scholarly journals Preparation of Magnetic Composite Polyaniline/Fe3O4−Hydrotalcite and Performance in Removal of Methyl Orange

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Thi Tuong An Tran ◽  
Huynh Thanh Linh Duong ◽  
Thi Thuy Phuong Pham ◽  
Tri Nguyen ◽  
Thi Dung Nguyen ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Organic Dyes ◽  
Freundlich Isotherm ◽  
Batch Adsorption ◽  
Magnetic Composite ◽  
Order Kinetic ◽  
Solution Ph ◽  
Isotherm Adsorption ◽  
Order Kinetic Model ◽  
And Performance

Magnetic composite fabricated from polyaniline and Fe3O4-hydrotalcite (Pan/MHT) was successfully applicated for removal of methyl orange (MO) from wastewater. The structure and properties of Pan/MHT were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, and Brunauer-Emmett-Teller adsorption isotherm. Adsorption kinetic results indicated that the adsorption process followed pseudosecond-order kinetic model ( R 2 = 0.999 ), MO adsorption onto Pan/MHT was well described by Freundlich isotherm ( R 2 = 0.994 ), and the MO adsorption capacity of 2 Pan/MHT obtained the highest with Q e = 156.25   mg / g . Batch adsorption experiments were carried out using magnetic composite with the effects of initial MO concentration, solution pH, and adsorbent dosage. The results revealed that the magnetic Pan/MHT exhibited efficient adsorption of MO in the aqueous solution as a result of the affinity for organic dyes, microporous structure, and suitable surface area for adsorption (15,460 m2/g). The superparamagnetic behavior of Pan/MHT (with H c = 18.56   Oe , M s = 23.38 × 10 − 3   emu / g , and M r = 0.91 × 10 − 3   emu / g ) helps that it could be separated from the solution and performs as an economical and alternative adsorbent to removal and degrade azo dye from wastewater. Pan/MHT was also investigated to reuse after desorption of MO in 0.1 M HCl, and the results show that 2 Pan/MHT can be reused for 4 cycles with Q e = 79.66   mg / g .

scholarly journals Adsorption of Congo Red from Aqueous Solutions by Porous Soybean Curd Xerogels

2018 ◽  
Vol 20 (3) ◽  
pp. 95-102 ◽  
Author(s):  
Zhao Zhang ◽  
Yanhui Li ◽  
Qiuju Du ◽  
Qi Li
Keyword(s):  
Aqueous Solutions ◽  
Congo Red ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Drying Method ◽  
Solution Ph ◽  
Soybean Curd ◽  
High Quality Protein ◽  
Isotherm Adsorption ◽  
Order Kinetic Model

Abstract Soybean curd is a very popular food containing high-quality protein, polyunsaturated fats, vitamins, minerals and other nutrients. This study aims to prepare porous soybean curd xerogels via a vacuum freeze drying method and uses them as adsorbents to remove congo red from aqueous solutions. The morphology and functional groups of the soybean curd xerogels were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The adsorption properties of congo red onto the soybean curd xerogels were carried out through investigating the infl uencing experimental parameters such as the drying method, solution pH, adsorbent dose, contact time and temperature. The results showed that the adsorption isotherm data were fitted well to the Freundlich isotherm. Adsorption kinetics of congo red onto the soybean curd followed the pseudo-second-order kinetic model. The thermodynamic parameters, such as ΔG0, ΔH0 and ΔS0, were also determined.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

scholarly journals Adsorption of Hexavalent Chromium from Aqueous Solution Using Chemically Activated Carbon Prepared from Locally Available Waste of Bamboo (Oxytenanthera abyssinica)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tamirat Dula ◽  
Khalid Siraj ◽  
Shimeles Addisu Kitte
Keyword(s):  
Activated Carbon ◽  
Hexavalent Chromium ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Batch Adsorption ◽  
Koh Activation ◽  
Order Kinetic ◽  
Oxytenanthera Abyssinica ◽  
Equilibrium Data ◽  
Order Kinetic Model

This study reports on the adsorption of Hexavalent Chromium from aqueous solutions using activated carbon prepared from bamboo (Oxytenanthera abyssinica) waste by KOH activation heating in an electrical furnace at 1073 K for 3 hrs. Batch adsorption experiments were also carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo-second-order kinetic model. Thermodynamic parameters showed that adsorption on the surface of BWAC was feasible, spontaneous in nature, and exothermic between temperatures of 298 and 318 K. The equilibrium data better fitted the Freundlich isotherm model for studying the adsorption behavior of Hexavalent Chromium by BWAC. IR spectrum for loaded and unloaded BWAC was obtained using FT-IR spectrophotometer. Adsorption efficiency and capacity of Hexavalent Chromium were found to be 98.28% at pH 2 and 59.23 mg/g at 300 K.

