scholarly journals Experimental Investigations on Adsorption of Reactive Toxic Dyes Using Hedyotis umbellate Activated Carbon

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jayachandran Sheeja ◽  
Krishnan Sampath ◽  
Ramasamy Kesavasamy
Keyword(s):  
Activated Carbon ◽  
Thermal Activation ◽  
Adsorption Mechanism ◽  
Entropy Change ◽  
Experimental Investigations ◽  
Control Parameters ◽  
Gibbs Free Energy Change ◽  
Multilayer Adsorption ◽  
Monolayer Adsorption ◽  
Adsorption Data

Hedyotis umbellate activated carbon (HUAC) was prepared by chemical and thermal activation. The adsorption behavior of Hedyotis umbellate activated carbon in aqueous basic green 4 (BG4) and acid fuchsin (AF) was investigated and characterized by UV-vis, FTIR, and FESEM. The possible mechanism of the adsorption of BG4 and AF dyes on the HUAC surface was framed. The influence of various adsorption control parameters like the initial dye concentration, pH, adsorbent dose, contact time, and temperature was studied. The data confirmed excellent BG4 removal of 97.94% at pH 10 and AF removal of 76.7% at pH 4. The experimental data were fitted using Langmuir, Freundlich, and Temkin isotherms to examine the adsorption mechanism. The adsorption data revealed monolayer adsorption of BG4 with the maximum capacity of 102.38 mg/g and multilayer adsorption of AF with the capacity of 139.33 mg/g. The kinetic data for different initial dye concentrations were computed using pseudofirst order, pseudosecond order, and intraparticle diffusion models. Thermodynamic parameters like Gibbs free energy change ∆ G 0 , enthalpy change ∆ H 0 , and entropy change ∆ S 0 were evaluated. From the values obtained, the negative values of ∆ G 0 and ∆ H 0 indicate that the adsorption of BG4 and AF by HUAC is spontaneous and exothermic.

Physicochemical Properties of Carbons Prepared from Physic Nut Waste by Phosphoric Acid and Potassium Hydroxide Activations

2007 ◽  
Vol 561-565 ◽  
pp. 1719-1722 ◽  
Author(s):  
Chiravoot Pechyen ◽  
Duangdao Aht-Ong ◽  
Duangduen Atong ◽  
Viboon Sricharoenchaikul
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Physicochemical Properties ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Potassium Hydroxide ◽  
Bet Surface Area ◽  
Physic Nut ◽  
Monolayer Adsorption ◽  
Adsorption Data

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the preparation of activated carbon by chemical impregnation of phosphoric acid and potassium hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively. Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the physic nut residue activated carbon was comparable to commercial activated carbon.

Adsorption of Mercury Ion on Activated Carbons from Rice Husk

2012 ◽  
Vol 161 ◽  
pp. 162-166 ◽  
Author(s):  
Xiao Lan SONG ◽  
Ying Zhang ◽  
Cheng Yin Yan ◽  
Wen Juan Jiang ◽  
Hong Jiang Xie
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Activated Carbons ◽  
Langmuir Model ◽  
Mercury Ion ◽  
Maximum Adsorption Capacity ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Adsorption Data

The adsorption performance of mercury ion onto activated carbon prepared from rice husk with NaOH was carried out at initial concentration of 100 mg/L. The activated carbon obtained at 800 °C possessed the outstanding specific surface area of 2786 m2/g. And the results showed that the maximum adsorption capacity of Hg2+ was recorded as 342.0 mg/g due to abundant micropores of 1.076 nm. In addition, the adsorption data were well explained by the Langmuir model with the monolayer adsorption capacity of 555.6 mg/g.

scholarly journals Removal of Phenol ando-Cresol by Adsorption onto Activated Carbon

2008 ◽  
Vol 5 (2) ◽  
pp. 224-232 ◽  
Author(s):  
A. Edwin Vasu
Keyword(s):  
Activated Carbon ◽  
Kinetic Studies ◽  
Batch Mode ◽  
Phenol Solution ◽  
Adsorption Capacities ◽  
Monolayer Adsorption ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Dilute Aqueous Solutions ◽  
Isotherm Equations

