scholarly journals The efficiency of nano-TiO2 and γ-Al2O3 in copper removal from aqueous solution by characterization and adsorption study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ezati ◽  
Ebrahim Sepehr ◽  
Fatemeh Ahmadi

AbstractWater pollution is a major global challenge given the increasing growth in the industry and the human population. The present study aims to investigate the efficiency of TiO2 and γ-Al2O3 nanoadsorbents for removal of copper (Cu(II)) from aqueous solution as influenced by different chemical factors including pH, initial concentration, background electrolyte and, ionic strength. The batch adsorption experiment was performed according to standard experimental methods. Various isotherm models (Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich) were fitted to the equilibrium data. According to geochemical modeling data, adsorption was a predominant mechanism for Cu(II) removal from aqueous solution. Calculated isotherm equations parameters were evidence of the physical adsorption mechanism of Cu(II) onto the surface of the nanoparticles. The Freundlich adsorption isotherm model could well fit the experimental equilibrium data at different pH values. The maximum monolayer adsorption capacity of TiO2 and γ-Al2O3 nanosorbents were found to 9288 and 3607 mg kg−1 at the highest pH value (pH 8) and the highest initial Cu(II) concentration (80 mg L−1) respectively. Copper )Cu(II) (removal efficiency with TiO2 and γ-Al2O3 nanoparticles increased by increasing pH. Copper )Cu(II) (adsorption deceased by increasing ionic strength. The maximum Cu(II) adsorption (4510 mg kg−1) with TiO2 nanoparticles was found at 0.01 M ionic strength in the presence of NaCl. Thermodynamic calculations show the adsorption of Cu(II) ions onto the nanoparticles was spontaneous in nature. Titanium oxide (TiO2) nanosorbents could, therefore, serve as an efficient and low-cost nanomaterial for the remediation of Cu(II) ions polluted aqueous solutions.

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
O. O. Ajayi ◽  
A. O. Adebayo

The feasibility of using powdered cow hooves (CH) for removing Ni2+ from aqueous solution was investigated through batch studies. The study was conducted to determine the effect of pH, adsorbent dosage, contact time, adsorbent particle size, and temperature on the adsorption capacity of CH. Equilibrium studies were conducted using initial concentration of Ni2+ ranging from 15 to 100 mgL−1 at 208, 308, and 318 K, respectively. The results of our investigation at room temperature indicated that maximum adsorption of Ni2+ occurred at pH 7 and contact time of 20 minutes. The thermodynamics of the adsorption of Ni2+ onto CH showed that the process was spontaneous and endothermic. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were used to quantitatively analysed the equilibrium data. The equilibrium data were best fitted by Freundlich isotherm model, while the adsorption kinetics was well described by pseudo-second-order kinetic equation. The mean adsorption energy obtained from the D-R isotherm revealed that the adsorption process was dominated by physical adsorption. Powdered cow hooves could be utilized as a low-cost adsorbent at room temperature under the conditions of pH 7 and a contact time of 20 minutes for the removal of Ni(II) from aqueous solution.


2020 ◽  
Vol 10 (1) ◽  
pp. 22-32
Author(s):  
Abdoulaye Demba N'diaye ◽  
Youcef Aoulad El Hadj Ali ◽  
Mohamed Abdallahi Bollahi ◽  
Mostafa Stitou ◽  
Mohamed Kankou ◽  
...  

In this work, batch adsorption experiments were carried out for the removal of Methylene Blue (MB) from aqueous solutions using Typha australis leaf as a low cost adsorbent. The effects of some variables governing the efficiency of the process such as adsorbent mass, pH, ionic strength, contact time and temperature were investigated. The adsorption kinetic data were analyzed using the Pseudo First Order (PFO) and Pseudo Second Order (PSO) models. The experimental equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The results show that the PSO model is the best for describing the adsorption of MB by Typha australis for all initial MB concentrations. The equilibrium data fitted well with the Langmuir model with the monolayer adsorption capacity for MB-Typha australis leaf system was of 103.12 mg g-1. The values of activation parameters such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were also determined as - 4.44 kJ mol−1, 55.13 kJ mol−1 and 203.21 J mol−1 K−1, respectively. The thermodynamics parameters of MB-Typha australis system indicate spontaneous and endothermic process. These results indicate that the Typha australis leaf can be feasibly employed for the eradication of MB from aqueous solution.


