scholarly journals Equilibrium, Kinetics and Thermodynamics of the Bleaching of Palm Oil Using Activated Nando Clay

2018 ◽  
pp. 1-13
Author(s):  
Nwabanne, Joseph T. ◽  
Onu, Chijioke E. ◽  
Nwankwoukwu, Okwudili C.
Keyword(s):  
Palm Oil ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Bleaching Efficiency ◽  
Rate Limiting Step ◽  
Equilibrium Data ◽  
Intra Particle Diffusion ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Rate Limiting

The effectiveness of Nando clay in the bleaching of palm oil was studied in this work. The clay was prepared by activating it with hydrochloric acid. The bleaching was carried out at different temperatures, adsorbent dosage and particle sizes. The result suggests that increase in temperature and adsorbent dosage increases the bleaching efficiency while the increase in particle size decreases the bleaching efficiency. Both the pseudo-first-order and the pseudo-second-order kinetic models describe efficiently the experimental data of the bleaching process. Intra-particle diffusion though involved in the adsorptive bleaching mechanism, is not the sole rate-limiting step in the bleaching of palm oil with activated Nando clay. The equilibrium data were described better by Langmuir and Freundlich models. The enthalpy, entropy and activation energy were determined to be 6.127 KJ/mol, 3.982 KJ/mol and 15.281 KJ respectively. The free energy was found to vary between- 3.999 to- 3.760 KJ/mol. The result indicates that bleaching efficiency of up to 96% can be obtained with the activated clay as an adsorbent.

scholarly journals Removal of copper from an electroplating industrial effluent using the native and modified spirogyra

2018 ◽  
Vol 78 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Nimra Ilyas ◽  
Sadia Ilyas ◽  
Sajjad-ur-Rahman ◽  
Sidra Yousaf ◽  
Aqsa Zia ◽  
...  
Keyword(s):  
Industrial Effluent ◽  
Order Kinetic ◽  
Sorption Data ◽  
Freundlich Model ◽  
First Order ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Rate Limiting

Abstract In the present study, biosorption behavior of a green filamentous alga, spirogyra in its native and modified states was investigated for copper removal from an electroplating industrial effluent. For this, the effluent containing 194 mg·L−1 Cu2+ in sulfate medium was contacted with both forms of spirogyra, under the parametric variations of effluent pH, adsorbent dosage, contact time, and sorption temperature. The study revealed spirogyra as a prominent candidate for removing contaminant metal cation; however, at the same condition, biosorption capacity of modified biomass in gel form was higher than the native spirogyra. At the optimized condition with 6 g sorbent dosage treated to 100 mL effluent for 30 min at pH 6.0 and temperature 20 °C, the maximum 82.8% and 96.4% copper could be adsorbed by the native and modified spirogyra, respectively. The batch sorption data using native biomass followed pseudo-first-order kinetic; exhibiting the multilayer sorption mechanism via surface diffusion could be defined by the Freundlich model. In contrast, the sulfuric acid treated modified spirogyra followed pseudo-second-order kinetics and intra particle diffusion as the rate-limiting step.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

Removal of Mg from spring water using natural clinoptilolite

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 81-92 ◽  
Author(s):  
S. Tomić ◽  
N. Rajić ◽  
J. Hrenović ◽  
D. Povrenović
Keyword(s):  
Ion Exchange ◽  
Kinetic Studies ◽  
Spring Water ◽  
Zeolite A ◽  
Zeolitic Tuff ◽  
Rate Limiting Step ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Natural Clinoptilolite ◽  
Rate Limiting

AbstractNatural zeolitic tuff from Brus (Serbia) consisting mostly of clinoptilolite (about 90%) has been investigated for the reduction of the Mg concentration in spring water. The sorption capacity of the zeolite is relatively low (about 2.5 mg Mg g-1for the initial concentration of 100 mg Mg dm-3). The zeolitic tuff removes Mg from water solutions by ion exchange, which has been demonstrated by energy dispersive X-ray analysis (EDS). The extent of ion exchange was influenced by the pH and the initial Mg concentration. Kinetic studies revealed that Lagergen's pseudo-second order model was followed. Intra-particle diffusion of Mg2+influenced the ion exchange, but it is not the rate-limiting step. Rather than having to dispose of the Mg-loaded (waste) zeolite, a possible application was tested. Addition to a wastewater with a low concentration of Mg showed that it could successfully make up for the lack of Mg micronutrient and, accordingly, enabled the growth of phosphate-accumulating bacteriaA. Junii, increasing the amount of phosphate removed from the wastewater.

scholarly journals Evaluation of Pb (II) Removal from Water Using Sodium Alginate/Hydroxypropyl Cellulose Beads

2020 ◽  
Vol 148 ◽  
pp. 02002 ◽  
Author(s):  
Rodel Guerrero ◽  
Catherine Acibar ◽  
Christine Marie Alarde ◽  
Jane Maslog ◽  
Christine Joy Pacilan
Keyword(s):  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Contact Time ◽  
Hydroxypropyl Cellulose ◽  
Order Kinetic ◽  
Hydrogel Beads ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Adsorption Kinetic Model

