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All Journal Reaktor Journal of Engineering and Technological Sciences
Ardiyan Harimawan
Department of Chemical Engineering, Faculty of Industrial Technology, Institut Teknologi Bandung
Chemical Engineering, Chemistry & Bioengineering Control & Systems Engineering Energy Engineering Materials Science & Nanotechnology

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Journal : Reaktor

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INFLUENCE OF INITIAL pH SOLUTION ON BIOFILM FORMATION AND CORROSION OF CARBON STEEL BY Serratia marcescens Ardiyan Harimawan; Hary Devianto; Ignatius Chandra Kurniawan; Josephine Christine Utomo
Reaktor Volume 17 No. 2 Juni 2017
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (954.677 KB) | DOI: 10.14710/reaktor.17.2.89-95

Abstract

 The growth of Serratia marcescens depends on its metabolism, which is influenced by environmental factors, such as pH and temperature. The metabolic activity of Serratia marcescens may influence the corrosion of carbon steel by forming a biofilm on the metal surface. This research is focused on determining the effect of pH on carbon steel corrosion caused by Serratia marcescens. The medium used as immersion solution was a mixture of synthetic seawater and Luria-Bertani medium with a volume ratio of 4:1. The carbon steel coupons with a size of 1 cm x 1 cm were immersed in the solution with initial pH of 5, 7, and 9. The analyses of biofilm were conducted by total plate count (TPC), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Biofilm was detected evenly on the metal surface and decreased with an increase in incubation pH. The biofilm consists of some functional groups, such as alcohol, alkane, amine, nitro, sulphate, carboxylic acid, and polysulfide. The analyses of the corrosion were conducted by gravimetric and X-ray diffraction (XRD). The pHs of 5 and 9 were found to give an increase in the corrosion rate. The average corrosion rate at pH variations of 5, 7, and 9 were 2.5309 g/m2.day; 2.2844 g/m2.day; and 2.9756 g/m2.day, respectively. Nevertheless, the corrosion products were not detected by XRD analysis. Keywords: biocorrosion; carbon steel; pH; seawater; Serratia marcescens   Abstrak PENGARUH pH AWAL LARUTAN PADA PEMBENTUKAN BIOFILM DAN KOROSI BAJA KARBON OLEH Serratia marcescens. Laju pertumbuhan Serratia marcescens bergantung pada aktivitas metabolise mikroba, yang akan sangat dipengaruhi oleh faktor lingkungan, seperti pH dan temperatur. Aktivitas metabolisme Serratia marcescens dapat memengaruhi korosi pada baja karbon dengan membentuk lapisan biofilm pada permukaan logam. Penelitian ini bertujuan untuk menentukan efek pH pada korosi baja karbon yang disebabkan oleh Serratia marcescens. Media yang digunakan sebagai larutan perendam adalah campuran air laut sintetis dan media Luria-Bertani dengan perbandingan volume sebesar 4:1. Kupon baja karbon dengan ukuran 1 cm x 1 cm direndam dalam larutan dengan pH awal 5, 7, dan 9. Analisis lapisan biofilm dilakukan dengan total plate count (TPC), scanning electron microscopy (SEM) dan Fourier transform infrared spectroscopy (FTIR). Lapisan biofilm tumbuh secara merata pada permukaan logam dan berkurang seiring dengan peningkatan pH inkubasi. Lapisan biofilm mengandung berbagai gugus fungsional, seperti alkohol, alkana, amin, nitro, sulfat, asam karboksilat, dan polisulfida. Analisa korosi dilakukan dengan gravimetri dan X-ray diffraction (XRD). Penggunaan pH 5 dan 9 memberikan peningkatan terhadap laju korosi. Laju korosi rata-rata pada pH 5, 7, dan 9 ditentukan sebesar 2,5309 g/m2.day; 2,2844 g/m2.day; and 2,9756 g/m2.day. Namun, produk korosi tidak terdeksi oleh analisis XRD. Kata kunci: biokorosi; baja karbon; pH; air laut; Serratia marcescens
Antioxidant Activity of Vitamin E Concentrate from Magnesium Salts of Palm Fatty Acid Distillate (Mg-PFAD) Dianika Lestari; Khalisa Putri Aqilah; Salsafia Putri; Ardiyan Harimawan; Diky Mudhakir; Muhamad Insanu
Reaktor Volume 21 No. 1 March 2021
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (829.293 KB) | DOI: 10.14710/reaktor.21.1.35-43

