Kinetics of Oxidative Depolymerization of κ-carrageenan by Ozone

Prasetyaningrum, Aji; Ratnawati, Ratnawati; Jos, Bakti

doi:10.9767/bcrec.12.2.805.235-242

Cited by 11 publications

(3 citation statements)

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“…Modelling the ozonation kinetic of polysaccharides is complex. Prasetyaningrum et al(2017) 33 proposed a kinetic model to explain the depolymerization of κ-carrageenan by ozone using viscosity data. In the present work, a model for the ozone-starch reaction in alkaline solution was proposed, being [St] (g/L) the starch concentration as a function of time, [St] 0 (g/L) the initial starch concentration and k St the kinetic constant for the reaction:…”

Section: Kinetic Modeling Of Starch Oxidation With Ozone In Basic Sol...mentioning

confidence: 99%

Kinetic modeling of advanced starch oxidation with ozone in basic solutions

Ávila-Sierra

Vicaria

Martínez-Gallegos

et al. 2022

Preprint

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Ozonation of cornstarch at pH 13 was performed using a semi-batch reactor to analyse the influence of a continuous ozone-oxygen gas flow (40 NL/h) at different ozone concentrations (0-42.30 g/Nm3) and temperatures (20-60ºC). A pseudofirst-order kinetic model was proposed to elucidate the reaction mechanisms associated with ozone at high pH conditions. The radical concentration remains constant and proportional to the ozone continuous dose, being a non-limiting factor independent of temperature (activation energy 14.2-14.5 KJ/mol). The oxidation kinetic of starch was studied monitoring the Chemical Oxygen Demand, finding a reduction in ozone concentration when both temperature and time increased (activation energy 8.1 KJ/mol). Therefore, the model proposed for the starch ozonation at high alkaline solutions provides a better understanding of the oxidation processes of common product additives such as starch, also making it possible to determine the environmental impact of such solutions by Chemical Oxygen Demand measurement.

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Section: Kinetic Modeling Of Starch Oxidation With Ozone In Basic Sol...mentioning

confidence: 99%

Kinetic modeling of advanced starch oxidation with ozone in basic solutions

Ávila-Sierra

Vicaria

Martínez-Gallegos

et al. 2022

Preprint

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“…The ozone treatment was assessed to be more efficient than UV irradiation, as Table 1 shows the individual kinetic rate constant of ozone to be 7.877×10 -5 min -1 at a dosage of 125 mg/L. However, a previous study by Prasetyaningrum et al [35] demonstrated value of 7.21×10 -5 min -1 at pH 10 and a temperature of 30 °C. Interestingly, a combination of UV/O3 has been affiliated with an increase in the kinetic rate constant value, which was reported as 1.924×10 -4 min -1 , using a treatment with 125 mg/L ozone and a UV lamp intensity of 40.00 mW/cm 2 .…”

Section: Kineticsmentioning

confidence: 99%

UV Irradiation and Ozone Treatment of κ-Carrageenan: Kinetics and Products Characteristics

Prasetyaningrum

Widayat

Jos

et al. 2020

Bull. Chem. React. Eng. Catal.

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The low molecular weight (LMW) of sulfated polysaccharides including k-carrageenan, is shows a wide spectrum of biological activities. This research investigates the influence of UV irradiation, ozone (O3), and the combination of O3/UV methods on the depolymerization of k-carrageenan. The depolymerization kinetics of k-carrageenan using the Advanced Oxidation Process (UV/O3) was also studied. Furthermore, the intrinsic viscosity method was used to determine the average molecular weight of the research sample, and a mathematical model was developed to predict the kinetic rate constant, as a function of ozone dosage and UV irradiation intensity. Therefore, the physicochemical and morphological properties of the degraded k-carrageenan were analyzed by FT-IR, SEM, and XRD. The intrinsic viscosity k-carrageenan decreases with increasing UV light intensity and ozone concentration. The combination of UV/O3 treatment appeared to be more effective than the individual approaches, as the highest kinetic rate constant for depolymerization was 1.924×10-4 min-1, using 125 mg/L ozone concentration and 40 mW/cm2 of UV lamp intensity. This research also evaluated the relationship between various experimental conditions, including UV lamp power dissipation and ozone concentration on the reaction kinetics model, and the results suggest that lower effect is contributed by UV irradiation intensity. In addition, FT-IR spectra showed the absence of any significant change in the functional properties of k-carrageenan treated with UV and O3 processes, although the morphological properties of the LMW k-carrageenan were rougher and more porous than the native k-carrageenan. Copyright © 2020 BCREC Group. All rights reserved

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“…K-carrageenan can be depolymerized using various techniques, such as thermal depolymerization [6], acid-catalyzed hydrolysis [7][8][9][10][11], enzymatic hydrolysis [2], ozone oxidation [12], and ultrasound irradiation [13]. When a polysaccharide solution is subjected to an ultrasound irradiation, the ultrasound wave will cause a cavitation which consists of the nucleation, growth, and collapse of microbubbles.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Thermodynamics Study of Ultrasound-Assisted Depolymerization of k-Carrageenan in Acidic Solution

Ratnawati

Indriyani

2020

Bull. Chem. React. Eng. Catal.

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K-carrageenan is a natural polymer with high molecular weight ranging from 100 to 1000 kDa. The oligocarrageenan with low molecular weight is widely used in biomedical application. The aim of this work was to depolymerize k-carrageenan in an acidic solution with the assistance of ultrasound irradiation. The ultrasonication was conducted at various pH (3 and 6), temperatures (30-60 °C), and depolymerization time (0-24 minutes). The results show that the depolymerization reaction follows pseudo-first-order kinetic model with reaction rate constant of 1.856×10-7 to 2.138×10-6 s-1. The reaction rate constant increases at higher temperature and lower pH. The Q10-temperature coefficients of the depolymerization are 1.25 and 1.51 for pH 6 and 3, respectively. The enthalpy of activation (ΔH‡) and the Gibbs energy of activation (ΔG‡) are positive, while the entropy of activation (ΔS‡) is negative, indicating that the activation step of the ultrasound-assisted depolymerization of k-carrageenan is endothermic, non-spontaneous, and the molecules at the transition state is more ordered than at the ground state. The ΔH‡ and the ΔS‡ are not affected by temperature, while the ΔG‡ is a weak function of temperature. The ΔH‡ and ΔS‡ become smaller at higher pH, while the ΔG‡ increases with the increase of pH. The kinetics and thermodynamics analysis show that the ultrasound-assisted depolymerization of k-carrageenan in acidic solution is possibly through three mechanisms, i.e. bond cleavage due to cavitational effect of microbubbles, hydroxyl radical and hydrogen peroxide, as well as proton. Copyright © 2020 BCREC Group. All rights reserved

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Kinetics of Oxidative Depolymerization of κ-carrageenan by Ozone

Cited by 11 publications

References 50 publications

Kinetic modeling of advanced starch oxidation with ozone in basic solutions

Kinetic modeling of advanced starch oxidation with ozone in basic solutions

UV Irradiation and Ozone Treatment of κ-Carrageenan: Kinetics and Products Characteristics

Kinetics and Thermodynamics Study of Ultrasound-Assisted Depolymerization of k-Carrageenan in Acidic Solution

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