scholarly journals Sorption Profile of Phosphorus Ions onto ZnO Nanorods Synthesized via Sonic Technique

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
M. F. Elkady ◽  
H. Shokry Hassan ◽  
Eslam Salama
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
High Efficiency ◽  
Zno Nanorods ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Oxide Material ◽  
Order Kinetic ◽  
Phosphorus Sorption ◽  
Pseudo Second Order

High surface area zinc oxide material in nanorod morphological structure was synthesized using an ultrasonic technique in the presence of polyvinyl pyrrolidone as stabilizing agent. The crystallite, morphology, and surface area of the prepared white powder material were identified using XRD, SEM, and BET techniques, respectively. X-ray analysis confirms the high purity of synthesized ZnO. The evaluated specific surface area of prepared ZnO was 16.7 m2/g; this value guarantees high efficiency for water purification. The feasibility of synthesized ZnO nanorods for phosphorus sorption from aqueous solution was established using batch technique. Nano-zinc oxide exhibits high efficiency for phosphorus removal; the equilibrium state was recorded within 90 minutes. The most effective hydrogen ion concentration of the polluted solution was recorded at pH = 1 for phosphorus decontamination. The equilibrium of phosphorus sorption onto ZnO nanorods was well explained using both Langmuir and Temkin isotherm models. The calculated maximum monolayer sorption capacity was 89 mg/g according to Langmuir isotherm at 27°C. In order to explain the phosphorus sorption mechanism onto the prepared ZnO nanorods, three simplified kinetic models of pseudo-first order, pseudo-second order, and intraparticle diffusion rate models were tested. Kinetics was well fitted by pseudo-second order kinetic model with a contribution of intraparticle diffusion.

scholarly journals Cadmium(II) Removal from Aqueous Solution Using Microporous Eggshell: Kinetic and Equilibrium Studies

2018 ◽  
Vol 18 (2) ◽  
pp. 265 ◽  
Author(s):  
Behzad Shamsi Zadeh ◽  
Hossein Esmaeili ◽  
Rauf Foroutan
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
High Efficiency ◽  
Second Order ◽  
Order Kinetic ◽  
Mixing Rate ◽  
Equilibrium Studies ◽  
Initial Concentration ◽  
Adsorbent Dosage ◽  
Pseudo Second Order

Heavy metals are soluble in the environment and can be dangerous for many species. So, removal of heavy metals from the water and wastewater is an important process. In this study, an adsorbent made of eggshell powder was employed to remove cadmium ions from aqueous solution. A number of parameters were studied including pH of the aqueous solution, adsorbent dosage, contact time, the initial concentration of cadmium ion and mixing rate. The best efficiency for the removal of Cd(II) was obtained 96% using this adsorbent. The optimal parameters were ambient temperature of 30 °C, mixing rate of 200 rpm, pH of 9, an adsorbent dosage of 5 g/L and initial concentration of cadmium was 200 ppm. In order to study the kinetics of adsorbent, the pseudo-first-order and pseudo-second-order kinetic models and intra-particle diffusion model were applied. According to the pre-determined correlation coefficients (R2), the pseudo-second-order kinetic model showed a better correlation between the kinetic behaviors of the adsorbent. Furthermore, to study the equilibrium behavior of adsorbent, Langmuir and Freundlich models used and both models showed high efficiency in isotherm behavior of the adsorbent. So, this adsorbent can be used as a natural and cheap adsorbent.

scholarly journals Removal of Basic Orange 2 dye and Ni2+ from aqueous solutions using alkaline-modified nanoclay

2021 ◽  
Author(s):  
Armin Geroeeyan ◽  
Ali Niazi ◽  
Elaheh Konoz
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Dye Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Diffusion Kinetic ◽  
Pseudo Second Order

Abstract In the present research, the removal of Basic Orange 2 (BO2) dye using alkaline-modified clay nanoparticles was studied. To characterize the adsorbent, XRD, FTIR, FESEM, EDX, BET and BJH analyses were performed. The effect of the variables influencing the dye adsorption process such as adsorbent dose, contact time, pH, stirring rate, temperature, and initial dye concentration was investigated. Furthermore, the high efficiency of Ni2+ removal indicated that it is possible to remove both dye and metal cation under the same optimum conditions. The experimental data were analyzed by Langmuir and Freundlich isotherm models. Fitting the experimental data to Langmuir isotherm indicated that the monolayer adsorption of dye occurred at homogeneous sites. Experimental data were also analyzed with pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetic equations for kinetic modeling of the dye removal process. The adsorption results indicated that the process follows a pseudo-second-order kinetic model. The thermodynamic parameters of the dye adsorption process such as enthalpy, entropy, and Gibbs free energy changes were calculated and revealed that the adsorption process was spontaneous and endothermic in nature. The results presented the high potential of the modified nanoclay as a cost-effective adsorbent for the removal of BO2 dye and Ni2+ from aqueous medium.

