Statistical Modeling, Optimization and Kinetics of Mn2+ Adsorption in Aqueous Solution Using a Biosorbent

2019 ◽  
Vol 233 (8) ◽  
pp. 1201-1214 ◽  
Author(s):  
Elaheh Tajari ◽  
Narges Samadani Langeroodi ◽  
Mahnaz Khalafi
Keyword(s):  
Wheat Bran ◽  
Low Cost ◽  
Weight Ratio ◽  
P Value ◽  
Core Shell ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Shell Weight ◽  
Removal Ratio ◽  
Kinetics Of

Abstract This paper describes the adsorption of Mn2+ ions from water with a mixture of wheat bran and Japanese medlar core shell (weight ratio of 30–70 wheat bran to Japanese medlar core shell) as low-cost adsorbent. Scanning Electron Microscope was used to characterize the adsorbent. The response surface methodology (RSM) that is usually approximated by a second-order regression model was employed to evaluate the effects of solution pH, initial Mn2+ concentration, adsorbent weight and contact time on the removal ratio of the Mn2+ ions. In this regard, the significant variables initial Mn2+ ions concentration, pH, adsorbent weight and square pH were found based on the small P-value for the model coefficients. The predicted optimal conditions were also performed. In the process optimization, maximal value of the removal ratio of Mn2+ was achieved as 96.91%. Additionally, this paper discusses the kinetic of adsorption in optimal conditions.

scholarly journals Improvement of Hydrogen Desorption Characteristics of MgH2 With Core-shell Ni@C Composites

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3113 ◽  
Author(s):  
Cuihua An ◽  
Qibo Deng
Keyword(s):  
Low Cost ◽  
Hydrogen Desorption ◽  
Core Shell ◽  
Desorption Kinetics ◽  
Hydrogen Storage Materials ◽  
High Hydrogen ◽  
Dehydrogenation Kinetics ◽  
Materials Research ◽  
High Theoretical Capacity ◽  
Kinetics Of

Magnesium hydride (MgH2) has become popular to study in hydrogen storage materials research due to its high theoretical capacity and low cost. However, the high hydrogen desorption temperature and enthalpy as well as the depressed kinetics, have severely blocked its actual utilizations. Hence, our work introduced Ni@C materials with a core-shell structure to synthesize MgH2-x wt.% Ni@C composites for improving the hydrogen desorption characteristics. The influences of the Ni@C addition on the hydrogen desorption performances and micro-structure of MgH2 have been well investigated. The addition of Ni@C can effectively improve the dehydrogenation kinetics. It is interesting found that: i) the hydrogen desorption kinetics of MgH2 were enhanced with the increased Ni@C additive amount; and ii) the dehydrogenation amount decreased with a rather larger Ni@C additive amount. The additive amount of 4 wt.% Ni@C has been chosen in this study for a balance of kinetics and amount. The MgH2-4 wt.% Ni@C composites release 5.9 wt.% of hydrogen in 5 min and 6.6 wt.% of hydrogen in 20 min. It reflects that the enhanced hydrogen desorption is much faster than the pure MgH2 materials (0.3 wt.% hydrogen in 20 min). More significantly, the activation energy (EA) of the MgH2-4 wt.% Ni@C composites is 112 kJ mol−1, implying excellent dehydrogenation kinetics.

scholarly journals Sustainable Removal of Cr(VI) by Lime Peel and Pineapple Core Wastes

2019 ◽  
Vol 9 (10) ◽  
pp. 1967 ◽  
Author(s):  
Emilio Rosales ◽  
Silvia Escudero ◽  
Marta Pazos ◽  
Mª Angeles Sanromán
Keyword(s):  
Distribution Coefficient ◽  
Desirability Function ◽  
Low Cost ◽  
Scale Up ◽  
Fixed Bed ◽  
Distribution Coefficients ◽  
Environmental Benefits ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Lime Peel

The search for efficient and environmentally friendly adsorbents has positioned lignocellulosic materials as attractive and low-cost alternatives instead of synthetic materials. Consequently, the present work investigates the efficacy of untreated lime peel (LM) and pineapple core (PP) as biosorbents for Cr(VI) removal. The maximum adsorption capacities (acquired at 24 h) of these sorbents were 9.20 and 4.99 mg/g, respectively. The use of these sorbents is expected to offer a rapid and efficient solution to treat effluents containing Cr(VI). Pineapple core showed the best biosorption properties and good distribution coefficients (distribution coefficient KD 8.35–99.20 mL/g) and the optimization of the adsorption was carried out by a response surface methodology using the Box–Behnken design. Thus, the effect of pH, biosorbent dosage, and temperature were assessed during the whole procedure. Three different responses were studied—Cr(VI) removal, Cr biosorption, and distribution coefficient—and the optimal conditions for maximizing the responses were identified by numerical optimization applying the desirability function. The resulting optimal conditions were: initial solution pH 2.01, biosorbent dosage 30 g/L, and temperature 30.05 °C. Finally, the process scale-up was evaluated by the simulation of the process working with a column of 100 L using the Fixed-bed Adsorption Simulation Tool (FASTv2.1). This research presents the obtained environmental benefits: i) reduction of pineapple waste, ii) Cr(VI) reduction and biosorption, iii) shortest sorption time for Cr, iv) properties that allow the biosorption process on the flow system, and v) low-cost process.

