scholarly journals Kinetics of Phenol Removal from Aqueous Solution by Adsorption onto Peanut Shell Acid-Activated Carbon

2005 ◽  
Vol 23 (4) ◽  
pp. 289-302 ◽  
Author(s):  
Elio E. Gonzo ◽  
Luis F. Gonzo

A pseudo-second-order rate equation describing the kinetic adsorption of phenol onto peanut shell acid-activated carbon at different initial concentrations, carbon dosages and particle sizes has been developed. The adsorption kinetics were followed on the basis of the amount of phenol adsorbed at various time intervals at 22°C. The rate constant and the equilibrium adsorption capacity were calculated. From these parameters, empirical correlations for predicting the equilibrium adsorption capacity as a function of the C0/D ratio, and for estimating the rate constant as a function of the relation D/(C0dp)0.5, were derived. This allowed a general rate expression for design purposes to be obtained which was valid for C0/D ≤ 1.5. The operation line for each case studied was constructed and the equilibrium adsorption capacity obtained. A comparison was undertaken with the experimental adsorption isotherm as previously determined. The effect of the initial phenol concentration, the carbon dose and the particle size on the initial adsorption rate was also analyzed.

2012 ◽  
Vol 550-553 ◽  
pp. 1561-1565 ◽  
Author(s):  
Tian Tian Xu ◽  
Chu Rui Huang ◽  
Yuan Yuan Luo ◽  
Qiang Du ◽  
Shi Lin Zhao

The new adsorption material was prepared by grafting the larch tannin onto aminated silica beads with the glutaraldehyde as the cross-linking agent. The adsorption properties of Pr3+and Nd3+on the new adsorbent material in aqueous solution were investigated. The results showed that the equilibrium adsorption capacities of this adsorbent to Pr3+, Nd3+were 402.12mg/g, 305.43mg/g at 303K when the initial concentrations of each ions were 442.7mg/L, 432.6mg/L, respectively and the pH value was 5.5; the maximum adsorption quantities of each ions were 576.34mg/g, 497.02mg/g at 303K when the initial concentrations of each ions were 704.5mg/L, 721.0mg/L, respectively and the pH value was 5.5. The effect of pH value was significant to the equilibrium adsorption capacity, the optimum pH values of this material to Pr3+and Nd3+were both 5.5; while the effect of the temperature was not obvious to the equilibrium adsorption capacity. The adsorption thermodynamics meet Freundlich equation, and the adsorption kinetics data of this adsorbent to Pr3+, Nd3+fitted with the pseudo-second-order rate equation dynamics model.


2017 ◽  
Vol 124 ◽  
pp. 425-434 ◽  
Author(s):  
Long Pan ◽  
Yuki Nishimura ◽  
Hideki Takaesu ◽  
Yoshihiko Matsui ◽  
Taku Matsushita ◽  
...  

2010 ◽  
Vol 26-28 ◽  
pp. 452-456
Author(s):  
Zhi Ping Zhu ◽  
Ke Long Huang ◽  
Yi Zhou

A new type and high efficiency adsorbent was prepared with powder activated carbon and polyurethane vesicant and surfactant, which being used to adsorb humic acid (HA) in boiler feedwater. The batch adsorption experiments were carrid at different pH value, different adsorbent dosage and different initial concentration to investigate HA removal rate and adsorption capacity by as-produced adsorbent. Their adsorption kinetics experiments data was fitted with pseudo-second-order rate model, its quation was 1/qt=0.094+5.51/t, and equilibrium adsorption capacity obtained from fitting curve was 10.6mg/g, consistent with the experimental results(11.5mg/g).The adsorption isotherm test was carried at 25°C-50°C, the equilibrium adsorption capacity was 10.9mg/g by Langmuir model, which being similar with experiment results, the free energy (ΔG), enthalpy(ΔH) and entropy (ΔS) were obtanined with Clapeyron-Clausius and Gibbs-Helmholtz equation in the adsorption isotherm, which all were negative, indicated that HA adsorbed by as-produced adsorbent was an exothermic process of entropy reduction.


2021 ◽  
Vol 21 (3) ◽  
pp. 1711-1720
Author(s):  
Thainá Gusmão Andrade ◽  
Mayra Soares Santos ◽  
Luiz Fernando Oliveira Maia ◽  
Tamise Emanuele Oliveira de Aquino ◽  
Lucas Zeferino da Silva ◽  
...  

