scholarly journals Fluoride sorption using Cynodon dactylon based activated carbon

2011 ◽  
Vol 65 (1) ◽  
pp. 23-35 ◽  
Author(s):  
G. Alagumuthu ◽  
V. Veeraputhiran ◽  
R. Venkataraman

This study deals the application of Cynodon dactylon based thermally activated carbon for fluoride toxicity. The batch adsorption techniques was followed at neutral pH as the functions of contact time, adsorbent dose, adsorbate concentration, temperature and the effect of co-anions. The data indicate that the prepared adsorbent surface sites are heterogeneous in nature and that fits into a heterogeneous site-binding model. The present system followed the Redlich-Peterson isotherm as well as Langmuir adsorption isotherm model. Lagergren pseudo-first-order, pseudo-second-order, intra particle diffusion and Elovich kinetics were modeled to describe the adsorption rate of fluoride and determined as this scheme followed pseudo-second-order kinetics. The calculated enthalpy change, ?H?, and entropy change, ?S?, for the adsorption process are +8.725 kJ/mol and +0.033 J/mol K respectively and shows endothermic experience. Instrumental analysis of XRD, FTIR and SEM gives the idea about the fluoride binding ability of adsorbent.

2017 ◽  
Vol 75 (10) ◽  
pp. 2454-2464 ◽  
Author(s):  
O. S. Lawal ◽  
O. S. Ayanda ◽  
O. O. Rabiu ◽  
K. O. Adebowale

The biosorption characteristics of Pb (II) ions from aqueous solution using black walnut (Juglans nigra) seed husk (WSH) biomass were investigated using batch adsorption techniques. The effects of pH, contact time, initial Pb (II) ion concentration, and temperature were studied. The Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data. It was found that the adsorption of Pb (II) ions onto WSH was best described by the Freundlich adsorption model. Biosorption kinetics data were tested using the pseudo-first order and pseudo-second order models, and it was observed that the kinetics data fitted the pseudo-second order model. Thermodynamic parameters such as standard Gibbs free energy change (ΔG0), standard enthalpy change (ΔH0) and standard entropy change (ΔS0) were evaluated. The result showed that biosorption of Pb (II) ions onto WSH was spontaneous and endothermic in nature. The FTIR study showed that the following functional groups: O-H, C = O, C-O, C-H and N-H were involved in binding Pb (II) ions to the biomass.


2011 ◽  
Vol 148-149 ◽  
pp. 357-360
Author(s):  
Jin Bo Huang ◽  
Min Cong Zhu ◽  
Zhi Fang Zhou ◽  
Hong Xia Zhang

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.


2021 ◽  
Vol 9 (11) ◽  
pp. 62-72
Author(s):  
Akissi Lydie Chantal Koffi ◽  
◽  
Djamatche Paul Valery Akesse ◽  
Herman Yapi Yapo ◽  
David Leonce Kouadio ◽  
...  

The aim of this research is to investigate the feasibility of using activated carbon from cocoa pod shells, waste from agriculture to adsorb methylene blue from aqueous solutions through batch tests. Various physiochemical parameters such as, contact time, initial dye concentration, adsorbent dosage, pH of dye solution and temperature were investigated in a batch-adsorption technique. The process followed the pseudo-second order kinetics model which showed chemical adsorption. Langmuir and Freundlich isotherm models were used to determine adsorption constants. The maximum adsorption capacity at 30°C is 526.31 mg/g. Thermodynamic parameters such as enthalpy change (∆Hº), free energy change (∆Gº) and entropy change (∆Sº) were studied, and the adsorption process of BM was found to be exothermic and spontaneous.