Abstract

Vitamin E concentrate was produced through saponification of palm fatty acid distillates (PFAD) and magnesium oxide to form Mg-PFAD, followed by three-stages vitamin E extraction with isopropanol, hexane, or ethanol. The vitamin E-rich extracts were evaporated to remove solvent and produced vitamin E concentrate. The objectives of this research were to investigate the effect of organic solvent’s types and solvent to Mg-PFAD mass ratios on vitamin E concentration, solvent selectivity, and antioxidant activity of the vitamin E concentrate. Vitamin E concentrates obtained after isopropanol extraction had vitamin E concentration of 784 ppm with vitamin E recovery of 16 mg tocopherol/100 mg tocopherol in Mg-PFAD, while vitamin E concentrates obtained after hexane extraction had vitamin E concentration of 574 ppm with vitamin E recovery of 35 mg tocopherol/100 mg tocopherol in Mg-PFAD. Isopropanol extraction produced vitamin E concentrate with the highest selectivity for vitamin E and the highest antioxidant activity of 79% IC. It was found that vitamin E concentration was not proportional to the antioxidant activity of the vitamin E concentrate.Keywords: Direct solvent extraction, palm fatty acid distillate, saponification, vitamin E, unsaponifiable matter 
Dynamic and Steady Model Development of Two-Chamber Batch Microbial Fuel Cell (MFC) Ardiyan Harimawan
Reaktor Volume 21 No.4 December 2021
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.1.1.160-169

Abstract

As an alternative source of renewable energy that has piqued researchers’ interest, Microbial Fuel Cell’s (MFC) limitation of low power density requires further development. Various factors affect the performance, but performing all will be costly and time-consuming. Through a combination of dynamic and steady-state mathematical model modified from past research, effect of microbe types towards dynamic biofilm formation and stead-state OCV can be observed, followed by steady-state simulation to determine maximum power density and its’ corresponding voltage. Similarity with previous research has been observed, with maximum OCV of 838.93 mV achieved by heterotrophic biomass in 75-100 hours with biofilm thickness of 2.087 x 10-4 m, while generating maximum power density of 2050.12 mW//m2 and voltage of 408.16 mV. Lowest OCV value of 838.76 mV was observed in C. sporogenes in 450-475 hours with a biofilm thickness of 2.079 x 10-4 m, while the lowest value of maximum power density was observed in anaerobic microbial communities at 8.48 mW/m2 with voltage of 90.43 mV. Furthermore, it has been observed that variations with higher  and lower  results in higher stead-state OCV in the shortest amount of time, while increasing power density and its’ corresponding voltage. @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-536869121 1107305727 33554432 0 415 0;}@font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-469750017 -1073732485 9 0 511 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman",serif; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;}.MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-fareast-font-family:Calibri; mso-hansi-font-family:Calibri; mso-ansi-language:IN; mso-fareast-language:IN;}div.WordSection1 {page:WordSection1;}
Co-Authors Abdu Ravi Zakaria Al-Aziz, Rd. Habib R. M. T. Awalina Satya Bork Ilsemann Devianto, Hary Dian Shofinita Dianika Lestari Dianika Lestari Diky Mudhakir Dwi Rokhmat Setiawan Gadis Sri Haryani Ignatius Chandra Kurniawan Ilsemann, Bork Josephine Christine Utomo Khalisa Putri Aqilah Melia Laniwati Mike Reich Muhamad Insanu Pusparizkita, Yustina Metanoia Rd. Habib R. M. T. Al-Aziz Reich, Mike Salsafia Putri Schmahl, Wolfgang Setiadi, Tjandra Shelly Shelly Shofinita, Dian Wolfgang Schmahl Yustina Metanoia Pusparizkita