scholarly journals Adsorption of cobalt from aqueous solutions onto Bark of Eucalyptus

2018 ◽  
Vol 7 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Youness Essaadaoui ◽  
Ahmed Lebkiri ◽  
EL Houssein Rifi ◽  
Lamya Kadiri ◽  
Abdelkarim Ouass

In this work, we used the bark of eucalyptus grafted with acrylic acid (EAA) as an adsorbent for removing of Co2+ ions from aqueous solutions. EAA was characterized using Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray diffraction (XRD), and bohemian method. The bulk density and the zero-charge point (pzch) were also determined. The results showed that eucalyptus grafted with acrylic acid (EAA) is rich in COOH and OH groups and pzch is acidic. We also valorized the Bark of Eucalyptus (EB) in the removing of Co2+ ions from aqueous solutions. The kinetic study showed that the extraction equilibrium of Co2+ ions by EB is reached after 40 min and the extraction process is expressed by the second-order kinetic model. The effect of Co2+ concentration and initial pH on the removal efficiency showed that the binding capacity increases with increasing in the pHi and the concentration of Co2+ ions and the maximum capacity is 55.55 mg/g. The mathematical modelling study of the adsorption of Co2+ ions on the BE showed that the adsorption process follows the Langmuir model. The kinetics of desorption is 8 times faster than the extraction and our material is regenerated with higher performance.

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.


2019 ◽  
Vol 800 ◽  
pp. 181-186 ◽  
Author(s):  
Nour El Houda Larbi ◽  
Djilali Redha Merouani ◽  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
Amine Khelifa

Heavy metals are very toxic water pollutant. Their presence not only affect human beings but also animals and vegetation because of their mobility in aqueous ecosystem, toxicity and non-biodegradability [1].in the aim of removing heavy metals from aqueous solutions, an eco-friendly biosorbent was prepared from lagoon sludge by a humification process. The biosorption of Cd2+ and Al3+ ions from aqueous solutions was investigated as a function of initial pH,contact time, initial metal ions concentration, and temperature. Langmuir and Freundlich models were used to determine the sorption isotherm. Optimum pH for the removal of cadmium and aluminum was found respectively to be around 6 and 4 [2] . The equilibrium was obtained in 60 min with the pseudo-second-order kinetic model. The Langmuir model was a better fit with the experimental data for both cadmium and aluminum adsorption with a regression coefficient up to 0.99 and Qmax of 100 and 142 mg.g-1 respectively for Cd2+and Al3+.


2011 ◽  
Vol 71-78 ◽  
pp. 2988-2991
Author(s):  
Yuan Hong Wang ◽  
Yun Yu ◽  
Rui Qun Liu ◽  
Wei Feng Liu

Present study deals with the evaluation of biosorptive removal of nickel byFlavobacterium sp.Experiments have been carried out to find the effect of various parameters such as initial pH, contact time and initial metal ion concentration. Adsorption equilibrium studies showed that Ni(II) adsorption data followed the Langmuir model, the maximum binding capacity of Ni(II) was 64.20 mg/g at pH 7.0. Kinetics of nickel biosorption by Flavobacterium sp.biomass is better described by pseudo second order kinetic model. The equilibrium isotherm data are very well represented by Langmuir isotherm equation, which confirmed the monolayer coverage of nickel onto Flavobacterium sp.biomass. It was also clearly observed that The present study indicated thatFlavobacterium sp.biomass may be used as an inexpensive and effective biosorbent for the removal of Ni(II) ions from environmental wastewater.


2019 ◽  
Vol 33 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Mohammad Hasan Zarghi ◽  
Aliakbar Roudbari ◽  
Sahand Jorfi ◽  
Neamat Jaafarzadeh

The aim of this study was to investigate the removal of estrogen hormones (17β-estradiol and estrone) from aqueous solutions using rice husk extracted silica. Rice husk was collected from rice factories in Mazandaran province (Iran) and the adsorbent was prepared in a furnace at 800 °C for 4 h, after acid leaching with hydrochloric and sulfuric acid mixture. Optimal operating parameters for estrogen removal were determined, including initial pH values (4–9), adsorbent dosages (0.5, 1, 1.5, and 2 g L–1), contact times (30, 60, 90, and 120 min), and initial concentrations of 17β-estradiol and estrone (10, 40, 70 and 100 ng L–1); one-factor-at-a-time method was used. The method of electrochemiluminescence was used to measure the concentration of hormones. Kinetic adsorption models and adsorption isotherms were also studied. The maximum removal efficiency (%) of 17β-estradiol (E2) and estrone (E1) hormones of 95.5 and 93.1 %, respectively, was obtained at optimal conditions of pH 4, 1.5 g L–1 of adsorbent dosage, 60 min of contact time and 10 ng L–1 initial concentrations of E2 and E1. Pseudo first-order kinetic model and Langmuir adsorption isotherm had the best fit with experimental data for both estrogen hormones, following nonlinear regression procedure. Rice husk silica could be considered as effective and accessible adsorbent for removal of estrogenic hormones.


2013 ◽  
Vol 712-715 ◽  
pp. 482-486
Author(s):  
He Bin Shi ◽  
Yu Liu ◽  
Hong Zhong ◽  
Xing Tian ◽  
Ming Hang Liao

A middle grade siliceous phosphorite from Yunnan province was selected to treat Cd2+ bearing aqueous solutions. The siliceous phosphorite was tested by X-ray fluorescence spectrometer, X-ray diffraction, infrared spectrometer and scanning electron microscopy. The results present that the valuable mineral is nanostructured carbonated fluorapatite and the major gangue mineral is quartz. The amount of Cd2+ sorbed by the siliceous phosphorite tends to increase with the increase of initial pH or the initial Cd2+ concentration of the simulated waste water. The reaction process of Cd2+ removal from aqueous solutions is highly fitted with the pseudo-second order kinetic model. The results indicate that nanostructured carbonated fluorapatite bearing siliceous phosphorite can effectively immobilize aqueous Cd2+.