If not properly treated, water contaminated with chromium (Cr(VI)) and lead (Pb(II)) can cause severe damage to health due to the accumulation of those toxic metals in the human body. Therefore, in this work, three iron oxides, i.e., δ-FeOOH, cystine-functionalized δ-FeOOH (Cys-δ-FeOOH), and Fe3O4, were synthesized and used as adsorbents for Cr(VI) and Pb(II) in water. The results indicated that the Cr(VI) is best adsorbed on cys-δ-FeOOH followed by δ-FeOOH and Fe3O4. It was because of the enhanced interaction between Cr(VI) and the cysteine functional groups on the δ-FeOOH surface. The Cr(VI) adsorption capacity of cys-δ-FeOOH, δ-FeOOH, and Fe3O4 was 217, 14, and 8 mg g−1, respectively. On the other hand, Pb(II) was preferentially adsorbed directly on δ-FeOOH achieving a maximum Pb(II) adsorption capacity of 174 mg g−1. The Pb(II) adsorption capacity of cys-δ-FeOOH and Fe3O4 was 97 and 74 mg g−1, respectively. The Cr(VI) adsorption on cys-δ-FeOOH was best described by the Langmuir-Freundlich model, whereas Pb(II) adsorption on δ-FeOOH followed the Langmuir model. Both Cr(VI) and Pb(II) adsorption on the adsorbents was well-fitted to pseudo-second-order kinetics. The Cr(VI) was more quickly adsorbed by cys-δ-FeOOH (h0 = 0.10 mg g−1 min−1) while the initial adsorption rate of Pb(II) onto δ-FeOOH was significantly faster (h0 = 16.34 mg g−1 min−1). Finally, the synthesized adsorbents were efficient to remove Cr(VI) and Pb(II) from water samples of the Doce river after the environmental disaster of Mariana city, Brazil, thus showing its applicability to remediate real water samples.


2012 ◽  
Vol 164 ◽  
pp. 297-301 ◽  
Author(s):  
Wei Fang Dong ◽  
Li Hua Zang ◽  
Qing Chao Gong ◽  
Cun Cun Chen ◽  
Cai Hong Zheng ◽  
...  

Low cost carbonaceous materials were evaluated for their ability to remove phenol from wastewater. The effects of adsorbents dosage, contact time and maximum adsorption capacity were investigated for granular activated carbon, powdered activated carbon, petroleum coke and multi-walled carbon nanotube (MWNT). Equilibrium studies were conducted in 50mg/L initial phenol concentration, solution pH of 5 and at temperature of 23°C. The results showed the adsorption process was fast and it reached equilibrium in 3 h. Petroleum coke and MWNT had poor adsorption which could reach the removal efficiency of phenol with 43.18% and 36.64% respectively. The granular activated carbon possessed good adsorption ability to phenol with 96.40% at the optimum dosage 5g and optimum time 90min.The powdered activated carbon was an effective adsorbent with a maximum adsorption capacity of 42.32 mg/g.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6781-6790
Author(s):  
Moammar Elbidi ◽  
Agab Hewas ◽  
Rajab Asar ◽  
Mohamad Amran Mohd Salleh

Removal of phenol from wastewater using local biochar (BC) was investigated, while using activated carbon (AC) as a reference material. The main parameters affecting the sorption process were initial concentration, contact time, pH, and temperature. Statistical analysis of the results showed that the maximum removal percent when using AC and BC were 95% and 55%, respectively. Experimental data showed that the removal of phenol has fast kinetics and reached equilibrium within 5 minutes. The Langmuir and Freundlich isotherm models were applied to fit the adsorption experimental data. Pseudo-first order and pseudo-second order kinetic models were employed.


2020 ◽  
Vol 15 ◽  
pp. 155892502091984
Author(s):  
Moussa Abbas ◽  
Zahia Harrache ◽  
Mohamed Trari

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 962
Author(s):  
Kuo-Yu Chen ◽  
Wei-Yu Zeng

Poly-γ-glutamate/apatite (PGA-AP) nanoparticles were prepared by chemical coprecipitation method in the presence of various concentrations of poly-γ-glutamate (γ-PGA). Powder X-ray diffraction pattern and energy-dispersive spectroscopy revealed that the main crystal phase of PGA-AP was hydroxyapatite. The immobilization of γ-PGA on PGA-AP was confirmed by Fourier transform infrared spectroscopy and the relative amount of γ-PGA incorporation into PGA-AP was determined by thermal gravimetric analysis. Dynamic light scattering measurements indicated that the particle size of PGA-AP nanoparticles increased remarkably with the decrease of γ-PGA content. The adsorption of aqueous Cu(II) onto the PGA-AP nanoparticles was investigated in batch experiments with varying contact time, solution pH and temperature. Results illustrated that the adsorption of Cu(II) was very rapid during the initial adsorption period. The adsorption capacity of PGA-AP nanoparticles for Cu(II) was increased with the increase in the γ-PGA content, solution pH and temperature. At a pH of 6 and 60 °C, a higher equilibrium adsorption capacity of about 74.80 mg/g was obtained. The kinetic studies indicated that Cu(II) adsorption onto PGA-AP nanoparticles obeyed well the pseudo-second order model. The Langmuir isotherm model was fitted well to the adsorption equilibrium data. The results indicated that the adsorption behavior of PGA-AP nanoparticles for Cu(II) was mainly a monolayer chemical adsorption process. The maximum adsorption capacity of PGA-AP nanoparticles was estimated to be 78.99 mg/g.


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