scholarly journals Selective Removal of Sodium Ions from Aqueous Media Using Effective Adsorbents: Optimization by RSM and Genetic Algorithm

2021 ◽  
Vol 68 (4) ◽  
pp. 791-803
Author(s):  
Lei Yao ◽  
Chao Hong ◽  
Hani Dashtifard ◽  
Hossein Esmaeili

This study aimed to determine the best adsorbent among Moringa oleifera-derived activated carbon (AC), eggshell-derived CaO nanoparticles and CaO/Fe3O4 for sodium (Na+) removal from aqueous media. In the first step, the appropriate adsorbent for sodium adsorption was determined among the three adsorbents, which the results showed that the AC had the highest sorption efficiency. Then, response surface methodology (RSM) was used to evaluate the impact of different factors on the Na+ ion sorption efficiency using the AC. The highest removal efficiency was obtained to be 95.91% at optimum conditions such as pH of 11, contact time of 45 min, temperature of 25 °C, sodium ion concentration of 900 mg/L, and adsorbent dosage of 5 g/L. Also, the best conditions using the genetic algorithm was obtained at contact time of 94.97 min, adsorbent dosage of 3.52 g/L, Na+ ion concentration of 939.92 mg/L and pH value of 10.92. Moreover, the maximum sorption capacity using the Langmuir model was obtained to be 249.67 mg/g, which was a significant value. Besides, the equilibrium and kinetic studies indicated that the experimental data of sodium adsorption process were fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. Furthermore, the thermodynamic study indicated that the sorption process was endothermic. Generally, among the three adsorbents used, activated carbon with a high removal efficiency and significant sorption capacity can be considered as a promising adsorbent for the removal of sodium from wastewater on an industrial scale.

2010 ◽  
Vol 7 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Reza Shokoohi ◽  
Vahid Vatanpoor ◽  
Mansuor Zarrabi ◽  
Akram Vatani

Adsorption process by activated carbon is widely used for removal of dyes. Because of economical limits, activated carbon derived from low cost materials seem to be economical. The aim of this work is preparation of activated carbon from poplar wood and investigation of its ability to removal of (AR18) dye. In this work, we prepared the activated carbon by chemical activation method in electric furnace. In addition we have investigated effect of various parameters such as pH, contact time, dye concentration and adsorbent dosage on dye removal. Langmuir and Freundlich isotherm models have been investigated. Pseudo-first order, pseudo-second order and modified pseudo-first order kinetic models have been used for experimental data. The results showed that removal efficiency was increased with increasing of adsorbent dosage, contact time and decreasing of pH, but with increasing of dye concentration, the removal efficiency was decreased. Adsorption isotherm models showed that Langmuir isotherm model was best fitted onto collected data (r2>0.978). In addition, kinetic models showed that sorption of AR18 onto activated carbon prepared from poplar wood follows the pseudo-first order model (r2>0.9758).


Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.


2020 ◽  
Author(s):  
Tolera Seda Badessa ◽  
Esayas Wakuma ◽  
Ali Mohammed Yimer

Abstract Chromium is an extremely toxic metal in the form of Cr (VI) that causes severe environmental and health problems. Therefore, the aim of this study was to remove chromium ions from wastewater by using cost effective and environmentally friendly bio-sorbents; Moringa stenopetala Seed Powder (MSSP), and Banana Peel Powder (BPP) and to evaluate its adsorption capacities as bio-sorbents. FT-IR characterization of the adsorbents showed that there was a change in the functional groups of the structure of both adsorbents before and after the adsorption that might be due to the adsorption processes taken place on the surface of adsorbent. Adsorption experiments were carried out as batch studies with different contact times, pH, adsorbent dose, initial metal ion concentration, and temperature. Results showed maximum removal efficiency for Cr (VI) at 120 minutes contact time, adsorbent dose of 20 g/L and pH 2 by MSSP and pH 4 by BPP. The percentage removal of Cr(VI) increased with increasing adsorbent dose( from 5g/L to 20 g/L) and contact time (from 60 min to 120 min). Freundlich isotherm model showed a better fit to the equilibrium data than the Langmuir model. The kinetics of adsorption for chromium was well represented by pseudo-second order kinetic model and the calculated equilibrium sorption capacity of the model showed good agreement with the sorption capacity obtained from Experimental results.


BMC Chemistry ◽  
2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Tolera Seda Badessa ◽  
Esayas Wakuma ◽  
Ali Mohammed Yimer

