scholarly journals Effective Adsorption of Hexavalent Chromium and Divalent Nickel Ions from Water through Polyaniline, Iron Oxide, and Their Composites

2020 ◽  
Vol 10 (8) ◽  
pp. 2882 ◽  
Author(s):  
Amir Muhammad ◽  
Anwar ul Haq Ali Shah ◽  
Salma Bilal
Keyword(s):  
Hexavalent Chromium ◽  
Contact Time ◽  
Environmental Problem ◽  
Freundlich Isotherm ◽  
Industrial Wastes ◽  
Solution Ph ◽  
Adsorption Ability ◽  
Nickel Ions ◽  
Adsorption Data ◽  
Divalent Nickel

Water pollution caused by industrial wastes containing heavy metals and dyes is a major environmental problem. This study reports on the synthesis, characterization, and utilizations of Polyaniline (PANI) and its composites with Fe3O4 for the removal of hexavalent chromium Cr(VI) and divalent nickel Ni(II) ions from water. The adsorption data were fitted in Freudlich, Langmuir, Tempkin, Dubbanin–Ruddishkawich (D–R), and Elovich adsorption isotherms. The Freundlich isotherm fits more closely to the adsorption data with R2 values of 0.9472, 0.9890, and 0.9684 for adsorption of Cr(VI) on Fe3O4, PANI, and PANI/Fe3O4 composites, respectively, while for adsorption of Ni(II) these values were 0.9366, 0.9232, and 0.9307 respectively. The effects of solution pH, initial concentration, contact time, ionic strength, and adsorbent dosage on adsorption behavior were investigated. The adsorption ability of composites was compared with pristine PANI and Fe3O4 particles. Activation energy and other thermodynamic properties such as changes in enthalpy, entropy, and Gibbs free energy indicated spontaneous and exothermic adsorption.

scholarly journals Adsorption Behaviors of Oxytetracycline onto Sediment in the Weihe River, Shaanxi, China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dong-Hui Cheng ◽  
Sheng-Ke Yang ◽  
Yue Zhao ◽  
Jing Chen
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Impact Factors ◽  
Isotherm Models ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Adsorption Data ◽  
Negative Effect ◽  
Weihe River ◽  
The Impact

Adsorption behaviors of oxytetracycline onto sediment in the Weihe River were described. The impact factors in the processes of adsorption, such as contact time, solution pH, temperature, and ionic strength, were determined by experiments. The experimental results were analyzed by kinetic and isotherm models. The adsorption kinetics was found to follow a pseudo-first-order model. The equilibrium adsorption data fitted well with the Langmuir and Freundlich isotherm models. However, the Langmuir isotherm was more suitable to describe the adsorption. Thermodynamics parameters such as Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated. Results showed that the adsorption was feasible, spontaneous, entropy increasing, and endothermic in nature, which reached equilibrium in about 24 hours. The adsorption capacity did not cause obvious change at solution pH 4.0–7.0, and both decreased in solution pH 7.0–10.0 and 4.0–2.0. The presence of electrolytes such as NaCl in aqueous solution had a significant negative effect on the adsorption. The mechanisms controlling the adsorption were supposed to be chemisorption.

scholarly journals Synthesis of acid treated carbonized mandarin peel for purification of copper

2020 ◽  
Vol 15 (2) ◽  
pp. 460-471
Author(s):  
T. Unugul ◽  
F. U. Nigiz
Keyword(s):  
Contact Time ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Adsorption Kinetic ◽  
Adsorption Behaviour ◽  
Solution Ph ◽  
Copper Adsorption ◽  
Adsorbent Dosage ◽  
Mandarin Peel ◽  
Pseudo Second Order

Abstract In this study; acid treated carbonized mandarin peel (CMP) adsorbent was prepared and the adsorption behaviour of the adsorbent for copper removal was investigated. In the adsorption studies the effects of initial metal concentration, solution pH, adsorbent dosage and contact time on the removal were investigated. As a result; the highest removal of 100% was achieved when the copper concentration in water was 5 mg/L and the adsorbent dosage was 3.75 g/L at a solution pH of 7. Isotherm studies were also done and the appropriate isotherm was obtained as the Freundlich isotherm. According to the kinetic studies, the copper adsorption onto CMP adsorbent was adopted to the pseudo-second-order adsorption kinetic. After HCl regeneration, the adsorbent maintained 94% of its activity.

scholarly journals Adsorption of cadmium and copper onto natural clay: isotherm, kinetic and thermodynamic studies

2018 ◽  
Vol 20 (2) ◽  
pp. 198-207 ◽  
Keyword(s):  
Mass Transfer ◽  
Metal Ions ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Adsorption Rate ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Adsorption Data ◽  
Removal Of Heavy Metals ◽  
Heavy Metals Ions

Clay of the Middle Atlas Mountains region, Morocco, was used to investigate the removal of heavy metals ions (Cadmium and Copper) from aqueous solutions with respect to several experimental conditions including pH, contact time, initial solute concentrations, temperature and ionic strength. Kinetic study revealed that metal ions uptake was fast with 90% or more of the adsorption occurring within first 30 min of contact time. Adsorption rate increased with the increasing initial metal ions concentrations and the sorption rate was well fitted by the pseudo-second-order rate model. The data according to mass transfer and intraparticle diffusion models confirmed diffusion of solutes inside the clay particles as the rate-controlling step and more important for the adsorption rate than the external mass transfer. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherm models. Equilibrium and kinetic adsorption data showed that clay displays a high selectivity with an affinity order of Cd > Cu. Thermodynamic parameters including the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes indicated that the present adsorption process was feasible and endothermic in the temperature range of 25–45 °C.

