scholarly journals Synthesis of locust bean gum-based terpolymer bentonite composite: evaluation for indigo carmine adsorption

2017 ◽  
Vol 5 (2) ◽  
pp. 61 ◽  
Author(s):  
Vishalakshi Badalamoole ◽  
Sirajo Abubakar Zauro

A terpolymer gel compositeis made up of locust bean gum (LBG), diallyldimethylammonium chloride (DADMAC), 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and bentonite (BNT) was prepared using methylenebisacrylamide (MBA) as crosslinker via microwave irradiation and characterized using FTIR, TGA and SEM techniques. Swelling behavior of the composite was studied under different pH conditions. The composite was also evaluated for adsorption of anionic dye ‘Indigo Carmine’ (IC). The behaviour of the composite was compared with the terpolymer gel without the clay component. The gel showed remarkably higher swelling under neutral pH compared to the composite. The adsorption capacity of the terpolymer gel without clay for Indigo Carmine dyeis also found to be higher (17.36 mg/g) compared to the clay composite (11.99 mg/g). The adsorption data were subjected to three different isotherm models namely; Freundlich, Langmuir and Temkin and were observed to be explained best by Freundlich model. The adsorption of indigo Carmine on the terpolymer gel and the composite is observed to be a second order kinetic process.

2020 ◽  
Vol 38 (9-10) ◽  
pp. 413-434
Author(s):  
Jessica Badillo-Camacho ◽  
Eulogio Orozco-Guareño ◽  
Gregorio G Carbajal-Arizaga ◽  
Ricardo Manríquez-Gonzalez ◽  
Icela D Barcelo-Quintal ◽  
...  

The discharges enriched with heavy metals, particularly Cr(VI), are a serious environmental problem. In this work, it is presented the use of biosorbents from eggshells membranes of ostrich, quail, duck and chicken; the membranes were easily prepared and studied for the removal of Cr(VI) from aqueous solutions. Maximum uptake of 1.41 mmol g−1 membrane permitted the identification of ostrich membrane as the material with the highest Cr(VI) uptake. N2 adsorption experiments permitted to classify ostrich membranes as mesoporous materials, since they had pore size of 14.8 nm. This represented an advantage on the nature of these membranes to be used as biosorbents with respect to other membranes. The adsorption isotherm models such as Langmuir and Freundlich were verified using experimental data. Langmuir model described the adsorption process satisfactorily at pH 1 and 2 whereas Freundlich model fitted data better at pH 3 and 5. The adsorption kinetic data were adjusted to a pseudo-second order kinetic model. TGA results permitted demonstrating a low thermal stability of ostrich membrane, since it starts decomposing at around 50°C due to the fact that membranes have about 60% protein. Through SEM microscopy was possible to observe the morphology of the membrane surfaces before and after Cr(VI) uptake which reflects the textural characteristics of the biosorbent. FTIR and XPS analyses suggested that Cr was adsorbed on ostrich membranes through the amine groups of proteins conforming the fibers of membranes. Despite the oxygen shows higher electronegativity than N, Cr shows more preference toward N due to fact that pH conditions favor the positive charges on the surface of the membrane. Our results make evident that this waste material is a novel and efficient option for the removal of Cr(VI) from aqueous solutions.


Author(s):  
Xiaoxi Cai ◽  
Jiang Li ◽  
Yunguo Liu ◽  
Xinjiang Hu ◽  
Xiaofei Tan ◽  
...  

Biochar obtained by pyrolysis of the fiber plant kenaf was mixed with bismuth ferrite (BiFeO3) in a chitosan-containing acetic acid solution, magnetized, and modified to prepare a chitosan-crosslinked BiFeO3/biochar coupled magnetic material. The adsorption properties of the composite were investigated using methylene blue dissolved in water, and the effects of external conditions, such as pH, methylene blue concentration, reaction time, and temperature, on the adsorption performance were studied. The adsorption data were fitted and analyzed with kinetic and isotherm models, and the results showed that the BiFeO3/biochar coupled magnetic material effectively adsorbed methylene blue. The amounts adsorbed onto this magnetic material increased with increasing initial methylene blue concentration, reaction time, and temperature, and the adsorption performance improved under neutral and alkaline conditions. The pseudo-first-order kinetic and Langmuir isotherm models satisfactorily fitted the adsorption data, showing that the adsorption of methylene blue involved both chemical and physical adsorption. The maximum adsorption capacity of methylene blue onto the BiFeO3/biochar coupled magnetic material reached 18.942 mg·g−1 at 25 °C, confirming the excellent dye binding activity of this material.


