Ultrasound-assisted removal of tetracycline from aqueous solution by mesoporous alumina

2013 ◽  
Vol 69 (4) ◽  
pp. 819-824 ◽  
Author(s):  
Huiyuan Li ◽  
Xin Zhong ◽  
Hui Zhang ◽  
Luojing Xiang ◽  
Sebastien Royer ◽  
...  

This work describes the removal of tetracycline (TC) from aqueous solution using a mesoporous alumina (meso-Al2O3) as adsorbent in the presence of ultrasonic irradiation. Adsorption of TC was investigated under various operating conditions, including pH, adsorbent dosage, ultrasound power, and initial TC concentration. The results showed that the rate of TC sorption was enhanced with the assistance of ultrasound. The TC removal increased with the increase in sorbent dosage, pH and ultrasound power, but decreased with the increase in initial TC concentration. The adsorption isotherm data were fitted properly with the Freundlich model under ultrasonic irradiation, and the adsorption process followed a pseudo-second-order kinetic model.

2014 ◽  
Vol 805 ◽  
pp. 581-584 ◽  
Author(s):  
Débora Martins Aragão ◽  
Maria de Lara P.M. Arguelho ◽  
Carolina Mangieri Oliveira Prado ◽  
José do Patrocinio Hora Alves

Natural kaolinite clay collected in the State of Sergipe (northeast Brazil) was used as an adsorbent for the ions Pb2+, Cd2+, and Cu2+present in aqueous solution. Adsorption equilibrium was reached rapidly, enabling use of a contact time of 30 minutes, and maximum adsorption was achieved at pH 7.0. For all three metal ions, the adsorption data could be fitted using the Langmuir isotherm and the adsorption process obeyed a pseudo-second order kinetic model.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Saeedeh Hashemian ◽  
Mohammad Reza Shahedi

Ag/kaolin nanocomposite was prepared by reduction of Ag+ion with ethanol at alkaline condition on kaolin surface. Nanocomposite was characterized by FTIR, XRD, TEM, and BET methods. Results showed the Ag/kaolin composite has particle size 50 nm. The surface area was increased from kaolin to Ag/kaolin from 1.0215 to 7.409 m2 g−1, respectively. Ag/kaolin nanocomposite was used for adsorption of acid cyanine 5R (AC5R) from aqueous solution. The effect of parameters such as contact time, pH, and mass of nano composite has been investigated. The maximum percentage of adsorption of AC5R was found at pH 3 and contact time of 60 min. The higher percentage removal of AC5R by Ag/kaolin than kaolin can be attributed to catalytic activity of Ag on the surface of kaolin. The experimental data was fitted by pseudo-second-order kinetic model. The adsorption isotherm data could be well interpreted by Langmuir isotherm model. From the results of thermodynamic study, the adsorption process of AC5R onto Ag/kaolin nanocomposite was spontaneous and endothermic process. The process is clean and safe for purifying of water pollution.


Clay Minerals ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 627-637 ◽  
Author(s):  
J. X. Zhang ◽  
Q. X. Zhou ◽  
W. Li

AbstractThe removal of enrofloxacin, a fluoroquinolone antibiotic, from aqueous solution by adsorption onto bentonite was investigated in this study. The effects of initial concentrations, contact time and temperature on the adsorption of enrofloxacin were studied via batch experiments. The adsorption equilibrium was achieved within 60 min for all studied concentrations. The adsorption capacity increased with the increase of initial concentration within a concentration range. Higher temperatures were favourable for the adsorption. The change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) were evaluated and the results indicate that the adsorption should be an endothermic and spontaneous process. The Langmuir isotherm model fitted to the experimental data better than the Freundlich model. The adsorption follows the pseudo-second order kinetic model.


2020 ◽  
Vol 20 (4) ◽  
pp. 755
Author(s):  
Nurul Ain Safiqah Md Sandollah ◽  
Sheikh Ahmad Izaddin Sheikh Mohd Ghazali ◽  
Wan Nazihah Wan Ibrahim ◽  
Ruhaida Rusmin

The efficiencies of raw (RK) and acid activated (0.5 M AAK) kaolinite clay minerals to remove methylene blue (MB) dyes in aqueous solution were investigated and compared. The 0.5 M AAK was prepared by treatment of RK in dilute 0.5 M HCl aqueous solution under reflux. Kaolinite adsorbents were characterized and their MB removal performances were evaluated via the batch method. MB desorption from spent kaolinites was investigated at pH 4 to 8. The MB removal was increased with increasing initial dye concentration, agitation speed and adsorbent dosage in 60 min reaction time at pH 6. Both kaolinites showed high MB removal (up to 97%). The Freundlich model has the best-fit equilibrium adsorption isotherm model for RK and 0.5 M AAK. The kinetic data for both adsorbents showed strong agreement with the pseudo second order kinetic model (r2 > 0.98). Nevertheless, the spent RK adsorbent demonstrated a significant higher MB retention than 0.5 M AAK in desorption experiments. Kaolinite clays have great potential as cost-effective materials for dyes removal in wastewater treatment.


