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All Journal CHEMISTRY PROGRESS UNEJ e-Proceeding Indonesian Journal of Chemistry
Restu Kartiko Widi
Department of Chemical Engineering, Faculty of Engineering, University of Surabaya, TG Building 6th floor, Jl. Raya Kalirungkut Surabaya 60293
Chemical Engineering, Chemistry & Bioengineering Chemistry Education

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Immobilization of Lipase on Surfactant-Modified Bentonite and Its Application for Biodiesel Production from Simulated Waste Cooking Oil Chrisnasari, Ruth; Yonardi, Angelina; Lie, Hesti; Widi, Restu Kartiko; Purwanto, Maria Goretti Marianti
UNEJ e-Proceeding Indonesian Protein Society (IPS), International Seminar and Workshop 2014
Publisher : UNEJ e-Proceeding

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Abstract

The influence of bentonite modification by cationic surfactant hexadecyl-trimethyl-ammonium bromide (HDTMA-Br) and tetramethyl ammonium hydroxide (TMAOH) on its capability to immobilize lipase was studied. Modification of bentonite was conducted by the adding of 4-6% (v/v) HDTMA-Br and TMAOH respectively. The obtained immobilized lipases then were characterized to observe the optimum pH and temperature as well as their stability during reuse application. The observed results show that there is no significant difference between the variations of HDTMA-Br concentrations to the percentage of immobilized enzyme which can immobilize lipase up to 75-78%. However, the best concentration of TMAOH is 4% (v/v) which can immobilize lipase up to 97.95%. The obtained immobilized lipases on HDTMA-Br-modified bentonite show the optimum catalytic activity on reaction temperature of 35-40 oC and pH of 7.5. In other hand, the optimum catalytic activity of immobilized lipases on TMAOH-modified bentonite is 40oC of incubation temperature and pH of 7. The immobilized lipases on both HDTMA-Br and TMAOH modified bentonite are stable enough so it could be re-used four times before its activity decreased by 48,565% and 46.83 % respectively. Keywords: Lipase, Cationic Surfactant, Bentonite, HDTMA-Br, TMAOH, Biodiesel, Immobilization.
CATALYTIC ACTIVITY TEST OF MO-V-TE-NB-OXIDE IN AMMOXIDATION OF PROPANE TO ACRYLONITRILE Widi, Restu Kartiko
CHEMISTRY PROGRESS Vol 7, No 1 (2014)
Publisher : Sam Ratulangi University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35799/cp.7.1.2014.4846

Abstract

The ammoxidation of propane has been investigated at a multicomponent oxidic, MoVTeNb catalyst in the temperature of 673 K. The catalyst was prepared by sol-gel method, and dried by spray dried method. The activity test of the catalyst has been carried out using micro reactor and showed that it was active for ammoxidation of propane to acrylonitrile.   Keywords : ammoxidation, propane, mixed metal oxide catalyst, acryilonitrile
Glucose Oxidase Immobilization on TMAH-Modified Bentonite Ruth Chrisnasari; Zerlina Gabriela Wuisan; Arief Budhyantoro; Restu Kartiko Widi
Indonesian Journal of Chemistry Vol 15, No 1 (2015)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (365.594 KB) | DOI: 10.22146/ijc.21219

Abstract

The influence of bentonite modification by tetramethyl ammonium hydroxide (TMAH) on its capability to immobilize glucose oxidase (GOX) was studied. Modification of bentonite was conducted by the adding of 0-5% (v/v) TMAH. The observed results show that the different concentrations of TMAH affect the percentage of immobilized enzyme. The results of this study show that the best concentration of TMAH is 5% (v/v) which can immobilize up to 84.71% of GOX. X-ray diffraction (XRD) and Fourier Transforms Infrared Spectroscopy (FTIR) studies have been carried out to observe the structural changes in bentonite due to TMAH modification. The obtained immobilized GOX show the optimum catalytic activity on reaction temperature of 40-50 °C and pH of 7. The immobilized GOX kinetics at the optimum conditions determined the Km and Vmax value to be 4.96x10-2 mM and 4.99x10-3 mM.min-1 respectively. In addition, the immobilized GOX on TMAH-modified bentonite is stable enough so it could be re-used six times before its activity decreased by 39.44%.
Co-Authors Angelina Yonardi, Angelina Arief Budhyantoro Hesti Lie, Hesti Maria Goretti Marianti Purwanto Ruth Chrisnasari RUTH CHRISNASARI Zerlina Gabriela Wuisan