2014 ◽  
Vol 49 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Syed Usman Nasrin Banu ◽  
G. Maheswaran

The feasibility of preparing activated carbon from Eichornia crassipes by chemical activation was investigated. Batch experiments were carried out for the sorption of Methylene Blue (MB) and Rhodamine B (RB) onto the prepared activated carbon. The variables studied were initial dye concentration, pH, adsorbent dose, and contact time. Equilibrium data for the adsorption of the dyes onto activated carbon were obtained from batch adsorption experiments. Two-parameter isotherm models including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich were employed for fitting equilibrium data. Three-parameter isotherm models including Redlich–Peterson, Toth, and Koble–Corrigan models were also employed for fitting the equilibrium data. Linear and non-linear regression methods were used to determine the best fit model to the equilibrium data. It was found that non-linear regression is a better method for determining isotherm parameters. The data were fitted to pseudo-first-order, pseudo-second-order, intraparticle diffusion model, and Elovich equation. The pseudo-second-order model gave the best fit to the equilibrium data as seen from correlation coefficient values. Fourier transform infrared spectroscopy and scanning electron microscopic investigations were carried out to confirm the morphological characteristics of the adsorbent. The prepared activated carbon had greater affinity for adsorbing MB when compared to RB.


2016 ◽  
Vol 875 ◽  
pp. 1-15 ◽  
Author(s):  
Arush Sharma ◽  
Gaurav Sharma ◽  
Amit Kumar ◽  
Zia Mahmood Siddiqi ◽  
Gaurav Sharma

In this study, Cornulacamonacantha stem (CMS) has been used for the preparation of highly competent, ecofriendly and low-cost activated carbon (CMSAC) biosorbent. It was characterized by some instrumental techniques such as Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The biosorbent was evaluated for the eradication of hazardous malachite green (MG) dye from aqueous solution. Batch experiments were conducted to assess the effect of various adsorption parameters such initial dye concentration, sorbent dosage, pH, agitation time and temperature. The results indicated that maximum sorption of MG was occurred at the pH ranged from 10.0 to 12.0. Langmuir, Freundlich and Tempkin isotherms were applied for the interpretation of experimental data and Langmuir model was found to be strongly fitted with higher R2 (0.999). The kinetics studies were examined using pseudo-first-order, pseudo-second-order, Elovich model. The sorption process was described by pseudo-second-order kinetics. The thermodynamic parameters such as energy change (ΔG°), enthalpychange (ΔH°) and entropy change (ΔS°) were found to be-6.21kJ/mol, 46.17 kJ/mol and 172.81 J/mol/K, respectively. The adsorption performance of malachite green dye onto gleaming activated carbon developed from Cornulacamonacantha stem was found to be spontaneous, feasible and endothermic process.


Author(s):  
Abdelkader Ouakouak ◽  
Leila Youcef ◽  
Djihad Boulanouar ◽  
Samia Achour

The objective of this work is to study the phosphate adsorption from natural waters by using a granular activated carbon (GAC). Experiments were carried out with synthetic solutions of phosphate prepared using groundwater (mineralized drinking water). Batch tests were carried out in order to study different operating parameters such as the effect of contact time, pH, initial phosphate concentration and adsorbent dosage. In addition, the adsorption kinetic data were simulated using the pseudo first order, the pseudo second-order and the intra-particle diffusion model. The sorption equilibrium was analyzed by Langmuir, Freundlich and Dubinin–Radushkevich isotherms model. Results show that the phosphate adsorption was reversible and the quantity adsorbed reached its maximum value (2.82 mg/g) after 30 min. It was also found that phosphate uptake was affected by variation of pH, initial concentration of phosphate and granular activated carbon dosage. The adsorption improved with increase in pH values, initial concentration and adsorbent dosage. The results of kinetic studies revealed that pseudo-second-order model adequately described the adsorption phosphate on GAC and the intra-particle diffusion involved in the adsorption mechanism. Also, isotherm study showed that Langmuir isotherm best fit the data and the adsorption was a physical type.


2015 ◽  
Vol 11 (9) ◽  
pp. 3876-3887
Author(s):  
Prakash Bhila Wagh ◽  
V.S Shrivastava ◽  
V.S Shrivastava

 The kinetics and equilibrium study of crystal violate dye adsorption on mixture of activated carbon (PWCAC) and (CSAC) was studied. The use of low cost ecofriendly adsorbent has been investigated as an ideal alternative to the current expensive methods of removing of dye from aqueous solution. This study was done by batch adsorption techniques. The quantitative adsorption kinetic and equilibrium parameter for crystal violate dye were studied using uv-visible adsorption spectroscopy. The effect of initial dye concentration, pH,adsorbent dose, temperature, particle size were determined to find the optimal condition for adsorption. The percentage removal of dye was found to be most effective at pH10and contact time 120 min and at an adsorbent dose 4 g/L of dye. The study indicates that’s, the percentage removal of dye increases with increasing initial dye concentration, adsorption dose and contact time and attains equilibrium at optimum conditions.The equilibrium study of adsorption of crystal violate dye on to mixture of activated carbon was investigated using pseudo first order and pseudo second order kinetic models. The adsorption kinetics was found to follow pseudo second order kinetic model. The equilibrium adsorption data of crystal violate dye on PWCAC and CSAC mixture was analyzed by Langmuir and Freundlich adsorption model. The results show that the Langmuir model provides the best correlation.