Abstract Chromium is an extremely toxic metal in the form of Cr(VI) that causes severe environmental and health problems. Therefore, the aim of this study was to remove chromium ions from wastewater by using cost effective and environmentally friendly bio-sorbents; Moringa stenopetala seed powder (MSSP), and banana peel powder (BPP) and to evaluate its adsorption capacities as bio-sorbents. FT-IR characterization of the adsorbents showed that there was a change in the functional groups of the structure of both adsorbents before and after the adsorption that might be due to the adsorption processes taken place on the surface of adsorbent. Adsorption experiments were carried out as batch studies with different contact times, pH, adsorbent dose, initial metal ion concentration, and temperature. Results showed maximum removal efficiency for Cr(VI) at 120 min contact time, adsorbent dose of 20 g/L and pH 2 by MSSP and pH 4 by BPP. The percentage removal of Cr(VI) increased with increasing adsorbent dose (from 5 to 20 g/L) and contact time (from 60 to 120 min). Freundlich isotherm model showed a better fit to the equilibrium data than the Langmuir model. The kinetics of adsorption for chromium was well represented by pseudo-second order kinetic model and the calculated equilibrium sorption capacity of the model showed good agreement with the sorption capacity obtained from experimental results.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1161
Author(s):  
Somayeh Rahdar ◽  
Abbas Rahdar ◽  
Mostafa Sattari ◽  
Laleh Divband Hafshejani ◽  
Athanasia K. Tolkou ◽  
...  

Dyes are known as one of the most dangerous industrial pollutants which can cause skin diseases, allergy, and provoke cancer and mutation in humans. Therefore, one of the important environmental issues is the effective removal of dyes from industrial wastewater. In the current work, BaFe12O19/CoFe2O4@polyethylene glycol (abbreviated as BFO/CFO@PEG) nanocomposite was synthesized and evaluated regarding its capacity for adsorptive removal of a model dye Acid Blue 92 (denoted as AB92) from aqueous solutions. The characteristics of the prepared nanocomposite was determined by tests such as X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetization (VSM), and Fourier transform infrared spectroscopy (FTIR). The effects of conditional parameters including pH (2–12), initial concentration of dye (20–100 mg/L), adsorbent dosage (0.02–0.1 g/L) and contact time (0-180 min) on the adsorption of dye were investigated and then optimized. The results indicated that with the increase of the adsorbent dosage from 0.02 to 0.1 g/L, the removal efficiency increased from 74.1% to 78.6%, and the adsorbed amount decreased from 148.25 to 31.44 mg/g. The maximum removal efficiency (77.54%) and adsorption capacity (31.02 mg/g) were observed at pH 2. Therefore, the general optimization conditions revealed that the maximum adsorption efficiency of dye was obtained in condition of initial concentration of 20 mg/L, contact time of 1 h and pH of solution equal 2. The adsorption isotherm and kinetic data were evaluated using a series of models. The pseudo-second order kinetic model and Freundlich isotherm model show the best fitting with experimental data with R2∼0.999.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4430
Author(s):  
Nor Hakimin Abdullah ◽  
Mazlan Mohamed ◽  
Norshahidatul Akmar Mohd Shohaimi ◽  
Azwan Mat Lazim ◽  
Ahmad Zamani Abdul Halim ◽  
...  

The presence of organic dyes from industrial wastewater can cause pollution and exacerbate environmental problems; therefore, in the present work, activated carbon was synthesized from locally available oil palm trunk (OPT) biomass as a low-cost adsorbent to remove synthetic dye from aqueous media. The physical properties of the synthesized oil palm trunk activated carbon (OPTAC) were analyzed by SEM, FTIR-ATR, and XRD. The concurrent effects of the process variables (adsorbent dosage (g), methylene blue (MB) concentration (mg/L), and contact time (h)) on the MB removal percentage from aqueous solution were studied using a three-factor three-level Box–Behnken design (BBD) of response surface methodology (RSM), followed by the optimization of MB adsorption using OPTAC as the adsorbent. Based on the results of the analysis of variance (ANOVA) for the three parameters considered, adsorbent dosage (X1) is the most crucial parameter, with an F-value of 1857.43, followed by MB concentration (X2) and contact time (X3) with the F-values of 95.60 and 29.48, respectively. Furthermore, the highest MB removal efficiency of 97.9% was achieved at the optimum X1, X2, and X3 of 1.5 g, 200 mg/L, and 2 h, respectively.


2019 ◽  
Vol 6 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Dariush Naghipour ◽  
Abdoliman Amouei ◽  
Kamran Taher Ghasemi ◽  
Kamran Taghavi

Background: Metoprolol (MTP) with its low biodegradability is one of the most dominant micropollutant in the effluent of wastewater treatment plants. The aim of this study was to investigate the removal of metoprolol from aqueous solutions by the activated carbon prepared from pine cones. Methods: The pine cones were activated using thermal activation method. Characteristics of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). In this study, the influent of different parameters such as pH, contact time, initial concentrations of metoprolol, adsorbent dose, temperature, adsorption isotherms, and kinetics were investigated. Results: The maximum removal efficiency of MTP (89.2%) was obtained at pH=8.5, adsorbent dose=1.5 g, contact time=60 min, and initial concentration=50 mg/L. By increasing the adsorbent dose, the removal efficiency also increased, but the adsorption capacity decreased, however, by increasing the initial concentration, the removal efficiency decreased, but the adsorption capacity increased. The isotherm experimental data for metoprolol was best fitted using the Langmuir model, and kinetic data were better described by pseudo-second-order kinetic model. The thermodynamic study indicated that the adsorption of MTP by the adsorbent was feasible, spontaneous, and endothermic. Conclusion: MTP removal by the activated carbon prepared from pine cones showed that this natural adsorbent is appropriate for removal of metoprolol from aqueous solutions regarding cost, efficiency, and production method.


