scholarly journals Adsorption Kinetics for the Removal of Fluoride from Aqueous Solution by Activated Carbon Adsorbents Derived from the Peels of Selected Citrus Fruits

2010 ◽  
Vol 7 (s1) ◽  
pp. S419-S427 ◽  
Author(s):  
C. Chakrapani ◽  
Ch. Suresh Babu ◽  
K. N. K. Vani ◽  
K. Somasekhara Rao

Activated carbons (ACs) were prepared from the peels ofCitrus documana, Citrus medicaandCitrus aurantifoliafruits. Adsorption of fluoride onto these activated carbons was investigated. Effect of contact time in the removal of fluoride from aqueous solution at neutral pH was studied. Five kinetic models; the pseudo first- and second-order equations, intraparticle diffusion, pore diffusion and the Elovich equation, were selected to follow adsorption process. Adsorption of fluoride onto adsorbents could be described by pseudo second-order equation. Kinetic parameters; rate constants, equilibrium adsorption capacities and correlation coefficients, for each kinetic equation were calculated and discussed. The good fitting of kinetic data to pore diffusion and Elovich equations indicate that pore diffusion plays a vital role in controlling the rate of the reaction.

2011 ◽  
Vol 236-238 ◽  
pp. 155-158
Author(s):  
Li Fang Zhang ◽  
Shu Juan Dai ◽  
Ying Ying Chen

In this study, Biosorption of hexavalent chromium ions from aqueous solution by using biomass ofAspergillus nigerwas investigated. Different parameters such as initial pH, biosorbent amount, contact time and temperature were explored. The biosorption of Cr (VI) ions was highly pH dependent and the optimum pH for biosorption of Cr (VI) ions was found to be 2.0. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The biosorption equilibrium was established in about 120min of contact time. Equilibrium uptake of Cr (VI) ions onto biomass increased from 12.57 mg/g at 20°C to 19.48 mg/g at 40 °C for 20mg/L Cr (VI) ions concentration. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.997 in all studied temperatures. These results suggest that the biomass ofAspergillus nigeris a promising biosorbent for removal of chromium (VI) ions from the wastewater.


Author(s):  
Pyae Phyo Aung ◽  
Olga A. Veselova ◽  
Irina D. Troshkina

The kinetics of scandium sorption with impregnate-containing extractant – phosphine oxide based on hypercrosslinked polystyrene from nitric acid solutions was studied using a method of limited solution volume. A sample of sorbent obtained by impregnation contained 0.233 g extractant/g impregnate. Under batch conditions, the influence of temperature in the range 293-313 K on the kinetics of scandium sorption by impregnate was studied. It was revealed that the saturation of impregnate by scandium is established in 20-30 min. For the processing of integral kinetic scandium sorption curves, the pseudo-first and pseudo-second-order models, as well as the Elovich equation, were used. The values of the rate constants calculated from the pseudo-second-order model, describing the kinetic data with the best correlation coefficients (R2 0.931-0.995), reach (9.51-10.4) g∙(mmol∙min)-1. The activation energy of scandium sorption, calculated by an equation similar to the Arrhenius equation, is (2.8±0.2) kJ / mol. Due to the improved kinetic characteristics compared with traditional sorbents, hypercrosslinked polystyrene impregnates containing phosphine oxide can be used to extract of scandium from solutions formed during the processing of scandium-containing raw materials.Forcitation:Pyae Phyo Aung, Veselova O.A., Troshkina I.D. Kinetics of scandium sorption by impregnate containing phosphinoxide. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 28-30.


2018 ◽  
Vol 783 ◽  
pp. 109-114
Author(s):  
Nor Salmi Abdullah ◽  
Syazrin Syima Sharifuddin ◽  
Mohd. Hazwan Hussin

The adsorption ability of powdered activated carbons (PAC) derived from palm kernel shell (PKS) was investigated. PAC was prepared by chemical activation method using ZnCl2as an activating agents. The adsorption studies of Hg(II) was carried out under control condition with constant pH, solution temperature (30 °C), treatment time (90 min) and absorbent dosage (2.0 g L-1). It was revealed that PAC efficiently removed as much as 10 mg L-1of Hg(II) with the percentage of removal up to 97.7 %. Both Langmuir and Freundlich adsorption isotherms were used to explain the adsorption behavior. Freundlich model was found to be fitted well and favored multilayer adsorption. The kinetics data were fitted with pseudo-first order and pseudo-second order, and it was found to obeys the pseudo-second order kinetic order. Recent finding suggest that PKS has the potential to be a promising precursor for the production of activated carbon with the excellent adsorption capacity to remove Hg(II) from aqueous solution.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Is Fatimah ◽  
Iwan Sumarlan ◽  
Tuty Alawiyah

A photodegradation process of methylene blue (MB) in aqueous solution using Fe(III)/TiO2-montmorillonite photocatalyst is presented. The photocatalyst material was prepared using Indonesian natural montmorillonite in TiO2pillarization process followed by Fe(III) ion exchange. Kinetic study on MB degradation was conducted and evaluated by three kinetic models: the pseudo-first- and second-order equations and the Elovich equation. From the results, it is concluded that the degradation under the photo-Fenton-like process utilizing Fe(III)/TiO2-montmorillonite photocatalyst conformed to the Elovich kinetic model.


