scholarly journals Removal of aniline from aqueous solutions by activated carbon coated by chitosan

2015 ◽  
Vol 5 (4) ◽  
pp. 610-618 ◽  
Author(s):  
Qian Liu ◽  
Lujie Zhang ◽  
Pan Hu ◽  
Ruihua Huang

In this work, activated carbon (AC) coated by chitosan was synthesized and characterized by Fourier transform infrared spectrophotometer and scanning electron microscope (SEM) techniques. The removal of aniline from aqueous solutions by AC coated by chitosan was investigated. The factors affecting the adsorption of aniline onto AC coated by chitosan, including the ratio of AC to chitosan, adsorbent dosage, pH value of solution, initial aniline concentration, and contact time were evaluated. These results showed that the optimum operating conditions were: the ratio of AC to chitosan = 0.5, adsorbent dosage = 0.2 g, and the adsorption of aniline from aqueous solutions had better removal in the concentration range of 20–50 mg/L. This adsorbent allowed high removal toward aniline in a wide range of pH. The equilibrium time was 100 minutes. The Freundlich model exhibited better correlation of the equilibrium adsorption data. The pseudo-second-order kinetic equation could better describe the kinetic behavior of aniline adsorption.

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Y. S. Mohammad ◽  
E. M. Shaibu-Imodagbe ◽  
S. B. Igboro ◽  
A. Giwa ◽  
C. A. Okuofu

Modeling of adsorption process establishes mathematical relationship between the interacting process variables and process optimization is important in determining the values of factors for which the response is at maximum. In this paper, response surface methodology was employed for the modeling and optimization of adsorption of phenol onto rice husk activated carbon. Among the action variables considered are activated carbon pretreatment temperature, adsorbent dosage, and initial concentration of phenol, while the response variables are removal efficiency and adsorption capacity. Regression analysis was used to analyze the models developed. The outcome of this research showed that 99.79% and 99.81% of the variations in removal efficiency and adsorption capacity, respectively, are attributed to the three process variables considered, that is, pretreatment temperature, adsorbent dosage, and initial phenol concentration. Therefore, the models can be used to predict the interaction of the process variables. Optimization tests showed that the optimum operating conditions for the adsorption process occurred at initial solute concentration of 40.61 mg/L, pretreatment temperature of 441.46°C, adsorbent dosage 4 g, adsorption capacity of 0.9595 mg/g, and removal efficiency of 97.16%. These optimum operating conditions were experimentally validated.


2013 ◽  
Vol 68 (9) ◽  
pp. 2074-2081 ◽  
Author(s):  
Qian Liu ◽  
Ruihua Huang ◽  
Bingchao Yang ◽  
Yanping Liu

In this work, enhanced chitosan/bentonite composite was prepared by treating chitosan/bentonite composite with concentrated hydrochloric acid (HCl). The adsorption of fluoride ions from aqueous solution onto the enhanced chitosan/bentonite composite was investigated. Adsorption studies were performed in a batch system, and the effects of various parameters, such as the pH value of the solution, adsorbent dosage and initial fluoride concentration, were evaluated. The optimum operating conditions for fluoride removal by the enhanced chitosan/bentonite composite were pH = 7 or so, and adsorbent dosage =1.2 g. Increasing initial fluoride concentration reduced the adsorption of fluoride onto the enhanced chitosan/bentonite composite. Furthermore, the presence of other co-anions weakened the adsorption of fluoride onto this adsorbent. The equilibrium adsorption isotherms were well described by both the Freundlich and Langmuir models. The maximum monolayer adsorption capacity was 2.95 mg/g at 293 K.


