scholarly journals Nickel adsorption onto polyurethane ethylene and vinyl acetate sorbents

2017 ◽  
Vol 76 (1) ◽  
pp. 219-235 ◽  
Author(s):  
Munawar Iqbal ◽  
Zahid Ali ◽  
M. Afzal Qamar ◽  
Abid Ali ◽  
Fida Hussain ◽  
...  

The present study was conducted to appraise the efficiencies of polyurethane ethylene sorbent (PES) and vinyl acetate sorbent (VAS) for nickel (Ni) adsorption. Process variables, i.e. Ni(II) ions initial concentration, pH, contact time and adsorbent dosage were optimized by response surface methodology (RSM) approach. The Ni(II) adsorption was fitted to the kinetic models (pseudo-first-order and pseudo-second-order) and adsorption isotherms (Freundlich and Langmuir). At optimum conditions of process variables, 171.99 mg/g (64.7%) and 388.08 mg/g (92.7%) Ni(II) was adsorbed onto PES and VAS, respectively. The RSM analysis revealed that maximum Ni(II) adsorption can be achieved at 299 mg/L Ni(II) ions initial concentration, 4.5 pH, 934 min contact time and 1.3 g adsorbent dosage levels for PES, whereas the optimum values for VAS were found to be 402 mg/L Ni(II) ions initial concentration, 4.6 pH, 881 min contact time and 1.2 g adsorbent dosage, respectively. The —OH and —C = O— were involved in the Ni(II) adsorption onto PES and VAS adsorbents. At optimum levels, up to 53.67% and 80.0% Ni(II) was removed from chemical industry wastewater using PES and VAS, respectively, which suggest that PES and VAS could possibly be used for Ni(II) adsorption from industrial wastewater.

2012 ◽  
Vol 66 (8) ◽  
pp. 1699-1707 ◽  
Author(s):  
A. K. Giri ◽  
R. K. Patel ◽  
P. C. Mishra

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.


2010 ◽  
Vol 160-162 ◽  
pp. 182-188 ◽  
Author(s):  
Peng Cai ◽  
Hong Zheng ◽  
Peng Liang ◽  
Shu Ping Liang

Competitive adsorption experiment of fluoride and phosphate on MgAl-CO3 LDHs has been conducted. A series of batch experiments were performed to study the influence of various experimental parameters such as pH, adsorbent dosage and contact time on the adsorption of fluoride and phosphate on MgAl-CO3 LDHs. Three kinetic models have been evaluated in order to attempt to fit the experimental data, namely the pseudo-first order, the pseudo-second order and the Weber and Morris intraparticle diffusion model. The effects of the initial concentration and the addition order of fluoride and phosphate on their adsorption by MgAl-CO3 LDHs were also investigated. The results show that the optimal pH is 4 to 5, adsorbent dosage is 2 g/L and it takes about 2 hours to attain equilibrium. It was found that the pseudo-second order most closely describes the kinetics. The initial concentration and the addition order of fluoride and phosphate influence the adsorption of fluoride to a certain extent, but they have relatively small influence to the adsorption of phosphate on MgAl-CO3 LDHs.


Author(s):  
C. Obi ◽  
N. C. Ngobiri ◽  
L. C. Agbaka ◽  
M. U. Ibezim-Ezeani

The study focused on the investigation of the effectiveness of the pericarp of monkey kola (Cola lepidota) biomass (CLPB) in the removal of toluene from aqueous system. X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and phytochemical screening methods were used for characterizing the biosorbent. The effects of contact time, pH, and concentration on biosorption process were studied. The phytochemical screening showed the presence of alkaloids, flavonoids, tannins, carbohydrate, saponins and steroids. Carboxylic, alkene and alcohol groups were found to be the principal functional groups. The highest percentage removal was 99.63% at toluene initial concentration of 40 mg/L and 98.30% at pH 8. The contact time 30 minutes gave better removal efficiency of 99.89%. Among the biosorption isotherm models tested (Langmuir, Freundlich, Dubinin Radushkevich and Temkin, respectively), the Langmuir model equation gave a better fit of the equilibrium data with a correlation coefficient (R2) of 0.99. The equilibrium data was tested with pseudo-first order and pseudo-second order models and pseudo-second order model (R² = 0.99) fitted more than the pseudo-first order model (R² = 0.85). This study has revealed that Cola lepidota is a potential biosorbent for the removal of toluene from aqueous medium under the operating conditions of contact time of 30 minutes, pH of 8 and initial concentration of 40 mg/g.