Removal and Recovery of Cr(VI) from Synthetic and Industrial Wastewater using Bark of Pinus roxburghii as an Adsorbent

2005 ◽  
Vol 40 (4) ◽  
pp. 462-468 ◽  
Author(s):  
Rais Ahmad ◽  
Rifaqat Ali Khan Rao ◽  
Mir Mohammad Masood
Keyword(s):  
Contact Time ◽  
Industrial Wastewater ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Batch Process ◽  
Ion Concentration ◽  
Solution Ph ◽  
Pinus Roxburghii ◽  
Column Operation ◽  
Removal And Recovery

Abstract In the present study, the potential of Pinus roxburghii bark as an adsorbent for the removal of heavy metals such as Cr(VI), Ni(II), Cu(II), Cd(II) and Zn(II) from aqueous solution at ambient temperature was investigated. Adsorption capacity of the material was found to be 4.15, 3.89, 3.81, 3.53 and 3.01 mg g-1 for Cr(VI), Zn(II), Cu(II), Ni(II) and Cd(II), respectively, at an initial metal ion concentration of 50 mg L-1 at pH 6.5. The effect of concentration, contact time, adsorbent dose, solution pH, adsorbent particle size, salinity and hardness on the adsorption of Cr(VI) were studied in detail in batch experiments. The equilibrium contact time for Cr(VI) adsorption was found to be 1 h. Adsorption equilibrium data fit well to the Freundlich isotherm in the concentration range studied. The maximum adsorption (96.2%) was recorded at pH 3 for the initial Cr(VI) concentration of 50 mg L-1. The adsorbed metal ions from industrial wastewater were recovered using 0.1 M HCl solution. The column operation was found to be more effective compared to batch process. The percent recovery of Cr(VI) from industrial wastewater by column operation and batch process was found to be 85.8 and 65%, respectively. The results show that Pinus roxburghii bark can be used as a cost-effective adsorbent for the removal and recovery of Cr(VI) from wastewater.

Adsorption of Methyl Violet Dye from Aqueous Solutions by Activated Carbon Produced from Tamarind Seeds

2014 ◽  
Vol 911 ◽  
pp. 326-330 ◽  
Author(s):  
Piaw Phatai ◽  
Jutharatana Klinkaewnarong ◽  
Surachai Yaiyen
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Copper Ions ◽  
Binary Solution ◽  
Methyl Violet ◽  
Solution System ◽  
Solution Ph ◽  
Batch System ◽  
Adsorption Data ◽  
Adsorbent Dose

The present work proposes the adsorption of methyl violet (MV) from two solution systems including single MV and binary MV-Cu2+systems by activated carbon (AC) prepared from tamarind seeds in a batch system. Parameters including contact time, solution pH, adsorbent dose, and initial dye concentration were studied. The morphology of the AC was determined by scanning electron microscopy (SEM). The results showed the maximum adsorption of MV dye onto the AC at a contact time of 60 min, solution pH of 9.0 and adsorbent dose of 0.2 and 0.5 g for the single and binary solution systems, respectively. The presence of copper ions in binary solution system decreased the adsorption efficiency of MV dye onto the AC. The equilibrium adsorption data were analyzed using Langmuir, Freundlich and Temkin isotherms.

Adsorption Studies of Nitrobenzene onto Aminated Lignin

2011 ◽  
Vol 695 ◽  
pp. 117-120 ◽  
Author(s):  
Xiao Yan Lin ◽  
Jian Ping Zhang ◽  
Xue Gang Luo ◽  
Chi Zhang
Keyword(s):  
Hydrogen Bond ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Batch Experiments ◽  
Adsorption Ability ◽  
Hydrogen Bond Interaction ◽  
Adsorption Performance ◽  
Strong Adsorption ◽  
Adsorption Data ◽  
Pseudo Second Order

Adsorption performance of aminated lignin (AmL) for nitrobenzene (NB) removal was investigated through batch experiments. The results showed that AmL possessed strong adsorption ability for NB with hydrogen bond interaction. The equilibrium adsorption data were well represented by the Freundlich isotherm model and the saturated adsorption capacity could reach 24.2mg/g. The adsorption process was found to follow pseudo-second-order kinetics. The maximum adsorption of NB on AmL occurred around the neutral pH.

