scholarly journals Application of modified clay for removal of phenol and PO43− ions from aqueous solutions

2017 ◽  
Vol 35 (7-8) ◽  
pp. 692-699 ◽  
Author(s):  
Agnieszka Gładysz-Płaska

Simultaneous adsorption of phenol and phosphate(V) ions on the surfactant-modified clay from the binary mixture was studied and compared with the single phenol or phosphate(V) sorption. The maximum adsorption capacity of hexadecyltrimethylammonium–bentonite was 18.8 mg/g for phenol and 38.5 mg/g for phosphate(V) at simultaneous adsorption of both of them. The optimal pH values of adsorption on hexadecyltrimethylammonium–bentonite was found to be 7.0 and >7 for phosphate(V) and phenol, respectively. The kinetic studies showed that the adsorption followed a pseudo-second-order reaction for both. The equilibrium data were analyzed using the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models.

2017 ◽  
Vol 18 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Selim Selimoglu ◽  
Esra Bilgin Simsek ◽  
Ulker Beker

Abstract In the current work, alumina modified natural zeolite (Z-Al) was used for fluoride adsorption in aqueous solution. Effects of process parameters such as pH, temperature, initial concentration and contact time were investigated. Box–Behnken design was found effective in defining the operating conditions for fluoride sorption onto Z-Al. Confirmatory experiments were conducted to examine the reliability of the regression equation. The predicted (2.261 mg g−1) and experimental (2.289 mg g−1) capacities were found to be similar, demonstrating the accuracy of the model. The fluoride adsorption onto Z-Al was well described by the Freundlich model. Kinetic studies revealed that the adsorption followed a pseudo-second-order reaction. Thermodynamic parameters depicted that the fluoride adsorption on the alumina modified zeolite was a spontaneous and exothermic process. The co-existing ions affected the defluoridation performance significantly. Regeneration of exhausted Z-Al was achieved with H2SO4.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Bayram Kizilkaya ◽  
A. Adem Tekınay

Removal of lead (II) from aqueous solutions was studied by using pretreated fish bones as natural, cost-effective, waste sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacities of the adsorbent was investigated. The maximum adsorption capacity for Pb (II) was found to be 323 mg/g at optimum conditions. The experiments showed that when pH increased, an increase in the adsorbed amount of metal of the fish bones was observed. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of Pb (II) adsorption and the value ofRLfor Pb (II) was found to be 0.906. The thermodynamic parameters related to the adsorption process such asEa,ΔG°,ΔH°, andΔS° were calculated andEa,ΔH°, andΔS° were found to be 7.06, 46.01 kJ mol−1, and 0.141 kJ mol−1K−1for Pb (III), respectively.ΔH° values (46.01 kJmol−1) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to the experimental equilibrium data. The fish bones were effectively used as sorbent for the removal of Pb (II) ions from aqueous solutions.


2014 ◽  
Vol 1043 ◽  
pp. 219-223 ◽  
Author(s):  
Noor Shawal Nasri ◽  
Jibril Mohammed ◽  
Muhammad Abbas Ahmad Zaini ◽  
Usman Dadum Hamza ◽  
Husna Mohd. Zain ◽  
...  

Concern about environmental protection has increased over the years and the presence of volatile organic compounds (VOCs) in water poses a threat to the environment. In this study, coconut shell activated carbon (PHAC) was produced by potassium hydroxide activation via microwave for benzene and toluene removal. Equilibrium data were fitted to Langmuir, Freundlich and Tempkin isotherms with all the models having R2 > 0.94. The equilibrium data were best fitted by Langmuir isotherm, with maximum adsorption capacity of 212 and 238mg/g for benzene and toluene, respectively. The equilibrium parameter (RL) falls between 0 and 1 confirming the favourability of the Langmuir model. Pseudo-second-order kinetic model best fitted the kinetic data. The PHAC produced can be used to remediate water polluted by VOCs.


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.