Author(s):  
Alica Pastierová ◽  
Maroš Sirotiak

Abstract This paper presents a study into dynamic behaviour of the methylene blue adsorption (MB) on activated carbon. Effect of four parameters were studied: effect of the adsorbent dosage, effect of contact time, effect of pH, and effect of the initial concentration of methylene blue. The adsorption kinetic data were modelled using the pseudo-first and pseudo-second orders. Results show that, based on the experimental data, the pseudo-second order could be considered satisfactory. Thermodynamic parameters proved that adsorption of dye was spontaneous owing to increase in temperature and endothermic nature. Taguchi method was applied to determine the optimum conditions for removal of methylene blue by activated carbon. The optimum conditions were found to be pH = 7, contact time 60 min, initial concentration of MB 4 mg/L.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Faranak Pishgar ◽  
Homayon Ahmad Panahi ◽  
Ali Akbar Khodaparast Haghi ◽  
Vahid Motaghitalab ◽  
Amir Hesam Hasani

Diazinon and chlorpyrifos are two common organophosphorus poisons to fight the pests in Iran. The removal of these poisons from water by thermosensitive nanosphere polymer (TNP), synthesized from the copolymerization of N-isopropylacrylamide and 3-allyloxy-1,2-propanediol, was investigated. The effect of pH, contact time, and the initial concentration on the removal amount was studied. The highest removal amount of these poisons by TNP occurred at pH 7. The contact time increase improves the removal amount and the equilibrium contact time for diazinon and chlorpyrifos was 10 and 18 min, respectively. For low concentration of less than 50 mgL−1it was shown that removal capacity remains above 95%. The initial concentration above 50 mgL−1decreased the removal amount, in which chlorpyrifos showed a greater decrease. The kinetic data has been checked using pseudo first-order, pseudo second-order, and intraparticle diffusion equations. The intraparticle diffusion model had the best conformability for the adsorption process.


2018 ◽  
Vol 21 (2) ◽  
pp. 91-97

<p>Searching for low cost, accessible, simple implementation, and environmentally friendly adsorbents has been one of the concern of researchers in recent years. Therefore, the aim of this study was to investigate the efficient phenol removal from a synthetic aqueous solution using iron-coated pumice and LECA as an available adsorbents. Bath adsorption experiments were carried out to evaluate the effects of the independent variables such as pH (3-5-7-9-11), initial concentration of phenol (10-50mg/L), contact time (10-60 min) and different concentrations of pumice and LECA (0.2-1 g/100 cc) on the phenol adsorption. The results of the experiments showed that there was a direct relationship between the phenol removal efficiency and increasing the contact time and the adsorbent dosage but it has reverse relationship with the increasing of pH and phenol initial concentration. The optimal condition of parameters for phenol removal were 200 rpm agitation speed, 0.6 g adsorbent dosage, 30 min contact time, and 20 mg/L initial phenol concentration. The study of isotherm and kinetic models showed that the experimental data of the phenol adsorption process were correlated with Freundlich (R2pumice=0.9749, R2LECA=0.9487) and Pseudo-second order (R2pumice=0.9745, R2LECA=0.9486) models. Based on this study’s results, the modified pumice and LECA have a high ability to remove the phenol compounds from aqueous solution.</p>


2020 ◽  
Vol 9 (1) ◽  
pp. 122-138

Hexavalent chromium Cr (VI) is a toxic material used in many industries such as tanneries and electroplating industries. Most of the previous researches studied the removal of chromium at lower concentrations up to 600 mg/L but did not tackle the behavior at higher concentrations, which resemble the real concentration of studied tanneries effluents. The present research is a comparative study of different agricultural low cost adsorbents in the removal of high Chromium concentration from industrial wastewater up to 1000 mg/L, compared to a commercial activated carbon. The tested adsorbents are (Banana Waste (BW), Sawdust (SD), Phragmites Australis (PA), Sugarcane Bagasse (SCB), Pea pod peels (PPP) and Rice straw (RS)). The materials were chemically pretreated with acid-alkali except BW was treated with acid only, to improve adsorbent metal binding capacity. Batch experiments were conducted to study the effect of pH, adsorbent dosage, contact time, initial Chromium concentration and temperature on the removal efficiency of Chromium from wastewater. The experiments were conducted in two sets, one for lower concentration (25-50-100-200-400) mg/L and the other for higher concentration (600-800-1000) to simulate the concentration of Chromium in tannery industry effluents. At 1000 mg/L initial concentration, BW achieved the optimum removal efficiency of 73.28% at pH = 3, adsorbent dosage = 25 g/L and contact time of 3 hours with the adsorption capacity was 39 mg/g. For SD at pH=2, 3 hours contact time, 10 g/L dosage, and 30oC the removal ratio was 64.83% and the adsorption capacity was 86.30 mg/g. The equilibrium data for various agricultural adsorbents was being tested with various adsorption isotherm models such as Langmuir, Freundlich and Tempkin. At low concentrations, AC, BW, PA and SCB follows Freundlich isotherm model while SD follows Langmuir isotherm model. At higher concentrations, BW, SD, PA follows Langmuir isotherm while SCB follows Tempkin isotherm model. To evaluate the mechanism of Cr adsorption on different adsorbents, Pseudo-first-order and Pseudo-second-order equations were used. The adsorption process follows Pseudo-second-order for all adsorbents, which confirms the chemisorption of Cr (VI) on different adsorbents.


