Experimental and Modeling Studies of Sorption of Tetracycline onto Zeolite in the Presence of Copper(II)

2012 ◽  
Vol 512-515 ◽  
pp. 2355-2360 ◽  
Author(s):  
Hong Huang ◽  
Yan Li Zou ◽  
Ya Nan Li

The sorption performance of tetracycline on zeolite under different conditions was investigated in presence and absence of Cu(Ⅱ).The presence of Cu(Ⅱ) greatly increased the adsorption of tetracycline on zeolite. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto zeolite in the presence and absence of Cu(Ⅱ), and intra-particle diffusion was not the only rate-limiting in the sorption process. The qmax value calculated from Langmuir model were 17.37 and 68.26 mg/g in the absence and the presence of Cu(Ⅱ). The value of E calculated from Dubinin-Radushkevich (D-R) model confirmed that the adsorption in the absence and presence of Cu(Ⅱ) were mainly controlled by physical combined with chemical adsorption mechanism. The tetracycline sorption amount decreased in the absence of Cu(Ⅱ) and increased in the presence of Cu(Ⅱ) as the pH increasing. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% in the presence of Cu(Ⅱ) and 34.5% in the absence of Cu(Ⅱ) when the dosage of zeolite was 0.05g.

2012 ◽  
Vol 573-574 ◽  
pp. 43-47 ◽  
Author(s):  
Yan Li Zou ◽  
Hong Huang ◽  
Ming Chu ◽  
Jian Wei Lin ◽  
Da Qiang Yin ◽  
...  

The sorption performance of tetracycline (TC) on HCl-modified zeolite under different conditions was investigated. HCl-modified zeolite exhibited more than two times higher adsorption capacity than natural one. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto natural and HCl-modified zeolites, and intra-particle diffusion was not the only rate-limiting in the sorption process. The results from sorption equilibrium studies showed that the Langmuir and Dubinin-Radushkevich (D-R) isotherm models were well fitted to experimental data, the value of E confirmed that the adsorption was controlled by physical combined with chemical adsorption mechanism. The sorption removal capacity is relatively higher at low pH. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% when the dosage of treated zeolite was 0.05g.


2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Fang Li ◽  
Chunmei Ding

Different degree of deacetylation (DD) chitosan was prepared and used for the removal of a Reactive black M-2R (RBM) from aqueous solution. The effects of temperature (298 K~323 K), chitosan dosage, degree of deacetylation on RBM removal were investigated. The adsorption equilibrium was reached within one hour. In order to determine the adsorption capacity, the sorption data were analyzed by using linear form of Langmuir, Freundlich and Tempkin isotherm equation. Langmuir equation shows higher conformity than the other two equations. From the kinetic experiment data, it was found that the sorption process follows the pseudo-second-order kinetic model. Activation energy value for sorption process was found to be 58.28 kJ mol-1. Chitosan with 66% deacetylation degree (DD) exhibited good adsorption performance for RBM. In order to determine the interactions between RBM and chitosan, FTIR analysis was also conducted.


2019 ◽  
Vol 80 (2) ◽  
pp. 300-307
Author(s):  
Di Zhang ◽  
Jiaxin Liu ◽  
Shibei Zhu ◽  
Huixin Xiong ◽  
Yiqun Xu

Abstract The aim of this work is to study the performances of isomeric α-, β-, and γ-FeOOH (goethite, akaganéite and lepidocrocite, including five samples named as Gth1 and Gth2, Aka1 and Aka2, and Lep, respectively) for removing hexavalent chromium (Cr(VI)) from aqueous solutions. The adsorption mechanisms were explored by kinetic and isothermal experiments. Adsorption efficiencies under the different pH values, anions, and the levels of adsorbate and adsorbent were also measured. Results showed that the Cr(VI) adsorption by isomeric FeOOH could be best described by pseudo-second-order kinetic model. The processes of Cr(VI) isothermal adsorption could be greatly fitted by the Langmuir and Freundlich equations with the high correlation coefficients of R2 (>0.92). Also, there were the optimum pH values of 3.0–8.0 for FeOOH to adsorb Cr(VI), and their adsorption capacities were tightly related with the active sites of adsorbents. Cr(VI) adsorptions by these adsorbents were easily influenced by H2PO4–, and then SO42–, while there were little effects by Cl–, CO32– and NO3–. These obtained results could provide a potentially theoretical evidence for isomeric FeOOH materials applied in the engineering treatment of the polluted chromate-rich waters.


2006 ◽  
Vol 54 (10) ◽  
pp. 1-8 ◽  
Author(s):  
S. Deng ◽  
Y.P. Ting ◽  
G. Yu

A novel biosorbent was prepared by chemically grafting of polyethylenimine (PEI) onto the fungal biomass of Penicillium chrysogenum through a two-step reaction. The modified biosorbent is favorable for the removal of anionic Cr(VI) species from aqueous solution due to the protonation of amine groups on the biomass surface. The sorption capacity for Cr(VI) increased by 7.2-fold after surface modification. Sorption kinetics results show that the pseudo-second-order kinetic model described the experimental data well. During the sorption process, X-ray photoelectron spectroscopy (XPS) was used to analyze the chromium species on the biosorbent surface and the results indicate that part of the Cr(VI) ions were reduced to Cr(III) ions which can be chelated with the amine groups on the biomass surface. The reduced Cr(III) ions formed some aggregates on the surface at higher solution pHs.