2016 ◽  
Vol 1133 ◽  
pp. 542-546 ◽  
Author(s):  
Safoura Daneshfozoun ◽  
Bawadi Abdullah ◽  
M. Azmuddin Abdullah

Oil Palm Empty Fruit Bunch (OPEFB) contributes more than 50% of oil palm biomass wastes in Malaysia. This provides tremendous opportunities for value-added product generation from recycling and utilizing its latent capacity. In this work, the performance of physically-pretreated OPEFB fibers without any chemical treatment for Pb2+ removal from aqueous system was evaluated. Three different size ranges (1-5 cm, 0.5-2 mm and 0.005-0.02 mm) of raw sorbent, pH (4-10) and contact time (2-150 min) for Pb2+ batch adsorption were tested. The kinetic data were evaluated by the pseudo-first-order, pseudo-second-order and intra-particle diffusion model. The experimental data were well described by the pseudo-second-order model with r2=0.997. Adsorption efficiency was size-dependent with about 38% sorption increase at 0.005-0.02 mm, and reached 94% efficiency, achieved 47.49 mg/g capacity with 500 ppm Pb2+ at pH 7.5, in 60 min. The eco-friendly, low cost sorbent can be applied as green, effective adsorbent in waste water remediation.


2015 ◽  
Vol 11 (9) ◽  
pp. 3876-3887
Author(s):  
Prakash Bhila Wagh ◽  
V.S Shrivastava ◽  
V.S Shrivastava

 The kinetics and equilibrium study of crystal violate dye adsorption on mixture of activated carbon (PWCAC) and (CSAC) was studied. The use of low cost ecofriendly adsorbent has been investigated as an ideal alternative to the current expensive methods of removing of dye from aqueous solution. This study was done by batch adsorption techniques. The quantitative adsorption kinetic and equilibrium parameter for crystal violate dye were studied using uv-visible adsorption spectroscopy. The effect of initial dye concentration, pH,adsorbent dose, temperature, particle size were determined to find the optimal condition for adsorption. The percentage removal of dye was found to be most effective at pH10and contact time 120 min and at an adsorbent dose 4 g/L of dye. The study indicates that’s, the percentage removal of dye increases with increasing initial dye concentration, adsorption dose and contact time and attains equilibrium at optimum conditions.The equilibrium study of adsorption of crystal violate dye on to mixture of activated carbon was investigated using pseudo first order and pseudo second order kinetic models. The adsorption kinetics was found to follow pseudo second order kinetic model. The equilibrium adsorption data of crystal violate dye on PWCAC and CSAC mixture was analyzed by Langmuir and Freundlich adsorption model. The results show that the Langmuir model provides the best correlation.


2015 ◽  
Vol 11 (5) ◽  
pp. 651-658 ◽  
Author(s):  
Hossein Ahdno ◽  
Hoda Jafarizadeh-Malmiri

Abstract The present work studies the removal of colored components from date syrup by activated carbon powder. The clarification process was carried out at an experimental batch set up and the role of activated carbon content, temperature and residence time was investigated on adsorption efficiency. The experimental data were analyzed by intra-particle diffusion, pseudo first- and second-order models. The adsorption capacity of activated carbon increases with increase of process temperature. Adsorption kinetics could be best modeled by the pseudo second-order model. Also, Langmuir isotherm describes the equilibrium data variation better than Freundlich and Temkin equations. The feasibility of adsorption was evaluated by measuring color removal at three temperatures and Van’t Hoff equation was used for computation of Gibbs energy. Thermodynamically, the process is endothermic accompanied with increase in randomness and decrease in Gibbs energy. Finally, the optimum temperature for clarification of date syrup was determined to be 50°C.


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