A commercial activated carbon was utilized for the adsorptive removal of phenol and o-cresol from dilute aqueous solutions. Batch mode adsorption studies were performed by varying parameters such as concentration of phenol solution, time, pH and temperature. The well known Freundlich, Langmuir and Redlich-Peterson isotherm equations were applied for the equilibrium adsorption data and the various isotherm parameters were evaluated. The Langmuir monolayer adsorption capacities were found to be 0.7877 and 0.5936 mmole/g, respectively, for phenol and o-cresol. Kinetic studies performed indicate that the sorption processes can be better represented by the pseudo-second order kinetics. The processes were found to be endothermic and the thermodynamic parameters were evaluated. Desorption studies performed indicate that the sorbed phenol molecules can be desorbed with dil. HCl.

Adsorption Mechanism of Attapulgite for Cu(ΙΙ) in Aqueous Solution

2014 ◽  
Vol 1065-1069 ◽  
pp. 1867-1870
Author(s):  
Jun Ren ◽  
Ya Qiong Zhao ◽  
Dong Dong Gou ◽  
Ling Tao ◽  
Mei Wei Zhang
Keyword(s):  
Adsorption Mechanism ◽  
Entropy Change ◽  
Order Kinetic ◽  
Gibbs Free Energy Change ◽  
Temperature Dependent ◽  
Sorption Data ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Isotherm

Adsorption of Cu(Ⅱ) onto natural attapulgite was investigated with respect to temperature, initial concentration and contact time. The adsorption process can be well described by the pseudo-second-order kinetic model, and the equilibrium adsorption isotherm was closely fitted with the Freundlich model. Enthalpy change(△H0), entropy change(△S0) and Gibbs free energy change(△G0) were calculated from the temperature dependent sorption data, and the results indicated that the sorption of Cu(Ⅱ) on attapulgite was a spontaneous process, and the sorption was endothermic.

Capture of Toluene Vapors Using Adsorption and Microwave Irradiation Regeneration

2011 ◽  
Vol 99-100 ◽  
pp. 1092-1095
Author(s):  
Xiao Qiang Cao ◽  
Sheng Rong Liu ◽  
Xue Min Huang
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Adsorption Capacity ◽  
Langmuir Isotherm ◽  
Experimental Investigations ◽  
Gas Velocity ◽  
Adsorption Data ◽  
Regeneration Efficiency ◽  
Superficial Gas Velocity ◽  
Langmuir Constants

Experimental investigations using granular activated carbon (GAC) adsorption and then desorpted with microwave irradiation for toluene abatement are reported in this paper. The results indicated that the adsorption capacity of GAC for toluene was 198 mg (toluene) / g (GAC) at 303 K. Isotherm analysis of adsorption data obtained at 303 K showed that the adsorption pattern of toluene on GAC followed the Langmuir isotherm. The Langmuir constants Q0 and b were found to be 208.33 mg/g and 0.0023 m3/mg, respectively. At 313 K, the saturated GAC could achieve more than 90% regeneration efficiency in 40 minutes. In this investigation, the reasonable regeneration temperature and superficial gas velocity were 313 K and 0.073 m/s, respectively.

Adsorption mechanism of NH3, NO, and O2 molecules over FexOy/AC catalyst surface: a DFT-D3 study

2021 ◽  
Author(s):  
Chaoyue Xie ◽  
Yunlan Sun ◽  
Baozhong Zhu ◽  
Weiyi Song ◽  
Minggao Xu
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Catalyst Surface ◽  
Specific Adsorption ◽  
Adsorption Mechanisms ◽  
Iron Based ◽  
Iron Based Catalysts ◽  
Supported Iron ◽  
Denox Efficiency

