Effect of mono- and divalent extra-framework cations on the structure and accessibility of porosity in chabazite zeolites

CrystEngComm ◽  
2021 ◽  
Author(s):  
Huan V. Doan ◽  
Ka Ming Leung ◽  
Valeska P. Ting ◽  
Asel Sartbaeva
Keyword(s):  
Nitrogen Sorption ◽  
Sorption Ability

The differences in valence and size between extra-framework cations exert a significant effect on the nitrogen sorption ability in the synthesised chabazite zeolites (K-CHA, Cs-CHA, Ca-CHA, Ba-CHA, Sr-CHA and Zn-CHA).

scholarly journals Synthesis of Silver-Impregnated Magnetite Mesoporous Silica Composites for Removing Iodide in Aqueous Solution

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 175
Author(s):  
Sang-Eun Jo ◽  
Jung-Weon Choi ◽  
Sang-June Choi
Keyword(s):  
Aqueous Solution ◽  
Langmuir Isotherm ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Maximum Adsorption Capacity ◽  
Initial Contact ◽  
Order Kinetic ◽  
Sorption Ability ◽  
High Sorption

Mag@silica-Ag composite has a high sorption ability for I− in aqueous solution due to its high surface area and strong affinity for the studied anion. The material adsorbed I− rapidly during the initial contact time (in 45 min, η = 80%) and reached adsorption equilibrium after 2 h. Moreover, mag@silica-Ag proved to selectively remove I− from a mixture of Cl−, NO3− and I−. The adsorption behavior fitted the Langmuir isotherm perfectly and the pseudo-second-order kinetic model. Based on the Langmuir isotherm, the maximum adsorption capacity of mag@silica-Ag was 0.82 mmol/g, which is significantly higher than previously developed adsorbents. This study introduces a practical application of a high-capacity adsorbent in removing radioactive I− from wastewaters.

scholarly journals Characterizing Bacterial Cellulose Produced byKomagataeibacter sucrofermentans H-110 on Molasses Medium and Obtaining a Biocomposite Based on It for the Adsorption of Fluoride

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1422
Author(s):  
Viktor V. Revin ◽  
Alexander V. Dolganov ◽  
Elena V. Liyaskina ◽  
Natalia B. Nazarova ◽  
Anastasia V. Balandina ◽  
...  
Keyword(s):  
Composite Material ◽  
Adsorption Capacity ◽  
Bacterial Cellulose ◽  
Functional Materials ◽  
Degree Of Crystallinity ◽  
Maximum Adsorption Capacity ◽  
Fluoride Ions ◽  
Sorption Ability ◽  
Wide Range ◽  
Biocomposite Material

Currently, there is an increased demand for biodegradable materials in society due to growing environmental problems. Special attention is paid to bacterial cellulose, which, due to its unique properties, has great prospects for obtaining functional materials for a wide range of applications, including adsorbents. In this regard, the aim of this study was to obtain a biocomposite material with adsorption properties in relation to fluoride ions based on bacterial cellulose using a highly productive strain of Komagataeibacter sucrofermentans H-110 on molasses medium. Films of bacterial cellulose were obtained. Their structure and properties were investigated by FTIR spectroscopy, NMR, atomic force microscopy, scanning electron microscopy, and X-ray structural analysis. The results show that the fiber thickness of the bacterial cellulose formed by the K. sucrofermentans H-110 strain on molasses medium was 60–90 nm. The degree of crystallinity of bacterial cellulose formed on the medium was higher than on standard Hestrin and Schramm medium and amounted to 83.02%. A new biocomposite material was obtained based on bacterial cellulose chemically immobilized on its surface using atomic-layer deposition of nanosized aluminum oxide films. The composite material has high sorption ability to remove fluoride ions from an aqueous medium. The maximum adsorption capacity of the composite is 80.1 mg/g (F/composite). The obtained composite material has the highest adsorption capacity of fluoride from water in comparison with other sorbents. The results prove the potential of bacterial cellulose-based biocomposites as highly effective sorbents for fluoride.

scholarly journals Amine-Grafted Mesoporous Carbons as Benzocaine-Delivery Platforms

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2188
Author(s):  
Joanna Goscianska ◽  
Aleksander Ejsmont ◽  
Anita Kubiak ◽  
Dominika Ludowicz ◽  
Anna Stasiłowicz ◽  
...  
Keyword(s):  
Release Kinetics ◽  
The Body ◽  
Therapeutic Drug ◽  
Mesoporous Carbons ◽  
Precise Control ◽  
Pharmaceutical Ingredients ◽  
Sorption Ability ◽  
Porous Carriers ◽  
Textural Parameters ◽  
Amine Groups

Smart porous carriers with defined structure and physicochemical properties are required for releasing the therapeutic drug with precise control of delivery time and location in the body. Due to their non-toxicity, ordered structure, and chemical and thermal stability, mesoporous carbons can be considered modern carriers for active pharmaceutical ingredients whose effectiveness needs frequent dosing algorithms. Here, the novel benzocaine delivery systems based on ordered mesoporous carbons of the cubic structure were obtained with the use of a hard template method and functionalization with amine groups at 40 °C for 8 h. It has been shown that amine grafting strongly modifies the surface chemistry and textural parameters of carbons. All samples indicated good sorption ability towards benzocaine, with evident improvement following the functionalization with the amine groups. The sorption capacity and drug release kinetics were strongly affected by the porosity of carbon carriers and the surface functional groups. The smallest amount of benzocaine (~12%) was released from pristine mesoporous carbon, which could be correlated with strong API–carrier interactions. Faster and more efficient release of the drug was observed in the case of triethylenetetramine modified carbon (~62%). All benzocaine delivery platforms based on amine-grafted mesoporous carbons revealed high permeability through the artificial membrane.