Removal of fluoride from aqueous solution by adsorption onto Kanuma mud

2010 ◽  
Vol 62 (8) ◽  
pp. 1888-1897 ◽  
Author(s):  
Nan Chen ◽  
Zhenya Zhang ◽  
Chuanping Feng ◽  
Miao Li ◽  
Rongzhi Chen ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Solution Ph ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Solid Liquid Interface ◽  
Solid Liquid

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.

scholarly journals Adsorption Behaviour of Chromium(VI) onto Surface Modified Sugarcane Waste

2013 ◽  
Vol 28 (1-2) ◽  
pp. 113-122
Author(s):  
Kedar Nath Ghimire ◽  
Deepak Wagle ◽  
Suman Lal Shrestha
Keyword(s):  
Volume Ratio ◽  
Freundlich Isotherm ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Method ◽  
Chromium Vi ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Surface Modified

An effective chemically modified adsorbent based on sugarcane waste has been prepared by treating with concentrated sulphuric acid in 2:1weight/volume ratio. Thus prepared adsorbent has been found to be effective in the adsorption of chromium from aqueous medium. The efficacy of the adsorbent in the removal of chromium was evaluated by batch adsorption method. The effect of initial concentration, contact time and pH of the solution was investigated. The maximum adsorption capacity onto this adsorbent was found to be 195 mg/g at their optimal pH 1 at which unmodified bagasse has only 58 mg/g. The characterization of adsorbent was done by determining surface area and Boehm’s titration method. Freundlich isotherm and pseudo-second order kinetic model gave better explanation of the adsorption process.

scholarly journals β-Cyclodextrin conjugated bifunctional isocyanate linker polymer for enhanced removal of 2,4-dinitrophenol from environmental waters

2018 ◽  
Vol 5 (8) ◽  
pp. 180942 ◽  
Author(s):  
J. M. Anne ◽  
Y. H. Boon ◽  
B. Saad ◽  
M. Miskam ◽  
M. M. Yusoff ◽  
...  
Keyword(s):  
Freundlich Isotherm ◽  
Environmental Water ◽  
Hexamethylene Diisocyanate ◽  
Toluene Diisocyanate ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Environmental Waters ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Optimized Conditions

In this work, we reported the synthesis, characterization and adsorption study of two β-cyclodextrin (βCD) cross-linked polymers using aromatic linker 2,4-toluene diisocyanate (2,4-TDI) and aliphatic linker 1,6-hexamethylene diisocyanate (1,6-HDI) to form insoluble βCD-TDI and βCD-HDI. The adsorption of 2,4-dinitrophenol (DNP) on both polymers as an adsorbent was studied in batch adsorption experiments. Both polymers were well characterized using various tools that include Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer–Emmett–Teller analysis and scanning electron microscopy, and the results obtained were compared with the native βCD. The adsorption isotherm of 2,4-DNP onto polymers was studied. It showed that the Freundlich isotherm is a better fit for βCD-TDI, while the Langmuir isotherm is a better fit for βCD-HMDI. The pseudo-second-order kinetic model represented the adsorption process for both of the polymers. The thermodynamic study showed that βCD-TDI polymer was more favourable towards 2,4-DNP when compared with βCD-HDI polymer. Under optimized conditions, both βCD polymers were successfully applied on various environmental water samples for the removal of 2,4-DNP. βCD-TDI polymer showed enhanced sorption capacity and higher removal efficiency (greater than 80%) than βCD-HDI (greater than 70%) towards 2,4-DNP. The mechanism involved was discussed, and the effects of cross-linkers on βCD open up new perspectives for the removal of toxic contaminants from a body of water.

scholarly journals Comparative Study of Ni-Zn LHS and Mg-Al LDH Adsorbents of Navy Blue and Yellow F3G Dye

