scholarly journals Removal of lead from aqueous solutions using three biosorbents of aquatic origin with the emphasis on the affective factors

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Maryam Rezaei ◽  
Nima Pourang ◽  
Ali Mashinchian Moradi

AbstractThe biosorptive potentials of three aquatics-based biosorbents, including shells of a bivalve mollusk and scales of two fish species for Pb removal from aqueous solutions were evaluated, for the first time. A Box–Behnken design with the response surface methodology was used to investigate the effects of the seven important variables (contact time, temperature, initial concentration, dosage, size, salinity and pH) on the sorption capacity of the sorbents. Among the seven studied factors, the effects of biosorbent dosage, initial concentration and pH were significant for all the response variables, while biosorbent size was not significant for any of the responses. The initial concentration was the most influential factor. The presence of Pb ions on the surfaces of the biosorbents after the adsorption was clearly confirmed by the SEM–EDX and XRF analyses. The maximum sorption capacities of the biosorbents were comparable to the literature and the descending order was as follows: scales of Rutilus kutum and Oncorhynchus mykiss and the shells of Cerastoderma glaucum. The isotherm studies revealed Langmuir model applicability for the Pb adsorption by R. kutum and O. mykiss scales, while Freundlich model was fitted to the adsorption C. glaucum shells.

2015 ◽  
Vol 12 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.


2011 ◽  
Vol 239-242 ◽  
pp. 2855-2858 ◽  
Author(s):  
Hui Yun Zhou ◽  
Dong Ju Zhou ◽  
Chen Jie Fan ◽  
Xi Guang Chen

Chitosan/cellulose acetate multimicrospheres (CCAM) were prepared by the method of W/O/W emulsion with no toxic reagents and had the size interval of 200--280µm. It was investigated as an ideal alternative to enhancement the adsorption of water-soluble dyes from wastewater. The correlation coefficients of adsorption isotherm showed that the Freundlich model was comparable to the Langmuir model. The 1/n was lower than 1.0, indicating that malachite green was favorably adsorbed by CCAM. Furthermore, the amount of malachite green absorbed steeply increased with increasing time and reached plateau values within 2 h and increased with increasing of initial concentration of malachite green from 5 to 25 mg/g.


2012 ◽  
Vol 573-574 ◽  
pp. 150-154
Author(s):  
Yun Bo Zang ◽  
Nai Ying Wu

In this study, removal of copper ions from aqueous solutions by synthetic Mg-Al-HTlc was investigated as a function of contact time, EDTA and addition sequences at room temperature. It is found that HTlc could reduced copper ions concentration effectively. The kinetics closely fit pseudo-second order kinetics with necessary time 9 h to reach equilibrium. The sorption process followed langmuir model. The maximum sorption capacity calculated was found to be 39.4 mg/g. The presence of EDTA and addition sequences could affect sorption of Cu(II) onto HTlc.


2018 ◽  
Vol 5 (4) ◽  
pp. 187-196 ◽  
Author(s):  
Soheila Chavoshan ◽  
Maryam Khodadadi ◽  
Negin Nasseh ◽  
Ayat Hossein Panahi ◽  
Aliyeh Hosseinnejad

Background: Drugs, especially antibiotics, are one of the serious problems of modern life and the main pollution sources of the environment, especially in the last decade, which are harmful to human health and environment. The aim of this study was to investigate the removal of penicillin G from aqueous solutions using single-walled and multi-walled carbon nanotubes. Methods: In this study, the effect of different parameters including pH (3, 5, 7, 9, and 11), initial concentration of pollutant (50, 100, 150, and 200 mg/l), absorbent dose (0.25, 0.5, 0.75, and 1 g/L), mixing speed (0, 100, 200, and 300 rpm), and temperature (10, 15, 25, 35, 45°C) were investigated. The Langmuir, Freundlich, Temkin, BET, Dubinin-Radushkevich isotherms and adsorption kinetics of the first- and second-order equations were determined. Results: The results showed that the efficiency of single-walled and multi-walled carbon nanotubes in the removal of penicillin G was 68.25% and 56.37%, respectively, and adsorption capacity of the nanotubes was 141 mg/g and 119 mg/g at initial concentration of 50 mg/l and pH=5 with adsorption dose of 0.8 g/L for 105 minutes at 300 rpm and temperature of 10°C from aqueous solutions. Also, it was revealed that the adsorption process had the highest correlation with the Langmuir model and secondorder kinetics, and the maximum adsorption capacity based on Langmuir model was 373.80 mg/g. Conclusion: According to the results, it was found that single-walled and multi-walled carbon nanotubes can be used as effective absorbents in the removal of penicillin G from aqueous solutions.


2016 ◽  
Vol 104 (9) ◽  
pp. 635-647 ◽  
Author(s):  
Sabriye Yusan ◽  
Anastasia Bampaiti ◽  
Sema Erenturk ◽  
Fotini Noli ◽  
Mahmut A. A. Aslani ◽  
...  