2021 ◽  
Vol 6 (3) ◽  
pp. 209-217
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Alfan Wijaya ◽  
Aldes Lesbani

Modification of Cu/Cr layered double hydroxides (LDHs) has been conducted by intercalation using Keggin type polyoxometalate [a-SiW12O40]4- to form CuCr-[a-SiW12O40]. The materials were analyzed by XRD, FTIR, and surface area analyses. Furthermore, materials were used as selectivity adsorbents of cationic dyes such as malachite green, rhodamine-B and methylene blue. The malachite green is more selective than others from an aqueous solution. The adsorption of malachite green showed that the adsorption capacity of CuCr-[a-SiW12O40] was higher than pristine LDHs. The adsorption process was followed pseudo second order kinetic model and Langmuir isotherm adsorption. The Qmax value of CuCr-[a-SiW12O40] reached 55.322 mg/g at 323 K after 100 minutes adsorption time. Thermodynamic parameters such as ΔG, ΔH and ΔS confirm that the adsorption process was endothermic, spontaneous, and more favorable at high temperatures. The intercalated material was higher structural stability toward reusability adsorbent than pristine LDHs.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Ouissal Assila ◽  
Karim Tanji ◽  
Morad Zouheir ◽  
Abdellah Arrahli ◽  
Loubna Nahali ◽  
...  

This study investigates the possibility of applying an adsorption process using two abundant natural minerals M1 and M2. Without pretreatment or activation, the adsorbents were used to treat real textile wastewater samples (collected from Fez city, Morocco). As a cost-effective alternative, these materials were characterized by different analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Chemical oxygen demand (COD) and biological oxygen demand (BOD) were used to characterize the textile wastewater. Additionally, the influence of operating conditions (contact time, adsorbent dosages, and pH) was evaluated. Results show that the adsorption process takes place quickly, reaching the equilibrium at 90 and 160 min for M1 (88% COD) and M2 (79% COD). Both materials show a higher affinity to Cr (39%) and lower affinity to Cu (28%). A pseudo-second-order kinetic model provides the best fit to the experimental adsorption data. Germination tests indicate a low toxicity after the adsorption process. Performance of both materials was compared with that of other literature studies.


2017 ◽  
Vol 76 (10) ◽  
pp. 2851-2857 ◽  
Author(s):  
Yan Liu ◽  
Xiaoyi Shen

Abstract Surface-modified magnetic Ni2.33Fe alloy nanoparticles were prepared using a hydrothermal method. Thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) tests demonstrated that the surface was successfully modified by sodium citrate. The surface-modified particles can be used for removing nickel ions from aqueous solution. The adsorption kinetics studies were performed and the pseudo-second-order kinetic model successfully described the kinetic data. The diffusion model indicated the adsorption was regulated by both surface and intraparticle diffusion processes. The Freundlich and Langmuir adsorption models were adopted for the mathematical description of adsorption equilibrium, and it was found that the experimental data fitted very well to the Freundlich model.


2011 ◽  
Vol 474-476 ◽  
pp. 786-791
Author(s):  
Fang Wen Li ◽  
Juan Yang ◽  
Song Jiang Ma ◽  
Nian Fen Wu ◽  
Mei Ling Fu ◽  
...  

The effect of operating conditions, such as adsorption time, adsorbent dosage, influent pH and influent oil concentration, on the performance of organic modified sepiolite used for the treatment of steel rolling oily wastewater was investigated via single factor method, and the adsorption kinetics and thermodynamics were also studied with batch test. Results indicated that oil removal rate reached 96.78% in 45 min which increased by 55.44% compared with crude sepiolite. Reasons for oil removal efficiency rise with organic modified sepiolite included augmentation of interlayer distance (0.007 nm larger than crude sepiolite), increase of specific surface area (from 41.63 to 104.40 m2/g) and stronger hydrophobic. The pseudo second order kinetic model well described experiment data with a perfect correlation coefficient value of 0.9999. Thermodynamic parameters including the Gibbs free energy (△G0), enthalpy (△H0), and entropy (△S0) revealed that adsorption process was a spontaneous, exothermic and physical adsorption process. <b></b>


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.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3575-3595
Author(s):  
Wanting Li ◽  
Ruifeng Shan ◽  
Yuna Fan ◽  
Xiaoyin Sun

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.


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