scholarly journals Spent mushroom substrate: a crucial biosorbent for the removal of ferrous iron from groundwater

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
D. Menaga ◽  
S. Rajakumar ◽  
P. M. Ayyasamy
Keyword(s):  
Ferrous Iron ◽  
Tamil Nadu ◽  
Contaminated Water ◽  
Spent Mushroom Substrate ◽  
Pseudo First Order Reaction ◽  
Time Intervals ◽  
New Approach ◽  
First Order ◽  
Sorption Ability ◽  
Pseudo Second Order

Abstract A new approach was carried out with the spent mushroom substrate (SMS) of Pleurotus florida on ferrous iron (Fe2+) removal using live, dead and pretreated substrate. In this study, the various dosage levels of SMS namely, 0.25, 0.50, 1.0 and 1.50 g/50 mL were used for the removal of Fe2+ at different time intervals for 90 min. The effect of various temperatures and pH on Fe2+ removal was studied with optimized dosages and time intervals. The biosorption potential of P. florida SMS was checked against the iron-contaminated groundwater collected from in and around Salem, Namakkal and Dharmapuri districts of Tamil Nadu. The biosorption data were obtained and analyzed in terms of their kinetic behavior. Among the SMS of P. florida, the live SMS showed potential Fe2+ removal (100%) from aqueous metal solution in all the tested concentrations. SMS of P. florida showed high potential removal of Fe2+ in neutral pH, at room temperature and explored an efficient sorption ability (100%) in the tested water sample (SW10). The adsorption kinetic values fitted very well with pseudo-second-order when comparing with pseudo-first-order reaction. FTIR, SEM and EDX analysis proved the accumulation of Fe2+ by the SMS. The present study confirmed that the live SMS of P. florida may serve as a potential and eco-friendly biosorbent for removal of Fe2+ from the iron-contaminated water. Graphic abstract

Dyeing Adsorption Isotherm and Equilibrium Modeling Characteristics of Enzymatic and Caustic Pre-Treated Lyocell Fibers

2011 ◽  
Vol 332-334 ◽  
pp. 568-571
Author(s):  
Yi Jun Pan ◽  
Chien Teng Hsieh ◽  
Chien Kuo Yen
Keyword(s):  
Treatment Condition ◽  
Enzymatic Treatment ◽  
Equilibrium Modeling ◽  
Sorption Ability ◽  
Treatment Stage ◽  
Lyocell Fibers ◽  
Lyocell Fiber ◽  
Consequent Effect ◽  
Pre Treatment ◽  
Dyes Adsorption

The purpose of this study is to achieve a better understanding of the influences of enzymatic and caustic pretreatments on the dying adsorption behavior of Lyocell yarns. The substantivity behavior, dyeing adsorption isotherms and their correlation between the equilibrium modeling and equilibrium isotherm parameters of the pre-treated Lyocell fibers have been studied. Although the conditions of each treatment were the same, changing the processing sequences caused substantially different modifications on the Lyocell fiber fine structure with consequent effect on dyeing behaviors. In general, pretreatment by caustic soda and/or enzyme can improve their dyeability of Lyocell fibers. The results of dyes adsorption show that for the same enzymatic treatment condition if the enzymatic treatment stage is applied before the caustic pre-treatment, the dyeability and sorption ability of small molecule dye on pre-treated Lyocell can be improved over that which can be obtained for caustic pre-treated yarn.

scholarly journals Removal of toxic metals from aqueous solution by biochars derived from long-root Eichhornia crassipes

2018 ◽  
Vol 5 (10) ◽  
pp. 180966 ◽  
Author(s):  
Qiang Li ◽  
Lizhou Tang ◽  
Jiang Hu ◽  
Ming Jiang ◽  
Xiaodong Shi ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Eichhornia Crassipes ◽  
Adsorption Process ◽  
Correlation Coefficients ◽  
Sorption Ability ◽  
Different Temperatures ◽  
Lead Zinc ◽  
Pseudo Second Order ◽  
Cyano Groups ◽  
Maximum Removal

Biochars were produced from long-root Eichhornia crassipes at four temperatures: 200, 300, 400 and 500°C, referred to as LEC200, LEC300, LEC400 and LEC500, respectively. The sorption ability of lead, zinc, copper and cadmium from aqueous solutions by four kinds of biochars was investigated. All the biochars had lower values of CEC and higher values of pH. LEC500 was the best one to bind toxic metals which can be reflected in the results of SEM, BET and elemental analyser. It was also found that alkyl, carboxyl, phosphate and cyano groups in the biochars can play a role in binding metals. In addition, the sorption processes of four metals by the biochars in different metal concentration were all excellently represented by the pseudo-second-order model with all correlation coefficients R 2 > 0.95. And the sorption processes of four metals in different temperatures could be described satisfactorily by the Langmuir isotherms. According to calculated results by the Langmuir equation, the maximum removal capacities of Pb(II), Zn(II), Cu(II) and Cd(II) at 298 K were 39.09 mg g −1 , 45.40 mg g −1 , 48.20 mg g −1 and 44.04 mg g −1 , respectively. The positive value of the Δ H 0 confirmed the adsorption process was endothermic and the negative value of Δ G 0 confirmed the adsorption process was spontaneous. The sorption capacities were compared with several other lignocellulosic materials which implied the potential of long-root Eichhornia crassipes waste as an economic and excellent biosorbent for eliminating metal ions from contaminated waters.

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