Abstract In this study, for the first time ZnO nanoparticles and diatomite-supported ZnO nanocomposite have been utilized as adsorbent for the removal of Th(IV) ions from aqueous solutions under different experimental conditions. The Langmuir, Freundlich, Temkin and Dubinin– Radushkevich (D–R) isotherms were used to analyze the equilibrium data. The sorption equilibrium data were fitted well to the Langmuir isotherm with maximum sorption capacities values was found to be 1.105 mmol/g and 0.320 mmol/g for ZnO nanoparticles and diatomite supported ZnO nanocomposite, respectively. Pseudo-first and pseudo-second order equations, Intraparticle diffusion and Bangham’s models were considered to evaluate the rate parameters and sorption mechanism. Sorption kinetics were better reproduced by the pseudo-second order model (R2 > 0.999), with an activation energy (Ea) of +99.74 kJ/mol and +62.95 kJ/mol for ZnO nanoparticles and diatomite-supported ZnO nanocomposite, respectively. In order to specify the type of sorption reaction, thermodynamic parameters were also determined. The evaluated ΔG* and ΔH* indicate the non-spontaneous and endothermic nature of the reactions. The results of this work suggest that both of the used materials are fast and effective adsorbents for removing Th(IV) from aqueous solutions and chemical sorption plays a role in controlling the sorption rate.


2015 ◽  
Vol 50 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Gholamreza Tolian ◽  
Seyed Ali Jafari ◽  
Saeid Zarei

In the present paper, the biosorption capacity of an indigenous seaweed Enteromorpha sp. was assessed and compared for nickel(II) and cadmium(II) removal from aqueous solution. Response surface methodology based on Box–Behnken design was employed to achieve the optimum removal conditions as well as investigating the effects of some independent variables on the process performance. It was found that the maximum nickel(II) removal achieved was 87.16% under optimum conditions of pH 4.79, biomass concentration of 1,000 mg/L, contact time 70 min and temperature of 25 °C. For cadmium the optimum conditions were defined as pH 4.88, biomass concentration of 1,000 mg/L, contact time 50 min and temperature fixed at 65 °C which resulted in a maximum 75.16% removal. Equilibrium isotherm studies revealed that Freundlich and Langmuir models were more successful for describing nickel(II) and cadmium(II) biosorption data, respectively. The maximum sorption capacities of biomass, qmax, for nickel(II) and cadmium(II) were predicted as 250 and 167 mg/g, respectively, by the Langmuir model. The results suggest Enteromorpha seaweed as an eco-friendly and suitable biosorbent for nickel(II) and cadmium(II) removal from aqueous solutions.


2014 ◽  
Vol 1051 ◽  
pp. 583-587
Author(s):  
Ling Tao ◽  
Xiao Wei Song ◽  
Jian Li Yuan ◽  
Jun Ren ◽  
Yan Zhuo Zhang

Adsorption of Cr6+ onto purified attapulgite was investigated with respect to temperature, initial concentration and contact time. The kinetics data related to the adsorption of chromium from aqueous solutions are in good agreement with the pseudo-second order equation in ranges of initial concentration of 20~200 mg/L, and temperature of 298~328K. The thermodynamic experiment results show that the equilibrium adsorption isotherm was closely fitted with the Langmuir model.


2004 ◽  
Vol 39 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Lua'y Zeatoun ◽  
Noor Younis ◽  
Rana Rafati

Abstract Locally available tar sands were used for the removal of phenol and cadmium ions from their aqueous solutions. Batch sorption experiments showed that tar sands did not remove phenol from aqueous solutions, but they were effective in cadmium adsorption. Cadmium uptake was found to increase with an increase in initial concentration of the metal ions, temperature, pH and sorbent amount. On the other hand, the presence of ions such as sodium, Na+, suppressed the uptake of cadmium ions. Physical activation of the tar sands influenced the adsorption process negatively. The sorption process was relatively fast and the equilibrium isotherm data were well represented by the Langmuir model.


2015 ◽  
Vol 60 (3) ◽  
pp. 677-686
Author(s):  
Agnieszka Bożęcka ◽  
Stanisława Sanak-Rydlewska

Abstract This article presents the results of research on the Cd2+ ions sorption from model aqueous solutions on sunflower hulls, walnut shells and plum stones. The effect of various factors, such as mass of the natural sorbent, the pH, the time and the temperature was studied. The process of Cd2+ ions sorption on studied sorbents was described by the Langmuir model. The best sorption capacity has been achieved for sunflower hulls. The maximum sorption capacity for this material was 19.93 mg/g.


2012 ◽  
Vol 65 (3) ◽  
pp. 490-495 ◽  
Author(s):  
C. H. Wu ◽  
C. Y. Kuo ◽  
C. H. Yeh ◽  
M. J. Chen

In this study, C.I. Reactive Red 2 (RR2) was removed from aqueous solutions by chitin. Exactly how the RR2 concentration, chitin dosage, pH, and temperature affected adsorption of RR2 by chitin was then determined. After reaction for 120 min, the amount of 10 and 20 mg/L RR2 absorbed onto chitin was 5.7 and 7.5 mg/g, respectively. The adsorption percentage increased from 56 to 94% when the chitin dosage was increased from 1.5 to 2.5 g/L. Experimental results indicated that the pseudo-second-order model best represents adsorption kinetics. Adsorption of RR2 increased as the temperature increased; however, it decreased with an increased pH. Experimental results further demonstrated that the Freundlich model is superior to the Langmuir model in fitting experimental isotherms. The ΔH0 and ΔS0 were 16.34 kJ/mol and 152.10 J/mol K, respectively. ΔH0 suggested that adsorption of RR2 onto chitin was via physisorption.


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