Isotherm and Kinetics Modeling of Fluoride Removal from Industrial Effluent by Alumina

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Z. V. P. Murthy ◽  
Telu Prabhakar ◽  
Raj Kumar
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Kinetic Models ◽  
Fluoride Concentration ◽  
Industrial Effluent ◽  
Second Order ◽  
Fluoride Removal ◽  
Wide Range ◽  
Pseudo Second Order ◽  
High Level

Fluoride contamination occurs in a wide range of industrial wastewater that has to be regulated from time to time. In the present study, wastewater from a polybutadiene rubber plant of Indian Petrochemicals Corporation Limited, Vadodara, Gujarat, India with a higher temperature, acidic pH and high level of fluoride concentration is treated with alumina. The contact time between the adsorbent and the adsorbate should be sufficient for the adsorption to be effective. Though synthetic resins have good adsorption capacity for the wastewater, they have some disadvantages; therefore, alumina has been tried. Properties of alumina, such as pH, bulk density, surface area, pore specific volume, and bulk crushing strength, have been found. Adsorption by alumina is found to be favorable. Five equilibrium adsorption isotherms, viz. Freundlich, Langmuir, Temkin, Harkins-Jura and Halsey, have been tested. It is found that the Halsey and Freundlich adsorption isotherms are fitting the data well. Four kinetic models, viz. Lagergren, pseudo-first-order, second-order, pseudo-second-order and Elovich have been used to find the rate constants. Out of the four kinetic models tested, the pseudo-second-order model fitted the data well in the present case. It is found that when the pH of the wastewater is acidic the adsorption capacity is high. It is also seen that as the temperature of the wastewater increases, the capacity of adsorption also increases.

scholarly journals Enhancing Adsorption Capacity of Clay and Application in Dye Removal from Waste Water

2014 ◽  
Vol 39 ◽  
pp. 35-51 ◽  
Author(s):  
O.T. Ogunmodede ◽  
O.L. Adebayo ◽  
A.A. Ojo
Keyword(s):  
Waste Water ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Kinetic Models ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Small Surface ◽  
Intercalation Process ◽  
Pseudo Second Order

Natural clay has been considered as a potential absorbent for removing pollutants from water and waste water. Nonetheless, the effective application of clay for water treatment is limited due to small surface area and presence of net negative surface charge, leading to it low adsorption capacity. The absorption capacity was boosted via intercalation of CaO derived from snail shell (SS). The methylene blue sorption potential, PZC, and the surface area of unmodified clay sample were substantially enhanced by the intercalation process. The process of sorption of MB from solution was analyzed using five different isotherm models (Langmuir, Freundlich, Temkin, Harkins-Jura, and Halsey isotherm equations). The value of the Langmuir monolayer sorption capacity qm (mg/g) increased from 50.12 to 88.71, PZC values increased from 4.50 to 7.40, and the surface area (m2/g) value increased from 27 m2/g to 123 m2/g after the intercalation process. The experimental data were fitted into two kinetic models: Lagergren pseudo-first order and the chemisorptions pseudo-second order. It was observed that chemisorptions pseudo-second order kinetic model described the sorption process with high coefficients of determination (r2) better than pseudo first other kinetic models. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework.

scholarly journals REMOVAL OF FLUORIDE USING NEEM LEAVES BATCH REACTOR: KINETICS AND EQUILIBRIUM STUDIES

2018 ◽  
Vol 11 (3) ◽  
pp. 237
Author(s):  
Tej Pratap Singh ◽  
Majumder Cb
Keyword(s):  
Removal Efficiency ◽  
Batch Reactor ◽  
Low Cost ◽  
Fluoride Concentration ◽  
Second Order ◽  
Fluoride Removal ◽  
Equilibrium Studies ◽  
Neem Leaves ◽  
Pseudo Second Order ◽  
Adsorbent Dose

 Objective: The aim of this paper is to study the fluoride removal efficiency of the neem leaves low-cost biosorbent for defluoridation of sewage wastewater.Methods: For finding the best operating condition for maximum removal of fluoride, batchwise experiments were performed at different contact times and keeping other parameters to be constant such as pH, initial fluoride concentration, and adsorbent dose. Various kinetic models such as intraparticle diffusion model, Bangham’s model, and Elovich model had been investigated for determining the suitable adsorption mechanism. The rate of adsorption of fluoride on neem leaves has been determined by pseudo-first-order and pseudo-second-order rate models.Results: The adsorption kinetics rate and mechanism was best described by the pseudo-second-order model and Bangham’s model, respectively. The optimum pH, initial concentration, adsorbent dose, and contact time were found to be 7, 20 mg/L, 10 g/L, and 40 min, respectively, for which there was maximum fluoride removal.Conclusion: The result obtained from the experiments show that the neem leaves have been proved to be a low-cost biosorbent for the defluoridation of the sewage wastewater and have high fluoride removal efficiency.

