scholarly journals Simulation of Enzyme Catalysis in Calcium Alginate Beads

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Ameel M. R. Al-Mayah
Keyword(s):  
Flow Rate ◽  
Calcium Alginate ◽  
Corn Starch ◽  
Fixed Bed ◽  
Average Diameter ◽  
Alginate Beads ◽  
Starch Hydrolysis ◽  
Steady State Condition ◽  
Hydrogel Beads ◽  
Constant Ph

A general mathematical model for a fixed bed immobilized enzyme reactor was developed to simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α-amylase were used as a model for this study. Corn starch hydrolysis was carried out at a constant pH of 5.5 and temperature of . The substrate flow rate was ranging from 0.2 to 5.0 mL/min, substrate initial concentrations 1 to 100 g/L. α-amylase was immobilized on to calcium alginate hydrogel beads of 2 mm average diameter. In this work Michaelis-Menten kinetics have been considered. The effect of substrate flow rate (i.e., residence time) and initial concentration on intraparticle diffusion have been taken into consideration. The performance of the system is found to be affected by the substrate flow rate and initial concentrations. The reaction is controlled by the reaction rate. The model equation was a nonlinear second order differential equation simulated based on the experimental data for steady state condition. The simulation was achieved numerically using FINITE ELEMENTS in MATLAB software package. The simulated results give satisfactory results for substrate and product concentration profiles within the biocatalyst bead.

scholarly journals Simulation of Enzyme Catalysis in Calcium Alginate Beads

2013 ◽  
Vol 6 (3) ◽  
pp. 40-63
Author(s):  
Ameel M. Al-Mayah
Keyword(s):  
Flow Rate ◽  
Calcium Alginate ◽  
Corn Starch ◽  
Fixed Bed ◽  
Alginate Beads ◽  
Starch Hydrolysis ◽  
Steady State Condition ◽  
Constant Ph ◽  
Intra Particle Diffusion ◽  
General Mathematical Model

In the present study, a general mathematical model for a fixed bed–immobilized enzymereactor was developedto simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α–amylase was used as a model for this study. Corn starch hydrolysis was carried out at constant pH of 5.5 and temperature of 50°C. The substrate flowrate was ranging from 0.2 – 5.0 ml/min, substrate initial concentrations 1 to 100 g/L. α–amylase was immobilized on to calcium alginate hydro-gel beads of 2mm average diameter.In this work Michaelis–Menten kinetics has been considered. The effect of substrate flow rate (i.e. residence time) and initial concentration on intra-particle diffusion has been taking into consideration. The performance of the system is found to be affected by the substrate flow rate and initial concentrations. The reaction is controlled by the reaction rate. The model equation was a non-linear second order differential equation simulated based on the experimental data for steady state condition. The simulation was achieved numerically using FINITE ELEMENTS in MATLABSoftware package. The simulated results give satisfactory results for substrate and product concentration profile within the biocatalyst bead.

scholarly journals Removal of Cu(II) by Fixed-Bed Columns Using Alg-Ch and Alg-ChS Hydrogel Beads: Effect of Operating Conditions on the Mass Transfer Zone

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2345
Author(s):  
Ilse Paulina Verduzco-Navarro ◽  
Nely Rios-Donato ◽  
Carlos Federico Jasso-Gastinel ◽  
Álvaro de Jesús Martínez-Gómez ◽  
Eduardo Mendizábal
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Linear Regression Analysis ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Column Height ◽  
Thomas Model ◽  
Hydrogel Beads ◽  
Mass Transfer Zone ◽  
Transfer Zone

The removal of Cu(II) ions from aqueous solutions at a pH of 5.0 was carried out using fixed-bed columns packed with alginate-chitosan (Alg-Ch) or alginate-chitosan sulfate (Alg-ChS) hydrogel beads. The effect of the initial Cu(II) concentration, flow rate, pH, and height of the column on the amount of Cu removed by the column at the breakpoint and at the exhaustion point is reported. The pH of the solution at the column’s exit was initially higher than that at the entrance, and then decreased slowly. This pH increase was attributed to proton transfer from the aqueous solution to the amino and COO− groups of the hydrogel. The effect of operating conditions on the mass transfer zone (MTZ) and the length of the unused bed (HLUB) is reported. At the lower flow rate and lower Cu(II) concentration used, the MTZ was completely developed and the column operated efficiently; by increasing column height, the MTZ has a better opportunity to develop fully. Experimental data were fitted to the fixed-bed Thomas model using a non-linear regression analysis and a good correspondence between experimental and Thomas model curves was observed.