scholarly journals Enhancing Adsorption Capacity of Clay and Application in Dye Removal from Waste Water

2014 ◽  
Vol 39 ◽  
pp. 35-51 ◽  
Author(s):  
O.T. Ogunmodede ◽  
O.L. Adebayo ◽  
A.A. Ojo
Keyword(s):  
Waste Water ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Kinetic Models ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Small Surface ◽  
Intercalation Process ◽  
Pseudo Second Order

Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic models: Lagergren pseudo-first order and the chemisorptions pseudo-second order. It was observed that chemisorptions pseudo-second order kinetic model described the sorption process with high coefficients of determination (r2) better than pseudo first other kinetic models. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework.

Modified Carbon Nanostructures Obtained From Sugarcane Bagasse Hydrochar for Treating Chromium-Polluted Water

2020 ◽  
Vol 16 ◽  
Author(s):  
Nady A. Fathy ◽  
Sahar M. El-Khouly ◽  
Ola I. El-Shafey
Keyword(s):  
Electron Microscope ◽  
Surface Area ◽  
Functional Groups ◽  
Sugarcane Bagasse ◽  
Carbon Nanostructures ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Polluted Water ◽  
Initial Concentration ◽  
Pseudo Second Order

Background: Application of nanotechnology in wastewater treatment is the solving key to cope with the conflict between people’s increasing demand for water and the world-wide water shortage. The main goal of this study is to prepare modified carbon nanostructures (CNSs) from sugarcane bagasse waste (SCB) as effective adsorbents for removing toxic Cr(VI) ions from their aqueous solutions. Methods: The preparation of CNSs was performed via catalytic hydrothermal/carbonization of SCB. The resultant CNSs sample was oxidized by oxidation with HNO3/H2O2 (O-CNSs) and then followed by coating with diethylenetriamine (N-CNSs). Transmission electron microscope (TEM), scanning electron microscope attached to energy-dispersive X-ray (SEM/EDX), fourier transform infrared (FTIR) and nitrogen adsorption analyses were used to determine the morphology and surface properties of CNSs. Adsorption and desorption studies of Cr(VI) ions onto these modified CNSs were investigated. Effects of initial concentration of Cr(VI), pH of solution and temperature in batch mode were estimated. Adsorption studies were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich models. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were undertaken to follow the adsorption mechanism. Results: The prepared samples composed of carbon nanotubes and graphene sheets as evident by TEM and SEM. The adsorption of Cr(VI) is exothermic in nature, well-fitted with Langmuir, described by pseudo-second order kinetic model and then is uncontrolled by intraparticle diffusion step. It was found that the adsorption of Cr(VI) was higher uptake over O-CNSs (56 mg/g) than that by N-CNSs (44 mg/g). This was ascribed to that the first sample is enriched with acidic O-functional groups and possessed higher specific surface area (188 m2/g). Desorption studies were achieved by HNO3 and NaOH reagents for recovering the Cr(VI) from O-CNSs. Results revealed that about 90% of Cr(VI) can be recovered by HNO3 more than that by NaOH till the third run. Conclusions: Two modified CNSs samples were successfully prepared from SCB. Adsorption of Cr(VI) is highly relied on initial concentration of Cr(VI), pH and temperature. The main factors controlling the adsorption behavior of Cr(VI) are the acidic functional groups and the accessible surface area on O-CNSs. Furthermore, the O-CNSs attained high stability in recycling tests for Cr(VI) removal.

Experimental Investigation on Adsorptive Removal of Phenolic Compounds from Aqueous Solution by Cr-Bentonite

2010 ◽  
Vol 160-162 ◽  
pp. 163-170
Author(s):  
Hong Zheng ◽  
Yang Wang ◽  
Peng Liang ◽  
Hong Bin Qi
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Phenolic Compounds ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Synthetic Wastewater ◽  
Order Kinetic ◽  
Sorption Data ◽  
Adsorptive Removal ◽  
Pseudo Second Order