2016 ◽  
Vol 74 (9) ◽  
pp. 2021-2035 ◽  
Author(s):  
Mohammad Ali Zazouli ◽  
Ali Azari ◽  
Samaneh Dehghan ◽  
Razieh Salmani Malekkolae

In this study, eucalyptus bark and Crataegus oxyacantha core-based activated carbon were synthesized and their morphological features characterized by scanning electron microscopy and Fourier transform infrared spectroscopy techniques. The efficiency of synthesized adsorbents in removal of methylene blue (MB) from aqueous solution was investigated in a series of batch experiments. Furthermore, the influences of various experimental factors involving the contact time, the initial dye concentration, the adsorbent dosage, and the pH of the dye solution were investigated. The point of zero charge (pHpzc) of the applied adsorbents was also determined. In addition, the experimental data were expressed by Langmuir, Freundlich and Tempkin isotherms and pseudo-first order and pseudo-second order kinetic models. Adsorption equilibrium of the two adsorbents was reached within 1 h for MB concentrations of 20 to 100 mg/L. The equilibrium data obtained at optimum conditions of MB sorption by eucalyptus bark activated carbon and Crataegus oxyacantha core activated carbon were best fitted to Tempkin and Langmuir isotherm models, respectively. Besides, it was revealed that the adsorption rate follows a pseudo-second order kinetic model. From the findings of this study, it can be postulated that these adsorbents could be of great potential as a new class of adsorbents for organic dye removal from polluted water.


2014 ◽  
Vol 556-562 ◽  
pp. 286-289
Author(s):  
Li Fang Zhang ◽  
Chun Yang Jiang ◽  
Zhao Shao

In this study, Biosorption of Cr (VI) ions from aqueous solution by using biomass of Aspergillus niger was investigated. The effects of initial solution pH, biosorbent amount, contact time, initial concentration and temperature were explored. In batch experiments, the biosorption capacity of Cr (VI) decreased with increase in solution pH. The biosorption of Cr (VI) ions with pH range of 2.0-8.0 was found to be optimal at pH 2. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The bosorption capacity was increased with the increasing initial Cr (VI) concentration and temperature in studied range. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.9997 in all studied temperatures. These results suggest that the biomass of Aspergillus niger is a promising biosorbent for removal of Cr (VI) ions from the wastewater.


2010 ◽  
Vol 152-153 ◽  
pp. 791-796
Author(s):  
Hui Jun Xie ◽  
Qiang Ma ◽  
Wei Tan ◽  
Jian Zhang

Removal of Phthalate Easters (PAEs) by softstem bulrush carbon (SBC) in aqueous solution was studied. In this work, the effects of pH, adsorbent dosage (0.8-2.8g), and initial DMP concentration (20-100 mg/L) on the adsorption system were investigated. It turned out that the effective pH was 7.0 and the optimum adsorbent dose was 2.0 g/L. Equilibrium experimental data at 283, 293 and 308 K were better represented by Freundlich isotherm than Langmuir isotherm. In addition, adsorption kinetics was determined using pseudo-first-order model, pseudo-second-order model. The results indicated that the adsorption of DMP onto SBC followed pseudo-second-order model.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Hülya Karaca ◽  
Turgay Tay ◽  
Merih Kıvanç

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.


2020 ◽  
Vol 74 (1) ◽  
pp. 65-70
Author(s):  
Bojana Obradovic

Adsorption processes are widely used in different technological areas and industry sectors, thus continuously attracting attention in the scientific research and publications. Design and scale-up of these processes are essentially based on the knowledge and understanding of the adsorption kinetics and mechanism. Adsorption kinetics is usually modeled by using several well-known models including the pseudo-first and pseudo-second order models, the Elovich equation, and the intra-particle diffusion based models. However, in the scientific literature there are a significant number of cases with the inappropriate use of these models, utilization of erroneous expressions, and incorrect interpretation of the obtained results. This paper is especially focused on applications of the pseudo-second order, intra-particle diffusion and the Weber-Morris models, which are illustrated with typical examples. Finally, general recommendations for selection of the appropriate kinetic model and model assumptions, data regression analysis, and evaluation and presentation of the obtained results are outlined.


2012 ◽  
Vol 27 ◽  
pp. 11-18
Author(s):  
Timi Tarawou ◽  
Michael Horsfall

The adsorption of chromium (VI) ions from aqueous solution was studied using pure and carbonized fluted pumpkin waste biomass (FPWB). The kinetic data shows a pseudo-first-order mechanism with rate constants of 1.26 × 10-2 and 1.933 × 10-2 mg g-1 min-1 for the pure and carbonized FPWB, respectively. While the pseudo-second-order mechanism has rate constants of 0.93 × 10-1 and 1.33 × 10-1 mg g-1 min-1 for the pure and carbonized waste biomass respectively. The pseudo-second order kinetic model was found to be more suitable for describing the experimental data based on the correlation coefficient values (R2) of 0.9975 and 0.9994 obtained for pure waste biomass (PWB) and carbonized waste biomass (CWB), respectively. The results obtained from this study show that PWB and CWB have very high removal capacity for chromium (VI) from aqueous solution over a range of reaction conditions. Thus, fluted pumpkin waste biomass (Telfairia occidentalis Hook F) is a potential sorbent for the treatment of industrial effluents containing chromium (VI) contaminant.DOI: http://dx.doi.org/10.3126/jncs.v27i1.6436 J. Nepal Chem. Soc., Vol. 27, 2011 11-18Uploaded date: 16 July, 2012


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