2009 ◽  
Vol 610-613 ◽  
pp. 65-68 ◽  
Author(s):  
Xue Gang Luo ◽  
Feng Liu ◽  
Xiao Yan Lin

Konjac glucomannan (KGM) was converted into water insoluble konjac glucomannan (WIKGM) by treating with NaOH through completely deacetylated reaction. Adsorption study was carried out for the adsorption of Pb2+ from aqueous solution using water insoluble konjac glucomannan. The influences of pH, contact time, temperature and initial Pb2+ concentration on the absorbent were studied. Results of kinetic data showed that the Pb2+ adsorption rate was fast and good correlation coefficients were obtained for the pseudo second-order kinetic model. The equilibrium process was described well by the Langmuir isotherm model with maximum adsorption capacity of 9.18 mg/g on WIKGM at 25°C.


2010 ◽  
Vol 62 (8) ◽  
pp. 1888-1897 ◽  
Author(s):  
Nan Chen ◽  
Zhenya Zhang ◽  
Chuanping Feng ◽  
Miao Li ◽  
Rongzhi Chen ◽  
...  

Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water. The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies. The rate of adsorption was rapid with equilibrium being attained after about 2 h, and the maximum removal of fluoride was obtained at pH 5.0–8.0. The Freundlich isotherm model was found to represent the measured adsorption data well. The negative value of the thermodynamic parameter ΔG suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive ΔH value. The negative ΔS value for adsorbent denoted decreased randomness at the solid/liquid interface. The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model. Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process. It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12. This indicates the material could be easily recycled.


2014 ◽  
Vol 955-959 ◽  
pp. 2440-2443 ◽  
Author(s):  
Jing Li ◽  
Dong Mei Jia ◽  
Chang Hai Li ◽  
Bao Qing Yu

The ammonia modified cotton stalks (CS) were utilized to adsorb the Ni2+and Cu2+ions from wastewaters, and the effect parameters (i.e. pH, contact time, adsorbent dose, and temperature) were also investigated by batch adsorption experiments. The maximum uptake was attained, i.e., 99.4% and 98.8%, respectively, for nickel and copper ions, under the optimum conditions (adsorbent dose: 10 g/L; pH: 6.0 (Ni2+), 5.0 (Cu2+); t: 75min; T: 20 °C) when the initial concentration of heavy metal ions was 20 mg/L. The adsorption process of nickel and copper ions on ammonia modified CS was well described by the pseudo-second-order kinetic model.


2011 ◽  
Vol 183-185 ◽  
pp. 362-366 ◽  
Author(s):  
Jun Li ◽  
Ming Zhen Hu

Adsorption removal of a cationic dye, rhodamine B (RhB) from water onto rectorite and sepiolite was investigated. The rectorite and sepiolite were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Attempts were made to fit the isothermal data using Langmuir and Freundlich equations. The experimental results have demonstrated that the equilibrium data are fitted well by a Freundlich isotherm equation. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the rectorite exhibited higher adsorption capacity for the removal of RhB than sepiolite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.


2021 ◽  
Vol 68 (2) ◽  
pp. 363-373
Author(s):  
Roya Salahshour ◽  
Mehdi Shanbedi ◽  
Hossein Esmaeili

In the present work, methylene blue was eliminated from aqueous solution using activated carbon prepared by lotus leaves. To perform the experiments, batch method was applied. Also, several analyses such as SEM, FTIR, EDAX and BET were done to determine the surface properties of the activated carbon. The results showed that the maximum sorption efficiency of 97.59% was obtained in initial dye concentration of 10 mg/L, pH of 9, adsorbent dosage of 4 g/L, temperature of 25 °C, contact time of 60 min and mixture speed of 400 rpm. Furthermore, the maximum adsorption capacity was determined 80 mg/g, which was a significant value. The experimental data was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, which the results showed that the pseudo-second order kinetic model could better describe the kinetic behavior of the sorption process. Also, the constant rate of the pseudo-second order kinetic model was obtained in the range of 0.0218–0.0345 g/mg.min. Moreover, the adsorption equilibrium was well described using Freundlich isotherm model. Furthermore, the thermodynamic studies indicated that the sorption process of methylene blue dye using the activated carbon was spontaneous and exothermic.


2020 ◽  
Vol 69 (7) ◽  
pp. 678-693
Author(s):  
R. Aouay ◽  
S. Jebri ◽  
A. Rebelo ◽  
J. M. F. Ferreira ◽  
I. Khattech

Abstract Hydroxyapatite powders were synthesized according to a wet precipitation route and then subjected to heat treatments within the temperature range of 200–800 °C. The prepared samples were tested as sorbents for cadmium in an aqueous medium. The best performances were obtained with the material treated at 200 °C (HAp200), as the relevant sorbent textural features (SBET – specific surface area and Vp – total volume of pores) were least affected at this low calcination temperature. The maximum adsorption capacity at standard ambient temperature and pressure was 216.6 mg g−1, which increased to 240.7 mg g−1 by increasing the temperature from 25 to 40 °C, suggesting an endothermic nature of the adsorption process. Moreover, these data indicated that a thermal treatment at 200 °C enhanced the ability of the material in Cd2+ uptake by more than 100% compared to other similar studies. The adsorption kinetic process was better described by the pseudo-second-order kinetic model. Langmuir, Freundlich, and Dubinin–Kaganer–Radushkevich isotherms were applied to describe the sorption behaviour of Cd2+ ions onto the best adsorbent. Furthermore, a thermodynamic study was also performed to determine ΔH°, ΔS°, and ΔG° of the sorption process of this adsorbent. The adsorption mechanisms were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy-transmission electron microscopy (SEM-TEM) observations.


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