This study examined the removal of Pb2+ ions from aqueous solution with two different lead concentrations using a hydrogel-forming polymer based on hydroxypropyl cellulose (HPC) and sodium alginate (SA). The feasibility of the adsorption behavior of SA/HPC beads has been investigated with three varying ratios of 50:50, 75:25 and 100:0 under a stir condition. The adsorption experiments were done to determine the effects of contact time, lead concentration and SA-HPC ratio to the adsorption capacity of SA-HPC hydrogel beads. The results showed that the ratio 75:25 showed higher adsorption capacity compared to 100:0 and 50:50. It showcased 47.72 mg/g adsorption capacity and 95.45% adsorption percentage after three hours of contact time. The adsorption kinetic model indicated that the adsorption of Pb2+ ions onto the beads followed a pseudo-second order kinetic equation. This means that the adsorption mechanism shows a chemisorption process and its sole rate-limiting step is intraparticle diffusion.

Experimental and Modeling Studies of Sorption of Tetracycline onto Zeolite in the Presence of Copper(II)

2012 ◽  
Vol 512-515 ◽  
pp. 2355-2360 ◽  
Author(s):  
Hong Huang ◽  
Yan Li Zou ◽  
Ya Nan Li
Keyword(s):  
Removal Rate ◽  
Sorption Process ◽  
Order Kinetic ◽  
Adsorption Removal ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Equilibrium Process ◽  
Presence And Absence ◽  
Rate Limiting

The sorption performance of tetracycline on zeolite under different conditions was investigated in presence and absence of Cu(Ⅱ).The presence of Cu(Ⅱ) greatly increased the adsorption of tetracycline on zeolite. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto zeolite in the presence and absence of Cu(Ⅱ), and intra-particle diffusion was not the only rate-limiting in the sorption process. The qmax value calculated from Langmuir model were 17.37 and 68.26 mg/g in the absence and the presence of Cu(Ⅱ). The value of E calculated from Dubinin-Radushkevich (D-R) model confirmed that the adsorption in the absence and presence of Cu(Ⅱ) were mainly controlled by physical combined with chemical adsorption mechanism. The tetracycline sorption amount decreased in the absence of Cu(Ⅱ) and increased in the presence of Cu(Ⅱ) as the pH increasing. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% in the presence of Cu(Ⅱ) and 34.5% in the absence of Cu(Ⅱ) when the dosage of zeolite was 0.05g.

scholarly journals OPTIMIZATION OF NICKEL (II) AND CHROMIUM (III) REMOVAL FROM CONTAMINATED WATER USING SORGHUM BICOLOR

2017 ◽  
Vol 36 (3) ◽  
pp. 960-972
Author(s):  
LT Adewoye ◽  
SI Mustapha ◽  
AG Adeniyi ◽  
JO Tijani ◽  
MA Amoloye ◽  
...  
Keyword(s):  
Sorghum Bicolor ◽  
Metal Ion ◽  
Ion Concentration ◽  
Optimum Process ◽  
Process Conditions ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Adsorbent Dosage ◽  
Equilibrium Data ◽  
Pseudo Second Order

A central composite design (CCD) under the response surface methodology (RSM)was used to study the effect of three adsorption variables (pH, initial concentration, and adsorbent dosage) in order to determine the optimum process conditions for the adsorptions of Ni (II) and Cr (III) onto sulphuric acid modified sorghum bicolor activated carbon (SBAC).This study yielded removal efficiency of 98.89 % for Ni (II) and 94.27 % for Cr (III) ion under optimal conditions of pH (8), initial metal ion concentration (25 mg/L), adsorbent dosage (10 mg) and pH (7), initial metal ion concentration (5 mg/L), dosage (15 mg);respectively. Statistical analysis of variance results showed a good correlation existed between the experimental and predicted data with R2 values of 0.99 for Ni and 0.98 for Cr. The equilibrium data for Ni (II) adsorption was best described using Freundlich model while Langmuir model best fit Cr (III) adsorption. The mechanism of adsorption for both Ni and Cr adsorptions on SBAC followed Pseudo second order kinetic model.  http://dx.doi.org/10.4314/njt.v36i3.41

scholarly journals Adsorptive Removal of Aqeous Disperse Dye by using Flocs

2020 ◽  
Vol 9 (6) ◽  
pp. 767-771
Keyword(s):  
Ferric Chloride ◽  
Ferrous Sulphate ◽  
Aluminium Sulphate ◽  
Colour Removal ◽  
Adsorptive Removal ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Rate Limiting

Ferric chloride, Aluminium sulphate, and Ferrous sulphate flocs were used as an adsorbent in the decolourisation of aqueous dye C.I. Disperse yellow 3. To evaluate the potentiality of adsorbents, non-flow agitated experiments were carried out to find the equilibrium contact time, optimum equilibrium adsorbent dose. Preformed flocs at pH:: 4 rather than pH:: 10 produced excellent colour removal. Adsorption capacity of flocs of Ferric chloride, Aluminium sulphate and Ferrous sulphate was obtained as 500 mg/g, 333mg/g and 23.3mg/g at pH:4. The equilibrium data sorption follows Langmuir Isotherm and kinetic data follows pseudo second order stating that chemisorptions is the rate limiting step.