Two-pot oxidative preparation of dicarboxylic acid containing cellulose for the removal of Beryllium (Be2+) from aqueous solution.

2020 ◽  
Vol 16 ◽  
Author(s):  
Vedat Tolga Özdemir ◽  
Himmet Mert Tuğaç ◽  
Özgür Arar
Keyword(s):  
Aqueous Solution ◽  
Low Cost ◽  
Initial Step ◽  
Sorption Process ◽  
Hydroxyl Groups ◽  
Solution Ph ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Aldehyde Groups ◽  
Kinetics Of

Background: Cellulose is one of the most abundant, non-toxic, and renewable natural biopolymers. The presence of hydroxyl groups in cellulose leads to further modification of it. Preparation and modification of cellulose-based sorbents and their applications on water treatment gained traction in recent years. Objective: A low-cost and eco-friendly biosorbent was designed and fabricated by introducing the acetate functional groups into cellulose for removing Beryllium (Be2+) from an aqueous solution. The so rption of Be2+ on acetate containing cellulose was evaluated for varying sorbent doses and initial solution pH values. Method: The sorbent was prepared by a two-step oxidation process. In the initial step, cellulose reacted with NaIO4 and aldehyde groups were introduced to cellulose. In the second step, newly obtained aldehyde groups were oxidized to create acetate groups. Results: The kinetics of the sorption process showed that Be2+ uptake reached equilibrium in 3 minutes. The sorption isotherm was well fitted in the Langmuir model, and maximum sorption capacity was 4.54 mg/g. Moreover, the thermodynamic studies demonstrated that Be2+ sorption is spontaneous and exothermic. Furthermore, the prepared sorbent can be regenerated by using 0.1 M HCl or H2SO4 solutions. Conclusion: Removal of Be2+ is pH dependent and it is favorable at high solution pH. The kinetics of the prepared sorbent is rapid and equilibrium attained in 3 minutes. The prepared sorbent can be regenerated with 0.1 M acid solution with > 99% efficiency.

Studies of Pb2+ adsorption by Moringa oleifera Lam. seeds from an aqueous medium in a batch system

2013 ◽  
Vol 69 (1) ◽  
pp. 163-169 ◽  
Author(s):  
Ana Paula Meneghel ◽  
Affonso Celso Gonçalves ◽  
César Ricardo Teixeira Tarley ◽  
José Renato Stangarlin ◽  
Fernanda Rubio ◽  
...  
Keyword(s):  
Contact Time ◽  
Moringa Oleifera ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Desorption Rate ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Desorption Process ◽  
Batch System ◽  
Moringa Oleifera Lam

The efficiency of Moringa (Moringa oleifera Lam.) seeds for removing lead ions (Pb2+) from water was evaluated. Parameters such as solution pH, adsorbent mass, contact time between solution and adsorbent, isotherms, thermodynamic, kinetics, and desorption were evaluated. The maximum adsorption capacity of the biosorbent was found to be 12.24 mg g−1. In order to verify the effectiveness of this material, comparative studies were performed with activated carbon under the same optimal conditions for the construction of isotherms and the desorption process. Average desorption rate values led to the assumption that a strong interaction took place between the adsorbents and the metal ions. Thus, it has been concluded that the biosorbent studied herein can be considered very effective and feasible for remediating Pb2+-contaminated solutions, since this material is itself an untreated and low-cost byproduct.

scholarly journals Polydispersity vs. Monodispersity. How the Properties of Ni-Ag Core-Shell Nanoparticles Affect the Conductivity of Ink Coatings

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2304
Author(s):  
Anna Pajor-Świerzy ◽  
Dawid Staśko ◽  
Radosław Pawłowski ◽  
Grzegorz Mordarski ◽  
Alexander Kamyshny ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Weight Ratio ◽  
Core Shell ◽  
Optimal Conditions ◽  
Mass Ratio ◽  
Metallic Films ◽  
Ag Nps ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
20 Nm