2013 ◽  
Vol 743-744 ◽  
pp. 463-468
Author(s):  
Yu Dong Lu ◽  
Wen Lu Wu ◽  
Shan Lin ◽  
Rui Yun You ◽  
Zong Hua Wu

The use of camellia oleifera abel shells as biosorbent has been successfully demonstrated in the removal of Cr (VI) from aqueous solution. The effects of different parameters, such as, contact time, initial concentration of Cr (VI), pH and temperature on Cr (VI) adsorption were investigated. The results showed that the maximum uptake of Cr (VI) was up to 190.69 mg/g at a pH value of around 1.0, under the initial Cr (VI) concentration of 400mg/L and at the temperature of 298 K. The adsorption kinetics could be described by pseudo-first order and pseudo-second order kinetics models.


2018 ◽  
Vol 78 (10) ◽  
pp. 2158-2170 ◽  
Author(s):  
Mohammad Malakootian ◽  
Alireza Nasiri ◽  
Hakimeh Mahdizadeh

Abstract Ciprofloxacin (CIP) is considered as a biological resistant pollutant. The CoFe2O4/activated carbon@chitosan (CoFe2O4/AC@Ch) prepared as a new magnetic nanobiocomposite and used for adsorption of CIP. CoFe2O4/AC@Ch was characterized by Fourier transform-infrared (FT-IR), field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) surface area measurements. The pHZPC value of the nanobiocomposite was estimated to be 6.4 by solid addition method. The prepared magnetic nanobiocomposites can be separated easily from water by an external magnet and reused. The effect of CIP concentration (10–30 mg/L), adsorbent dosage (12–100 mg/L), contact time (5–30 min) and pH (3–11) as independent variables on ciprofloxacin removal efficiency was evaluated. Optimum conditions were obtained in CIP concentration: 10 mg/L, adsorbent dosage: 100 mg/L, contact time: 15 min and pH: 5. In this condition, maximum CIP removal was obtained as 93.5%. The kinetic and isotherm equations showed that the process of adsorption followed the pseudo-second order kinetic and Langmuir isotherm. The results indicate that the prepared magnetic nanobiocomposite can be used as good adsorbent for the removal of CIP from aqueous solution and can be also recycled.


2013 ◽  
Vol 12 (06) ◽  
pp. 1350044 ◽  
Author(s):  
N. M. MUBARAK ◽  
M. RUTHIRAAN ◽  
J. N. SAHU ◽  
E. C. ABDULLAH ◽  
N. S. JAYAKUMAR ◽  
...  

The effectiveness of stannum ( Sn 2+) removal from aqueous solution by using magnetic biochar and functionalized multiwalled carbon nanotube (FMWCNT) was investigated. The effect of various factors, namely pH, adsorbent dosage, agitation speed and contact time was statistically studied through analysis of variance (ANOVA). Statistical analysis revealed that the optimum conditions for the highest removal of Sn 2+ are at pH 5, dosage 0.1 g with agitation speed and time of 100 rpm and 90 min, respectively. At the initial concentration of 0.1 mg/L, the removal efficiency of Sn 2+ using FMWCNTs was 93% and 85% with magnetic biochar. The Langmuir and Freundlich constant for both FMWCNTs and magnetic biochar were 13.397 L/mg, 18.634 L/mg and 17.719 L/mg, 25.204 L/mg, respectively. Hence, results prove that FMWCNTs are a better adsorbent with a higher adsorption capacity compared to magnetic biochar. Adsorption kinetic obeyed pseudo-second-order.


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