scholarly journals Au-O-MWCNTs and TiO2-O-MWCNTs as Efficient Nanocarriers for Dexamethasone: Adsorption Isotherms and Kinetic Studies

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Maryam Haghighi ◽  
Azadeh Khoshfetrat
Keyword(s):  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Adsorption Isotherms ◽  
Multiwall Carbon Nanotubes ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Second Order ◽  
X Ray Diffraction ◽  
Pseudo Second Order ◽  
Drug Nanocarriers

In this research, the fabrication of drug delivery systems based on oxidized multiwall carbon nanotubes (O-MWCNTs) was studied. Herein, TiO2 and Au were conjugated with O-MWCNTs to prepare efficient nanocarriers for dexamethasone (dex). The samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In addition, dex loading was studied using adsorption isotherms including Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich. The results show that dex adsorption agreed well with the Freundlich isotherm. Increasing the TiO2 to O-MWCNT ratio from (1 : 4) to (1 : 2) can improve the adsorption capacity from 290   mg ⋅ g − 1 to 320 320   mg ⋅ g − 1 . The increasing Au amount increases the adsorption capacity from 437.78   mg ⋅ g − 1 (SA1) to maximum 476.19   mg ⋅ g − 1 (SA6). The maximum equilibrium binding energy A T 1.67   L ⋅ mg − 1 was obtained for SA2, and SA7 shows high binding strength between dex and the nanoadsorbent. Carbon nanotubes (CNTs) show good affinity with high loading capabilities for dexamethasone adsorption. The synthesized TiO2-O-MWCNTs:1/2 with the maximum removal percent (80%) was proposed as an appropriate nanocarrier for dexamethasone. Pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion models were investigated for all synthesized drug nanocarriers. According to regression coefficients, experimental data are in good agreement with the pseudo-second order model for all adsorbents except O-MWCNT/CTAB. Experimental results revealed that the Elovich model could account for the O-MWCNT/CTAB adsorbent.

Adsorption of Fluoride on Limestone-Derived Apatite

2012 ◽  
pp. 128-138
Author(s):  
Cyprian Murutu ◽  
Maurice S. Onyango ◽  
Aoyi Ochieng ◽  
Fred Otieno
Keyword(s):  
Drinking Water ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Dental And Skeletal Fluorosis ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Permissible Levels ◽  
Ph Range

Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. Adsorptive based defluoridation is the most popular technique with several end-user applications. Consequently, this paper describes the fluoride removal potential of a novel sorbent, limestone-derived apatite from drinking water. The adsorbent was prepared by calcining limestone followed by reacting with orthophosphoric acid. Batch sorption studies were performed as a function of contact time, pH, initial fluoride concentration, temperature and adsorbent dose. Sorption of fluoride was found to be pH dependent with a maximum occurring in the pH range of 5-9. The authors also observed that the material had a buffering effect on the same pH range. Meanwhile, the adsorption capacity was found to increase with temperature, depicting the endothermic nature of the adsorption process and decreases with adsorbent mass. The equilibrium data was well described by the conventional Langmuir isotherm, from which isotherm the maximum adsorption capacity was determined as 22.2 mg/g. From the kinetic perspective, the fluoride adsorptive reaction followed the pseudo-second order mechanism.

scholarly journals FLUORIDE REMOVAL USING ACTIVATED ALUMINA: A CASE STUDY OF BHOOMA CHOTA WATER

2013 ◽  
Vol 21 (21) ◽  
pp. 61-77
Author(s):  
R. AGRAWAL ◽  
M. K. MISHRA ◽  
K. MARGANDAN ◽  
K. SINGH ◽  
R. ACHARYA ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Absorption Capacity ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Least Square ◽  
Fluoride Removal ◽  
Activated Alumina ◽  
Surface Absorption ◽  
Fluoride Adsorption ◽  
Pseudo Second Order

The adsorption of fluoride, from a fluoride, contaminated groundwater sample from the village, Bhooma Chota, District Sikar, in the State of Rajasthan, India, has been studied using alumina grade DF-101. The fluoride adsorption capacity (q1) has been fitted into the pseudo-first-order adsorption, pseudo-second-order adsorption, Elovich, and intraparticle diffusion models. It has been found that the kinetic data fits best in the pseudo-second-order rate equation giving a very high correlation coefficient (R2 = 0.991). the modeled fluoride absorption capacity (q1) has been calculated from the various equations using the constants derived from the least square regression plots. The calculated q1 values, model the experimental data very well, for the pseudo-second-order and Elovich equations, as is evident from the sum of square error calculations. Fluoride removal is through a combination of surface absorption and intraparticle diffusion. A study of the fluoride removal process with increasing dosage of activated alumina reveals that though the percentage of fluoride removal increases with activated alumina, the adsorption capacity at equilibrium decreases. The minimum dosage of activated alumina which causes the maximum percentage removal of fluoride from water, while at the same time brings forth its highest equilibrium absorption capacity has been determined.