2018 ◽  
Vol 16 (1) ◽  
pp. 36 ◽  
Author(s):  
Idha Yulia Ikhsani ◽  
Sri Juari Santosa ◽  
Bambang Rusdiarso
Keyword(s):  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Disperse Dyes ◽  
Order Kinetic ◽  
Initial Ph ◽  
Isotherm Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Adsorption of disperse dyes from wastewater onto Ni-Zn LHS (layered hydroxide salts) and Mg-Al LDH (layered double hydroxides) has been compared in this study. Effects of initial pH solution, contact time and initial dye concentration were investigated. The ability of the adsorbent to be reused was also studied. The results showed that acidic condition was favorable for the adsorption of each dyes onto both adsorbent. The adsorption kinetics was studied using pseudo-first-order, pseudo-second-order and Santosa’s kinetics models. The experimental data fits well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherm models. The results showed that adsorption of navy blue onto both adsorbent followed Freundlich isotherm adsorption, while yellow F3G followed Langmuir isotherm adsorption. In the application for the adsorption the wastewater containing dyes, Ni-Zn LHS has a better adsorption capacity of 52.33 mg/g than that of Mg-Al LDH that 30.54 mg/g. Calcination of the adsorbent which has already been used increased the adsorption capacity of Mg-Al LDH to 84.75 mg/g, but decreased the adsorption capacity of the Ni-Zn LHS to 42.65 mg/g.

Adsorption of Cobalt Ions onto Mycobacterium phlei from Wastewaters

2011 ◽  
Vol 71-78 ◽  
pp. 2249-2252 ◽  
Author(s):  
Yan Xing
Keyword(s):  
Practical Implication ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Cobalt Ions ◽  
Mycobacterium Phlei ◽  
Order Kinetic Model ◽  
Economic Technology

This fundamental work deals with the biosorption removal of Co(II) using a Mycobacterium phlei strain. Several variables that have an effect on the capacity of cobalt biosorption from aqueous solution by Mycobacterium phlei were studied. particularly the effects of solution pH, initial Co(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Co(II) was 68.22 mg/g. The best correlation was provided by the second-order kinetic model, implying that chemical sorption was the rate-limiting step. The practical implication of this study is the development of an effective and economic technology for Co(II) removal from wastewaters.

scholarly journals Kinetics and adsorption studies of lead (II) onto activated carbon using low cost adsorbents

2018 ◽  
Vol 20 (2) ◽  
pp. 381-388 ◽  
Keyword(s):  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Rate Limiting Step ◽  
Bambusa Vulgaris ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Fagopyrum Esculentum Moench

The removal of Lead (II) from aqueous solutions using Fagopyrum esculentum Moench (Buckwheat) and Bambusa vulgaris (common bamboo) as adsorbents was investigated. The effects of various experimental parameters such as initial concentration, contact time and pH have been studied using batch adsorption technique. All the Adsorption isotherm models fitted well with the adsorption data. However, Freundlich isotherm displayed a better fitting model than the other two isotherm models due to high correlation coefficient (R2). This indicates the applicability of multilayer coverage of the Pb (II) on the surface of adsorbent. The adsorption kinetics was studied using four simplified models and it was found to follow the pseudo-second-order kinetic model which confirmed the applicability of the model. The adsorption mechanism was found to be chemisorption and the rate-limiting step was mainly surface adsorption.

scholarly journals Single-Step Hydrothermal Synthesis of Biochar from H3PO4-Activated Lettuce Waste for Efficient Adsorption of Cd(II) in Aqueous Solution

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 269
Author(s):  
Quyun Chen ◽  
Tian C. Zhang ◽  
Like Ouyang ◽  
Shaojun Yuan
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Low Temperature ◽  
Low Cost ◽  
Hydrothermal Carbonization ◽  
Single Step ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Solution Ph ◽  
Order Kinetic Model

Developing an ideal and cheap adsorbent for adsorbing heavy metals from aqueous solution has been urgently need. In this study, a novel, effective and low-cost method was developed to prepare the biochar from lettuce waste with H3PO4 as an acidic activation agent at a low-temperature (circa 200 °C) hydrothermal carbonization process. A batch adsorption experiment demonstrated that the biochar reaches the adsorption equilibrium within 30 min, and the optimal adsorption capacity of Cd(II) is 195.8 mg∙g−1 at solution pH 6.0, which is significantly improved from circa 20.5 mg∙g−1 of the original biochar without activator. The fitting results of the prepared biochar adsorption data conform to the pseudo-second-order kinetic model (PSO) and the Sips isotherm model, and the Cd(II) adsorption is a spontaneous and exothermic process. The hypothetical adsorption mechanism is mainly composed of ion exchange, electrostatic attraction, and surface complexation. This work offers a novel and low-temperature strategy to produce cheap and promising carbon-based adsorbents from organic vegetation wastes for removing heavy metals in aquatic environment efficiently.

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