Chitosan-coated black sesame (Sesamum indicum L.) seed pulp as a novel candidate adsorbent for Cr(VI) elimination

2019 ◽  
Vol 79 (4) ◽  
pp. 688-698
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna ◽  
Elif Özdemir ◽  
Erol Pehlivan

Abstract This study evaluates the application of Cr(VI) adsorption from the prepared synthetic solution by black sesame (Sesamum indicum L.) seed pulp (BSSP) and chitosan (Cts)-coated black sesame seed pulp beads (Cts-BSSP). BSSP and Cts-BSSP were used as an adsorbent without any chemical or physical treatment to remove Cr(VI) from an aqueous medium. The results indicated that the Cr(VI) removal was pH-dependent and reached an optimum at pH 2.0. It has been observed that the percentage of adsorption increased from 62% to 95% when the amount of Cts-BSSP increased from 0.0125 g to 0.0250 g. The required adsorbent amount for the maximum removal was 0.05 g and 0.1 g for Cst-BSSP and BSSP, respectively. The contact time for the adsorption was 120 min and 90 min for BSSP and Cst-BSSP, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to explore the possible adsorption mechanism for Cr(VI). The equilibrium data for the BSSP and Cts-BSSP were used with the Langmuir and Freundlich adsorption isotherm models to assess the adsorption capacity and relevant mechanism. The adsorption capacity of the Cts-BSSP for Cr(VI) is relatively high compared to BSSP. The monolayer maximum adsorption capacities for Cr(VI) ions were 31.44 and 18.32 mg/g for Cts-BSSP and BSSP, respectively.

2016 ◽  
Vol 74 (1) ◽  
pp. 236-245 ◽  
Author(s):  
Narges Samadani Langeroodi ◽  
Elaheh Safaei

The objective of this study was to investigate the use of carbonized medlar-core particles as a new biosorbent to remove Cu2+ from aqueous solution. Fourier transform infrared spectroscopy and scanning electron microscopy were used to characterize the biosorbent. This paper reports the effects of adsorbent dose, pH, temperature and concentration of adsorbate. Batch isotherm studies were also performed to understand the ability of the adsorbent. The adsorption behavior of the Cu2+ was studied using Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity determined from the Langmuir adsorption equation has been found as 43.478 mg.g−1 at 298.15 K. The adsorption of Cu2+ by medlar core in carbonized form was spontaneous and endothermic. It was also found that the biosorption of Cu2+ followed second-order kinetics. Carbonized medlar-core particles showed great potential in aqueous solution due to the high adsorption capacity.


2021 ◽  
Author(s):  
CI Chemistry International

In view of promising adsorption efficiency of clay based materials, a modified iron-kaolin clay was used as an adsorbent of Pb(II) and Cd(II) ions from aqueous solutions. The effects of various experimental parameters, such as initial metal ions concentration, contact time, temperature and pH were investigated. The Langmuir and Freundlich adsorption isotherm models were applied to the experimental equilibrium data at different temperatures. The maximum adsorption capacities of Pb(II) and Cd(II) ions were 76.92 and 75.19 (mg/g), respectively. Thermodynamic parameters such as the change of Gibbs free energy, enthalpy and entropy of adsorption were also calculated and it was found that the lead and cadmium ions uptake by modified kaolin clay is endothermic and spontaneous in nature.


2001 ◽  
Vol 19 (3) ◽  
pp. 197-210 ◽  
Author(s):  
A. Hashem ◽  
Reda M. El-Shishtawy

The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by IR analysis. The ability of cationized cellulose to adsorb anionic dyes, viz. Acid Orange 7, Direct Blue 75 and Direct Violet 31, was investigated at 25°C and 50°C. The equilibrium data obtained were fitted by the Langmuir and Freundlich isotherm models, allowing the corresponding adsorption parameters to be determined. The results showed that the adsorption capacity was dependent on the adsorbent, temperature, the nature of the dye and (to some extent) on van der Waals and hydrogen bonding. Cationized cellulose exhibited a much better adsorption capacity towards anionic dyes than cellulose.


2012 ◽  
Vol 9 (3) ◽  
pp. 1389-1399 ◽  
Author(s):  
R. Hema Krishna ◽  
A. V. V. S. Swamy

The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad(min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.


2018 ◽  
Vol 5 (2) ◽  
pp. 91-99
Author(s):  
Marzieh Bagheri ◽  
Mohammad Nasiri ◽  
Bahareh Bahrami

Nowadays, due to increasing usage of dye in various industries and its destructive effects on health and environment, it is necessary to remove dyes from industrial wastes. Although few studies can be found on using pine cone for removal of different dyes, it has not been used yet to remove Reactive Blue 203 (RB203) dye. The purpose of this study is to investigate RB203 dye adsorption using activated carbon produced from pine cone. Optimal values of influencing factors for RB203 dye removal were obtained. The results showed that the maximum removal was occurred at a pH of 2, temperature of 30˚C, dye concentration of 30 mg/L, adsorbent dosage of 100 mg/L, and contact time of 15 min. The maximum removal percentage was 98.48%. In order to study the synthesized activated carbon, some characterization methods including scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and Brunauer-Emmett-Teller (BET) have been used. Investigation of adsorption isotherm models revealed that adsorption of RB203dye can be described through D-R and Temkin isotherm models. Additionally, RB203 dye removal follows the pseudo-firstorder kinetic equation.


2019 ◽  
pp. 268-277
Author(s):  
Srdjan Stankovic ◽  
Tatjana Sostaric ◽  
Mladen Bugarcic ◽  
Aleksandra Janicijevic ◽  
Katarina Pantovic-Spajic ◽  
...  