Adsorption of Fluoride on Limestone-Derived Apatite

2010 ◽  
Vol 1 (3) ◽  
pp. 13-22 ◽  
Author(s):  
Cyprian Murutu ◽  
Maurice S. Onyango ◽  
Aoyi Ochieng ◽  
Fred Otieno
Keyword(s):  
Drinking Water ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity ◽  
Dental And Skeletal Fluorosis ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Permissible Levels ◽  
Ph Range

Fluoride in drinking water above permissible levels is responsible for human dental and skeletal fluorosis. Adsorptive based defluoridation is the most popular technique with several end-user applications. Consequently, this paper describes the fluoride removal potential of a novel sorbent, limestone-derived apatite from drinking water. The adsorbent was prepared by calcining limestone followed by reacting with orthophosphoric acid. Batch sorption studies were performed as a function of contact time, pH, initial fluoride concentration, temperature and adsorbent dose. Sorption of fluoride was found to be pH dependent with a maximum occurring in the pH range of 5-9. The authors also observed that the material had a buffering effect on the same pH range. Meanwhile, the adsorption capacity was found to increase with temperature, depicting the endothermic nature of the adsorption process and decreases with adsorbent mass. The equilibrium data was well described by the conventional Langmuir isotherm, from which isotherm the maximum adsorption capacity was determined as 22.2 mg/g. From the kinetic perspective, the fluoride adsorptive reaction followed the pseudo-second order mechanism.

scholarly journals Kinetic Study of the Bioadsorption of Methylene Blue on the Surface of the Biomass Obtained from the Algae D. antarctica

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo
Keyword(s):  
Methylene Blue ◽  
Kinetic Study ◽  
Adsorption Capacity ◽  
Scientific Community ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Pseudo Second Order ◽  
Best Fit ◽  
Total Elimination ◽  
Purification Of Water

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.

Kinetics of lead ion biosorption from aqueous solution onto lyophilized Aspergillus niveus

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç
Keyword(s):  
Adsorption Capacity ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Lead Ions ◽  
Lead Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Aspergillus Niveus ◽  
Pseudo Second Order

The biosorption of lead ions (Pb2+) onto lyophilized fungus Aspergillus niveus was investigated in aqueous solutions in a batch system with respect to pH, contact time and initial concentration of the ions at 30 °C. The maximum adsorption capacity of lyophilized A. niveus was found to be 92.6 mg g−1 at pH 5.1 and the biosorption equilibrium was established about in 30 min. The adsorption capacity obtained is one of the highest value among those reported in the literature. The kinetic data were analyzed using the pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion equations. Kinetic parameters, such as rate constants, equilibrium adsorption capacities, and related correlation coefficients for the kinetic models were calculated and discussed. It was found that the adsorption of lead ions onto lyophilized A. niveus biomass fit the pseudo-second-order kinetic model well. The Langmuir and Freundlich isotherm parameters for the lead ion adsorption were applied and the Langmuir model agreed better with the adsorption of lead ions onto lyophilized A. niveus.

scholarly journals Harnessing of Newly Tailored Poly (Acrylonitrile)-Starch Nanoparticle Graft Copolymer for Copper Ion Removal via Oximation Reaction

2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary
Keyword(s):  
Experimental Data ◽  
Adsorption Capacity ◽  
Graft Copolymer ◽  
Adsorption Kinetics ◽  
Copper Ions ◽  
Copper Ion ◽  
Second Order ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.

Regeneration Effect of Fluoride-Rich Granular Activated Alumina on Desorption Regent NaOH Solution

2013 ◽  
Vol 316-317 ◽  
pp. 653-656
Author(s):  
Bai Jie Niu ◽  
Wen Ming Ding ◽  
Dan Dang
Keyword(s):  
Adsorption Capacity ◽  
Sodium Hydroxide Solution ◽  
Fluoride Concentration ◽  
Column Experiment ◽  
Fluoride Removal ◽  
Activated Alumina ◽  
Optimal Method ◽  
Column Adsorption ◽  
Naoh Solution ◽  
Regeneration Effect

As an effective adsorbent, granular activated alumina (GAA) has been widely used in defluoridation. In order to reduce cost and operate environment-friendly, the adsorbent should be regenerated. In this paper, column experiment was done to characterize the fluoride removal properties and to develop an optimal method to regenerate fluoride-rich modified activated alumina (MGAA). The MGAA can be regenerated by utilizing sodium hydroxide solution desorption, deionized water washing and ferric sulfate reactivation and then used for futher defluoride operation. The influence of the concentration of desorption agent (NaOH solution) and desorbing time on desorption rate and the adsorption capacity of regenerated MGAA were studied. The optimal desorption condition was: 1% NaOH solution for desorption agent, desorbing time in 1.5h.In addition, when the regenerated MGAA was used again for column adsorption test, its adsorption capacity reached 94% of that of original sorbent in 1mg/L outlet fluoride concentration.

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