2011 ◽  
Vol 322 ◽  
pp. 436-439 ◽  
Author(s):  
Xi Chan Zhang ◽  
Xing Guang Li

Present study deals with the evaluation of biosorptive removal of copper byFlavobacterium sp.Experiments have been carried out to find the effect of various parameters such as initial pH, contact time and initial metal ion concentration. Adsorption equilibrium studies showed that Cu(II) adsorption data followed the Langmuir model, the maximum binding capacity ofwas 55.20 mg/g at pH 6.0. Kinetics of copper biosorption by Flavobacterium sp. biomass is better described by pseudo second order kinetic model. It was also clearly observed that The present study indicated thatFlavobacterium sp.biomass may be used as a cost and effective biosorbent for the removal of Cu(II) ions from wastewater.


2016 ◽  
pp. 39-48
Author(s):  
Pathompong Vibhatabandhu ◽  
Sarawut Srithongouthai

Biosorptionis an effective process for removal and recovery of heavy metal ions from aqueous solutions. In the present study, batch adsorption experiments were carried out for the removal of copper (Cu II) from aqueous solutions using cuttlebone powder (<100 μm)as a bio-adsorbent. The effects of initial pH, adsorbent dosage, initial concentration, and contact time on adsorption efficiency and capacity were studied to evaluate the optimum conditions for copper removal.The results found optimal conditions at initial pH of 5.0, 10 g L-1cuttlebone, 500 mg L-1initial concentration of Cu II in solution, and 150 min of equilibrium time.The Langmuir isotherm and pseudo-second order kinetic model were fitted to the experimental adsorption data. The maxi-mum adsorption capacity calculated from theLangmuir isotherm was 54.05 mg g-1. This result shows that cuttlebone is an effective bio-adsorbent, constituting a promising, efficient, low-cost, and eco-friendly technology bio-sorbent for reducing copper pollution during wastewater treatment.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 217-224 ◽  
Author(s):  
Z. Reddad ◽  
C. Gérente ◽  
Y. Andrès ◽  
P. Le Cloirec

In the present work, sugar beet pulp, a common waste from the sugar refining industry, was studied in the removal of metal ions from aqueous solutions. The ability of this cheap biopolymer to sorb several metals namely Pb2+, Cu2+, Zn2+, Cd2+ and Ni2+ in aqueous solutions was investigated. The metal fixation capacities of the sorbent were determined according to operating conditions and the fixation mechanisms were identified. The biopolymer has shown high elimination rates and interesting metal fixation capacities. A pseudo-second-order kinetic model was tested to investigate the adsorption mechanisms. The kinetic parameters of the model were calculated and discussed. For 8 × 10-4 M initial metal concentration, the initial sorption rates (v0) ranged from 0.063 mmol.g-1.min-1 for Pb2+ to 0.275 mmol.g-1.min-1 for Ni2+ ions, with the order: Ni2+ &gt; Cd2+ &gt; Zn2+ &gt; Cu2+ &gt; Pb2+. The equilibrium data fitted well with the Langmuir model and showed the following affinity order of the material: Pb2+ &gt; Cu2+ &gt; Zn2+ &gt; Cd2+ &gt; Ni2+. Then, the kinetic and equilibrium parameters calculated qm and v0 were tentatively correlated to the properties of the metals. Finally, equilibrium experiments in multimetallic systems were performed to study the competition of the fixation of Pb2+, Zn2+ and Ni2+ cations. In all cases, the metal fixation onto the biopolymer was found to be favourable in multicomponent systems. Based on these results, it is demonstrated that this biosorbent represents a low-cost solution for the treatment of metal-polluted wastewaters.


2021 ◽  
pp. 174751982198996
Author(s):  
Moussa Abbas

Among the different photocatalysts, TiO2 ( Eg = 3.1 eV, zero charge point (pHpzc = 6.3), and surface = 55 m2/g) is currently the most efficient and the most studied semiconductor due to its strong photocatalytic activity, non-toxicity, and chemical stability. The elimination of DR-80 on TiO2 is studied by adsorption in batch mode and by application of heterogeneous photocatalysis onto TiO2 under UV irradiation. The effects of contact time (0–60 min), initial pH (3–11), dose of the adsorbent (0.5–3 g L−1), and DR-80 concentration (40–60 mg L−1) on the adsorption of DR-80 by TiO2 are studied for optimization of these parameters. The kinetic parameters, rate constants, and equilibrium adsorption capacities are calculated and discussed for each applied theoretical model. The adsorption of DR-80 is well described by the pseudo-first-order kinetic model. The fitting of the adsorption isotherms shows that the models of Langmuir and Temkin offering a better fit and an adsorption 64.102 mg/g at 25 °C of DR-80 are eliminated. The results showed that the photocatalytic efficiency strongly depends on the pH while the initial rate of photodegradation is proportional to the catalyst dose, and becomes almost constant above a threshold value. It was found that the photodegradation is favored at low DR-80 concentrations in accordance with the Langmuir–Hinshelwood model with the constants Kad = 6.5274 L/mg and KL–H = 0.17818 mg L−1 min. However, the adsorption is improved for high DR-80 concentrations. It is found that the degradation depends on both the temperature and the pH with a high elimination rate at high temperature. The photocatalyst TiO2 has a better activity for the degradation of DR-80, compared to some commercial catalysts that have been described in the literature.


2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.


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