Annual production of the sunflower seed in Serbia is between 650,000-720,000 tons. Most of this amount is used in vegetable oil industry. Abundant by-products from this processing are sunflower seed husks. Husks are usually incinerated by vegetable oil producers in order to obtain energy, used as an animal feed, or, unfortunately, landed up at some landfills. In order to promote new, added value for this abundant, renewable resource, the investigation presented in this paper was conducted. For that purpose, adsorption of Cu(II) ions from synthetic solution by unmodified sunflower seed husks was examined. ATR-FTIR was used to identify functional groups as potential active sites for Cu(II) sorption. Zeta potential values were determined to reveal the surface charge, while the cation exchange capacity (CEC) was determined to reveal the amount of exchangeable ions on its surface. ATR-FTIR analysis revealed the presence of specific functional groups (hydroxyl, carboxyl, carbonyl, and amine) responsible for removal of Cu(II) ions. The total CEC of sunflower husk is 47.74 meq/100g and Ca(II) and Mg(II) ions are in dominant exchangeable positions. The study of ion-exchange mechanism involvement was done and results confirmed that this mechanism is not the only mechanism which is involved in copper sorption. Also, the results show that the Cu(II) ions have preference for Mg(II) ions substitution. Sorption experiments were conducted in batch system. The effect of operating parameters (pH, contact time, initial concentration of Cu(II) ions and adsorbent dosage) on the adsorption capacity were investigated. The obtained experimental data were fitted by Langmuir and Freundlich isotherm models. The maximum adsorption capacity for Cu(II) ions calculated from Langmuir adsorption isotherm was 34.89 mg/g which is 15 to 35% higher than the capacity that other researchers reported previously for the same material and pollutant. These results are suggesting that sunflower seed husks have a potential to be applied as an effective adsorbent of copper ions from contaminated waters.


2016 ◽  
Vol 18 (2) ◽  
pp. 402-415 ◽  

<div> <p>Agriculture wastes like sugarcane bagasse are available in large quantities in Egypt. Various adsorbents from natural materials, industrial waste materials, agricultural by-products, and biomass based activated carbon can be used in the removal of various dyes. Raw Bagasse pith (RBP) was used to prepare activated carbon (AC) using phosphoric acid (H<sub>3</sub>PO<sub>4</sub>) as a chemical activating agent. C The raw BP and the synthesized adsorbent were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM). The effectiveness of AC prepared in adsorption of methylene blue (MB) has been studied as a function of adsorbent type, initial dye concentration and contact time. The effects of the initial dye concentration and contact time were evaluated. Adsorption isotherm models - Langmuir, Freundlich and Temkin were used to simulate the equilibrium data. Langmuir equation was found to have the highest value of R<sup>2</sup> compared with other models. Furthermore, it was found that sugarcane bagasse have a high adsorptive capacity towards MB.</p> </div> <p>&nbsp;</p>


2018 ◽  
Vol 7 (5) ◽  
pp. 386-395 ◽  
Author(s):  
Abdellah El Boukili ◽  
Nidae Loudiyi ◽  
Ahmed El Bazaoui ◽  
Abderrahim El Hourch ◽  
M'Hamed Taibi ◽  
...  

The present study was conducted in order to investigate the adsorption and desorption behavior of Mefenpyr-diethyl (MFD) using the batch equilibration technique in four soils, with different ranges of organic matter content, from different regions of Morocco orders of Benimellal (Soil 1), Settat (Soil 2), Sidi Bettach (Soil 3) and EL Hajeb (Soil 4). The adsorption isotherm models Langmuir, linear and Freundlich were used to compare the adsorption capacity of the soils. The results indicated that the Freundlich equation provided the best fit for all adsorption data. The values of KF and Kd ranged from 4.45 to 15.9 and 4.30 to 18.30 L.kg-1 , respectively. The calculated total percentage of desorption values from the Soil 1, Soil 2, Soil 3 and Soil 4 after the four desorption process were 59 %; 55,6 %; 37,5 % and 52,5%, respectively. Highest adsorption and desorption were observed in soil 1, and the lowest was in soil 3. According to the adsorption and desorption results, organic matter and clay seemed to be the most important factors influencing the adsorption capacity of MFD.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3054
Author(s):  
Huan Xu ◽  
Guilhem Boeuf ◽  
Zixian Jia ◽  
Kairuo Zhu ◽  
Mehrdad Nikravech ◽  
...  

In this study, ultraporous aluminas (UPA) were synthesized as new effective adsorbents for Remazol Brilliant Blue R (RBBR) removal from aqueous solutions. The UPA monoliths were grown via facile oxidation process, followed by isochronous annealing treatment in air at different temperatures, through which γ, θ, and α phase polycrystalline fibrous grains of UPA can be accordingly obtained. The experimental factors that affect the material adsorption performances including initial pH, contact time, and temperature were comprehensively studied by batch experiments. The RBBR adsorption isotherms of UPA(γ) and UPA(θ) powders were found almost identical, while UPA(α) powders showed low effectiveness. To obtain the desirable mechanical stability of the UPA monolith with considerable RBBR adsorption capacity, UPA(θ) powders were further studied. The UPA(θ) powders exhibited maximum RBBR adsorption at pH 2 due to the positively charged surface under acidic conditions. Compared with the Lagergren pseudo-first-order model, the pseudo-second-order model was found to explain the adsorption kinetics better. Despite the film diffusion dominating the adsorption process, the contributions of the intraparticle diffusion and chemical reactions were also found significant. The adsorption equilibrium data at different temperatures were fitted by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) isotherm models. The Langmuir model was found the most effective in the description of equilibrium data, and the maximum RBBR adsorption capacity retained by UPA(θ) powders was 122.55 mg·g−1 at 295 K. Thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated the adsorption process was spontaneous and exothermic in nature.


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