2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Olugbenga Solomon Bello ◽  
Kayode Adesina Adegoke ◽  
Samuel Oluwaseun Fagbenro ◽  
Olasunkanmi Seun Lameed

Abstract This study investigates the efficacy of acid activated coconut husk (CHA) for the removal of rhodamine-B (Rh-B) dye from aqueous solutions. The CHA prepared was characterized using various techniques: SEM, FTIR EDX, Boehm titration and pHpzc, respectively. The effects of different operational parameters including initial concentration, contact time and solution temperatures were examined. Kinetic data for Rh-B dye adsorption onto CHA fitted best to pseudo-second-order kinetic model considering the correlation regression (R2) and the sum of squares of error values. Adsorption data were fitted to Langmuir, Freundlich, Dubinin–Radushkevich and Temkin isotherm models. Langmuir isotherm was the most fitted among all the models used with maximum monolayer sorption capacity of 1666.67 mg g−1 and the highest regression value of 0.99 indicating that CHA has greater affinity for Rh-B dye adsorption due to increased pore development via acid activation. Thermodynamic studies revealed an endothermic adsorption process with the ΔH0 value of 62.77 kJ mol−1. Spontaneity was ascertained based on the negative values of ΔGo (ranging from − 26.38 kJ mol−1 to − 20.93 kJ mol−1). The positive value of ΔS0 (0.276 kJ mol−1 K−1) suggests increased randomness that exists between CHA and Rh-B dye. Cost analysis results revealed that CHA is six times cheaper than commercial activated carbon (CAC), providing a savings of 217 US$ kg−1. CHA adsorbent was found to be suitable for Rh-B dye removal from aqueous solution.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mona A. Shouman ◽  
Nady A. Fathy ◽  
Soheir A. Khedr ◽  
Amina A. Attia

The waste of palm branches (PB) was tested for its ability to remove chromium (VI) from aqueous solution by batch and column experiments. Palm branches chemically modified with an oxidizing agent (sulphuric acid) then coated with chitosan and surfactant (hexadecyl trimethyl ammonium bromide surfactant, HDTMA), respectively, were carried out to improve the removal performance of PB. The results of their Cr (VI) removal performances are pH dependent. The adsorption data could be well interpreted by the Langmuir, Freundlich, and Flory-Huggins isotherm models. The maximum adsorption capacity obtained from the Langmuir model for the chitosan coated oxidized palm branches is 55 mg/mg. The adsorption process could be described by pseudo-second-order kinetic model. The intraparticle diffusion study revealed that film diffusion might be involved. The biosorbents were successfully regenerated using 1 M HCL solution.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Fazel Mohammadi-Moghadam ◽  
Mohammad Mehdi Amin ◽  
Mehdi Khiadani (Hajian) ◽  
Fariborz Momenbeik ◽  
Heshmatollah Nourmoradi ◽  
...  

The aim of this paper is to investigate the removal of toluene from gaseous solution throughGlycyrrhiza glabraroot (GGR) as a waste material. The batch adsorption experiments were conducted at various conditions including contact time, adsorbate concentration, humidity, and temperature. The adsorption capacity was increased by raising the sorbent humidity up to 50 percent. The adsorption of toluene was also increased over contact time by 12 h when the sorbent was saturated. The pseudo-second-order kinetic model and Freundlich model fitted the adsorption data better than other kinetic and isotherm models, respectively. The Dubinin-Radushkevich (D-R) isotherm also showed that the sorption by GGR was physical in nature. The results of the thermodynamic analysis illustrated that the adsorption process is exothermic. GGR as a novel adsorbent has not previously been used for the adsorption of pollutants.