The effect of polydispersity of nickel-silver core-shell nanoparticles (Ni-Ag NPs) on the conductivity of ink coatings was studied. Ni-Ag NPs of various average diameters (100, 220, and 420 nm) were synthesized and utilized for the preparation of conductive inks composed of monodisperse NPs and their polydisperse mixtures. The shell thickness of synthesized Ni-Ag NPs was found to be in the range of 10–20 nm and to provide stability of a core metal to oxidation for at least 6 months. The conductivity of metallic films formed by inks with monodisperse Ni-Ag NPs was compared with those formed by polydisperse inks. In all cases, the optimal conditions for the formation of conductive patterns (weight ratio of monodisperse NPs for polydisperse composition, the concentration of the wetting agent, sintering temperature, and duration) were determined. It was found that metallic films formed by polydisperse ink containing 100, 220, and 420 nm Ni-Ag NPs with a mass ratio of 1:1.5:0.5, respectively, are characterized by the lowest resistivity, 10.9 µΩ·cm, after their thermal post-coating sintering at 300 °C for 30 min that is only 1.6 higher than that of bulk nickel.

scholarly journals Biosorption of pharmaceuticals from aqueous medium by Luffa Cylindrica Fibres: Application of the linear form of Redlich-Peterson isotherm equation

2020 ◽  
Author(s):  
Amel Aloui ◽  
NOUZHA BOUZIANE ◽  
Hacene Bendjeffal ◽  
yacine Bouhedja ◽  
Abdennour Zertal
Keyword(s):  
Active Sites ◽  
Low Cost ◽  
Correlation Coefficients ◽  
Pharmaceutical Products ◽  
Sem Analysis ◽  
P Value ◽  
Luffa Cylindrica ◽  
Solution Ph ◽  
Isotherm Equation ◽  
Kinetics Modelling

Abstract This study is focused on the removal of Dextropropoxyphene (DPP) and Paracetamol (PAR) from aqueous solutions by sorption on Luffa Cylindrica fibres, as a low-cost biosorbent, that was initially characterized using BET, FTIR spectroscopy, and SEM analysis. The sorption study has been realized by the batch method with the effect of the biosorbent amount, initial concentration, solution pH and batch temperature. The modelling of the sorption phenomenon was based on the mathematical approach of the modified Redlich-Peterson isotherm equation (RP), where the dimensionless form of this isotherm, corresponding to the optimal curve, allows the α parameter evaluation. The same value of α was obtained for both pharmaceutical compounds, while the values where 2 and 10 for DPP and PAR, respectively. The linear regression of the Redlich-Peterson isotherm equation was also confirmed by analysis of variance (ANOVA). The obtained results show that p-value is less than 0.05, with correlation coefficients (Radj2) equal to 0.9515 and 0.9283 for DPP and PAR, respectively. The kinetics modelling shows that the sorption mechanism obeys the pseudo-second-order and intraparticular diffusion. The adsorption process is exothermic, spontaneous and the molecules of the two pharmaceutical products have a random behaviour on the Luffa Cylindrica active sites.

Study of the Cu(II) removal from aqueous solutions by adsorption on titania

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Toxic Metals ◽  
Low Cost ◽  
Lateral Interaction ◽  
Tio2 Surface ◽  
High Toxicity ◽  
Removal Of Heavy Metals ◽  
Solution Parameters ◽  
Kinetics Of

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.

Kinetic of oxidation of methyl orange by vanadium(V) under conditions VO2+ and decavanadates coexist: Catalysis by Triton X-100 micellar medium

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methyl Orange ◽  
Solution Ph ◽  
Vanadium Concentration ◽  
Limiting Behavior ◽  
First Order ◽  
First Order Kinetics ◽  
Ph Range ◽  
Kinetic Pattern ◽  
Triton X ◽  
Kinetics Of

The kinetics of oxidation of methyl orange by vanadium(V) {V(V)} has been investigated in the pH range 2.3-3.79. In this pH range V(V) exists both in the form of decavanadates and VO2+. The kinetic results are distinctly different from the results obtained for the same reaction in highly acidic solution (pH < 1) where V(V) exists only in the form of VO2+. The reaction obeys first order kinetics with respect to methyl orange but the rate has very little dependence on total vanadium concentration. The reaction is accelerated by H+ ion but the dependence of rate on [H+] is less than that corresponding to first order dependence. The equilibrium between decavanadates and VO2+ explains the different kinetic pattern observed in this pH range. The reaction is markedly accelerated by Triton X-100 micelles. The rate-[surfactant] profile shows a limiting behavior indicative of a unimolecular pathway in the micellar pseudophase.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

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