2017 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Saad A Alkahtani ◽  
Samer S Abu-Alrub ◽  
Ashraf M Mahmoud

<p>The adsorption behavior of Allura red (E129)<strong> </strong>from aqueous solutions onto activated carbon was successfully investigated. All factors affecting the adsorption process were carefully studied and the conditions were optimized. Adsorption of E129 onto activated carbon was found to increase by decreasing the mass of activated carbon, pH and ionic strength of the solution and by increasing temperature. The adsorption capacity of the activated carbon for Allura red was relatively high. Under the optimum conditions, the maximum adsorption capacity for E129 dye was 72.85 mg/g. Three adsorption models; Langmuir, Freundlich and Temkin model were investigated regarding the adsorption of E129. The models’ parameters K<sub>L</sub>, qm, R2, (n) were determined and found to be 0.0222, 72.85 mg/g, 0.9057-0.9984, and 0.992, respectively. Also, pseudo first and second-order kinetic models were tested to determine the best-fit model to the adsorption of E129 dye onto activated carbon. The results showed that the adsorption of E129 onto activated carbon obeyed both the Freundlich isotherm and pseudo second-order kinetic models. Moreover, thermodynamic studies indicated that the adsorption of E129 dye onto the activated carbon was spontaneous. </p>


2016 ◽  
pp. 565-570
Author(s):  
Huang Qin ◽  
Zhu Si-ming ◽  
Zeng Di ◽  
Yu Shu-juan

Sugar beet pulp (SBP) was used as low value adsorbent for the removal of calcium from hard water. Batch experiments were conducted to determine the factors affecting adsorption of the process such as pH value and Ca concentration. The adsorption equilibrium of Ca2+ by the SBP is reached after 100min and a pseudo second-order kinetic model can describe the adsorption process. The initial concentrations of Ca varied from 927 to 1127mgCa2+/L. A dose of 30g/L sugar beet pulp was sufficient for the optimum removal of calcium. The overall uptake of Ca ions by sugar beet pulp has its maximum at pH=8. The adsorption equilibrium data fitted well with the Langmuir adsorption isotherm equation.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ &gt; Cd2+ &gt; Zn2+ &gt; Cu2+ &gt; Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ &gt; Cu2+ &gt; Zn2+ &gt; Cd2+ &gt; Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.


2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.


Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract


2002 ◽  
Vol 20 (4) ◽  
pp. 393-416 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Dheaya‘ Al-Rousan

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.


2003 ◽  
Vol 38 (2) ◽  
pp. 393-411 ◽  
Author(s):  
Soufiane Tahiri ◽  
Ali Messaoudi ◽  
Abderrahman Albizane ◽  
Mohamed Azzi ◽  
Mohamed Bouhria ◽  
...  

Abstract In this work, the ability of chrome shavings and of crust leather buffing dusts to remove dyes from aqueous solutions has been studied. Buffing dusts proved to be a much better adsorbent than chrome shavings for cationic dyes. The adsorption of anionic dyes is very important on two studied wastes. The pH has an obvious influence on the adsorption of dyes. Adsorption of cationic dyes is less favourable under acidic conditions (pH &lt;3.5) and at high pH values (pH &gt;10.5). The adsorption of anionic dyes on both adsorbents is more favourable under acidic conditions (pH &lt;3). The adsorption on chrome shavings is improved by the use of finer particles. The kinetic adsorption was also studied. Adsorption isotherms, at the optimum operating conditions, were determined. Adsorption follows the Langmuir model. The isotherm parameters have been calculated. The column technique could be applied to treat significant volumes of solutions.


2015 ◽  
Vol 72 (3) ◽  
pp. 478-483 ◽  
Author(s):  
Yunleiyu Guo ◽  
Tingting Shen ◽  
Chen Wang ◽  
Jing Sun ◽  
Xikui Wang

The removal of caffeine (CAF) in aqueous solution by peroxymonosulfate oxidant activated with cobalt ion was investigated under a variety of operating conditions. The effects of various operating parameters, such as oxone and Co2+ concentrations, pH value, and the coexistence of dissolved organic matter and inorganic anions on the removal of CAF have been investigated. The removal efficiency increased with the increase in the concentrations of oxone and Co2+ ion added. The additions of chloride, bicarbonate, and sodium humate have negative effects on the removal of CAF. Near-neutral condition (5.0 &lt; pH &lt; 7.0) is favorable for the removal of CAF. Based on our experiments, 100% degradation of 50 mg/L CAF can be achieved within 4 minutes under the conditions of 1.00 mM oxone and 0.10 mM Co2+ ion at pH 5.0–7.0.


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