2014 ◽  
Vol 1046 ◽  
pp. 34-38
Author(s):  
Shan Yu ◽  
Chang Hai Li ◽  
Dong Mei Jia

The hydroxyl alumina impregnated weakly basic resin composite (D301Al) successfully prepared through incorporation of hydroxyl alumina into the D301 resin for 2-naphthalenesulfonic acid (2-NSA) removal from aqueous solution. The structure of D301Al was examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption behaviors of 2-NSA on D301Al were investigated by static adsorption experiments. Effects of pH of solution, temperature and contact time were determined. The results indicated D301Al reached the maximum adsorption capacity to 2-NSA with pH 2.4. Nonlinear regression was used to estimate of Langmuir and Freundlich model parameters. And the Langmuir model can give a satisfactory fit of the experimental equilibrium data. The kinetic studies indicated that the adsorption of D301Al for 2-NSA can establish adsorption equilibrium at 8 h. The pseudo-first-order and pseudo-second-order rate models could characterize the kinetic data of 2-NSA adsorption on D301Al.


2017 ◽  
pp. 307-314
Author(s):  
Vesna Vucurovic ◽  
Vladimir Puskas ◽  
Uros Miljic

A simple, low cost, and effective method for the removal of acridine orange (AO), a mutagenic cationic dye, from aqueous model solutions by adsorption onto dried sugar beet pulp (SBP) was evaluated in the present study. The AO removal was enhanced along with the increase of the initial solution pH and dye concentration. It was found that the adsorption process closely follows a pseudo-second-order chemisorption kinetics. The obtained equilibrium data obey both the Freundlich and Langmuir isotherm models. The SBP was proved to be very promising adsorbent for AO removal. Maximum adsorption capacity of the Langmuir monolayer of SBP for AO was found to be 5.37, 34.6, 89.62, 144.53 and 324.58 mg/g, at 25?C for the solution pH of 2, 4, 5, 6, and 8, respectively.


Author(s):  
M. Smiri ◽  
F. Guey ◽  
H. Chemingui ◽  
A. B. Dekhil ◽  
S. Elarbaoui ◽  
...  

Synthesis, characterization and application of iron oxide nanoparticles have received much attention in recent years due to their interesting chemical and physics properties. Magnetite (Fe3O4) nanoparticles were synthesed by chemical co-precipitation and characterized using X ray diffraction (XDR), Fourier transmission spectroscopy (FT-IR), dynamic light scattering and (DLS). Fe3O4 nanoparticles were successfully removed humic acid (HA) from water. The influence of pH, contact time, adsorbent nanoparticle doses and HA concentrations were analyzed. Maximum HA removal occurred at pH 6 (89.63%), 40 mg.L-1 of Magnetite (88.8%), 0.03g of HA (96.64%) and contact time of 20 min (94.37%). Sorption data fit pseudo-second order kinetics, indicated a chemical adsorption process. The Langmuir, Freundlich and Temkin adsorption isotherm models were applied to describe equilibrium data. Adsorption of HA on magnetite nanoparticles was well described by Temkin model. The maximum adsorption capacity was 128.23 mg.g-1. Fe3O4 nanoparticles were promising potential adsorbents for HA removal from water.


2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong

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.


2010 ◽  
Vol 171-172 ◽  
pp. 15-18
Author(s):  
Zeng Quan Ji ◽  
Tian Hai Wang ◽  
Kai Hong Luo ◽  
Yao Qing Wang

An extracellular biopolymer (PFC02) produced by Pseudomonas alcaligenes was used as an alternative biosorbent to remove toxic Cd(II) metallic ions from aqueous solutions. The effect of experimental parameters such as pH, Cd(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Cd(II) was 6.0. The FTIR spectra showed carboxyl, hydroxyl and amino groups of the PFC02 were involved in chemical interaction with the Cd(II) ions. Equilibrium studies showed that Cd(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Cd(II) ions was estimated to be 93.55 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Cd(II) from wastewater.


Author(s):  
Mohamed Nasser Sahmoune ◽  
Krim Louhab ◽  
Aissa Boukhiar

Dead streptomyces rimosus was found to be an effective biosorbent for the removal of chromium from industrial tanning effluents. A sorption level of 65 mg/g was observed at pH 4.8 while the precipitation effect augmented this value at a higher pH range. Chromium desorption increased with decreasing desorption agents pH (including HCl and H2SO4) to a maximum value of 95% at approximately zero pH. The biosorption data of trivalent chromium by streptomyces rimosus has been used for kinetic studies based on fractional power, Elovich, pseudo-first order and pseudo-second order rate expressions. The time-dependent Cr (III) biosorption data were well-described by a pseudo-second-order kinetic model. The intraparticle diffusion is not the rate-limiting step for the whole reaction. It was found that the biosorption equilibrium data fit well with the Langmuir model.


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