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.


2016 ◽  
Vol 74 (6) ◽  
pp. 1335-1345 ◽  
Author(s):  
Fengfeng Ma ◽  
Baowei Zhao ◽  
Jingru Diao

The purpose of this work is to investigate adsorption characteristic of corn stalk (CS) biochar for removal of cadmium ions (Cd2+) from aqueous solution. Batch adsorption experiments were carried out to evaluate the effects of pH value of solution, adsorbent particle size, adsorbent dosage, and ionic strength of solution on the adsorption of Cd2+ onto biochar that was pyrolytically produced from CS at 300 °C. The results showed that the initial pH value of solution played an important role in adsorption. The adsorptive amount of Cd2+ onto the biochar decreased with increasing the adsorbent dosage, adsorbent particle size, and ionic strength, while it increased with increasing the initial pH value of solution and temperature. Cd2+ was removed efficiently and quickly from aqueous solutions by the biochar with a maximum capacity of 33.94 mg/g. The adsorption process was well described by the pseudo-second-order kinetic model with the correlation coefficients greater than 0.986. The adsorption isotherm could be well fitted by the Langmuir model. The thermodynamic studies showed that the adsorption of Cd2+ onto the biochar was a spontaneous and exothermic process. The results indicate that CS biochar can be considered as an efficient adsorbent.


2011 ◽  
Vol 148-149 ◽  
pp. 470-473
Author(s):  
Li Fang Zhang

The biosorption of Malachite Green from aqueous solution was investigated by using pretreated fungal biomass in a batch system. The effects of initial pH, NaCl concentration, initial dye concentration and temperature on dye biosorption were studied. The results showed that the pretreated fungal biomass exhibited higher dye removal at initial pH value of 5.0-6.0. The bosorption capacity was increased with the increasing temperature in studied temperature range. The Langmuir and Freundlich isotherm models were applied to experimental equilibrium data and the Langmuir model better described the equilibrium dye uptake than the Freundlich model. Thermodynamic studies revealed that the biosorption process was successful, spontaneous and endothermic in nature.


2014 ◽  
Vol 955-959 ◽  
pp. 2118-2122
Author(s):  
Kowit Suwannahong ◽  
Witsanusan Supa ◽  
Jutaluck Chaysuk ◽  
Torpong Kreetachat

Applying of low cost adsorbent for herbicide capturing is an important area of research in environmental field. The present work reports the adsorption potential of fly ash, a waste from power stations, for removal of herbicides namely paraquat and alachlor from aqueous solution. Batch experiment was employed to investigate the adsorption of herbicide in aqueous solution. The maximum capacity of the fly ash to adsorb paraquat and alachlor was found to be 2.02 and 1.70 mmole.g-1, respectively. The coefficient of adsorption on the basis of 3 models: Freundlich, Langmuir and Sips isotherm models were found. The results shown that the equilibrium data are better fitted by three-parameter models than two-parameter models. The experimental data agree to adsorption isotherms in the order of Sips > Langmuir > Freundlich isotherms.