Calcium-alginate/carbon nanotubes/TiO2 composite beads for removal of bisphenol A

2016 ◽  
Vol 74 (7) ◽  
pp. 1585-1593 ◽  
Author(s):  
Maria R. Hartono ◽  
Ariel Kushmaro ◽  
Robert S. Marks ◽  
Xiaodong Chen
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Flow Rate ◽  
Dose Response ◽  
Calcium Alginate ◽  
Fixed Bed ◽  
Isotherm Models ◽  
Removal Capacity ◽  
Composite Beads ◽  
Bed Height

In this study, composite calcium-alginate/carbon nanotubes/TiO2 beads were prepared and tested for their potential in the removal of bisphenol A (BPA) from aqueous solutions. The removal traits were inspected using a fixed-bed sorption column. By varying parameters such as bed height (15–20 cm), flow rate (2.0–6.0 mL.min−1) and inlet BPA concentration (10–30 mg.L−1) we assessed the removal capacity of these composites. The highest sorption capacity of 5.46 mg.g−1 was achieved at 10 mg.L−1 BPA concentration, 2.0 mL.min−1 flow rate and 20 cm bed height at saturation. Adams-Bohart, Yoon-Nelson and Dose-Response isotherm models were applied to evaluate the performance of the column at different inlet concentrations. The experimental data satisfactorily fit the Dose-Response model with high correlation (r2 > 0.97) across the breakthrough curve. Regeneration of the used adsorbent beads were performed by immersion in the desorption solvent followed by light irradiation. It was postulated that inclusion of TiO2 facilitates the desorbed pollutant degradation from the used adsorbent beads.

scholarly journals Probing the release of the chronobiotic hormone melatonin from hybrid calcium alginate hydrogel beads

2020 ◽  
Vol 70 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Marilena Vlachou ◽  
Angeliki Siamidi ◽  
Efstratia Goula ◽  
Panagiotis Georgas ◽  
Natassa Pippa ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Calcium Alginate ◽  
Aqueous Media ◽  
Sleep Onset ◽  
Alginate Beads ◽  
Poor Sleep ◽  
Hybrid Hydrogel ◽  
Hydrogel Beads ◽  
Degradation Properties

AbstractA variety of commonly used hydrogels were utilized in the preparation of calcium alginate beads, which incorporate the chronobiotic hormone melatonin (MLT). The in vitro release of the hormone in aqueous media at pH 1.2 and 6.8 was probed in the conjunction with the swelling of the beads and their thermal degradation properties. It has been found that the release of MLT from the beads was reversibly proportional to the extent of their expansion, which depends on the molecular mass/viscosity of the biopolymers present in the beads; the higher the molecular mass/viscosity of the hydrogels the greater the beads swelling and the less the MLT’s release. Thermogravimetric analysis (TGA) data support the presence of the components in the hybrid hydrogel beads and elucidate their effects on the thermal stability of the systems. Thus, the physicochemical properties of the biopolymers used, along with their stereoelectronic features modulate the release of MLT from the beads, providing formulations able to treat sleep onset related problems or dysfunctions arising from poor sleep maintenance.

Study on Shape Optimization of Calcium–Alginate Beads

2013 ◽  
Vol 648 ◽  
pp. 125-130 ◽  
Author(s):  
Zhao Qing Li ◽  
Li Da Hou ◽  
Zhen Li ◽  
Wei Zheng ◽  
Li Li
Keyword(s):  
Shape Optimization ◽  
Sodium Alginate ◽  
Flow Rate ◽  
Calcium Alginate ◽  
Calcium Salt ◽  
Solution Concentration ◽  
Alginate Beads ◽  
Cross Linking ◽  
Alginate Solution ◽  
Calcium Alginate Beads

In this paper, calcium–alginate beads have been manufactured by physically cross-linked technology, by dripping an aqueous alginate solution into a solution of calcium salt as a crosslinker. The effect of various elements controlling beads shape such as solution concentration, flow rate and the distance between the orifice tip and surface of the cross-linking solution were studied. The various elements affected the gelling rate and diameter and weight were studied. The findings indicated that shape of alginate beads in the hydrated state was strongly dependent on the flow rate and concentration of sodium alginate solutions.

Fabrication of monodisperse alginate microgel beads by microfluidic picoinjection: A chelate free approach

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Husnain Ahmed ◽  
Bjørn Torger Stokke
Keyword(s):  
Calcium Alginate ◽  
Biomedical Applications ◽  
Alginate Beads ◽  
Alginate Hydrogel ◽  
Hydrogel Beads ◽  
Ca Alginate

Micron-sized alginate hydrogel beads are extensively employed as an encapsulation medium for biochemical and biomedical applications. Here we report on the microfluidic assisted fabrication of calcium alginate (Ca-alginate) beads by...

Sign in / Sign up

Export Citation Format

Share Document