2020 ◽  
Vol 1002 ◽  
pp. 423-434 ◽  
Author(s):  
Muayad A. Shihab ◽  
Amer Talal Nawaf ◽  
Shaho A. Mohamedali ◽  
Mazin N. Alsalmaney

This work was focused on the removal of sulfur compounds via adsorption process from heavy naphtha using alkali agents-activated carbon nanotubes (ACNTs). Commercial CNTs were activated using three alkali agents (KOH, NaOH, and CaCl2) to amend their surfaces for application in the petroleum industry. The characterization of the physicochemical properties of as-received CNTs and CNTs/alkali agents was performed using a scanning electron microscope (SEM), N2 adsorption/desorption isotherm, and Fourier transform infrared spectroscopy (FTIR). The effects of three operating conditions including adsorbent dosage (1-3 g), agitation speed (330-1500 rpm), and contact time (30-70 min) on the removal efficiency of sulfur compounds at constant pressure and temperature were investigated. Studying of the removal efficiency at different operating conditions was adopted to effectively evaluate the surface modifications of adsorbents on the present process. The specific surface areas of the CNTs were found to be increased upon treatment with alkali agents especially KOH and NaOH. SEM images demonstrated the formation of many defects on the CNTs surface due to the strong etching effect of both alkali agents KOH and NaOH. FTIR spectra showed different relative intensities around band 3440 cm-1 for CNTs/KOH and CNTs/NaOH which was potentially attributed to the presence of hydroxyl functional groups. The sulfur removal experiments from heavy naphtha (initially had a sulfur concentration of 350 ppm) showed that the largest sulfur removal efficiency and adsorption capacity were 69.6% and 6.6 mg/g adsorbent respectively and obtained with CNTs/KOH which presented a superior adsorption efficiency over others. The highest sulfur removal efficiency was gained at adsorbent dosage=3 g, agitation speed=1500 rpm, and contact time=70 min. The study of adsorption kinetics demonstrated that the adsorption of organosulfur compounds from heavy naphtha obeyed the pseudo-second order kinetics


2018 ◽  
Vol 78 (10) ◽  
pp. 2158-2170 ◽  
Author(s):  
Mohammad Malakootian ◽  
Alireza Nasiri ◽  
Hakimeh Mahdizadeh

Abstract Ciprofloxacin (CIP) is considered as a biological resistant pollutant. The CoFe2O4/activated carbon@chitosan (CoFe2O4/AC@Ch) prepared as a new magnetic nanobiocomposite and used for adsorption of CIP. CoFe2O4/AC@Ch was characterized by Fourier transform-infrared (FT-IR), field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) surface area measurements. The pHZPC value of the nanobiocomposite was estimated to be 6.4 by solid addition method. The prepared magnetic nanobiocomposites can be separated easily from water by an external magnet and reused. The effect of CIP concentration (10–30 mg/L), adsorbent dosage (12–100 mg/L), contact time (5–30 min) and pH (3–11) as independent variables on ciprofloxacin removal efficiency was evaluated. Optimum conditions were obtained in CIP concentration: 10 mg/L, adsorbent dosage: 100 mg/L, contact time: 15 min and pH: 5. In this condition, maximum CIP removal was obtained as 93.5%. The kinetic and isotherm equations showed that the process of adsorption followed the pseudo-second order kinetic and Langmuir isotherm. The results indicate that the prepared magnetic nanobiocomposite can be used as good adsorbent for the removal of CIP from aqueous solution and can be also recycled.


2017 ◽  
Vol 4 (1) ◽  
pp. 6021-6021
Author(s):  
Mohammad Reza Samarghandi ◽  
Ali Poormohammadi ◽  
Samane Shanesaz ◽  
Kazem Godini

The current study aimed at comparing the performances of activated carbon and graphene in the removal of reactive red 198. The experiments were conducted in a batch reactor and the effects of some operational parameters including initial dye concentration, pH, contact time, and different doses of activated carbon and graphene on the removal efficiency of dye were investigated. The results showed that the adsorption efficiency was affected by initial dye concentration. In general, with increasing contact time up to 180 minutes, the removal efficiency increased significantly. The removal efficiency of reactive red 198 increased with increasing contact time, and after 60 minutes of contact time, adsorption phase reached the equilibrium. When activated carbon was used, the maximum removal efficiency happened at pH 3. At this pH value, reactive red 198 was removed completely (100%) after 120 minutes, whereas the minimum efficiency was observed at pH 10. A similar trend was also observed for graphene as an adsorbent. Moreover, the removal efficiency of the dye by both adsorbents increased with the increase of the adsorbent dosage. The experimental data showed that the adsorption of reactive red198 on both active carbon and graphene fitted well into the second-order kinetic model. Active carbon and graphene fitted well Langmuir 1 model. According to the results, graphene acts as suitable adsorbent and can be applied in treating several industrial effluents and contaminated water in greater scales. The main upside of grapheme, in comparison with activated carbon, is that it reaches the equilibrium in a shorter time. Further, grapheme adsorbed the dye nearly completely (98% to 100%).


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