2014 ◽  
Vol 16 (4) ◽  
pp. 597-608 ◽  

<div> <p>Removal of Fe(II) and Mn(II) ions from aqueous solution by fungal biosorbent <em>Aspergillus sp. TU-GM14</em>immobilized on <em>Detarium microcarpum</em> matrix was investigated in this study. Effects of biosorption parameters pH, biosorbent concentration, bead size and equilibrium time on Fe(II) and Mn(II) ions sorption were also determined. Equilibrium was attained within in 3 hours while optimum Fe(II) and Mn(II) ions removal was observed at pH 6, 8 mm bead size, 2 g l<sup>-1</sup> spore load respectively. Adsorption capacity was described using Langmuir, Freundlich and BET isotherm models. The experimental data fitted best to the Freundlich model (<em>R</em><sup>2</sup> 0.992 and 0.996 for Mn(II) and Fe(II) respectively). Favourable surface sorption process was described by Langmuir isotherm for both metals (<em>Q</em><sub>max </sub>34 and 14 mg g<sup>-1</sup> for Mn(II) and Fe(II) ions) while the BET isotherm constant, <em>B</em>, described high metals sorption beyond the biosorbent surface in a multi-layer sorption process (4.8 and 9.0 for Mn(II) and Fe(II)&nbsp; respectively). Results of the study showed that <em>Aspergillus sp. TU-GM14 </em>biosorbent can remove large quantities of Fe(II) and Mn(II) ions from solution in both surface and multi-layer sorption process with <em>Detarium microcarpum</em> acting as a cheap immobilization matrix.</p> </div> <p>&nbsp;</p>


Author(s):  
Ghildiyal s

Hydrodynamically Balanced systems have wide development as they have achieved the parameters of modern drug delivery system, it is a type of system which owes very tremendous and curative benefits for the delivery of oral controlled release dosage forms and have wide properties in many aspects such as its main role is to maintain the effective concentration in the system for longer period of time. To reduce the gastric mucosal irritation due to the presence of synthetic polymers, being a natural polymer incorporation of Plantago ovate (Psyllium Husk) could ease out the mucosal irritation in the gastric region. Due to its properties such as a rate-controlling polymer possessing a very good quality of swelling and good gelling nature, and also incorporated as a matrix-forming agent basically in the modified release formulation. Locust bean gum can be used as sustained-release carriers and release modifiers for the delivery of drugs. It is a neutral plant galactomannan extracted from the seeds (kernels) of the carob tree Ceratonia siliqua L fabaceae. Nowadays it is focussing polymer and a lot of researchers are focussing on exploring the potential in topical drug delivery, colonic drug delivery, oral sustained drug delivery, ocular drug delivery, buccal drug delivery.


2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.


Biopolymers ◽  
1995 ◽  
Vol 36 (5) ◽  
pp. 643-658 ◽  
Author(s):  
F. M. Goycoolea ◽  
R. K. Richardson ◽  
E. R. Morris ◽  
M. J. Gidley

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 105
Author(s):  
Yifan Yang ◽  
Shiyong Tao ◽  
Zhichun Dong ◽  
Jing Xu ◽  
Xiang Zhang ◽  
...  

Because of the diversification of industries in developing cities, the phenomenon of the simultaneous contamination of various kinds of pollutants is becoming common, and the environmental process of pollutants in multi-contaminated environmental mediums has attracted attention in recent years. In this study, p-arsanilic acid (ASA), a kind of organic arsenic feed additive that contains the arsenic group in a chemical structure, is used as a typical contaminant to investigate its adsorption on iron oxides and its implication for contaminated soils. The adsorption kinetics on all solids can be fitted to the pseudo-second-order kinetic model well. At the same mass dosage conditions, the adsorption amount per unit surface area on iron oxides follows the order α-FeOOH > γ-Fe2O3 > α-Fe2O3, which is significantly higher than that for actual soil, because of the lower content of iron oxides in actual soil. Lower pH conditions favor ASA adsorption, while higher pH conditions inhibit its adsorption as a result of the electrostatic repulsion and weakened hydrophobic interaction. The presence of phosphate also inhibits ASA adsorption because of the competitive effect. Correlations between the amount of ASA adsorption in actual soil and the Fe2O3 content, total phosphorus content, arsenic content, and organic matter content of actual soil are also investigated in this work, and a moderate positive correlation (R2 = 0.630), strong negative correlation (R2 = 0.734), insignificant positive correlation (R2 = 0.099), and no correlation (R2 = 0.006) are found, respectively. These findings would help evaluate the potential hazard of the usage of organic arsenic feed additives, as well as further the understanding of the geochemical processes of contaminants in complicated mediums.


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