scholarly journals A High-Efficiency Approach for the Synthesis of N235-Impregnated Resins and the Application in Enhanced Adsorption and Separation of Vanadium(V)

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 358 ◽  
Author(s):  
Bo Chen ◽  
Shenxu Bao ◽  
Yimin Zhang ◽  
Ruwei Zheng
Keyword(s):  
Chemical Reaction ◽  
High Efficiency ◽  
Order Kinetic ◽  
Equilibrium Time ◽  
Rate Limiting Step ◽  
Reaction Constant ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Rate Limiting

Trialkylamine (N235)-tributyl phosphate (TBP) impregnated resins (N-TIRs) were prepared, so as to evaluate the effects of the addition of TBP on the preparation and adsorption performance of N235-impregnated resins (NIRs). The results show that TBP can obviously increase the impregnation ratio and shorten the impregnation equilibrium time of the N-TIRs when compared to that of the NIRs (57.73% versus 36.95% and 5 min versus 240 min). It is confirmed that TBP can interact with N235 during the impregnation process, which shorten the adsorption equilibrium time and increases the adsorption capacity of the N-TIRs for V(V) when compared to that of the NIRs (6 h versus 10 h and 50.95 mg·g−1 versus 46.73 mg·g−1). The kinetics fitting results demonstrate that the adsorption of V(V) onto N-TIRs and NIRs all conform to pseudo-second order kinetic model and chemical reaction is the rate-limiting step of the whole adsorption process. In the meanwhile, the reaction constant (Ks) implies that the chemical reaction rate of V(V) with the impregnated extractants in N-TIRs is faster than that in NIRs. The N-TIRs present higher stability and selectivity than NIRs. This study manifests that the addition of a secondary reagent may be a potential and novel technique on the preparation of SIRs and the enhancement of adsorption and separation for ions.

Kinetics and Isotherm Studies on Nd(III) Adsorption onto Xanthated Chitosan

2016 ◽  
Vol 857 ◽  
pp. 530-534 ◽  
Author(s):  
Noorul Farhana Md Ariff ◽  
Megat Ahmad Kamal Megat Hanafiah ◽  
Zurhana Mat Hussin ◽  
Shariff Che Ibrahim ◽  
Wan Saime Wan Ngah
Keyword(s):  
Metal Ion ◽  
Adsorption Process ◽  
Earth Metal ◽  
Hydroxyl Groups ◽  
Optimum Conditions ◽  
Order Model ◽  
Adsorbent Dosage ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting

Xanthated chitosan (XC) beads synthesized from the reaction between sulphur and hydroxyl groups were applied to adsorb rare earth metal ion, Nd (III). Adsorption of Nd (III) was found to be a function of pH of initial solution, adsorbent dosage and contact time. The optimum conditions for Nd (III) adsorption were at pH 3 and adsorbent dosage of 0.02 g. Rapid adsorption process was observed as it took only 10 min for reaching the equilibrium state. Chemisorption was identified as the rate limiting step and the kinetics data correlated well with the pseudo-second-order model.

scholarly journals Removal of Cr(VI) from wastewater by silver-loaded natural clinoptilolite

2021 ◽  
Vol 280 ◽  
pp. 06008
Author(s):  
Marinela Panayotova
Keyword(s):  
Order Kinetic ◽  
Water And Wastewater Treatment ◽  
Rate Limiting Step ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Water And Wastewater ◽  
Natural Clinoptilolite ◽  
Modified Clinoptilolite ◽  
Rate Limiting ◽  
Order Kinetic Equation

Presence of hexavalent chromium, Cr(VI), in water is an important environmental and human health problem. Natural zeolites are widely accepted as non-expensive adsorbents for sustainable remediation, however they are not effective in removing metals in anionic form. The paper presents study on use of silver (Ag) modified natural clinoptilolite to immobilize Cr(VI) ions from model and real neutral to slightly alkaline wastewater. Increasing the initial pollutant concentration increases the removed amount (80 % removal from model wastewater in 45 min at initial concentration of 30 mg Cr(VI)/L). The pseudo-second order kinetic equation best describes the Cr(VI) immobilization by the Ag-modified zeolite, which is indicative for the chemical nature of the rate-limiting step of the process. The data obtained are best fitted to the Freundlich adsorption isotherm. The Ag-modified clinoptilolite removes in 30 min over 80 % of Cr(VI), over 75 % of Cu(II) and over 70 % of Zn(II) that present simultaneously in an industrial wastewater. Due to its ability to remove Cr(VI) species, in combination with some heavy metal ions, some organic pollutants and exhibited antibacterial activity, silver loaded clinoptilolite seems to be a possible multifunctional reagent in the water and wastewater treatment and deserves further investigation.

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