Activated carbon-supported iron-based catalysts (FexOy/AC) show excellent deNOx efficiency. However, the specific adsorption mechanisms of NH3, NO, and O2 molecules on their surfaces are still unknown. In this study, the...

scholarly journals Comparative studies on the removal of copper (II) by Ulva fasciata activated carbon and commercially activated carbon

2012 ◽  
Vol 14 (4) ◽  
pp. 88-94 ◽  
Author(s):  
R.P. Suresh Jeyakumar ◽  
V. Chandrasekaran
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Synthetic Wastewater ◽  
Batch Adsorption ◽  
First Order ◽  
Ulva Fasciata ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Adsorbent Dose

Abstract In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.

Adsorption of Liquids and Swelling of Wood. Part VI. Saturated Amounts and Some Thermodynamic Values of Adsorption

Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 91-97
Author(s):  
Kei Morisato ◽  
Yutaka Ishimaru ◽  
Hiroyuki Urakami
Keyword(s):  
Free Energy ◽  
Standard Free Energy ◽  
Molecular Size ◽  
Free Energy Change ◽  
Energy Change ◽  
Multilayer Adsorption ◽  
Monolayer Adsorption ◽  
Wood Part ◽  
Cohesive Interaction

Summary To understand the swelling phenomenon of wood in liquids,the saturated amount of adsorption of liquids onto wood and the standard free energy changes of the adsorption were determined. The saturated amount of adsorption obtained by regression for several liquids decreased with increasing molecular size of the solvents. The mechanism of wood swelling is discussed systematically taking all the liquids examined in previous experiments into account. Since methanol molecules require more energy for release from cohesive interactions within bulk liquids in the adsorption onto pre-swollen wood,the values of free energy change of adsorption for methanol were lower than the values for acetone,although the relative swelling with methanol was higher. These results suggest that although the cohesive interaction within the bulk liquids reduces adsorptivity,the phenomenon of wood swelling is influenced not only by monolayer adsorption but also by multilayer adsorption. Therefore,the cohesive interaction within the bulk liquids reduces adsorptivity but enhances the condensation which strongly influences the swelling of wood.

scholarly journals Removal of Ni (II) from Aqueous Solution by Adsorption onto Activated Carbon Prepared from Lapsi (Choerospondias axillaris) Seed Stone

2014 ◽  
Vol 9 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Rajeshwar M. Shrestha ◽  
Margit Varga ◽  
Imre Varga ◽  
Amar P. Yadav ◽  
Bhadra P. Pokharel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Low Cost ◽  
Chemical Characterization ◽  
Maximum Adsorption Capacity ◽  
Adsorption Data ◽  
Optimum Ph ◽  
Nickel Adsorption

Activated carbons were prepared from Lapsi seed stone by the treatment with H2SO4 and HNO3 for the removal of Ni (II) ions from aqueous solution. Two activated carbon have been prepared from Lapsi seed stones by treating with conc.H2SO4 and a mixture of H2SO4 and HNO3 in the ratio of 1:1 by weight for removal of Ni(II) ions. Chemical characterization of the resultant activated carbons was studied by Fourier Transform Infrared Spectroscopy and Boehm titration which revealed the presence of oxygen containing surface functional groups like carboxyl, lactones and phenols in the carbons. The optimum pH for nickel adsorption is found to be 5. The adsorption data were better fitted with the Langmuir equations than Freundlich adsorption equation to describe the equilibrium isotherms. The maximum adsorption capacity of Ni (II) on the resultant activated carbons was 28.25.8 mg g-1 with H2SO4 and 69.49 mg g-1 with a mixture of H2SO4 and HNO3. The waste material used in the preparation of the activated carbons is inexpensive and readily available. Hence the carbons prepared from Lapsi seed stones can act as potential low cost adsorbents for the removal of Ni (II) from water. DOI: http://dx.doi.org/10.3126/jie.v9i1.10680Journal of the Institute of Engineering, Vol. 9, No. 1, pp. 166–174

Sign in / Sign up

Export Citation Format

Share Document