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All Journal Reaktor TEKNIK METANA JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Bulletin of Chemical Reaction Engineering & Catalysis Seminar Nasional Teknik Kimia Kejuangan Majalah Ilmiah MOMENTUM Indonesian Journal of Chemistry Jurnal Pasopati : Pengabdian Masyarakat dan Inovasi Pengembangan Teknologi International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis JURNAL REKAYASA KIMIA & LINGKUNGAN

Bakti Jos

Departemen Teknik Kimia, Fakultas Teknik, Universitas Diponegoro, Kampus Undip Tembalang Jl. Prof. Soedarto, SH, Semarang, Indonesia 50275

Author-ID : 292934

Aerospace Engineering Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology

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UV Irradiation and Ozone Treatment of κ-Carrageenan: Kinetics and Products Characteristics Aji Prasetyaningrum; Widayat Widayat; Bakti Jos; Yudhy Dharmawan; Ratnawati Ratnawati
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 2 Year 2020 (August 2020)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.2.7047.319-330

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 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Inhibition Effect of Ca2+ Ions on Sucrose Hydrolysis Using Invertase Hargono Hargono; Bakti Jos; Abdullah Abdullah; Teguh Riyanto
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Department of Chemical Engineering - Diponegoro University

Fermentable sugar for bioethanol production can be produced from molasses due to its high sucrose content but Ca2+ ions found in the molasses may affect the hydrolysis. Therefore, this paper was focused to study the effect of Ca2+ ions as CaO on sucrose hydrolysis using invertase and to obtain the kinetic parameters. The kinetic parameters (KM and Vmax) were obtained using a Lineweaver-Burk plot. The value of KM and Vmax parameters were 36.181 g/L and 21.322 g/L.h, respectively. The Ca2+ ions act as competitive inhibitor in sucrose hydrolysis using invertase. Therefore, the inhibition mechanism was followed the competitive inhibition mechanism. The value of inhibition constant was 0.833 g/g. These parameters were obtained from the non-substrate inhibition process because this study used the low substrate concentrations which means the fermentable sugar production was low. Hence, there were still more challenges to studying the simultaneous effect of substrate and Ca2+ on sucrose hydrolysis to produce high fermentable sugar.

Kinetics of Oxidative Depolymerization of κ-carrageenan by Ozone Aji Prasetyaningrum; Ratnawati Ratnawati; Bakti Jos
Bulletin of Chemical Reaction Engineering & Catalysis 2017: BCREC Volume 12 Issue 2 Year 2017 (August 2017)
Publisher : Department of Chemical Engineering - Diponegoro University

Depolymerization kinetics of κ-carrageenan by ozone treatment has been studied at various pHs and times. The purified κ-carrageenan with the initial molecular weight of 271 kDa was dispersed in water to form (1 % w/v) solution. Ozone with 80±2 ppm concentration and constant flow rate of 3 L.min-1 was bubbled into the κ-carrageenan solution. The experiments were conducted at pH of 3, 7, and 10 at different times (5, 10, 15, and 20 minutes) of ozonation. The viscosity of the solution was measured using Ubbelohde capillary viscometer, which was then used to find the number-average molecular weight by Mark-Houwink equation. The number-average molecular weight data was treated using zero, first, and the second-order reaction kinetics model, to obtain the kinetics of κ-carrageenan depolymerization. The depolymerization is assumed to occur by random scission. The results show that the kinetics rate constant of κ-carrageenan depolymerization is higher at lower pHs. The second-order model is more suitable for describing the kinetics of depolymerization of κ-carrageenan by ozonation process. The rate constants for the second-order kinetics model are 5.45×10-4 min-1, 1.27×10-4 min-1, and 7.21×10-5 min-1 for pH 3, 7, and 10, respectively. The actual values of reaction order under acid and alkali conditions are ranging from 1.88 to 1.90.

Kinetics of the Enzymatic Hydrolysis of Sweet Cassava Starch and Bitter Cassava Flour and Gadung (Dioscorea hispida Dennst) Flour at Low Temperature Hargono Hargono; Bakti Jos; Andri Cahyo Kumoro
Bulletin of Chemical Reaction Engineering & Catalysis 2017: BCREC Volume 12 Issue 2 Year 2017 (August 2017)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Starch is a potential substrate for this purpose, but the extra cost is needed to hydrolyze it into reducing sugar. As an alternative to the expensive and energy demanding conventional hydrolysis process, the low-temperature hydrolysis is being studied. Granular Starch Hydrolysing Enzyme (GSHE) was used in the process to degrade starch into reducing sugar at 30°C and pH 4. The substrates included bitter cassava flour, sweet cassava starch, and gadung flour. Starch concentrations studied were 50, 100, 150, 200, 250, 300, 350, and 400 g/L, respectively, while concentration of enzyme was 1.5 % (w/w). The optimum condition of the process was hydrolysis using 200 g/L of substrate concentration and enzyme concentration of 1.5% for 12 h. It was found that the reducing sugar was 49.3 g/L and the productivity of reducing sugar (Qrs) was 4.11 (gL-1 h-1). Lineweaver-Burk plot of Michaelis-Menten equation was used to study the inhibition kinetics. The Michaelis-Menten constants (Km) for these three substrates were determined as 141.64 g/L, 137,64 g/L and 140.84 g/L for bitter cassava flour, sweet cassava starch, and gadung flour, respectively. The value of Vm/Km, which denotes the affinity of the enzyme to the substrate, were determined and compared, and the result showed that the affinity (Vm) to the enzyme to this substrate followed the order of sweet cassava starch˃ bitter cassava flour˃ gadung flour, and all are non-competitive inhibitor, while the Ki value was 0.022 h -1.

Co-Authors . Widayat A Abdullah Aat Zaki Mubarok Abdullah Abdullah Abdullah Abdullah Aji Prasetyaningrum Al Farrel A. Raemas Andri Cahyo Kumoro Angga Mei Sarah Aprianto Aprianto Bambang Pramudono Dessy Ariyanti Dessy Ariyanti Diah Susetyo Retnowati Dyah Hesti Wardhani Fadlillah Fani Feninda Nevrita Fitri Lafifa Gian Restu Prinanda Hantoro Satriadi Hargono Hargono Hargono Hargono Hargono Hargono Hargono Hargono Hargono Hargono Hargono Hargono Heri Cahyono Heri Cahyono Heru Susanto Isti Pudjiastuti Jonathan Ginting Listiyana Riska Muchlis Riki Darmawan Noer Abyor Handayani Nur Rokhati Patrick Andreas Praditya Nugraha Prayudi Eko Setyawan Prayudi Eko Setyawan Ratnawati Ratnawati Sadam Arrois Salsabila, Unik Hanifah Satrio Kuntolaksono Setiawan, Fajar Kasih Siswo Sumardiono Suherman Suherman Suherman, Suherman Sukaryo Sukaryo Teguh Riyanto Widayat Widayat Y Yufidani Yanuar Ariyanto Yudha Satria Yudha Satria Yudhy Dharmawan Zakaria, Muhammad Fahmi

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