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Journal : Reaktor

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
Hazard Assessment of LNG Loading-Unloading Process in Cirebon Port Hary Devianto; Mitra Eviani; Pramujo Widiatmoko; Isdiriayani Nurdin
Reaktor Volume 18 No. 2 June 2018
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (820.187 KB) | DOI: 10.14710/reaktor.18.2.117-121

Abstract

Cirebon Port has spacious work and water area that provides opportunities to be developed in industrial sectors, particularly the petrochemical industries such as ethylene and Liquefied Natural Gas (LNG). In atmospheric condition, they are classified as volatile gas. Either in processing or transporting, they are stored in closed system. However, they still have a probability to be released to the environment and may lead to a fire or explosion. This probability is increased in the existence of coal stockpile in the port area which can evoke a fire. Therefore, a safety study is needed to identify the risk of the loading-unloading activities. The problem was solved by following steps. First, the data such as physical properties, layout area, and geographical condition around the port were collected. Then, the hazardous nodes were identified qualitatively, and then the quantitative analysis was done using As Low As Reasonably Practicable (ALARP) analysis. From the safety study, a suitable handling and safety system is provided to ensure safety viability in the ethylene and LNG loading-unloading process at the Cirebon port.Keywords: ethylene; hazard assessment; LNG; loading-unloading process; Quantitative Risk Assessment (QRA)
Effect of Intermittent Spray Pyrolysis on the Characteristics of Fluorine-Doped Tin Oxide Conductive Glass for Dye Sensitized Solar Cell Isdiriayani Nurdin; Pramujo Widiatmoko; Hary Devianto; Anastasia Yuandy; Rendy Rendy
Reaktor Volume 19 No. 4 December 2019
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (804.925 KB) | DOI: 10.14710/reaktor.19.4.180-186

Abstract

One of dye sensitized solar cell’s (DSSC) component is conductive glass, a transparent glass substrate covered with semiconductor oxide, usually fluorine-doped tin oxide (FTO). An economic and scalable method used to deposit the FTO film is spray pyrolysis. A research conducted by Fukano et al. (2004) showed that introducing intermittence in spray pyrolysis using batch atomizer improves the glass’ characteristics. This research aims to observe the effect of intermittence on spray pyrolysis method using nebulizer. A compressor nebulizer and hotplate were used, where the glass’ surface temperature reached 300oC. Transmittance, conductance, morphology and composition of the glasses produced were analyzed. Deposition time and intermittence were varied. Variation of time were 5; 7.5; 10; 16; and 39 minutes. Deposition time of 7.5 minutes showed the highest figure of merit (FOM) of 7.83×10-3 Ω-1. Intermittence was performed by turning the nebulizer off during deposition, with varying period and amount of intermittence. Periods of intermittence were varied for 10, 20, and 30 seconds, and amounts of intermittence were varied 1, 2, and 3 times. Variation of 3 intermittences at 20 seconds each resulted in the highest FOM of 19.29×10-3 Ω-1. DSSC’s efficiency built using produced conductive glass are 1.9×10-4 % and 5.5×10-4 %.
The Study of Hydrothermal Carbonization and Activation Factors' Effect on Mesoporous Activated Carbon Production From Sargassum sp. Using a Multilevel Factorial Design Prakoso, Tirto; Rustamaji, Heri; Yonathan, Daniel; Devianto, Hary; Widiatmoko, Pramujo; Rizkiana, Jenny; Guan, Guoqing
Reaktor Volume 22 No.2 August 2022
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.22.2.59-69

Abstract

Seaweeds are large-scale multicellular marine algae categorized based on color as Chlorophyceae, Rhodophyceae, and Phaeophyceae. No information has been provided on the conditions affecting the production of mesoporous activated carbon from one member of the described aquatic plants, namely Sargassum sp. Therefore, this study aimed to determine the impact of the main factors and their interactions on Sargassum sp.-derived activated carbon manufactured (SAC) by hydrothermal carbonization and CO2 activation methods. A mathematical approach was employed using a multilevel factorial design with the main factors being the activator type (ZnCl2, CaCl2, & KOH), hydrothermal temperature (200, 225, & 250oC), and activator ratios (2 & 4). Meanwhile, the response variables were yield and BET surface area (SBET) of SAC. Morphological, functional, crystallographic, and porosity characterization was carried out on the samples. The SAC-Ca-200-2 sample had the highest yield, with the value being 26.5 percent of weight. The activators having the highest specific surface area (SBET) were SAC-Zn-250-4, SAC-Ca-225-2, and SAC-K-250-2, with 1552, 1368, and 1799 m2/g, respectively. The pore size distribution in SAC products ranged from 2.16 to 10 nm in diameter. The analysis conducted indicated the activator type and interaction with its ratio substantially impacted the SAC yield value; besides, only the activator type affects the formation of high surface area pores.
Co-Authors Aditya Farhan Arif Adriaan Adriaan Adriaan Adriaan Adriaan, Adriaan Aghietyas Choirun Az Zahra Aida Nur Ramadhani Al-Aziz, Rd. Habib R. M. T. Ananda, Wisnu Anastasia Yuandy Anies Mutiari Anna Sonya Asoka Ardiyan Harimawan Ardiyan Harimawan Aslan, Christian Auliardi, Dzaky Bork Ilsemann Dadan Kusdiana Daniel Yonathan, Daniel DARMANSYAH . Dian Shofinita Dicky Tri Jatmiko Eviani, Mitra Fauzi Yusupandi Febriyanto, Pramahadi Ferdyan Ihza Akbar Fitri, Hera Rahma Gatalie, Kreszen Livianus Guan, Guoqing Harimawan, Ardiyan Henry Natanail Purwito Heri Rustamaji Hilham Zamriko Koto Ignatius Chandra Kurniawan Ilsemann, Bork Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin Isdiriayani Nurdin James B. Winterburn Jerry Jerry Josephine Christine Utomo Khodiyat, Nicholas Koto, Hilham Zamriko Listiani Artha Melanie, Susiana Mhd Ridho Utomo Mike Reich Mitra Eviani Muhammad Mara Ikhsan Mutiari, Anies Nurdin, Isdiriayani Nurdin, Isdiriayani Pramahadi Febriyanto Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pramujo Widiatmoko Pusparizkita, Yustina Metanoia Rd. Habib R. M. T. Al-Aziz Reich, Mike Rendy Rendy Ridho Eka Yandra Rizkiana, Jenny Rizky Eka Ahmad Saputera, Wibawa Hendra Satria, Arysca Wisnu Schmahl, Wolfgang Setiadi, Tjandra Shofinita, Dian Simparmin br Ginting Sukmana, Ira Febrianty Sung Pil Yoon Susiana Melanie Tae-Hoon Lim Tatang Hernas Soerawidjaja Tatto Bustomi Thadeo, Francesco Tiara Calista Shandy Tirto Prakoso Tirto Prakoso Utomo, Mhd Ridho Vita Wonoputri Widiatmoko, Pramujo Winterburn, James B. Wisnu Ananda Wolfgang Schmahl Yandra, Ridho Eka Yustina Metanoia Pusparizkita Yusupandi, Fauzi