scholarly journals Sorption Behaviors of Light Lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and Cr(III) Using Nitrolite

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2256 ◽  
Author(s):  
Grzegorz Wójcik

The sorption of light lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and chromium(III) ions from acidic solutions on Nitrolite was studied at varying ions concentrations, pH, contact time and temperatures. The sorption capacity of lanthanides(III) and chromium(III) ions were examined in the ranges 2–9 and 2–5, respectively. The adsorption capacities of all metals are increase with the increasing pH (up to initial pH 9), despite the potential precipitation of metals at higher pH values. Therefore, an initial pH 9 of lanthanides gives the highest adsorption capacities. The kinetics of sorption chromium(III) and light lanthanides(III) were investigated. The experimental data were analyzed using the pseudo-first-order, pseudo-second-order forms, Elovich, and intra-particle diffusion models. The sorption kinetics of investigated ions was described by pseudo-second-order model the best. The results indicate the endothermic process of Cr(III), La(III), Ce(III), Pr(III) and Nd(III) ions sorption. The sorption capacities of La(III) 4.77 mg/g, Ce(III) 4.45 mg/g, Pr(III) 4.30 mg/g, Nd(III) 4.13 mg/g and Cr(III) 2.39 mg/g were calculated from the Langmiur model, which describes adsorption better than Freundlich and Dubinin–Radushkevich.

2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.


2011 ◽  
Vol 148-149 ◽  
pp. 357-360
Author(s):  
Jin Bo Huang ◽  
Min Cong Zhu ◽  
Zhi Fang Zhou ◽  
Hong Xia Zhang

Expanded graphite (EG) was prepared by microwave irradiation and evaluated as adsorbent for the removal of disperse blue 2BLN (DB) from aqueous solution by the batch adsorption technique under different conditions of initial pH value, adsorbent dosage, initial dye concentration and contact time. The experimental data were analyzed considering pseudo-first-order, pseudo-second-order and intra-particle diffusion approaches. The adsorption kinetics at room temperature could be expressed by the pseudo second order model very well. The results indicate that the adsorption rate is fast enough and more than eighty percent of the adsorbed DB can be removed in the first 15 min at room temperature, which makes the process practical for industrial application.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Asma Nasrullah ◽  
Hizbullah Khan ◽  
Amir Sada Khan ◽  
Zakaria Man ◽  
Nawshad Muhammad ◽  
...  

The ash ofC. polygonoides(locally called balanza) was collected from Lakki Marwat, Khyber Pakhtunkhwa, Pakistan, and was utilized as biosorbent for methylene blue (MB) removal from aqueous solution. The ash was used as biosorbent without any physical or chemical treatment. The biosorbent was characterized by using various techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The particle size and surface area were measured using particle size analyzer and Brunauer-Emmett-Teller equation (BET), respectively. The SEM and BET results expressed that the adsorbent has porous nature. Effects of various conditions such as initial concentration of methylene blue (MB), initial pH, contact time, dosage of biosorbent, and stirring rate were also investigated for the adsorption process. The rate of the adsorption of MB on biomass sample was fast, and equilibrium has been achieved within 1 hour. The kinetics of MB adsorption on biosorbent was studied by pseudo-first- and pseudo-second-order kinetic models and the pseudo-second-order has better mathematical fit with correlation coefficient value (R2) of 0.999. The study revealed thatC. polygonoidesash proved to be an effective, alternative, inexpensive, and environmentally benign biosorbent for MB removal from aqueous solution.


2019 ◽  
Vol 230 (10) ◽  
Author(s):  
Paweł Staroń ◽  
Paulina Sorys ◽  
Jarosław Chwastowski

Abstract The study investigated the sorption capacity of biosorbent-raphia sp. against ammonia. Raphia fibers were used without and with the modification of its surface with NaCl, NaNO3, and K2SO4. The data was analyzed in the state of equilibrium using four isotherm models such as Langmuir, Freudlich, Temkin, and Dubinin-Radushkevich. The equilibrium of ammonia sorption for all studied systems was best described by the Freudlich isotherm model. On its basis, it can be assumed that the studied process is of chemical nature, which results from the value of the coefficient 1/n < 1. In order to confirm the sorption mechanism, analysis of the kinetics of the ammonia sorption process on raphia fibers was performed. Four kinetic models of sorption were calculated: pseudo-first-order model, pseudo-second-order model, Elovich model, and Webber-Morris intermolecular diffusion model. The sorption kinetics of the modeled ammonia waste were carried out using unmodified palm fibers and all kinds of surface modification. This process was best described by the pseudo-second-order sorption model, which can be considered as a confirmation of the chemical nature of ammonia sorption on raphia sp. fibers.


2021 ◽  
Vol 83 (5) ◽  
pp. 1183-1197
Author(s):  
Jian Zhang ◽  
Wenjing Lu ◽  
Hui Li ◽  
Siyan Zhan ◽  
Ximo Wang ◽  
...  