2012 ◽  
Vol 18 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Jianwei Ren ◽  
Mokgadi Bopape ◽  
Katlego Setshedi ◽  
Jacob Kitinya ◽  
Maurice Onyango

This study explored the feasibility of using magnetic eggshell-Fe3O4 powder as adsorbent for the removal of Pb(II) and Cu(II) ions from aqueous solution. The metal ionsadsorption media interaction was characterized using XRD and FTIR. The effects of contact time, initial concentrations, temperature, solution pH and reusability of the adsorption media were investigated. The metal ions adsorption was fast and the amount of metal ions adsorbed increased with an increase in temperature, suggesting an endothermic adsorption. The kinetic data showed that the adsorption process followed the pseudo-second-order kinetic model. The optimal adsorption pH value was around 5.5 at which condition the equilibrium capacity was 263.2 mg/g for Pb(II) and 250.0 for Cu(II). The adsorption equilibrium data fitted very well to the Langmuir and Freundlich adsorption isotherm models. The thermodynamics of Pb(II) and Cu(II) adsorption onto the magnetic eggshell-Fe3O4 powder indicated that the adsorption was spontaneous. The reusability study has proven that magnetic eggshell-Fe3O4 powder can be employed as a low-cost and easy to separate adsorbent.


2018 ◽  
Vol 4 (3) ◽  
pp. 297-302
Author(s):  
S. Jayashree ◽  
Jeyavathana Samuel ◽  
R. Vashantha

The main objective of this study was to investigate the removal of cadmium(II) ions from aqueous solution using raw Cymbopogon citratus as an adsorbent. It was characterized by FT-IR, XRD, SEM-EDAX and its physical parameters were analyzed. Different factors such as pH, contact time, initial concentration and temperature were studied. Maximum adsorption was taken place at the optimum pH of 6 and the equilibrium data were analyzed by Langmuir, Freundlich and Temkin Isotherm models. Among those isotherm models Langmuir and Temkin were fitted well with good correlation coefficient (R2). The negative values of ΔG⁰ for all temperature shows the adsorption process for cadmium(II) ion was spontaneous in nature and feasible. The negative value of enthalpy change ΔH⁰ shows the adsorption process is exothermic and the positive value of ΔS⁰ indicates the disorderness or randomness process of adsorption. The positive value of Ea indicates the higher solution temperature favors the adsorption of metal ion onto RCC. The experimental data were analyzed by kinetic studies such as pseudo-first order, pseudo-second order and intra-particle diffusion models. Desorption was also studied and the recovery of the adsorbent was found to be 10%. Thus on the basis of these investigations the present study concludes that the raw Cymbopogon citratus (RCC) was found to be highly effective, nontoxic, environmental friendly and low cost adsorbent for the removal of toxic Cd(II) ions from aqueous solution.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Gamal Owes El-Sayed ◽  
Talaat Younis Mohammed ◽  
Ashraf Abd-Allah Salama

Sugarcane stalks powder was tested for its efficiency of removing a textile dye Maxilon Red GRL from aqueous solution. Different parameters affecting dye removal efficiency were studied. These parameters include contact time, initial dye concentration, adsorbent dose, ionic strength, pH, and temperature. Langmuir and Freundlich isotherm models were applied to the equilibrium data. The data fitted well with the Langmuir isotherm (). The maximum monolayer adsorption capacity () was found to be 20.96 mg/g at an initial pH of 7.2. The temperature variation study showed that dye adsorption is exothermic and spontaneous with increased randomness at the solid solution interface. The results indicated that sugarcane stalks could be an alternative for more costly adsorbents used for dye removal. The kinetic of the adsorption process followed the pseudo second-order kinetics model.


2011 ◽  
Vol 391-392 ◽  
pp. 1417-1422
Author(s):  
Yu Xin Ma ◽  
Feng Mei Shi ◽  
Miao Nan Wu

Removal of fluoride from aqueous solution by using Ca-bentonite and H-bentonite (acid-treated bentonite) was studied by batch equilibrium method. The fluoride sorption capacity of Ca-bentonite increases with the fluoride concentration increase or the pH-value decrease. H-bentonite has better affinity to fluoride than Ca-bentonite. H-bentonite can be used effectively for fluoride removal as a low cost adsorbent. The adsorption type of H-bentonite is ion exchange and the adsorption type of Ca-bentonite can be explained by ion exchange and physical adsorption.


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