuir and Freundlich isotherm models were employed to describe the adsorption equilibrium. The Freundlich model presented better fitting for the adsorption equilibrium, suggesting that the carbonized SCB surface had a heterogeneous nature. The maximum adsorption capacities calculated by the Langmuir model were 38.27, 41.72, and 44.70 mg/g at 25°C, 35°C, and 45°C, respectively. The calculated values of ΔG0 and ΔH0 indicated the spontaneous and exothermic nature of the adsorption process at the considered temperature range. The adsorption mechanism of nitrobenzene onto carbonized SCB cannot be described either as physical adsorption or chemisorption. This study demonstrated that SCB biochar is a potential sorbent for removing nitrobenzene from aqueous solutions.

scholarly journals Isotherms and Kinetic Studies on the Adsorption of Cd(II) onto Activated Carbon Prepared from Coconut (Cocos nucifera) Shell

2019 ◽  
Vol 40 ◽  
pp. 78-83
Author(s):  
Rajeshwar Man Shrestha ◽  
Sahira Joshi
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Contact Time ◽  
Cocos Nucifera ◽  
Kinetic Studies ◽  
Coconut Shell ◽  
Isotherm Models ◽  
Order Model ◽  
Batch Mode ◽  
Adsorbent Dose

Activated carbon prepared coconut shell using Phosphoric acid as an activating agent was investigated to find the feasibility ofits application for removal of Cd(II) from aqueous solution through the adsorption process. The activated carbon thus prepared has been characterized by SEM, XRD, FTIR. SEM morphology has revealed the pores of different diameters while FTIR showed the presence of surface functional groups such as carboxyl, phenolic and lactones. Batch mode kinetics and isotherm studies were carried out to evaluate the effects of contact time, adsorbent dose and pH. The optimum pH, contact time and adsorbent dose needed for the adsorption of the heavy metal have been found to be 6, 180 minutes and 2 g/L respectively. Langmuir and Freundlich isotherm models have been employed to analyze the adsorption equilibrium data. It was found that the adsorption isotherm of Cd(II) onto the activated carbon was the best described by Langmuir with an adsorption capacity of 33.71 mg/g. Kinetic studies showed that a pseudo second-order model was more suitable than the pseudo first-order model. It has been concluded that the activated carbon prepared from coconut shell can be used as an effective adsorbent for the removal of Cd(II) from aqueous solution.

scholarly journals Application of Acacia karroo charcoal for desalinating Ni(II) and Zn(II) from aqueous solutions through batch mode

2013 ◽  
Vol 3 (3) ◽  
pp. 268-276
Author(s):  
Joginder Singh ◽  
Renu Sharma ◽  
Amjad Ali
Keyword(s):  
Aqueous Solution ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Batch Mode ◽  
Acacia Karroo ◽  
Biosorption Process ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Heavy Metals Ions

Acacia karroo charcoal lumps were used for the biosorption of Ni(II) and Zn(II) from an aqueous solution using batch mode. The effect of various parameters viz., solution pH, adsorbent dose, contact time and initial metal concentrations were studied. Freundlich and Langmuir isotherm models were applied to the batch equilibrium data. The maximum biosorption capacity (qmax) for Ni(II) and Zn(II) was found to be 9.0 and 7.99 mg g−1 at pH 6.0 and 4.0 respectively. Experiments were performed to study the kinetics of Ni(II) and Zn(II) biosorption and the data obtained was best fitted to the pseudo-second-order kinetic model. Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) changes were also calculated and the observed values supported the spontaneity of the biosorption process. The exhausted adsorbent was regenerated three times using 0.1 N NaOH and its regeneration capacity was evaluated. These results illustrate that A. karroo charcoal lumps hold good potential for removing heavy metals ions from aqueous solution and could be used for desalinating metal ions from industrial wastewater.

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