Abstract In this study, the polyethyleneimine (PEI) modified waste bamboo powder (WBP-Na-PEI) was successfully prepared and applied to adsorbing Congo red (CR) dye from aqueous solution. The obtained materials were characterized by field emission scanning electron microscope, X-ray diffraction, Fourier transform-infrared, and thermogravimetric analysis. The results showed that WBP-Na-PEI(1.8 K-5) was synthesized successfully and PEI uniformly covered the WBP-Na-PEI(1.8 K-5) surface. In the process of adsorption, four kinds of influencing factors were discussed, and the adsorption mechanisms such as kinetics, isotherm, thermodynamics were explored. The maximum adsorption capacity of WBP-Na-PEI(1.8 K-5) was 992.94 mg·g−1 at 298 ± 1 K, and the removal efficiency was over 98%. Pseudo-first-order, pseudo-second-order and intra-particle diffusion models were studied, the results showed that the adsorption process conformed to the pseudo-second-order model, and the rate of this process was controlled by many steps. Furthermore, the removal efficiency of the adsorption kinetics reached 85% within 10 minutes. The results of the isotherm model and thermodynamics showed that the adsorption process was consistent with the Langmuir model and was mainly a spontaneous chemical endothermic process of monolayer. And the removal efficiency of the adsorbent reached 93% at the concentration of 400 mg/L, which can be expected to have a broad prospect in the treatment of CR industrial wastewater.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Zhang Xiao-teng ◽  
Jiang Dong-mei ◽  
Xiao Yi-qun ◽  
Chen Jun-chang ◽  
Hao Shuai ◽  
...  

The biosorption is an effective and economical method to deal with the wastewater with low concentrations of uranium. In this study, we present a systematic investigation of the adsorption properties, such as the kinetics, thermodynamics, and mechanisms, of modified rice stems. The rice stems treated with 0.5 mol/L NaOH solutions show higher removal percentage of uranium than those unmodified under the conditions of initial pH (pH = 4.0), absorbent dosage (5–8 g/L), temperature (T = 298 K), and adsorption equilibrium time (t = 180 min). The removal percentage of uranium(VI) decreases with increasing initial concentration of uranium(VI). The Langmuir isotherm model, which suggests predominant monolayered sorption, is better than Freundlich and Temkin models to elucidate the adsorption isotherm of adsorbed uranium. Kinetic analyses indicate that the uranium(VI) adsorption of the modified rice stem is mainly controlled by surface adsorption. The pseudo-second-order kinetic model, with the correlation coefficient of R2 = 0.9992, fits the adsorption process much better than other kinetic models (e.g., pseudo-second-order kinetic model, Elovich kinetic model, and intraparticle diffusion model). The thermodynamic parameters ΔG0, ΔH0, and ΔS0 demonstrate that the adsorption of uranium(VI) is an endothermic and spontaneous process, which can be promoted by temperature. The adsorption of uranium can change the morphology and the structure characteristics of the modified rice stem through interaction with the adsorption sites, such as O-H, C=O, Si=O, and P-O on the surface.


2011 ◽  
Vol 80-81 ◽  
pp. 421-425
Author(s):  
Li Fang Zhang ◽  
Ying Ying Chen ◽  
Shu Juan Dai

In this study, the biosorption of Malachite Green, a cationic dye from aqueous solution onto pretreated biomass of Penicilium sp. was examined. The biosorption studies were carried out under various parameters such as initial pH, contact time and initial dye concentration. The experimental results show that optimum pH for efficient dye biosorption was found to be 5.0-6.0 for pretreated biomass. The bosorption capacity was increased with the increasing initial dye concentration in studied dye concentration range. The kinetic data obtained at different concentrations were analyzed using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. It was obtained that the biosorption process followed the pseudo-second-order kinetic model.


2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.


2020 ◽  
Vol 74 (1) ◽  
pp. 65-70
Author(s):  
Bojana Obradovic

Adsorption processes are widely used in different technological areas and industry sectors, thus continuously attracting attention in the scientific research and publications. Design and scale-up of these processes are essentially based on the knowledge and understanding of the adsorption kinetics and mechanism. Adsorption kinetics is usually modeled by using several well-known models including the pseudo-first and pseudo-second order models, the Elovich equation, and the intra-particle diffusion based models. However, in the scientific literature there are a significant number of cases with the inappropriate use of these models, utilization of erroneous expressions, and incorrect interpretation of the obtained results. This paper is especially focused on applications of the pseudo-second order, intra-particle diffusion and the Weber-Morris models, which are illustrated with typical examples. Finally, general recommendations for selection of the appropriate kinetic model and model assumptions, data regression analysis, and evaluation and presentation of the obtained results are outlined.


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