The ability of Cr-bentonite prepared using synthetic wastewater containing chromium was investigated for adsorptive removal of 4-aminophenol and 4-chlorophenol from aqueous solution in a batch system at 25 °C. The physic-chemical parameters including pH value of solution and contact time were studied. The experimental data were analyzed by the Langmuir, Freundlich and Temkin models of sorption. The equilibrium sorption data for 4-aminophenol and 4-chlorophenol were well fitted to Langmuir adsorption isotherm and the monolayer sorption capacity was found to be 26.53 and 23.81 mg/g at 25 °C, respectively. The sorption energy calculated from Dubinin-Redushkevich (D-R) isotherm are 8.31 and 8.20 kJ/mol for the uptake of 4-aminophenol and 4-chlorophenol respectively which indicates that both the sorption processes are chemical in nature. The kinetic data were analyzed using pseudo-first order, pseudo-second order kinetic equation and intraparticle diffusion model. The experimental data fit very well the pseudo-second order kinetic model. Intraparticle diffusion affects 4-aminophenol and 4-chlorophenol uptake. Sorption studies carried out using industrial wastewater samples containing phenolic compounds show that there is significant potential for Cr-bentonite as an adsorbent material for phenollic compounds removal from aqueous solutions.

scholarly journals Glycidyl methacrylate macroporous copolymer grafted with diethylene triamine as sorbent for Reactive Black 5

2014 ◽  
Vol 68 (6) ◽  
pp. 685-699 ◽  
Author(s):  
Zvjezdana Sandic ◽  
Marija Zunic ◽  
Danijela Maksin ◽  
Aleksandra Milutinovic-Nikolic ◽  
Aleksandar Popovic ◽  
...  
Keyword(s):  
Glycidyl Methacrylate ◽  
Dye Removal ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Operating Conditions ◽  
Homogeneous Distribution ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Diethylene Triamine ◽  
Pseudo Second Order

In this paper, macroporous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer functionalized with diethylene triamine [PGME-deta], was evaluated as Reactive Black 5 (RB5) sorbent. Batch RB5 removal from aqueous solution by PGME-deta was investigated by varying pH, contact time, sorbent dosage, initial dye concentration and temperature. The sorption is pH sensitive having maximum at pH 2 (dye removal of 85%), decreasing with the increase of pH (dye removal of 24% at pH=11) after 60 min. Sorption kinetics was fitted to chemical-reaction and particle-diffusion models (pseudo-first-order, pseudo-second-order, intraparticle diffusion and Mckay models). The pseudo-second-order kinetic model accurately predicted the RB5 amount sorbed under all investigated operating conditions, while the intraparticle diffusion was the dominant rate-limiting mechanism. The diffusion mechanism was more prevalent with the decrease in temperature and the increase in concentration. The isotherm data was best fitted with the Langmuir model, indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption, with the maximum sorption capacity of 353 mg g-1. The calculated sorption rates improved with increasing temperature and an activation energy close to 40 kJ mol-1 was determined, suggesting that chemisorption was also rate-controlling.

scholarly journals High Efficiency of Natural Safiot Clay to Remove Industrial Dyes from Aqueous Media: Kinetic, Isotherm Adsorption and Thermodynamic Studies

2021 ◽  
Vol 11 (5) ◽  
pp. 12717-12731
Keyword(s):  
High Efficiency ◽  
Aqueous Media ◽  
Kinetic Equations ◽  
Experimental Tests ◽  
Batch Process ◽  
Second Order ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Pseudo Second Order

This study's objective was to demonstrate the potential of Natural Safiot Clay (NSC) for removing cationic dyes MB and Safranin from synthetic wastewater. The operation parameters investigated included initial concentrations, adsorbent dose, initial pH, and temperature. Experimental tests were conducted in a batch process. The experimental isotherms data were analyzed using Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models. The Langmuir model obtained the best fit with a maximum monolayer adsorption capacity of 68.49 mg/g for MB and 45.45 mg/g for safranin. Pseudo-first-order, pseudo-second-order kinetic equations, and intraparticle diffusion models were used to examine the experimental data at different initial concentrations. It was found that the pseudo-second-order kinetic model described the data of dyes adsorption on NSC adsorbent very well. Thermodynamic adsorption processes were found to be spontaneous, exothermic, and physical reactions. The natural safiot clay was characterized using the following technique: DRX, XRF, SEM, EDX, and FT-IR.

scholarly journals Adsorption of Pb Ions from Oily Wastewater by Anthraquinone Modified Carbon Nanotube

2021 ◽  
Vol 15 (1) ◽  
pp. 89-97
Author(s):  
Vahid Moghaddam Nansa ◽  
◽  
Maryam Otadi ◽  
Amir Heydarinasab ◽  
Rahebeh Amiri ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Adsorption Kinetics ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Order Kinetic ◽  
Batch Mode ◽  
Controllable Factors ◽  
Pseudo Second Order ◽  
Pb Ions ◽  
Four Levels