Adsorption of Dye from Aqueous Solution by Palm Leaves

2014 ◽  
Vol 539 ◽  
pp. 823-826
Author(s):  
Hong Hai Sun
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Rhodamine B ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Color Removal ◽  
Adsorption Behavior ◽  
Solution Ph ◽  
Batch Kinetics

In this study, the palm leaves powder was used as adsorbent for the removal of rhodamine B (RhB) from aqueous solutions. The effects of initial RhB concentrations, adsorbent dosage, initial solution pH and contact time on the amount of color removal was investigated. Batch kinetics and isotherm studies were conducted to evaluate the adsorption behavior of the palm leaves powder. TheLangmuir and Freundlich isotherm model were used to describe the equilibria data. Further, the kinetics involved in the sorption process was evaluated at different initial RhB concentrations.

scholarly journals Removal of nickel and cadmium heavy metals using nanofiber membranes functionalized with (3-mercaptopropyl)trimethoxysilane (TMPTMS)

2016 ◽  
Vol 14 (4) ◽  
pp. 630-639 ◽  
Author(s):  
Saeed Reza Zahabi ◽  
Seyed Abdolkarim Hosseini Ravandi ◽  
Alireza Allafchian
Keyword(s):  
Process Parameters ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Maximum Efficiency ◽  
Solution Ph ◽  
Filtration Process ◽  
Nickel Ions ◽  
Initial Concentration ◽  
Ion Rejection ◽  
Nanofiber Membranes

Functionalized nanofibrous membranes have been produced via electrospinning with a polymer solution of 19% (w/w) of nylon 66 prepared in a formic acid/chloroform mixture (75:25 v/v). The optimum parameters of electrospinning, like voltage, flow rate, tip and collector distances, were achieved and produced nanofiber membranes with a thickness of 287 nm. Then the nanofiber membranes were functionalized by (3-mercaptopropyl)trimethoxysilane (TMPTMS) at various amounts. Three different initial concentrations of metal ions and three different levels of pH were chosen. The effect of filtration process parameters such as the initial concentration of metal solution, pH of the solution, and the amount of functionalizer trimethoxysilane (TMPTMS) on the adsorption was studied. In surveying filtration process parameters, the results showed that metal ion rejection increased by increasing the pH of the solution and decreased by increasing the initial concentration of the effluent. By increasing the amount of functionalizer, removal efficiency increased. The results showed that the maximum efficiency of absorption of cadmium and nickel were 93.0 and 97.6%, respectively, and the filtering mechanism of the membrane is the blocking pores type. The adsorption data of cadmium and nickel ions fitted particularly well with the Freundlich isotherm.

scholarly journals Utilization of Cactus Peel as Biosorbent for the Removal of Reactive Dyes from Textile Dye Effluents

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Mebrahtu Gebrezgiher ◽  
Zebene Kiflie
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Textile Dye ◽  
Order Model ◽  
Solution Ph ◽  
Biosorption Process ◽  
Good Potential ◽  
Pseudo Second Order ◽  
Red Dye

Textile industries generate large quantities of dye containing wastewater which pose a serious environmental problem. Currently, biosorbents have become desirable for the removal of dyes from textile effluents. In this study, batch experiments were conducted to investigate the biosorption characteristics of cactus peel on the removal of reactive red dye from aqueous solutions. The effects of solution pH, biosorbent dosage, contact time, and initial concentration were studied. The interaction effects of process variables were analysed using response surface methodology. The results showed that removal efficiency increased as initial dye concentration and solution pH decreased and as biosorbent dosage and contact time increased. The highest removal efficiency (99.43%) was achieved at solution pH, initial dye concentration, biosorbent dose, and contact time of 3.0, 40 mg/l, 6 g, and 120 min, respectively. From regression analysis, the Langmuir isotherm was found to better (R2 = 0.9935) represent the biosorption process as compared with the Freundlich isotherm (R2 = 0.9722). Similarly, the pseudo-second-order model was seen to represent very well the biosorption kinetics. The results show that cactus peel has good potential for the removal of reactive red dye.

scholarly journals Uptake of CrO42- Ions by Fe-Treated Tri-Calcium Phosphate

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Juan Serrano-Gómez ◽  
Jorge Luis Ramírez-Sandoval ◽  
Juan Bonifacio- Martínez ◽  
Francisco Granados-Correa ◽  
Verónica Elizabeth Badillo-Almaraz
Keyword(s):  
Calcium Phosphate ◽  
Contact Time ◽  
Metal Ion ◽  
Freundlich Isotherm ◽  
Chromium Concentration ◽  
Ion Adsorption ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Adsorption Data ◽  
Chromium Adsorption

CrO42- ion adsorption on Fe-treated tri-calcium phosphate was studied by batch experiments as a function of contact time, initial concentration of metal ion and temperature. Adsorption results showed that at pH 5.5 and 1.0x10-4 M chromium concentration the adsorption capacity of Fe-treated tri-calcium phosphate for CrO42- ions was 7.10x10-3 mmol/g. Chromium adsorption data on Fe-treated tri-calcium phosphate at various initial concentration fitted the Freundlich isotherm. By temperature studies the thermodynamic parameters ∆H0, ∆G0 and ∆S0 were estimated and the obtained results showed that the adsorption reaction was endothermic and spontaneous.    

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