Synthesis and characterization of clinoptilolite-alginate beads for dye removal from water

2019 ◽  
Vol 14 (2) ◽  
pp. 311-318 ◽  
Author(s):  
F. U. Nigiz
Keyword(s):  
Natural Zeolite ◽  
Electrostatic Interactions ◽  
Dye Removal ◽  
Alginate Beads ◽  
Cationic Dye ◽  
Adsorption Performance ◽  
Composite Adsorbents ◽  
Positive Properties ◽  
Positively Charged

Abstract The aim of this study is to synthesize a superior adsorbent by combining positive properties of alginate and natural zeolite (clinoptilolite). Electrostatic interactions between the negatively charged carboxyl groups in alginate, porous sites in clinoptilolite and positively charged cationic dye in wastewater make alginate and clinoptilolite superior for dye removal. A model wastewater was prepared with varying concentrations of methylene blue (MB). Effects of MB concentration, adsorption time, pH, and adsorbent concentration on adsorption performance were evaluated. Composite adsorbents were also characterized using Fourier transform infrared spectroscopy. While 97.0% of removal was achieved using 5 g/L adsorbent, 98.8% of removal was obtained using 15 g/L adsorbent dosage. When the dye concentrations were gradually decreased from 5 mg/L to 2 mg/L, dye removal of 96.9%, 97.7%, 97.9% and 98.4% were observed at the end of 180 minutes.

Preparation and characterization of imino diacetic acid functionalized alginate beads for removal of contaminants from waste water: I. methylene blue cationic dye model

2012 ◽  
Vol 40 (1-3) ◽  
pp. 15-23 ◽  
Author(s):  
Mohamed Samir Mohy Eldin ◽  
Emad Ali Soliman ◽  
Ahmed Abdel Fattah Elzatahry ◽  
Mohamed Ramadan Elaassar ◽  
Marwa Farouk Elkady ◽  
...  
Keyword(s):  
Waste Water ◽  
Methylene Blue ◽  
Alginate Beads ◽  
Cationic Dye ◽  
Diacetic Acid ◽  
Removal Of Contaminants ◽  
Imino Diacetic Acid ◽  
Methylene Blue Cationic Dye

Preparation and characterization of imino diacetic acid functionalized alginate beads for removal of contaminants from waste water: I. Methylene blue cationic dye model

2012 ◽  
Vol 40 ◽  
pp. 15-23
Author(s):  
Mohamed Samir Mohy Eldin ◽  
Emad Ali Soliman ◽  
Ahmed Abdel Fattah Elzatahry ◽  
Mohamed Ramadan Elaassar ◽  
Marwa Farouk Elkady ◽  
...  
Keyword(s):  
Waste Water ◽  
Methylene Blue ◽  
Alginate Beads ◽  
Cationic Dye ◽  
Diacetic Acid ◽  
Removal Of Contaminants ◽  
Imino Diacetic Acid ◽  
Methylene Blue Cationic Dye

Characteristics of the Interaction between Thrombin Exosite1 and the Sequence 269-297 of Platelet Glycoprotein Ibα

1998 ◽  
Vol 80 (08) ◽  
pp. 310-315 ◽  
Author(s):  
Marie-Christine Bouton ◽  
Christophe Thurieau ◽  
Marie-Claude Guillin ◽  
Martine Jandrot-Perrus
Keyword(s):  
Platelet Activation ◽  
Electrostatic Interactions ◽  
Platelet Glycoprotein ◽  
Thrombin Receptor ◽  
Central Position ◽  
Amidolytic Activity ◽  
N Terminus ◽  
Hydrolysis Of ◽  
Chemical Cross Linking ◽  
Positively Charged

SummaryThe interaction between GPIb and thrombin promotes platelet activation elicited via the hydrolysis of the thrombin receptor and involves structures located on the segment 238-290 within the N-terminal domain of GPIbα and the positively charged exosite 1 on thrombin. We have investigated the ability of peptides derived from the 269-287 sequence of GPIbα to interact with thrombin. Three peptides were synthesized, including Ibα 269-287 and two scrambled peptides R1 and R2 which are comparable to Ibα 269-287 with regards to their content and distribution of anionic residues. However, R2 differs from both Ibα 269-287 and R1 by the shifting of one proline from a central position to the N-terminus. By chemical cross-linking, we observed the formation of a complex between 125I-Ibα 269-287 and α-thrombin that was inhibited by hirudin, the C-terminal peptide of hirudin, sodium pyrophosphate but not by heparin. The complex did not form when γ-thrombin was substituted for α-thrombin. Ibα 269-287 produced only slight changes in thrombin amidolytic activity and inhibited thrombin binding to fibrin. R1 and R2 also formed complexes with α-thrombin, modified slightly its catalytic activity and inhibited its binding to fibrin. Peptides Ibα 269-287 and R1 inhibited platelet aggregation and secretion induced by low thrombin concentrations whereas R2 was without effect. Our results indicate that Ibα 269-287 interacts with thrombin exosite 1 via mainly electrostatic interactions, which explains why the scrambled peptides also interact with exosite 1. Nevertheless, the lack of effect of R2 on thrombin-induced platelet activation suggests that proline 280 is important for thrombin interaction with GPIb.

Highly efficient and sustainable alginate/carboxylated lignin hybrid beads as adsorbent for cationic dye removal

2021 ◽  
pp. 104839
Author(s):  
Jong-Chan Kim ◽  
Jungkyu Kim ◽  
Jinseok Park ◽  
Jung-Kwon Oh ◽  
In-Gyu Choi ◽  
...  
Keyword(s):  
Dye Removal ◽  
Cationic Dye ◽  
Highly Efficient

scholarly journals Characterization of design grammar of peptides for regulating liquid droplets and aggregates of FUS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoto Kamagata ◽  
Rika Chiba ◽  
Ichiro Kawahata ◽  
Nanako Iwaki ◽  
Saori Kanbayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Electrostatic Interactions ◽  
Amyloid Fibrils ◽  
Droplet Formation ◽  
Liquid Droplets ◽  
Proof Of Concept ◽  
Aggregate Formation ◽  
Fused In Sarcoma ◽  
Dynamics Simulations

AbstractLiquid droplets of aggregation-prone proteins, which become hydrogels or form amyloid fibrils, are a potential target for drug discovery. In this study, we proposed an experiment-guided protocol for characterizing the design grammar of peptides that can regulate droplet formation and aggregation. The protocol essentially involves investigation of 19 amino acid additives and polymerization of the identified amino acids. As a proof of concept, we applied this protocol to fused in sarcoma (FUS). First, we evaluated 19 amino acid additives for an FUS solution and identified Arg and Tyr as suppressors of droplet formation. Molecular dynamics simulations suggested that the Arg additive interacts with specific residues of FUS, thereby inhibiting the cation–π and electrostatic interactions between the FUS molecules. Second, we observed that Arg polymers promote FUS droplet formation, unlike Arg monomers, by bridging the FUS molecules. Third, we found that the Arg additive suppressed solid aggregate formation of FUS, while Arg polymer enhanced it. Finally, we observed that amyloid-forming peptides induced the conversion of FUS droplets to solid aggregates of FUS. The developed protocol could be used for the primary design of peptides controlling liquid droplets and aggregates of proteins.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

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