The aim of this research was to investigate the adsorption properties of anthraquinone modified carbon nanotube (ACNT) in oily wastewaters containing Pb ions. The modified adsorbents were characterized using Fourier transform infra-red spectroscopy and SEM analysis. The adsorption and regeneration studies were conducted in batch mode using a Taguchi (L16) orthogonal array to optimize experimental runs. The controllable factors used in this study consisted of: pH of the solution (A); adsorbent dosage (B); adsorbent type (C); contact time (D); temperature (F). The effects of each factor were studied at four levels on the removal efficiency of metals from aqueous solution. Concentrations of metal ions were assessed by atomic absorption spectrometer. The total optimum adsorptive removal of lead ions was obtained with C0 = 10 mg•l-1, T = 338 K, pH = 6, m = 0.020 mg and t = 60 min. The Langmuir model was representative to simulate adsorption isotherms. The adsorption kinetics of Pb adsorption by ACNT was modeled using the pseudo-first order, the pseudo-second order, and intraparticle diffusion kinetics equations. The results indicate that the pseudo-second order kinetic equation and intraparticle diffusion model were adequate to describe the adsorption kinetics.

scholarly journals Adsorption of Chromium Ions on Activated Carbon Produced from Cow Bones

2019 ◽  
Vol 20 (2) ◽  
pp. 23-32
Author(s):  
Marah Waleed Khalid ◽  
Sami D. Salman
Keyword(s):  
Surface Area ◽  
Kinetic Equations ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Raw Material ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Chromium Ions ◽  
Pseudo Second Order

Due to the broad range uses of chromium for industrial purposes, besides its carcinogenic effect, an efficient, cost effective removal method should be obtained. In this study, cow bones as a cheap raw material were utilized to produce active carbon (CBAC) by physiochemical activation, which was characterized using: SEM to investigate surface morphology and BET to estimate the specific surface area. The best surface area of CBAC was 595.9 m2/gm which was prepared at 600 ᵒC activation temperature and impregnation ratio of 1:1.5. CBAC was used in aqueous chromium ions adsorption. The investigated factors and their ranges are: initial concentration (10-50 mg/L), adsorption time (30-300 min), temperature (20-50 ᵒC) and solution pH (2-11). Isotherm of adsorption and its kinetics were studied. The adsorption process was modeled statistically and was represented by an empirical model. Equilibrium data were fitted to the Langmuir and Freundlich isotherm models and the data best represented by Freundlich isotherm. Pseudo- first order and pseudo- second order kinetic equations were utilized to study adsorption kinetics, where chromium adsorption on CBAC fitted pseudo- second order fitted the data more adequately. The best removal efficiency was found to be 94.32%.

scholarly journals Steam-activated sawdust efficiency in treating wastewater contaminated by heavy metals and phenolic compounds

2021 ◽  
Author(s):  
Noureddine Elboughdiri ◽  
Babar Azeem ◽  
Djamel Ghernaout ◽  
Saad Ghareba ◽  
Karim Kriaa
Keyword(s):  
Heavy Metals ◽  
Adsorption Isotherm ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Industrial Wastewater ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Adsorption Capacities ◽  
Pseudo Second Order

Abstract This research study encompasses the utilization of new adsorbents fabricated from pine sawdust for the adsorption of heavy metals and phenol from simulated industrial wastewater. Batch trials are conducted to evaluate the activity of these adsorbents for a possible substitution of the costly commercial adsorbents. The maximum adsorption capacities are evaluated and linked to the physicochemical characteristics of the adsorbents. The maximum monolayer adsorption capacity (qmax) of the adsorbents corresponds to the specific surface area of the adsorbents. The adsorbents with the larger specific surface area have shown higher qmax estimates (phenol adsorption is an exception). The highest amount of the phenol pollutant adsorbed by steam-activated sawdust (SAS) is 10.0 mg/g. The performance of SAS is found to be of the same order as the commercial activated carbon for the removal of Pb and Zn. Equilibrium data for the metal removal are in concordance with the Freundlich adsorption isotherm, whereas the phenol elimination has satisfied the Langmuir adsorption isotherm model. Kinetic data are fitted to Lagergren pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models. Thus, kinetic parameters, rate constants, equilibrium adsorption capacities, and related correlation coefficients for each kinetic model are determined and discussed. The results suggest that the adsorption of Cr follows pseudo-second-order kinetics, indicating chemisorption for the tested adsorbents such that the intraparticle diffusion is not the only step that controls the overall process for Cr adsorption. At the end of this study, the production cost of the SAS adsorbent is estimated ($52 per kg) and compared to the cost of the commercial AC adsorbent in the industrial sector which has a great variation ($80–300 per kg) based on size and location plant. The results of this study can be used for the design of a suitable ecological control procedure to mitigate the harmful effects of industrial wastewater.

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